抛出无限循环的java stackoverflowerror

问题描述

我有以下函数启动jsvc守护程序来接收UDP消息：

I have the following function that starts a jsvc daemon for receiving UDP messages:

 @Override
public void start() throws Exception {
    byte[] buf = new byte[1000];

    DatagramPacket dgp = new DatagramPacket(buf, buf.length);
    DatagramSocket sk;

    sk = new DatagramSocket(1000);
    sk.setSoTimeout(0);

    byte[] rcvMsg = null;


    run(sk, dgp, rcvMsg);


}

超时为0时，套接字阻止直到另一条消息进入。这是触发连续运行以下while循环的原因：

With a timeout of 0, the socket blocks until a another message comes in. This is what triggers the continuous run through the following while loop:

 MessageConstructor tmc =null;
Message message = null;

public void run(DatagramSocket sk, DatagramPacket dgp, byte[] rcvMsg){
    while(true){
        try {
            sk.receive(dgp);
        } catch (IOException e) {
            e.printStackTrace();
        }
        rcvMsg = dgp.getData();

         tmc = new MessageConstructor();
         message = tmc.constructMessageFromBinary(rcvMsg);

        tmc =null;
        message = null;
     }


}

唯一新的创建的对象是下面的MessageConstructor：

The only new objects created are the MessageConstructor below:

在constructTagMessageFromBinary函数内部，一个从ByteArrayInputStream填充的Message，它将收到的UDP消息转换为int。

And inside of the constructTagMessageFromBinary function a Message that is populated from a ByteArrayInputStream which converts the received UDP message to an int.

 public Message constructTagMessageFromBinary(byte[] rcvMsg) {

Message message = new Message();
ByteArrayInputStream bais = new ByteArrayInputStream(rcvMsg);
DataInput input = new DataInputStream(bais);

    try {

        int MsgType = 0;
        MsgType = input.readShort();

        message.setType(MsgType);

        return message;

    } catch (IOException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }

    return null;
}

最后，消息是一个pojo。

Lastly, the message is a pojo.

公共类消息{

private int type;
 //getters and setters omitted

}

我已将内存泄漏缩小到以下几行：

I have narrowed the memory leak down to the lines:

 tmc = new MessageConstructor();
 message = tmc.constructMessageFromBinary(rcvMsg);

如果我将它们注释掉，只要守护程序运行，内存就不会增长并保持一致。

If I comment them out, the memory never grows and stays consistent for as long as the daemon runs.

我在MessageConstructor类中做错了什么来接收以下stackoverflower：

What am I doing wrong within the MessageConstructor class to receive the following stackoverflowerror:

Service exit with a return value of 143
java.lang.reflect.InvocationTargetException
        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:616)
        at org.apache.commons.daemon.support.DaemonLoader.start(DaemonLoader.java:243)
Caused by: java.lang.NullPointerException
        at MainDaemon.start(MainDaemon.java:116)
        ... 5 more
Cannot start daemon
Service exit with a return value of 5
java.lang.reflect.InvocationTargetException
        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:616)
        at org.apache.commons.daemon.support.DaemonLoader.start(DaemonLoader.java:243)
Caused by: java.lang.NullPointerException
        at MainDaemon.start(MainDaemon.java:117)
        ... 5 more
Cannot start daemon
Service exit with a return value of 5
Service exit with a return value of 143
Service exit with a return value of 143
Service exit with a return value of 143
Service exit with a return value of 143
Service exit with a return value of 143
Service exit with a return value of 143
Service exit with a return value of 143
Service exit with a return value of 143
java.lang.reflect.InvocationTargetException
        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:616)
        at org.apache.commons.daemon.support.DaemonLoader.start(DaemonLoader.java:243)
Caused by: java.lang.StackOverflowError

推荐答案

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