一、前言
留给自己的前言：这个线程池在运用中非常有用，能够捕获异常是非常重要的，否则在此期间很难发现你的异常在哪里提交了；
二 自己定义扩展线程池
1、首先构建一个基础的 执行线程
package jDKMulit;
import java.util.concurrent.*;
/**
* Created by ycy on 16/1/12.
*/
public class DviTask implements Runnable{
int a,b;
public void run() {
double re=a/b;
System.out.println(re);
}
public DviTask(int a,int b){
this.a=a;
this.b=b;
}
public static void main(String[] args) throws ExecutionException, InterruptedException {
ThreadPoolExecutor pools= new ThreadPoolExecutor(0,Integer.MAX_VALUE,0l, TimeUnit.SECONDS,new SynchronousQueue<Runnable>());
for (int i = 0; i <5 ; i++) {
// pools.execute(new DviTask(100,i));
Future re= pools.submit(new DviTask(100,i));
re.get();
}
}
}
2、扩展我们的线程池
package jDKMulit;
import java.util.concurrent.*;
/**
* Created by ycy on 16/1/13.
* 自己扩展线程池获取异常位置
* 重写submit:可以拉取异常
*/
public class VeryTraceThreadPoolExecutor extends ThreadPoolExecutor {
// 初始化
public VeryTraceThreadPoolExecutor(int corePoolSize, int maxmumPoolSize,
long keepAliveTime, TimeUnit unit, BlockingQueue<Runnable> workQueue){
super(corePoolSize,maxmumPoolSize,keepAliveTime,unit,workQueue);
}
//执行方法
@Override
public void execute(Runnable command) {
super.execute(command);
}
@Override
public Future<?> submit(Runnable task) {
return super.submit(wrap(task,clientTrace(),Thread.currentThread().getName()));
}
private Exception clientTrace(){
//扔出异常
return new Exception("client stack trace");
}
private Runnable wrap(final Runnable task,final Exception clientStack,String clientThreadName){
return new Runnable() {
public void run() {
try {
task.run();
} catch (Exception e) {
clientStack.printStackTrace();
try {
throw e;
} catch (Exception e1) {
e1.printStackTrace();
}
}
}
};
}
public static void main(String[] args) {
ThreadPoolExecutor pools=new VeryTraceThreadPoolExecutor(0,Integer.MAX_VALUE,0l,TimeUnit.SECONDS,new SynchronousQueue<Runnable>());
//错误堆栈中可以看到是在哪里提交的任务
for (int i = 0; i < 5; i++) {
pools.execute(new DviTask(100,i));
}
}
}
3、执行结果查询异常位置
异常查看；不仅仅可以得到异常发生Runnable的时限内的信息，而且得到了我们任务在哪里提交（红字体）；对于排除错误很重要
<span style="color:#ff0000;">java.lang.Exception: client stack trace</span> at jDKMulit.VeryTraceThreadPoolExecutor.clientTrace(VeryTraceThreadPoolExecutor.java:31) at jDKMulit.VeryTraceThreadPoolExecutor.execute(VeryTraceThreadPoolExecutor.java:21) at jDKMulit.VeryTraceThreadPoolExecutor.main(VeryTraceThreadPoolExecutor.java:57) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.lang.reflect.Method.invoke(Method.java:606) at com.intellij.rt.execution.application.AppMain.main(AppMain.java:144) java.lang.ArithmeticException: / by zero at jDKMulit.DviTask.run(DviTask.java:12) at jDKMulit.VeryTraceThreadPoolExecutor$1.run(VeryTraceThreadPoolExecutor.java:40) at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615) at java.lang.Thread.run(Thread.java:745) 100.0 25.0 33.0 50.0
