在未捕获的异常上附加jdb

Question

所以,我正在开始一个Java程序,如下所示

java -agentlib:jdwp=transport=dt_socket,address=8000, server=y,suspend=n  MyClass

然后我手动附加调试器,如下所示

jdb -attach 8000

我想知道是否有任何方式让我设置jdb,以便它在未捕获的异常情况下自动附加到正在运行的进程(仅)？

原因是我想避免调试器的开销直到出现未捕获的异常.但是我现在面临的问题是,如果没有附加调试器,那么一旦出现未捕获的异常,JVM就会中止.

编辑:

从Oracle 文档来看,似乎下面的命令可以满足我的需求,但对于Windows机器而言.

java -agentlib:jdwp=transport=dt_shmem,server=y,onuncaught=y,launch=d:\bin\debugstub.exe MyClass

谁知道linux等价？我试过下面的命令.

java -agentlib:jdwp=transport=dt_socket,address=8000,server=y,onuncaught=y,suspend=n,launch=jdb MyClass

调试器似乎连接但它会立即抛出IOError.

Initializing jdb ...

java.io.IOException: Input/output error
at java.io.FileInputStream.readBytes(Native Method)
at java.io.FileInputStream.read(FileInputStream.java:272)
at java.io.BufferedInputStream.read1(BufferedInputStream.java:273)
at java.io.BufferedInputStream.read(BufferedInputStream.java:334)
at sun.nio.cs.StreamDecoder.readBytes(StreamDecoder.java:283)
at sun.nio.cs.StreamDecoder.implRead(StreamDecoder.java:325)
at sun.nio.cs.StreamDecoder.read(StreamDecoder.java:177)
at java.io.InputStreamReader.read(InputStreamReader.java:184)
at java.io.BufferedReader.fill(BufferedReader.java:154)
at java.io.BufferedReader.readLine(BufferedReader.java:317)
at java.io.BufferedReader.readLine(BufferedReader.java:382)
at com.sun.tools.example.debug.tty.TTY.<init>(TTY.java:751)
at com.sun.tools.example.debug.tty.TTY.main(TTY.java:1067)

Answer 1

与其使用调试器并远程附加一个调试器，为什么不使用创建一个未捕获的异常处理程序Thread.UncaughtExceptionHandler呢？

public class ThreadCatch
{
    public static void main(String... args)
    {
        new ThreadCatch().go();
    }

    public void go()
    {
        try {
            Thread.setDefaultUncaughtExceptionHandler(new Thread.UncaughtExceptionHandler() {
                @Override
                public void uncaughtException(Thread t, Throwable e) {
                    System.out.println("Uncaught exception");
                    e.printStackTrace();
                }
            });

            final Thread thread = new Thread(new A());
            thread.start();
            thread.join();
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
    }

    class A implements Runnable
    {
        int x = 10;

        @Override
        public void run()
        {
            x++;
            ObjectTrackingException obj = new ObjectTrackingException();
            obj.setThrownFrom(this);
            throw obj;
        }
    }
}


class ObjectTrackingException extends RuntimeException
{
    private Object thrownFrom;

    public Object getThrownFrom() {
        return thrownFrom;
    }

    public void setThrownFrom(Object thrownFrom) {
        this.thrownFrom = thrownFrom;
    }
}