第8个例子讲了如何在线程中捕捉未检查异常,本例将介绍如何在线程组中处理未检查异常。
Task.java
package com.dylan.thread.ch1.c11.task; import java.util.Random; /** * Class that implements the concurrent task * */ public class Task implements Runnable { @Override public void run() { int result; // Create a random number generator Random random=new Random(Thread.currentThread().getId()); while (true) { // Generate a random number a calculate 1000 divide by that random number result=1000/((int)(random.nextDouble()*1000)); System.out.printf("%s : %f\n",Thread.currentThread().getId(),result); // Check if the Thread has been interrupted if (Thread.currentThread().isInterrupted()) { System.out.printf("%d : Interrupted\n",Thread.currentThread().getId()); return; } } } }
MyThreadGroup.java
package com.dylan.thread.ch1.c11.group; /** * Class that extends the ThreadGroup class to implement * a uncaught exceptions method * */ public class MyThreadGroup extends ThreadGroup { /** * Constructor of the class. Calls the parent class constructor * @param name */ public MyThreadGroup(String name) { super(name); } /** * Method for process the uncaught exceptions */ @Override public void uncaughtException(Thread t, Throwable e) { // Prints the name of the Thread System.out.printf("The thread %s has thrown an Exception\n",t.getId()); // Print the stack trace of the exception e.printStackTrace(System.out); // Interrupt the rest of the threads of the thread group System.out.printf("Terminating the rest of the Threads\n"); interrupt(); } }
Main.java
package com.dylan.thread.ch1.c11.core; import com.dylan.thread.ch1.c11.group.MyThreadGroup; import com.dylan.thread.ch1.c11.task.Task; /** * Main class of the example * */ public class Main { /** * Main method of the example. Creates a group of threads of * MyThreadGroup class and two threads inside this group * @param args */ public static void main(String[] args) { // Create a MyThreadGroup object MyThreadGroup threadGroup=new MyThreadGroup("MyThreadGroup"); // Create a Taks object Task task=new Task(); // Create and start two Thread objects for this Task for (int i=0; i<2; i++){ Thread t=new Thread(threadGroup,task); t.start(); } } }
运行结果:
10 : 11 : The thread 10 has thrown an Exception
The thread 11 has thrown an Exception
java.util.IllegalFormatConversionException: f != java.lang.Integer
at java.util.Formatter$FormatSpecifier.failConversion(Formatter.java:4302)
at java.util.Formatter$FormatSpecifier.printFloat(Formatter.java:2806)
at java.util.Formatter$FormatSpecifier.print(Formatter.java:2753)
at java.util.Formatter.format(Formatter.java:2520)
at java.io.PrintStream.format(PrintStream.java:970)
at java.io.PrintStream.printf(PrintStream.java:871)
at com.dylan.thread.ch1.c11.task.Task.run(Task.java:19)
at java.lang.Thread.run(Thread.java:745)
java.util.IllegalFormatConversionException: f != java.lang.Integer
at java.util.Formatter$FormatSpecifier.failConversion(Formatter.java:4302)
at java.util.Formatter$FormatSpecifier.printFloat(Formatter.java:2806)
at java.util.Formatter$FormatSpecifier.print(Formatter.java:2753)
at java.util.Formatter.format(Formatter.java:2520)
at java.io.PrintStream.format(PrintStream.java:970)
at java.io.PrintStream.printf(PrintStream.java:871)
at com.dylan.thread.ch1.c11.task.Task.run(Task.java:19)
at java.lang.Thread.run(Thread.java:745)
Terminating the rest of the Threads
Terminating the rest of the Threads