blocks|key|717933|text|一个调试java程序的有用工具，它给出了线程的数量和其他相关信息：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|717934|jconsole+<process-id>|offset|length|style|CODE|717935|entityMap^0|0|0|L|0^^$0|@$1|2|3|4|5|6|7|J|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|K|8|@$D|L|E|M|F|G]]|9|@]|A|$]]|$1|H|3|-4|5|6|7|N|8|@]|9|@]|A|$]]]|I|$]]

Useful tool for debugging java programs, it gives the number of threads and other relevant info on them:

<code>jconsole &lt;process-id&gt;</code>

blocks|key|717914|text|java.lang.Thread.activeCount()|type|code-block|depth|inlineStyleRanges|entityRanges|data|syntax|javascript|717915|它将返回当前线程的线程组中的活动线程数。|unstyled|offset|length|style|BOLD|717916|文档：http://docs.oracle.com/javase/7/docs/api/java/lang/Thread.html#activeCount()|717917|entityMap|0|LINK|mutability|MUTABLE|url|http://docs.oracle.com/javase/7/docs/api/java/lang/Thread.html#activeCount()^0|0|4|8|0|3|24|0|0^^$0|@$1|2|3|4|5|6|7|U|8|@]|9|@]|A|$B|C]]|$1|D|3|E|5|F|7|V|8|@$G|W|H|X|I|J]]|9|@]|A|$]]|$1|K|3|L|5|F|7|Y|8|@]|9|@$G|Z|H|10|1|11]]|A|$]]|$1|M|3|-4|5|F|7|12|8|@]|9|@]|A|$]]]|N|$O|$5|P|Q|R|A|$S|T]]]]

<pre><code>java.lang.Thread.activeCount()
</code></pre>

It will return the number of active threads in the current thread's thread group.

docs: <a href="http://docs.oracle.com/javase/7/docs/api/java/lang/Thread.html#activeCount()" rel="noreferrer">http://docs.oracle.com/javase/7/docs/api/java/lang/Thread.html#activeCount()</a>

blocks|key|1927972|text|ManagementFactory.getThreadMXBean().getThreadCount()不像Thread.activeCount()那样将自己限制在线程组中。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|1927973|entityMap|0|LINK|mutability|MUTABLE|url|http://java.sun.com/j2se/1.5.0/docs/api/java/lang/management/ManagementFactory.html#getThreadMXBean()^0|0|1G|1I|K|0|1G|0|0^^$0|@$1|2|3|4|5|6|7|N|8|@$9|O|A|P|B|C]|$9|Q|A|R|B|C]]|D|@$9|S|A|T|1|U]]|E|$]]|$1|F|3|-4|5|6|7|V|8|@]|D|@]|E|$]]]|G|$H|$5|I|J|K|E|$L|M]]]]

<a href="http://java.sun.com/j2se/1.5.0/docs/api/java/lang/management/ManagementFactory.html#getThreadMXBean()" rel="noreferrer"><code>ManagementFactory.getThreadMXBean().getThreadCount()</code></a> doesn't limit itself to thread groups as <code>Thread.activeCount()</code> does.

blocks|key|717896|text|JVM类上有一个静态方法，它将返回由Thread控制的活动线程的数量：|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|717897|Thread.activeCount()|717898|717899|返回当前线程的线程组中的活动线程数。|blockquote|717900|717901|717902|此外，如果您希望实时监视所有活动线程，则外部调试器应列出所有活动线程(并允许您挂起任意数量的线程)。|717903|entityMap^0|I|6|0|0|K|0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|R|8|@$9|S|A|T|B|C]]|D|@]|E|$]]|$1|F|3|G|5|6|7|U|8|@$9|V|A|W|B|C]]|D|@]|E|$]]|$1|H|3|-4|5|6|7|X|8|@]|D|@]|E|$]]|$1|I|3|J|5|K|7|Y|8|@]|D|@]|E|$]]|$1|L|3|-4|5|6|7|Z|8|@]|D|@]|E|$]]|$1|M|3|-4|5|6|7|10|8|@]|D|@]|E|$]]|$1|N|3|O|5|6|7|11|8|@]|D|@]|E|$]]|$1|P|3|-4|5|6|7|12|8|@]|D|@]|E|$]]]|Q|$]]

There is a static method on the <code>Thread</code> Class that will return the number of active threads controlled by the JVM:

<code>Thread.activeCount()</code>

<blockquote>
 Returns the number of active threads in the current thread's thread group.
</blockquote>

Additionally, external debuggers should list all active threads (and allow you to suspend any number of them) if you wish to monitor them in real-time.

blocks|key|625100|text|不需要像jconsole这样的GUI的通用解决方案(不能在远程终端上工作)，ps适用于非java进程，不需要安装JVM。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|625101|ps+-o+nlwp+<pid>|offset|length|style|CODE|625102|entityMap^0|0|0|G|0^^$0|@$1|2|3|4|5|6|7|J|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|K|8|@$D|L|E|M|F|G]]|9|@]|A|$]]|$1|H|3|-4|5|6|7|N|8|@]|9|@]|A|$]]]|I|$]]

Generic solution that doesn't require a GUI like jconsole (doesn't work on remote terminals), ps works for non-java processes, doesn't require a JVM installed. 

<code>ps -o nlwp &lt;pid&gt;</code>

blocks|key|2126885|text|我已经编写了一个程序来迭代所有创建的Threads并打印每个Thread的getState()|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|2126886|import+java.util.Set;

public+class+ThreadStatus+{
++++public+static+void+main(String+args[])+throws+Exception{
++++++++for+(+int+i=0;+i<+5;+i%2B%2B){
++++++++++++Thread+t+=+new+Thread(new+MyThread());
++++++++++++t.setName("MyThread:"%2Bi);
++++++++++++t.start();
++++++++}
++++++++int+threadCount+=+0;
++++++++Set<Thread>+threadSet+=+Thread.getAllStackTraces().keySet();
++++++++for+(+Thread+t+:+threadSet){
++++++++++++if+(+t.getThreadGroup()+==+Thread.currentThread().getThreadGroup()){
++++++++++++++++System.out.println("Thread+:"%2Bt%2B":"%2B"state:"%2Bt.getState());
++++++++++++++++%2B%2BthreadCount;
++++++++++++}
++++++++}
++++++++System.out.println("Thread+count+started+by+Main+thread:"%2BthreadCount);
++++}
}

class+MyThread+implements+Runnable{
++++public+void+run(){
++++++++try{
++++++++++++Thread.sleep(2000);
++++++++}catch(Exception+err){
++++++++++++err.printStackTrace();
++++++++}
++++}
}|code-block|syntax|javascript|2126887|输出：|2126888|java+ThreadStatus

Thread+:Thread[MyThread:0,5,main]:state:TIMED_WAITING
Thread+:Thread[main,5,main]:state:RUNNABLE
Thread+:Thread[MyThread:1,5,main]:state:TIMED_WAITING
Thread+:Thread[MyThread:4,5,main]:state:TIMED_WAITING
Thread+:Thread[MyThread:2,5,main]:state:TIMED_WAITING
Thread+:Thread[MyThread:3,5,main]:state:TIMED_WAITING
Thread+count+started+by+Main+thread:6|2126889|如果您删除以下条件|2126890|if+(+t.getThreadGroup()+==+Thread.currentThread().getThreadGroup())|2126891|你也会在输出中得到下面的线程，它们已经被系统启动了。|2126892|Reference+Handler,+Signal+Dispatcher,Attach+Listener+and+Finalizer。|2126893|entityMap^0|I|7|U|6|11|A|0|0|0|0|0|0|0|0|1U|0^^$0|@$1|2|3|4|5|6|7|Y|8|@$9|Z|A|10|B|C]|$9|11|A|12|B|C]|$9|13|A|14|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|15|8|@]|D|@]|E|$I|J]]|$1|K|3|L|5|6|7|16|8|@]|D|@]|E|$]]|$1|M|3|N|5|H|7|17|8|@]|D|@]|E|$I|J]]|$1|O|3|P|5|6|7|18|8|@]|D|@]|E|$]]|$1|Q|3|R|5|H|7|19|8|@]|D|@]|E|$I|J]]|$1|S|3|T|5|6|7|1A|8|@]|D|@]|E|$]]|$1|U|3|V|5|6|7|1B|8|@$9|1C|A|1D|B|C]]|D|@]|E|$]]|$1|W|3|-4|5|6|7|1E|8|@]|D|@]|E|$]]]|X|$]]

I have written a program to iterate all <code>Threads</code> created and printing <code>getState()</code> of each <code>Thread</code>

<pre><code>import java.util.Set;

public class ThreadStatus {
 public static void main(String args[]) throws Exception{
 for ( int i=0; i&lt; 5; i++){
 Thread t = new Thread(new MyThread());
 t.setName("MyThread:"+i);
 t.start();
 }
 int threadCount = 0;
 Set&lt;Thread&gt; threadSet = Thread.getAllStackTraces().keySet();
 for ( Thread t : threadSet){
 if ( t.getThreadGroup() == Thread.currentThread().getThreadGroup()){
 System.out.println("Thread :"+t+":"+"state:"+t.getState());
 ++threadCount;
 }
 }
 System.out.println("Thread count started by Main thread:"+threadCount);
 }
}

class MyThread implements Runnable{
 public void run(){
 try{
 Thread.sleep(2000);
 }catch(Exception err){
 err.printStackTrace();
 }
 }
}
</code></pre>

Output:

<pre><code>java ThreadStatus

Thread :Thread[MyThread:0,5,main]:state:TIMED_WAITING
Thread :Thread[main,5,main]:state:RUNNABLE
Thread :Thread[MyThread:1,5,main]:state:TIMED_WAITING
Thread :Thread[MyThread:4,5,main]:state:TIMED_WAITING
Thread :Thread[MyThread:2,5,main]:state:TIMED_WAITING
Thread :Thread[MyThread:3,5,main]:state:TIMED_WAITING
Thread count started by Main thread:6
</code></pre>

If you remove below condition

<pre><code>if ( t.getThreadGroup() == Thread.currentThread().getThreadGroup())
</code></pre>

You will get below threads in output too, which have been started by system.

<code>Reference Handler, Signal Dispatcher,Attach Listener and Finalizer</code>.

blocks|key|1925742|text|使用Linux+Top命令|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|1925743|top+-H+-p+(process+id)|1925744|您可以通过以下方法获取一个程序的进程id：|1925745|ps+aux+%7C+grep+(your+program+name)|1925746|例如：|1925747|ps+aux+%7C+grep+user.py|1925748|entityMap^0|8|3|0|0|M|0|0|0|X|0|0|0|L|0^^$0|@$1|2|3|4|5|6|7|R|8|@$9|S|A|T|B|C]]|D|@]|E|$]]|$1|F|3|G|5|6|7|U|8|@$9|V|A|W|B|C]]|D|@]|E|$]]|$1|H|3|I|5|6|7|X|8|@]|D|@]|E|$]]|$1|J|3|K|5|6|7|Y|8|@$9|Z|A|10|B|C]]|D|@]|E|$]]|$1|L|3|M|5|6|7|11|8|@]|D|@]|E|$]]|$1|N|3|O|5|6|7|12|8|@$9|13|A|14|B|C]]|D|@]|E|$]]|$1|P|3|-4|5|6|7|15|8|@]|D|@]|E|$]]]|Q|$]]

Using Linux <code>Top</code> command

<code>top -H -p (process id)</code>

you could get process id of one program by this method :

<code>ps aux | grep (your program name)</code>

for example : 

<code>ps aux | grep user.py</code>

blocks|key|717942|text|++++public+class+MainClass+{

++++++++public+static+void+main(String+args[])+{

++++++++++Thread+t+=+Thread.currentThread();
++++++++++t.setName("My+Thread");

++++++++++t.setPriority(1);

++++++++++System.out.println("current+thread:+"+%2B+t);

++++++++++int+active+=+Thread.activeCount();
++++++++++System.out.println("currently+active+threads:+"+%2B+active);
++++++++++Thread+all[]+=+new+Thread[active];
++++++++++Thread.enumerate(all);

++++++++++for+(int+i+=+0;+i+<+active;+i%2B%2B)+{
+++++++++++++System.out.println(i+%2B+":+"+%2B+all[i]);
++++++++++}
+++++++}
+++}|type|code-block|depth|inlineStyleRanges|entityRanges|data|syntax|javascript|717943|unstyled|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|G|8|@]|9|@]|A|$B|C]]|$1|D|3|-4|5|E|7|H|8|@]|9|@]|A|$]]]|F|$]]

<pre><code> public class MainClass {

 public static void main(String args[]) {

 Thread t = Thread.currentThread();
 t.setName("My Thread");

 t.setPriority(1);

 System.out.println("current thread: " + t);

 int active = Thread.activeCount();
 System.out.println("currently active threads: " + active);
 Thread all[] = new Thread[active];
 Thread.enumerate(all);

 for (int i = 0; i &lt; active; i++) {
 System.out.println(i + ": " + all[i]);
 }
 }
 }
</code></pre>

blocks|key|718088|text|使用jstack获取线程数|type|unstyled|depth|inlineStyleRanges|entityRanges|data|718089|jstack+<PID>+%7C+grep+'java.lang.Thread.State'+%7C+wc+-l|code-block|syntax|javascript|718090|上面代码的结果与top+-H+-p+<PID>或ps+-o+nlwp+<PID>有很大不同，因为jstack只从应用程序创建的线程中获取线程。|offset|length|style|CODE|718091|换句话说，jstack将不会获得GC线程|718092|entityMap^0|0|0|8|F|O|G|0|0^^$0|@$1|2|3|4|5|6|7|Q|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|R|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|S|8|@$I|T|J|U|K|L]|$I|V|J|W|K|L]]|9|@]|A|$]]|$1|M|3|N|5|6|7|X|8|@]|9|@]|A|$]]|$1|O|3|-4|5|6|7|Y|8|@]|9|@]|A|$]]]|P|$]]

Get number of threads using jstack
<pre><code>jstack &lt;PID&gt; | grep 'java.lang.Thread.State' | wc -l
</code></pre>
The result of the above code is quite different from <code>top -H -p &lt;PID&gt;</code> or <code>ps -o nlwp &lt;PID&gt;</code> because jstack gets only threads from created by the application.
In other words, jstack will not get GC threads

blocks|key|1928052|text|$+ps+-p+<pid>+-lfT+%7C+wc+-l|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|1928053|您可以使用以下命令获取pid：|1928054|$+top或$+ps+aux+%7C+grep+(your+program+name)|1928055|获取所有线程，而不仅仅是一个进程|1928056|$+ps+-elfT+%7C+wc+-l|1928057|这是针对centOS+/+Red+Hat机器的，它可能会在其他linux机器上运行，也可能不会。|1928058|entityMap^0|0|Q|0|0|0|5|6|Z|0|0|0|I|0|0^^$0|@$1|2|3|4|5|6|7|R|8|@$9|S|A|T|B|C]]|D|@]|E|$]]|$1|F|3|G|5|6|7|U|8|@]|D|@]|E|$]]|$1|H|3|I|5|6|7|V|8|@$9|W|A|X|B|C]|$9|Y|A|Z|B|C]]|D|@]|E|$]]|$1|J|3|K|5|6|7|10|8|@]|D|@]|E|$]]|$1|L|3|M|5|6|7|11|8|@$9|12|A|13|B|C]]|D|@]|E|$]]|$1|N|3|O|5|6|7|14|8|@]|D|@]|E|$]]|$1|P|3|-4|5|6|7|15|8|@]|D|@]|E|$]]]|Q|$]]

<code>$ ps -p &lt;pid&gt; -lfT | wc -l</code>
You can get the pid using:
<code>$ top </code>
or
<code>$ ps aux | grep (your program name)</code>
To get all threads, not only for one process
<code>$ ps -elfT | wc -l </code>
This is for centOS / Red Hat machines, it may or not work on other linux machines

blocks|key|2127025|text|另一种方法:使用jps命令获取进程名称，并在以下脚本片段中使用该名称：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|2127026|#+Get+the+process+id
processPid=$(jps+-l+%7C+grep+"Process+Name"+%7C+awk+'{print+$1}');+
#+Use+process+id+to+get+number+of+threads+using+ps+command+
ps+-M+$processPid%7C+wc+-l|code-block|syntax|javascript|2127027|已在macOS上测试。|2127028|entityMap^0|0|0|0^^$0|@$1|2|3|4|5|6|7|K|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|L|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|M|8|@]|9|@]|A|$]]|$1|I|3|-4|5|6|7|N|8|@]|9|@]|A|$]]]|J|$]]

Another way:
Get the process name using jps command and use that in below script snippet:
<pre><code># Get the process id
processPid=$(jps -l | grep &quot;Process Name&quot; | awk '{print $1}'); 
# Use process id to get number of threads using ps command 
ps -M $processPid| wc -l
</code></pre>
Tested on macOS.

How can I see the number of threads in a Java process?

How to get the number of threads in a Java process

翻译质量差，导致语言生硬或混乱。

没有提供实际的解决方法或示例。

解答不清晰，无法理解或解决问题。

页面排版不美观，阅读体验差。

文章

问答

视频

教程

学习中心

腾讯云实验室

直播

竞赛

腾讯云代码分析专区

腾讯iOA零信任安全管理系统专区

腾讯云架构师技术同盟交流圈

腾讯云数据库专区

腾讯云智能顾问专区

腾讯云原生专区

腾讯混元专区

腾讯云TCE专区

腾讯云Lighthouse专区

腾讯云HAI专区

腾讯云Edgeone专区

腾讯云存储专区

腾讯云智能专区

腾讯轻联专区 

腾讯云开发专区

TAPD专区

腾讯轻量云游戏服专区

EdgeOne AI 安全实战专区

腾讯云最具价值专家

腾讯云架构师技术同盟

腾讯云创作之星

腾讯云开发者先锋

腾讯云代码助手

云原生构建

TAPD 敏捷项目管理

Cloud Studio

SDK中心

API中心

命令行工具

涵盖代码开发、场景应用、自动测试全流程，助你从零构建专属AI助手

一站式MCP教程库，解锁AI应用新玩法

聚焦“写作效率、视觉美观与运行性能”三方面进行全面升级，为您提供更高效、稳定的创作环境

社区富文本&Markdown编辑器全新改版上线，欢迎大家体验!

诚挚邀请您参与本次调研，分享您的真实使用感受与建议。您的反馈至关重要，感谢您的支持与参与！

问如何获取Java进程中的线程数
EN

回答 11

Stack Overflow用户

Stack Overflow用户

Stack Overflow用户

社区

活动

圈层

关于

腾讯云开发者

热门产品

热门推荐

更多推荐

问如何获取Java进程中的线程数EN

回答 11

Stack Overflow用户

Stack Overflow用户

Stack Overflow用户

社区

活动

圈层

关于

腾讯云开发者

热门产品

热门推荐

更多推荐

问如何获取Java进程中的线程数
EN