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## Filter, Interceptor, Aop, 啥, 啥, 啥? 这些都是啥?

Posted on 2020-08-22 Edited on 2020-08-23 In Java , Spring , Filter , Interceptor - AOP , Servlet , Interceptor , AOP Views: Disqus:

本来是想取个像现在那些公众号转了又转的文章标题，”面试官再问你xxxxx，就把这篇文章甩给他看”这种标题，但是觉得实在太 low 了，还是用一部我比较喜欢的电影里的一句台词，《人在囧途》里王宝强对着那张老板给他的欠条，看不懂字时候说的那句，这些都是些啥（第四声）
当我刚开始面 Java 的时候，其实我真的没注意这方面的东西，实话说就是不知道这些是啥，开发中用过 Interceptor和 Aop，了解 aop 的实现原理，但是不知道 Java web 中的 Filter 是怎么回事，知道 dubbo 的 filter，就这样，所以被问到了的确是回答不出来，可能就觉得这个渣渣，这么简单的都不会，所以还是花点时间来看看这个是个啥，为了避免我口吐芬芳，还是耐下性子来简单说下这几个东西
首先是 servlet，怎么去解释这个呢，因为之前是 PHPer，所以比较喜欢用它来举例子，在普通的 PHP 的 web 应用中一般有几部分组成，接受 HTTP 请求的是前置的 nginx 或者 apache，但是这俩玩意都是只能处理静态的请求，远古时代 PHP 和 HTML 混编是通过 apache 的 php module，跟后来 nginx 使用 php-fpm 其实道理类似，就是把请求中需要 PHP 处理的转发给 PHP，在 Java 中呢，是有个比较牛叉的叫 Tomcat 的，它可以把请求转成 servlet，而 servlet 其实就是一种实现了特定接口的 Java 代码，

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    package javax.servlet;

    import java.io.IOException;

    /**
     * Defines methods that all servlets must implement.
     *
     * <p>
     * A servlet is a small Java program that runs within a Web server. Servlets
     * receive and respond to requests from Web clients, usually across HTTP, the
     * HyperText Transfer Protocol.
     *
     * <p>
     * To implement this interface, you can write a generic servlet that extends
     * <code>javax.servlet.GenericServlet</code> or an HTTP servlet that extends
     * <code>javax.servlet.http.HttpServlet</code>.
     *
     * <p>
     * This interface defines methods to initialize a servlet, to service requests,
     * and to remove a servlet from the server. These are known as life-cycle
     * methods and are called in the following sequence:
     * <ol>
     * <li>The servlet is constructed, then initialized with the <code>init</code>
     * method.
     * <li>Any calls from clients to the <code>service</code> method are handled.
     * <li>The servlet is taken out of service, then destroyed with the
     * <code>destroy</code> method, then garbage collected and finalized.
     * </ol>
     *
     * <p>
     * In addition to the life-cycle methods, this interface provides the
     * <code>getServletConfig</code> method, which the servlet can use to get any
     * startup information, and the <code>getServletInfo</code> method, which allows
     * the servlet to return basic information about itself, such as author,
     * version, and copyright.
     *
     * @see GenericServlet
     * @see javax.servlet.http.HttpServlet
     */
    public interface Servlet {

        /**
         * Called by the servlet container to indicate to a servlet that the servlet
         * is being placed into service.
         *
         * <p>
         * The servlet container calls the <code>init</code> method exactly once
         * after instantiating the servlet. The <code>init</code> method must
         * complete successfully before the servlet can receive any requests.
         *
         * <p>
         * The servlet container cannot place the servlet into service if the
         * <code>init</code> method
         * <ol>
         * <li>Throws a <code>ServletException</code>
         * <li>Does not return within a time period defined by the Web server
         * </ol>
         *
         *
         * @param config
         *            a <code>ServletConfig</code> object containing the servlet's
         *            configuration and initialization parameters
         *
         * @exception ServletException
         *                if an exception has occurred that interferes with the
         *                servlet's normal operation
         *
         * @see UnavailableException
         * @see #getServletConfig
         */
        public void init(ServletConfig config) throws ServletException;

        /**
         *
         * Returns a {@link ServletConfig} object, which contains initialization and
         * startup parameters for this servlet. The <code>ServletConfig</code>
         * object returned is the one passed to the <code>init</code> method.
         *
         * <p>
         * Implementations of this interface are responsible for storing the
         * <code>ServletConfig</code> object so that this method can return it. The
         * {@link GenericServlet} class, which implements this interface, already
         * does this.
         *
         * @return the <code>ServletConfig</code> object that initializes this
         *         servlet
         *
         * @see #init
         */
        public ServletConfig getServletConfig();

        /**
         * Called by the servlet container to allow the servlet to respond to a
         * request.
         *
         * <p>
         * This method is only called after the servlet's <code>init()</code> method
         * has completed successfully.
         *
         * <p>
         * The status code of the response always should be set for a servlet that
         * throws or sends an error.
         *
         *
         * <p>
         * Servlets typically run inside multithreaded servlet containers that can
         * handle multiple requests concurrently. Developers must be aware to
         * synchronize access to any shared resources such as files, network
         * connections, and as well as the servlet's class and instance variables.
         * More information on multithreaded programming in Java is available in <a
         * href
         * ="http://java.sun.com/Series/Tutorial/java/threads/multithreaded.html">
         * the Java tutorial on multi-threaded programming</a>.
         *
         *
         * @param req
         *            the <code>ServletRequest</code> object that contains the
         *            client's request
         *
         * @param res
         *            the <code>ServletResponse</code> object that contains the
         *            servlet's response
         *
         * @exception ServletException
         *                if an exception occurs that interferes with the servlet's
         *                normal operation
         *
         * @exception IOException
         *                if an input or output exception occurs
         */
        public void service(ServletRequest req, ServletResponse res)
                throws ServletException, IOException;

        /**
         * Returns information about the servlet, such as author, version, and
         * copyright.
         *
         * <p>
         * The string that this method returns should be plain text and not markup
         * of any kind (such as HTML, XML, etc.).
         *
         * @return a <code>String</code> containing servlet information
         */
        public String getServletInfo();

        /**
         * Called by the servlet container to indicate to a servlet that the servlet
         * is being taken out of service. This method is only called once all
         * threads within the servlet's <code>service</code> method have exited or
         * after a timeout period has passed. After the servlet container calls this
         * method, it will not call the <code>service</code> method again on this
         * servlet.
         *
         * <p>
         * This method gives the servlet an opportunity to clean up any resources
         * that are being held (for example, memory, file handles, threads) and make
         * sure that any persistent state is synchronized with the servlet's current
         * state in memory.
         */
        public void destroy();
    }

重点看 servlet 的 service方法，就是接受请求，处理完了给响应，不说细节，不然光 Tomcat 的能说半年，所以呢再进一步去理解，其实就能知道，就是一个先后的问题，盗个图
filter 跟后两者最大的不一样其实是一个基于 servlet，在非常外层做的处理，然后是 interceptor 的 prehandle 跟 posthandle，接着才是我们常规的 aop，就这么点事情，做个小试验吧(还是先补段代码吧)

## Filter

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    // ---------------------------------------------------- FilterChain Methods

        /**
         * Invoke the next filter in this chain, passing the specified request
         * and response.  If there are no more filters in this chain, invoke
         * the <code>service()</code> method of the servlet itself.
         *
         * @param request The servlet request we are processing
         * @param response The servlet response we are creating
         *
         * @exception IOException if an input/output error occurs
         * @exception ServletException if a servlet exception occurs
         */
        @Override
        public void doFilter(ServletRequest request, ServletResponse response)
            throws IOException, ServletException {

            if( Globals.IS_SECURITY_ENABLED ) {
                final ServletRequest req = request;
                final ServletResponse res = response;
                try {
                    java.security.AccessController.doPrivileged(
                        new java.security.PrivilegedExceptionAction<Void>() {
                            @Override
                            public Void run()
                                throws ServletException, IOException {
                                internalDoFilter(req,res);
                                return null;
                            }
                        }
                    );
                } catch( PrivilegedActionException pe) {
                    Exception e = pe.getException();
                    if (e instanceof ServletException)
                        throw (ServletException) e;
                    else if (e instanceof IOException)
                        throw (IOException) e;
                    else if (e instanceof RuntimeException)
                        throw (RuntimeException) e;
                    else
                        throw new ServletException(e.getMessage(), e);
                }
            } else {
                internalDoFilter(request,response);
            }
        }
        private void internalDoFilter(ServletRequest request,
                                      ServletResponse response)
            throws IOException, ServletException {

            // Call the next filter if there is one
            if (pos < n) {
                ApplicationFilterConfig filterConfig = filters[pos++];
                try {
                    Filter filter = filterConfig.getFilter();

                    if (request.isAsyncSupported() && "false".equalsIgnoreCase(
                            filterConfig.getFilterDef().getAsyncSupported())) {
                        request.setAttribute(Globals.ASYNC_SUPPORTED_ATTR, Boolean.FALSE);
                    }
                    if( Globals.IS_SECURITY_ENABLED ) {
                        final ServletRequest req = request;
                        final ServletResponse res = response;
                        Principal principal =
                            ((HttpServletRequest) req).getUserPrincipal();

                        Object[] args = new Object[]{req, res, this};
                        SecurityUtil.doAsPrivilege ("doFilter", filter, classType, args, principal);
                    } else {
                        filter.doFilter(request, response, this);
                    }
                } catch (IOException | ServletException | RuntimeException e) {
                    throw e;
                } catch (Throwable e) {
                    e = ExceptionUtils.unwrapInvocationTargetException(e);
                    ExceptionUtils.handleThrowable(e);
                    throw new ServletException(sm.getString("filterChain.filter"), e);
                }
                return;
            }

            // We fell off the end of the chain -- call the servlet instance
            try {
                if (ApplicationDispatcher.WRAP_SAME_OBJECT) {
                    lastServicedRequest.set(request);
                    lastServicedResponse.set(response);
                }

                if (request.isAsyncSupported() && !servletSupportsAsync) {
                    request.setAttribute(Globals.ASYNC_SUPPORTED_ATTR,
                            Boolean.FALSE);
                }
                // Use potentially wrapped request from this point
                if ((request instanceof HttpServletRequest) &&
                        (response instanceof HttpServletResponse) &&
                        Globals.IS_SECURITY_ENABLED ) {
                    final ServletRequest req = request;
                    final ServletResponse res = response;
                    Principal principal =
                        ((HttpServletRequest) req).getUserPrincipal();
                    Object[] args = new Object[]{req, res};
                    SecurityUtil.doAsPrivilege("service",
                                               servlet,
                                               classTypeUsedInService,
                                               args,
                                               principal);
                } else {
                    servlet.service(request, response);
                }
            } catch (IOException | ServletException | RuntimeException e) {
                throw e;
            } catch (Throwable e) {
                e = ExceptionUtils.unwrapInvocationTargetException(e);
                ExceptionUtils.handleThrowable(e);
                throw new ServletException(sm.getString("filterChain.servlet"), e);
            } finally {
                if (ApplicationDispatcher.WRAP_SAME_OBJECT) {
                    lastServicedRequest.set(null);
                    lastServicedResponse.set(null);
                }
            }
        }

注意看这一行
`filter.doFilter(request, response, this);`
是不是看懂了，就是个 filter 链，但是这个代码在哪呢，`org.apache.catalina.core.ApplicationFilterChain#doFilter`
然后是interceptor，

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    protected void doDispatch(HttpServletRequest request, HttpServletResponse response) throws Exception {
            HttpServletRequest processedRequest = request;
            HandlerExecutionChain mappedHandler = null;
            boolean multipartRequestParsed = false;
            WebAsyncManager asyncManager = WebAsyncUtils.getAsyncManager(request);

            try {
                try {
                    ModelAndView mv = null;
                    Object dispatchException = null;

                    try {
                        processedRequest = this.checkMultipart(request);
                        multipartRequestParsed = processedRequest != request;
                        mappedHandler = this.getHandler(processedRequest);
                        if (mappedHandler == null) {
                            this.noHandlerFound(processedRequest, response);
                            return;
                        }

                        HandlerAdapter ha = this.getHandlerAdapter(mappedHandler.getHandler());
                        String method = request.getMethod();
                        boolean isGet = "GET".equals(method);
                        if (isGet || "HEAD".equals(method)) {
                            long lastModified = ha.getLastModified(request, mappedHandler.getHandler());
                            if ((new ServletWebRequest(request, response)).checkNotModified(lastModified) && isGet) {
                                return;
                            }
                        }

                        /**
                         * 看这里看这里‼️
                         */
                        if (!mappedHandler.applyPreHandle(processedRequest, response)) {
                            return;
                        }

                        mv = ha.handle(processedRequest, response, mappedHandler.getHandler());
                        if (asyncManager.isConcurrentHandlingStarted()) {
                            return;
                        }

                        this.applyDefaultViewName(processedRequest, mv);
                        /**
                         * 再看这里看这里‼️
                         */
                        mappedHandler.applyPostHandle(processedRequest, response, mv);
                    } catch (Exception var20) {
                        dispatchException = var20;
                    } catch (Throwable var21) {
                        dispatchException = new NestedServletException("Handler dispatch failed", var21);
                    }

                    this.processDispatchResult(processedRequest, response, mappedHandler, mv, (Exception)dispatchException);
                } catch (Exception var22) {
                    this.triggerAfterCompletion(processedRequest, response, mappedHandler, var22);
                } catch (Throwable var23) {
                    this.triggerAfterCompletion(processedRequest, response, mappedHandler, new NestedServletException("Handler processing failed", var23));
                }

            } finally {
                if (asyncManager.isConcurrentHandlingStarted()) {
                    if (mappedHandler != null) {
                        mappedHandler.applyAfterConcurrentHandlingStarted(processedRequest, response);
                    }
                } else if (multipartRequestParsed) {
                    this.cleanupMultipart(processedRequest);
                }

            }
        }

代码在哪呢，`org.springframework.web.servlet.DispatcherServlet#doDispatch`，然后才是我们自己写的 aop，是不是差不多明白了，嗯，接下来是例子
写个 filter

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    public class DemoFilter extends HttpServlet implements Filter {
        @Override
        public void init(FilterConfig filterConfig) throws ServletException {
            System.out.println("==>DemoFilter启动");
        }

        @Override
        public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
            // 将请求转换成HttpServletRequest 请求
            HttpServletRequest req = (HttpServletRequest) servletRequest;
            HttpServletResponse resp = (HttpServletResponse) servletResponse;
            System.out.println("before filter");
            filterChain.doFilter(req, resp);
            System.out.println("after filter");
        }

        @Override
        public void destroy() {

        }
    }

因为用的springboot，所以就不写 web.xml 了，写个配置类

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    @Configuration
    public class FilterConfiguration {
        @Bean
        public FilterRegistrationBean filterDemo4Registration() {
            FilterRegistrationBean registration = new FilterRegistrationBean();
            //注入过滤器
            registration.setFilter(new DemoFilter());
            //拦截规则
            registration.addUrlPatterns("/*");
            //过滤器名称
            registration.setName("DemoFilter");
            //是否自动注册 false 取消Filter的自动注册
            registration.setEnabled(true);
            //过滤器顺序
            registration.setOrder(1);
            return registration;
        }

    }

然后再来个 interceptor 和 aop,以及一个简单的请求处理

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    public class DemoInterceptor extends HandlerInterceptorAdapter {
        @Override
        public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
            System.out.println("preHandle test");
            return true;
        }

        @Override
        public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception {
            System.out.println("postHandle test");
        }
    }
    @Aspect
    @Component
    public class DemoAspect {

        @Pointcut("execution( public * com.nicksxs.springbootdemo.demo.DemoController.*())")
        public void point() {

        }

        @Before("point()")
        public void doBefore(){
            System.out.println("==doBefore==");
        }

        @After("point()")
        public void doAfter(){
            System.out.println("==doAfter==");
        }
    }
    @RestController
    public class DemoController {

        @RequestMapping("/hello")
        @ResponseBody
        public String hello() {
            return "hello world";
        }
    }

好了，请求一下，看看 stdout，
搞定完事儿~

## 周末我在老丈人家打了天小工

Posted on 2020-08-16 In 生活 , 运动 , 跑步 , 干活 Views: Disqus:

这周回家提前约好了要去老丈人家帮下忙，因为在翻修下老房子，活不是特别整的那种，所以大部分都是自己干，或者找个大工临时干几天（我们这那种比较专业的泥工匠叫做大工），像我这样去帮忙的，就是干点小工（把给大工帮忙的，干些偏体力活的叫做小工）的活。从大学毕业以后真的蛮少帮家里干活了，以前上学的时候放假还是帮家里淘个米，简单的扫地拖地啥的，当然刚高考完的时候，还去我爸厂里帮忙干了几天的活，实在是比较累，不过现在想着是觉得自己那时候比较牛，而不是特别排斥这个活，相对于现在的工作来说，导致了一系列的职业病，颈椎腰背都很僵硬，眼镜也不好，还有反流，像我爸那种活反而是脑力加体力的比较好的结合。
这一天的活前半部分主要是在清理厨房，瓷砖上的油污和墙上天花板上即将脱落的石灰或者白色涂料层，这种活特别是瓷砖上的油污，之前在自己家里也干活，还是比较熟悉的，不过前面主要是LD 在干，我主要是先搞墙上和天花板上的，干活还是很需要技巧的，如果直接去铲，那基本我会变成一个灰人，而且吸一鼻子灰，老丈人比较专业，先接上软管用水冲，一冲效果特别好，有些石灰涂料层直接就冲掉了，冲完之后先用带加长杆的刀片铲铲了一圈墙面，说实话因为老房子之前租出去了，所以墙面什么的被糟蹋的比较难看，一层一层的，不过这还算还好，后面主要是天花板上的，这可难倒我了，从小我爸妈是比较把我当小孩管着，爬上爬下的基本都是我爸搞定，但是到了老丈人家也只得硬着头皮上了，爬到跳（一种建筑工地用的架子）上，还有点晃，小心脏扑通扑通跳，而且带加长杆的铲子还是比较重的，铲一会手也有点累，不过坚持着铲完了，上面还是比较平整的，不过下来的时候又把我难住了🤦‍♂️，往下爬的时候有根杆子要跨过去，由于裤子比较紧，强行一把跨过去怕抽筋，所以以一个非常尴尬的姿势停留休息了一会，再跨了过去，幸好事后问 LD，他们都没看到，哈哈哈，然后就是帮忙一起搞瓷砖上的油污，这个太有经验了，不过老丈人更有意思，一会试试啤酒，一会用用沙子，后面在午饭前基本就弄的比较干净了，就坐着等吃饭了，下午午休了会，就继续干活了。
下午是我这次体验的重点了，因为要清理以前贴的墙纸，真的是个很麻烦的活，只能说贴墙纸的师傅活干得太好了，基本不可能整个撕下来，想用铲子一点点铲下来也不行，太轻了就只铲掉表面一层，太重了就把墙纸跟墙面的石灰啥的整个铲下来了，而且手又累又酸，后来想着是不是继续用水冲一下，对着一小面墙试验了下，效果还不错，但是又发现了个问题，那一面墙又有一块是后面糊上去的，铲掉外层的石灰后不平，然后就是最最重头的，也是让我后遗症持续到第二天的，要把那一块糊上去的水泥敲下来，毛估下大概是敲了80%左右，剩下的我的手已经不会用力了，因为那一块应该是要糊上去的始作俑者，就一块里面凹进去的，我拿着榔头敲到我手已经没法使劲了，而且大下午，感觉没五分钟，我的汗已经糊满脸，眼睛也睁不开，不然就流到眼睛里了，此处获得成就一：用榔头敲墙壁，也是个技术加体力的活，而且需要非常好的技巧，否则手马上就废了，敲下去的反作用力，没一会就不行了，然后是看着老丈人兄弟帮忙拆一个柜子，在我看来是个几天都搞不定的活，他轻轻松松在我敲墙的那会就搞定了，以前总觉得我干的活非常有技术含量，可是这个事情真的也是很有技巧啊，它是个把一间房间分隔开的柜子，从底到顶上，还带着门，我还在旁边帮忙撬一下脚踢，一根木条撬半天，唉，成就二：专业的人就是不一样。
最后就是成就三了：我之前沾沾自喜的跑了多少步，做了什么锻炼，其实都是渣渣，像这样干一天活，没经历过的，基本大半天就废了，反过来说，如果能经常去这么干一天活，跑步啥的都是渣渣，消耗的能量远远超过跑个十公里啥的。

## Linux 下 grep 命令的一点小技巧

Posted on 2020-08-06 In Linux , 命令 , grep , 小技巧 , grep , 查日志 Views: Disqus:

用了比较久的 grep 命令，其实都只是用了最最基本的功能来查日志，

譬如

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    grep 'xxx' xxxx.log

然后有挺多情况比如想要找日志里带一些符号什么的，就需要用到一些特殊的

比如这样`\"userId\":\"123456\"`，因为比如用户 ID 有时候会跟其他的 id 一样，只用具体的值 123456 来查的话干扰信息太多了，如果直接这样

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    grep '\"userId\":\"123456\"' xxxx.log

好像不行，盲猜就是符号的问题，特别是`\`和`"`这两个，

之前一直是想试一下，但是没成功，昨天在排查一个问题的时候发现了，只要把这些都转义了就行了

`grep '\\\"userId\\\":\\\"123456\\\"' xxxx.log`

## 聊聊 Java 自带的那些*逆天*工具

Posted on 2020-08-02 Edited on 2020-09-13 In Java , Thread dump , 问题排查 , 工具 Views: Disqus:

原谅我的标题党，其实这些工具的确很厉害，之前其实介绍过一点相关的，是从我一次问题排查的过程中用到的，但是最近又有碰到一次排查问题，发现其实用 idea 直接 `dump thread` 是不现实的，毕竟服务器环境的没法这么操作，那就得用 Java 的那些工具了

### jstack & jps

譬如 `jstack`，这个命令其实不能更简单了
看看 help 信息
用`-l`参数可以打出锁的额外信息，然后后面的 pid 就是进程 id 咯，机智的小伙伴会问了（就你这个小白才问这么蠢的问题🤦‍♂️），怎么看 Java 应用的进程呢
那就是 `jps` 了，命令也很简单，一般直接用 `jps`命令就好了，不过也可以 help 看一下
稍微解释下，-q是只显示进程 id，-m是输出给main 方法的参数，比如我在配置中加给参数
然后用 `jps -m`查看
`-v`加上小 v 的话就是打印 jvm 参数
还是有点东西，然后就继续介绍 jstack 了，然后我们看看 jstack 出来是啥，为了加点内容我加了个死锁

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    public static void main(String[] args) throws InterruptedException {
            SpringApplication.run(ThreadDumpDemoApplication.class, args);
            ReentrantLock lock1 = new ReentrantLock();
            ReentrantLock lock2 = new ReentrantLock();
            Thread t1 = new Thread() {
                @Override
                public void run() {
                    try {
                        lock1.lock();
                        TimeUnit.SECONDS.sleep(1);
                        lock2.lock();
                    } catch (InterruptedException e) {
                        e.printStackTrace();
                    }
                }
            };
            Thread t2 = new Thread() {
                @Override
                public void run() {
                    try {
                        lock2.lock();
                        TimeUnit.SECONDS.sleep(1);
                        lock1.lock();
                    } catch (InterruptedException e) {
                        e.printStackTrace();
                    }
                }
            };
            t1.setName("mythread1");
            t2.setName("mythread2");
            t1.start();
            t2.start();
            Thread.sleep(10000);
        }

然后看看出来时怎么样的

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    2020-08-02 21:50:32
    Full thread dump Java HotSpot(TM) 64-Bit Server VM (25.201-b09 mixed mode):

    "DestroyJavaVM" #147 prio=5 os_prio=31 tid=0x00007fc9dd807000 nid=0x2603 waiting on condition [0x0000000000000000]
       java.lang.Thread.State: RUNNABLE

       Locked ownable synchronizers:
            - None

    "mythread2" #140 prio=5 os_prio=31 tid=0x00007fc9dd877000 nid=0x9903 waiting on condition [0x0000700006fb9000]
       java.lang.Thread.State: WAITING (parking)
            at sun.misc.Unsafe.park(Native Method)
            - parking to wait for  <0x000000076f5d4330> (a java.util.concurrent.locks.ReentrantLock$NonfairSync)
            at java.util.concurrent.locks.LockSupport.park(LockSupport.java:175)
            at java.util.concurrent.locks.AbstractQueuedSynchronizer.parkAndCheckInterrupt(AbstractQueuedSynchronizer.java:836)
            at java.util.concurrent.locks.AbstractQueuedSynchronizer.acquireQueued(AbstractQueuedSynchronizer.java:870)
            at java.util.concurrent.locks.AbstractQueuedSynchronizer.acquire(AbstractQueuedSynchronizer.java:1199)
            at java.util.concurrent.locks.ReentrantLock$NonfairSync.lock(ReentrantLock.java:209)
            at java.util.concurrent.locks.ReentrantLock.lock(ReentrantLock.java:285)
            at com.nicksxs.thread_dump_demo.ThreadDumpDemoApplication$2.run(ThreadDumpDemoApplication.java:34)

       Locked ownable synchronizers:
            - <0x000000076f5d4360> (a java.util.concurrent.locks.ReentrantLock$NonfairSync)

    "mythread1" #139 prio=5 os_prio=31 tid=0x00007fc9de873800 nid=0x9a03 waiting on condition [0x0000700006eb6000]
       java.lang.Thread.State: WAITING (parking)
            at sun.misc.Unsafe.park(Native Method)
            - parking to wait for  <0x000000076f5d4360> (a java.util.concurrent.locks.ReentrantLock$NonfairSync)
            at java.util.concurrent.locks.LockSupport.park(LockSupport.java:175)
            at java.util.concurrent.locks.AbstractQueuedSynchronizer.parkAndCheckInterrupt(AbstractQueuedSynchronizer.java:836)
            at java.util.concurrent.locks.AbstractQueuedSynchronizer.acquireQueued(AbstractQueuedSynchronizer.java:870)
            at java.util.concurrent.locks.AbstractQueuedSynchronizer.acquire(AbstractQueuedSynchronizer.java:1199)
            at java.util.concurrent.locks.ReentrantLock$NonfairSync.lock(ReentrantLock.java:209)
            at java.util.concurrent.locks.ReentrantLock.lock(ReentrantLock.java:285)
            at com.nicksxs.thread_dump_demo.ThreadDumpDemoApplication$1.run(ThreadDumpDemoApplication.java:22)

       Locked ownable synchronizers:
            - <0x000000076f5d4330> (a java.util.concurrent.locks.ReentrantLock$NonfairSync)

    "http-nio-8080-Acceptor" #137 daemon prio=5 os_prio=31 tid=0x00007fc9de1ac000 nid=0x9b03 runnable [0x0000700006db3000]
       java.lang.Thread.State: RUNNABLE
            at sun.nio.ch.ServerSocketChannelImpl.accept0(Native Method)
            at sun.nio.ch.ServerSocketChannelImpl.accept(ServerSocketChannelImpl.java:422)
            at sun.nio.ch.ServerSocketChannelImpl.accept(ServerSocketChannelImpl.java:250)
            - locked <0x000000076f1e4820> (a java.lang.Object)
            at org.apache.tomcat.util.net.NioEndpoint.serverSocketAccept(NioEndpoint.java:469)
            at org.apache.tomcat.util.net.NioEndpoint.serverSocketAccept(NioEndpoint.java:71)
            at org.apache.tomcat.util.net.Acceptor.run(Acceptor.java:95)
            at java.lang.Thread.run(Thread.java:748)

       Locked ownable synchronizers:
            - None

    "http-nio-8080-ClientPoller" #136 daemon prio=5 os_prio=31 tid=0x00007fc9dd876800 nid=0x6503 runnable [0x0000700006cb0000]
       java.lang.Thread.State: RUNNABLE
            at sun.nio.ch.KQueueArrayWrapper.kevent0(Native Method)
            at sun.nio.ch.KQueueArrayWrapper.poll(KQueueArrayWrapper.java:198)
            at sun.nio.ch.KQueueSelectorImpl.doSelect(KQueueSelectorImpl.java:117)
            at sun.nio.ch.SelectorImpl.lockAndDoSelect(SelectorImpl.java:86)
            - locked <0x000000076f2978c8> (a sun.nio.ch.Util$3)
            - locked <0x000000076f2978b8> (a java.util.Collections$UnmodifiableSet)
            - locked <0x000000076f297798> (a sun.nio.ch.KQueueSelectorImpl)
            at sun.nio.ch.SelectorImpl.select(SelectorImpl.java:97)
            at org.apache.tomcat.util.net.NioEndpoint$Poller.run(NioEndpoint.java:709)
            at java.lang.Thread.run(Thread.java:748)

       Locked ownable synchronizers:
            - None

    "http-nio-8080-exec-10" #135 daemon prio=5 os_prio=31 tid=0x00007fc9de1af000 nid=0x9d03 waiting on condition [0x0000700006bad000]
       java.lang.Thread.State: WAITING (parking)
            at sun.misc.Unsafe.park(Native Method)
            - parking to wait for  <0x000000076f26aa00> (a java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject)
            at java.util.concurrent.locks.LockSupport.park(LockSupport.java:175)
            at java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject.await(AbstractQueuedSynchronizer.java:2039)
            at java.util.concurrent.LinkedBlockingQueue.take(LinkedBlockingQueue.java:442)
            at org.apache.tomcat.util.threads.TaskQueue.take(TaskQueue.java:107)
            at org.apache.tomcat.util.threads.TaskQueue.take(TaskQueue.java:33)
            at java.util.concurrent.ThreadPoolExecutor.getTask(ThreadPoolExecutor.java:1074)
            at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1134)
            at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
            at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
            at java.lang.Thread.run(Thread.java:748)

       Locked ownable synchronizers:
            - None

    "http-nio-8080-exec-9" #134 daemon prio=5 os_prio=31 tid=0x00007fc9de1ab800 nid=0x6403 waiting on condition [0x0000700006aaa000]
       java.lang.Thread.State: WAITING (parking)
            at sun.misc.Unsafe.park(Native Method)
            - parking to wait for  <0x000000076f26aa00> (a java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject)
            at java.util.concurrent.locks.LockSupport.park(LockSupport.java:175)
            at java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject.await(AbstractQueuedSynchronizer.java:2039)
            at java.util.concurrent.LinkedBlockingQueue.take(LinkedBlockingQueue.java:442)
            at org.apache.tomcat.util.threads.TaskQueue.take(TaskQueue.java:107)
            at org.apache.tomcat.util.threads.TaskQueue.take(TaskQueue.java:33)
            at java.util.concurrent.ThreadPoolExecutor.getTask(ThreadPoolExecutor.java:1074)
            at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1134)
            at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
            at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
            at java.lang.Thread.run(Thread.java:748)

       Locked ownable synchronizers:
            - None

    "http-nio-8080-exec-8" #133 daemon prio=5 os_prio=31 tid=0x00007fc9de873000 nid=0x9f03 waiting on condition [0x00007000069a7000]
       java.lang.Thread.State: WAITING (parking)
            at sun.misc.Unsafe.park(Native Method)
            - parking to wait for  <0x000000076f26aa00> (a java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject)
            at java.util.concurrent.locks.LockSupport.park(LockSupport.java:175)
            at java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject.await(AbstractQueuedSynchronizer.java:2039)
            at java.util.concurrent.LinkedBlockingQueue.take(LinkedBlockingQueue.java:442)
            at org.apache.tomcat.util.threads.TaskQueue.take(TaskQueue.java:107)
            at org.apache.tomcat.util.threads.TaskQueue.take(TaskQueue.java:33)
            at java.util.concurrent.ThreadPoolExecutor.getTask(ThreadPoolExecutor.java:1074)
            at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1134)
            at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
            at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
            at java.lang.Thread.run(Thread.java:748)

       Locked ownable synchronizers:
            - None

    "http-nio-8080-exec-7" #132 daemon prio=5 os_prio=31 tid=0x00007fc9df0a1800 nid=0xa103 waiting on condition [0x00007000068a4000]
       java.lang.Thread.State: WAITING (parking)
            at sun.misc.Unsafe.park(Native Method)
            - parking to wait for  <0x000000076f26aa00> (a java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject)
            at java.util.concurrent.locks.LockSupport.park(LockSupport.java:175)
            at java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject.await(AbstractQueuedSynchronizer.java:2039)
            at java.util.concurrent.LinkedBlockingQueue.take(LinkedBlockingQueue.java:442)
            at org.apache.tomcat.util.threads.TaskQueue.take(TaskQueue.java:107)
            at org.apache.tomcat.util.threads.TaskQueue.take(TaskQueue.java:33)
            at java.util.concurrent.ThreadPoolExecutor.getTask(ThreadPoolExecutor.java:1074)
            at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1134)
            at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
            at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
            at java.lang.Thread.run(Thread.java:748)

       Locked ownable synchronizers:
            - None

    "http-nio-8080-exec-6" #131 daemon prio=5 os_prio=31 tid=0x00007fc9df242800 nid=0x6103 waiting on condition [0x00007000067a1000]
       java.lang.Thread.State: WAITING (parking)
            at sun.misc.Unsafe.park(Native Method)
            - parking to wait for  <0x000000076f26aa00> (a java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject)
            at java.util.concurrent.locks.LockSupport.park(LockSupport.java:175)
            at java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject.await(AbstractQueuedSynchronizer.java:2039)
            at java.util.concurrent.LinkedBlockingQueue.take(LinkedBlockingQueue.java:442)
            at org.apache.tomcat.util.threads.TaskQueue.take(TaskQueue.java:107)
            at org.apache.tomcat.util.threads.TaskQueue.take(TaskQueue.java:33)
            at java.util.concurrent.ThreadPoolExecutor.getTask(ThreadPoolExecutor.java:1074)
            at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1134)
            at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
            at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
            at java.lang.Thread.run(Thread.java:748)

       Locked ownable synchronizers:
            - None

    "http-nio-8080-exec-5" #130 daemon prio=5 os_prio=31 tid=0x00007fc9de872000 nid=0x5f03 waiting on condition [0x000070000669e000]
       java.lang.Thread.State: WAITING (parking)
            at sun.misc.Unsafe.park(Native Method)
            - parking to wait for  <0x000000076f26aa00> (a java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject)
            at java.util.concurrent.locks.LockSupport.park(LockSupport.java:175)
            at java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject.await(AbstractQueuedSynchronizer.java:2039)
            at java.util.concurrent.LinkedBlockingQueue.take(LinkedBlockingQueue.java:442)
            at org.apache.tomcat.util.threads.TaskQueue.take(TaskQueue.java:107)
            at org.apache.tomcat.util.threads.TaskQueue.take(TaskQueue.java:33)
            at java.util.concurrent.ThreadPoolExecutor.getTask(ThreadPoolExecutor.java:1074)
            at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1134)
            at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
            at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
            at java.lang.Thread.run(Thread.java:748)

       Locked ownable synchronizers:
            - None

    "http-nio-8080-exec-4" #129 daemon prio=5 os_prio=31 tid=0x00007fc9de1a6000 nid=0x5e03 waiting on condition [0x000070000659b000]
       java.lang.Thread.State: WAITING (parking)
            at sun.misc.Unsafe.park(Native Method)
            - parking to wait for  <0x000000076f26aa00> (a java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject)
            at java.util.concurrent.locks.LockSupport.park(LockSupport.java:175)
            at java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject.await(AbstractQueuedSynchronizer.java:2039)
            at java.util.concurrent.LinkedBlockingQueue.take(LinkedBlockingQueue.java:442)
            at org.apache.tomcat.util.threads.TaskQueue.take(TaskQueue.java:107)
            at org.apache.tomcat.util.threads.TaskQueue.take(TaskQueue.java:33)
            at java.util.concurrent.ThreadPoolExecutor.getTask(ThreadPoolExecutor.java:1074)
            at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1134)
            at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
            at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
            at java.lang.Thread.run(Thread.java:748)

       Locked ownable synchronizers:
            - None

    "http-nio-8080-exec-3" #128 daemon prio=5 os_prio=31 tid=0x00007fc9de871800 nid=0x5c03 waiting on condition [0x0000700006498000]
       java.lang.Thread.State: WAITING (parking)
            at sun.misc.Unsafe.park(Native Method)
            - parking to wait for  <0x000000076f26aa00> (a java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject)
            at java.util.concurrent.locks.LockSupport.park(LockSupport.java:175)
            at java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject.await(AbstractQueuedSynchronizer.java:2039)
            at java.util.concurrent.LinkedBlockingQueue.take(LinkedBlockingQueue.java:442)
            at org.apache.tomcat.util.threads.TaskQueue.take(TaskQueue.java:107)
            at org.apache.tomcat.util.threads.TaskQueue.take(TaskQueue.java:33)
            at java.util.concurrent.ThreadPoolExecutor.getTask(ThreadPoolExecutor.java:1074)
            at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1134)
            at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
            at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
            at java.lang.Thread.run(Thread.java:748)

       Locked ownable synchronizers:
            - None

    "http-nio-8080-exec-2" #127 daemon prio=5 os_prio=31 tid=0x00007fc9dead9000 nid=0x5b03 waiting on condition [0x0000700006395000]
       java.lang.Thread.State: WAITING (parking)
            at sun.misc.Unsafe.park(Native Method)
            - parking to wait for  <0x000000076f26aa00> (a java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject)
            at java.util.concurrent.locks.LockSupport.park(LockSupport.java:175)
            at java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject.await(AbstractQueuedSynchronizer.java:2039)
            at java.util.concurrent.LinkedBlockingQueue.take(LinkedBlockingQueue.java:442)
            at org.apache.tomcat.util.threads.TaskQueue.take(TaskQueue.java:107)
            at org.apache.tomcat.util.threads.TaskQueue.take(TaskQueue.java:33)
            at java.util.concurrent.ThreadPoolExecutor.getTask(ThreadPoolExecutor.java:1074)
            at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1134)
            at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
            at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
            at java.lang.Thread.run(Thread.java:748)

       Locked ownable synchronizers:
            - None

    "http-nio-8080-exec-1" #126 daemon prio=5 os_prio=31 tid=0x00007fc9ddb00000 nid=0x5a03 waiting on condition [0x0000700006292000]
       java.lang.Thread.State: WAITING (parking)
            at sun.misc.Unsafe.park(Native Method)
            - parking to wait for  <0x000000076f26aa00> (a java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject)
            at java.util.concurrent.locks.LockSupport.park(LockSupport.java:175)
            at java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject.await(AbstractQueuedSynchronizer.java:2039)
            at java.util.concurrent.LinkedBlockingQueue.take(LinkedBlockingQueue.java:442)
            at org.apache.tomcat.util.threads.TaskQueue.take(TaskQueue.java:107)
            at org.apache.tomcat.util.threads.TaskQueue.take(TaskQueue.java:33)
            at java.util.concurrent.ThreadPoolExecutor.getTask(ThreadPoolExecutor.java:1074)
            at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1134)
            at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
            at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
            at java.lang.Thread.run(Thread.java:748)

       Locked ownable synchronizers:
            - None

    "http-nio-8080-BlockPoller" #125 daemon prio=5 os_prio=31 tid=0x00007fc9df242000 nid=0xa503 runnable [0x000070000618f000]
       java.lang.Thread.State: RUNNABLE
            at sun.nio.ch.KQueueArrayWrapper.kevent0(Native Method)
            at sun.nio.ch.KQueueArrayWrapper.poll(KQueueArrayWrapper.java:198)
            at sun.nio.ch.KQueueSelectorImpl.doSelect(KQueueSelectorImpl.java:117)
            at sun.nio.ch.SelectorImpl.lockAndDoSelect(SelectorImpl.java:86)
            - locked <0x000000076f1eea30> (a sun.nio.ch.Util$3)
            - locked <0x000000076f1ee198> (a java.util.Collections$UnmodifiableSet)
            - locked <0x000000076f1ee010> (a sun.nio.ch.KQueueSelectorImpl)
            at sun.nio.ch.SelectorImpl.select(SelectorImpl.java:97)
            at org.apache.tomcat.util.net.NioBlockingSelector$BlockPoller.run(NioBlockingSelector.java:313)

       Locked ownable synchronizers:
            - None

    "container-0" #124 prio=5 os_prio=31 tid=0x00007fc9df06a000 nid=0x5803 waiting on condition [0x000070000608c000]
       java.lang.Thread.State: TIMED_WAITING (sleeping)
            at java.lang.Thread.sleep(Native Method)
            at org.apache.catalina.core.StandardServer.await(StandardServer.java:570)
            at org.springframework.boot.web.embedded.tomcat.TomcatWebServer$1.run(TomcatWebServer.java:197)

       Locked ownable synchronizers:
            - None

    "Catalina-utility-2" #123 prio=1 os_prio=31 tid=0x00007fc9de886000 nid=0xa80f waiting on condition [0x0000700005f89000]
       java.lang.Thread.State: WAITING (parking)
            at sun.misc.Unsafe.park(Native Method)
            - parking to wait for  <0x000000076c88ab58> (a java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject)
            at java.util.concurrent.locks.LockSupport.park(LockSupport.java:175)
            at java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject.await(AbstractQueuedSynchronizer.java:2039)
            at java.util.concurrent.ScheduledThreadPoolExecutor$DelayedWorkQueue.take(ScheduledThreadPoolExecutor.java:1088)
            at java.util.concurrent.ScheduledThreadPoolExecutor$DelayedWorkQueue.take(ScheduledThreadPoolExecutor.java:809)
            at java.util.concurrent.ThreadPoolExecutor.getTask(ThreadPoolExecutor.java:1074)
            at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1134)
            at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
            at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
            at java.lang.Thread.run(Thread.java:748)

       Locked ownable synchronizers:
            - None

    "Catalina-utility-1" #122 prio=1 os_prio=31 tid=0x00007fc9de884000 nid=0x5667 waiting on condition [0x0000700005e86000]
       java.lang.Thread.State: TIMED_WAITING (parking)
            at sun.misc.Unsafe.park(Native Method)
            - parking to wait for  <0x000000076c88ab58> (a java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject)
            at java.util.concurrent.locks.LockSupport.parkNanos(LockSupport.java:215)
            at java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject.awaitNanos(AbstractQueuedSynchronizer.java:2078)
            at java.util.concurrent.ScheduledThreadPoolExecutor$DelayedWorkQueue.take(ScheduledThreadPoolExecutor.java:1093)
            at java.util.concurrent.ScheduledThreadPoolExecutor$DelayedWorkQueue.take(ScheduledThreadPoolExecutor.java:809)
            at java.util.concurrent.ThreadPoolExecutor.getTask(ThreadPoolExecutor.java:1074)
            at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1134)
            at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
            at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
            at java.lang.Thread.run(Thread.java:748)

       Locked ownable synchronizers:
            - None

    "RMI Scheduler(0)" #15 daemon prio=5 os_prio=31 tid=0x00007fc9de9ee000 nid=0x5503 waiting on condition [0x0000700005d83000]
       java.lang.Thread.State: TIMED_WAITING (parking)
            at sun.misc.Unsafe.park(Native Method)
            - parking to wait for  <0x00000006c0015410> (a java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject)
            at java.util.concurrent.locks.LockSupport.parkNanos(LockSupport.java:215)
            at java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject.awaitNanos(AbstractQueuedSynchronizer.java:2078)
            at java.util.concurrent.ScheduledThreadPoolExecutor$DelayedWorkQueue.take(ScheduledThreadPoolExecutor.java:1093)
            at java.util.concurrent.ScheduledThreadPoolExecutor$DelayedWorkQueue.take(ScheduledThreadPoolExecutor.java:809)
            at java.util.concurrent.ThreadPoolExecutor.getTask(ThreadPoolExecutor.java:1074)
            at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1134)
            at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
            at java.lang.Thread.run(Thread.java:748)

       Locked ownable synchronizers:
            - None

    "Attach Listener" #13 daemon prio=9 os_prio=31 tid=0x00007fc9df149800 nid=0x3c07 waiting on condition [0x0000000000000000]
       java.lang.Thread.State: RUNNABLE

       Locked ownable synchronizers:
            - None

    "RMI TCP Accept-0" #11 daemon prio=5 os_prio=31 tid=0x00007fc9df100000 nid=0x4003 runnable [0x0000700005977000]
       java.lang.Thread.State: RUNNABLE
            at java.net.PlainSocketImpl.socketAccept(Native Method)
            at java.net.AbstractPlainSocketImpl.accept(AbstractPlainSocketImpl.java:409)
            at java.net.ServerSocket.implAccept(ServerSocket.java:545)
            at java.net.ServerSocket.accept(ServerSocket.java:513)
            at sun.management.jmxremote.LocalRMIServerSocketFactory$1.accept(LocalRMIServerSocketFactory.java:52)
            at sun.rmi.transport.tcp.TCPTransport$AcceptLoop.executeAcceptLoop(TCPTransport.java:405)
            at sun.rmi.transport.tcp.TCPTransport$AcceptLoop.run(TCPTransport.java:377)
            at java.lang.Thread.run(Thread.java:748)

       Locked ownable synchronizers:
            - None

    "Service Thread" #9 daemon prio=9 os_prio=31 tid=0x00007fc9df0ce800 nid=0x4103 runnable [0x0000000000000000]
       java.lang.Thread.State: RUNNABLE

       Locked ownable synchronizers:
            - None

    "C1 CompilerThread2" #8 daemon prio=9 os_prio=31 tid=0x00007fc9df0ce000 nid=0x4203 waiting on condition [0x0000000000000000]
       java.lang.Thread.State: RUNNABLE

       Locked ownable synchronizers:
            - None

    "C2 CompilerThread1" #7 daemon prio=9 os_prio=31 tid=0x00007fc9de0a3800 nid=0x3503 waiting on condition [0x0000000000000000]
       java.lang.Thread.State: RUNNABLE

       Locked ownable synchronizers:
            - None

    "C2 CompilerThread0" #6 daemon prio=9 os_prio=31 tid=0x00007fc9de89b000 nid=0x3403 waiting on condition [0x0000000000000000]
       java.lang.Thread.State: RUNNABLE

       Locked ownable synchronizers:
            - None

    "Monitor Ctrl-Break" #5 daemon prio=5 os_prio=31 tid=0x00007fc9df0ca000 nid=0x3303 runnable [0x0000700005468000]
       java.lang.Thread.State: RUNNABLE
            at java.net.SocketInputStream.socketRead0(Native Method)
            at java.net.SocketInputStream.socketRead(SocketInputStream.java:116)
            at java.net.SocketInputStream.read(SocketInputStream.java:171)
            at java.net.SocketInputStream.read(SocketInputStream.java:141)
            at sun.nio.cs.StreamDecoder.readBytes(StreamDecoder.java:284)
            at sun.nio.cs.StreamDecoder.implRead(StreamDecoder.java:326)
            at sun.nio.cs.StreamDecoder.read(StreamDecoder.java:178)
            - locked <0x00000006c001b760> (a java.io.InputStreamReader)
            at java.io.InputStreamReader.read(InputStreamReader.java:184)
            at java.io.BufferedReader.fill(BufferedReader.java:161)
            at java.io.BufferedReader.readLine(BufferedReader.java:324)
            - locked <0x00000006c001b760> (a java.io.InputStreamReader)
            at java.io.BufferedReader.readLine(BufferedReader.java:389)
            at com.intellij.rt.execution.application.AppMainV2$1.run(AppMainV2.java:64)

       Locked ownable synchronizers:
            - None

    "Signal Dispatcher" #4 daemon prio=9 os_prio=31 tid=0x00007fc9de824000 nid=0x4503 runnable [0x0000000000000000]
       java.lang.Thread.State: RUNNABLE

       Locked ownable synchronizers:
            - None

    "Finalizer" #3 daemon prio=8 os_prio=31 tid=0x00007fc9dd811800 nid=0x4f03 in Object.wait() [0x0000700005262000]
       java.lang.Thread.State: WAITING (on object monitor)
            at java.lang.Object.wait(Native Method)
            - waiting on <0x00000006c0008348> (a java.lang.ref.ReferenceQueue$Lock)
            at java.lang.ref.ReferenceQueue.remove(ReferenceQueue.java:144)
            - locked <0x00000006c0008348> (a java.lang.ref.ReferenceQueue$Lock)
            at java.lang.ref.ReferenceQueue.remove(ReferenceQueue.java:165)
            at java.lang.ref.Finalizer$FinalizerThread.run(Finalizer.java:216)

       Locked ownable synchronizers:
            - None

    "Reference Handler" #2 daemon prio=10 os_prio=31 tid=0x00007fc9de02a000 nid=0x5003 in Object.wait() [0x000070000515f000]
       java.lang.Thread.State: WAITING (on object monitor)
            at java.lang.Object.wait(Native Method)
            - waiting on <0x00000006c001b940> (a java.lang.ref.Reference$Lock)
            at java.lang.Object.wait(Object.java:502)
            at java.lang.ref.Reference.tryHandlePending(Reference.java:191)
            - locked <0x00000006c001b940> (a java.lang.ref.Reference$Lock)
            at java.lang.ref.Reference$ReferenceHandler.run(Reference.java:153)

       Locked ownable synchronizers:
            - None

    "VM Thread" os_prio=31 tid=0x00007fc9df00b800 nid=0x2c03 runnable

    "GC task thread#0 (ParallelGC)" os_prio=31 tid=0x00007fc9de805000 nid=0x1e07 runnable

    "GC task thread#1 (ParallelGC)" os_prio=31 tid=0x00007fc9de003800 nid=0x2a03 runnable

    "GC task thread#2 (ParallelGC)" os_prio=31 tid=0x00007fc9df002000 nid=0x5403 runnable

    "GC task thread#3 (ParallelGC)" os_prio=31 tid=0x00007fc9df002800 nid=0x5203 runnable

    "VM Periodic Task Thread" os_prio=31 tid=0x00007fc9df11a800 nid=0x3a03 waiting on condition

    JNI global references: 1087

    Found one Java-level deadlock:
    =============================
    "mythread2":
      waiting for ownable synchronizer 0x000000076f5d4330, (a java.util.concurrent.locks.ReentrantLock$NonfairSync),
      which is held by "mythread1"
    "mythread1":
      waiting for ownable synchronizer 0x000000076f5d4360, (a java.util.concurrent.locks.ReentrantLock$NonfairSync),
      which is held by "mythread2"

    Java stack information for the threads listed above:
    ===================================================
    "mythread2":
            at sun.misc.Unsafe.park(Native Method)
            - parking to wait for  <0x000000076f5d4330> (a java.util.concurrent.locks.ReentrantLock$NonfairSync)
            at java.util.concurrent.locks.LockSupport.park(LockSupport.java:175)
            at java.util.concurrent.locks.AbstractQueuedSynchronizer.parkAndCheckInterrupt(AbstractQueuedSynchronizer.java:836)
            at java.util.concurrent.locks.AbstractQueuedSynchronizer.acquireQueued(AbstractQueuedSynchronizer.java:870)
            at java.util.concurrent.locks.AbstractQueuedSynchronizer.acquire(AbstractQueuedSynchronizer.java:1199)
            at java.util.concurrent.locks.ReentrantLock$NonfairSync.lock(ReentrantLock.java:209)
            at java.util.concurrent.locks.ReentrantLock.lock(ReentrantLock.java:285)
            at com.nicksxs.thread_dump_demo.ThreadDumpDemoApplication$2.run(ThreadDumpDemoApplication.java:34)
    "mythread1":
            at sun.misc.Unsafe.park(Native Method)
            - parking to wait for  <0x000000076f5d4360> (a java.util.concurrent.locks.ReentrantLock$NonfairSync)
            at java.util.concurrent.locks.LockSupport.park(LockSupport.java:175)
            at java.util.concurrent.locks.AbstractQueuedSynchronizer.parkAndCheckInterrupt(AbstractQueuedSynchronizer.java:836)
            at java.util.concurrent.locks.AbstractQueuedSynchronizer.acquireQueued(AbstractQueuedSynchronizer.java:870)
            at java.util.concurrent.locks.AbstractQueuedSynchronizer.acquire(AbstractQueuedSynchronizer.java:1199)
            at java.util.concurrent.locks.ReentrantLock$NonfairSync.lock(ReentrantLock.java:209)
            at java.util.concurrent.locks.ReentrantLock.lock(ReentrantLock.java:285)
            at com.nicksxs.thread_dump_demo.ThreadDumpDemoApplication$1.run(ThreadDumpDemoApplication.java:22)

    Found 1 deadlock.

前面的信息其实上次就看过了，后面就可以发现有个死锁了，
上面比较长，把主要的截出来，就是这边的，这点就很强大了。

### jmap

惯例还是看一下帮助信息
这个相对命令比较多，不过因为现在 dump 下来我们可能会用文件模式，然后将文件下载下来使用 mat 进行分析，所以可以使用
`jmap -dump:live,format=b,file=heap.bin <pid>`
命令照着上面看的就是打印活着的对象，然后以二进制格式，文件名叫 heap.bin 然后最后就是进程 id，打印出来以后可以用 mat 打开
这样就可以很清晰的看到应用里的各种信息，jmap 直接在命令中还可以看很多信息，比如使用`jmap -histo <pid>`打印对象的实例数和对象占用的内存
`jmap -finalizerinfo <pid>` 打印正在等候回收的对象

#### 小tips

对于一些应用内存已经占满了，jstack 和 jmap 可能会连不上的情况，可以使用`-F`参数强制打印线程或者 dump 文件，但是要注意这两者使用的用户必须与 java 进程启动用户一致，并且使用的 jdk 也要一致

## 我是如何走上跑步这条不归路的

Posted on 2020-07-26 In 生活 , 运动 , 跑步 Views: Disqus:

这周因为没有准备技术方面的内容加之之前有想分享下我和跑步的一些事情，我从小学开始就是个体育渣，因为体重大非常胖，小学的时候要做仰卧起坐，基本是一个都起不来，然后那时候跑步也是要我命那种，跟另外一个比较胖的同学在跑步队尾苟延残喘，只有立定跳远还行。

时光飞逝，我在初中高中的时候因为爱打篮球，以为自己体质已经有了质的变化，所以在体育课跑步的时候妄图跟一位体育非常好的同学一起跑，结果跟的快断气了，最终还是确认了自己是个体育渣，特别是到了大学的第一次体测跑一千米，跑完直接吐了，一则是大学太宅不运动，二则的确是底子不好。那么怎么会去跑步了呢，其实也没什么特殊的原因，就是工作以后因为运动得更少，体质差，而且越来越胖，所以就想运动下，加之跑步也是我觉得成本最低的运动了，刚好那时候17 年租的地方附近小区周围的路车不太多，一圈刚好一公里多，就觉得开始跑跑看，其实想想以前觉得一千米是非常远的，学校塑胶跑道才 400 米，一千米要两圈半，太难了，但是后来在这个小区周围跑的时候好像跑了一圈以后还能再跑一点，最后跑了两圈，可把自己牛坏了，我都能跑两千米了，哈哈，这是个什么概念呢，大学里最让我绝望的两项体育相关的内容就是一千米和十二分钟跑，一千米把我跑吐了，十二分钟跑及格五圈半也能让我跑完花一周时间恢复以及提前一周心理压力爆炸，虽然我那时候跑的不快，但是已经能跑两千米了，瞬间让自己自信心爆炸，并且跑完步出完汗的感觉是非常棒的，毕竟吃奶茶鸡排都能心安理得了，谁叫我跑步了呢😄，其实现在回去看，那时候跑得还算快的，因为还比较瘦，现在要跑得那么快心跳就太快了，关于心跳什么的后面说，开始建立起自信心之后，对跑步这件事就开始不那么排斥跟害怕了，毕竟我能跑两千米了，然后试试三公里，哇，也可以了呢，三公里是什么概念呢，我大学里跑过最多的一次是十二分钟跑五圈半还是六圈，也就是两公里多，不到三公里，几乎是生涯最长了，一时间产生了一些我可能是个被埋没的运动天才的错觉，其实细想下也能明白，只是速度足够慢了就能跑多一点，毕竟提测一千米是要跑进四分钟才及格，自己跑的时候一千米跑六分多钟已经算不慢了（对我自己来说），但是即使是这样还是对把跑步坚持下去这件事有了很大的正面激励作用，并且由于那时候上下班骑车，整个体重控制的比较理想，导致一时间误会跑步就能非常快的减肥（其实这是我跑步历程中比较大的误区之一），因为会在跑步前后称下体重，如果跑个五公里（后面可以跑五公里了），可能体重就能降 0.5 千克，但实际上这只是这五公里跑步身体流失的水分，喝杯水就回来了，那时候能控制体重主要是骑车跟跑步一起的作用，并且工作压力相对来讲比较小，没有过劳肥。

后面其实跑步慢慢变得一个比较习惯的运动了，从三公里，到五公里，到七公里，再到十公里，十公里差不多对我来说是个坎，一直还不能比较轻松的跑十公里，可能近一两年好了一些（原谅我只是跟自己比较，跟那些大神比差得不知道多远），其实对我来说每次都是个突破，因为其实与他人比较没有特别大意义，比较顶尖的差得太远，比较普通的也不行，都会打击自信心，比较比我差的就更没意义了，所以其实能挑战自己，能把自己的上限提高才是最有意义的，这也是我看着朋友圈里的一些大神的速度除了佩服赞叹之外没什么其他的惭愧或者说嫌弃自己的感觉（阿 Q 精神😄）。

一直感性地觉得，跑步能解压，跑完浑身汗，有种把身体的负能量都排出去的感觉，也把吃太多的罪恶感排解掉了🤦‍♂️，之前朋友有看一本书，书名差不多叫越跑越接近自己，这个也是我觉得挺准确的一句话，当跑到接近极限了，还想再继续再跑一点，再跑一点就能突破自己上一次的最远记录了，再跑一点就能又一次突破自己了，成人以后，毕业以后，进入社会以后，世事总是难以件件顺遂，磕磕绊绊的往前走，总觉得要崩溃了，但是还是得坚持，再熬一下，再拼一下，可能还是失败，但人生呢，运气好的人和事总是小概率的，唯有面对挫折，还是日拱一卒，来日方长，我们再坚持下，没准下一次，没准再跑一会，就能突破自己，达到新的境界。

另外个人后期对跑步的一些知识和理解也变得深入一些，比如伤膝盖，其实跑步的确伤膝盖，需要做一些准备和防护，最好的是适合自己的跑鞋和比较好的路（最好的是塑胶跑道了），也要注意热身跟跑后的拉伸（虽然我做的很差），还有就是注意心率，每个人有自己的适宜心率，我这就不冒充科普达人了，可以自行搜索关键字，先说到这吧~