Question

在我的实现中，我使用Java序列化来发送一组二进制对象，这些二进制对象以通知标头开头，该通知标头告知将传递多少个对象以及它们各自的大小。刚开始进行简单测试，我就能够成功传输头对象，之后我尝试只发送一个1024字节的数据对象。但是在运行测试后，我会观察以下内容：

第一个数据对象正在成功传递并被接收。
当我发送第二个对象时，我看到来自第一个对象的一些数据仍然作为第二个数据集的前缀;导致第二个对象和InvalidClassException的截断。

有人可以提供一些指示，说明这个问题是什么以及如何解决这个问题？

接收器线程run（）方法如下所示。

public void run() {

    while (mRunning) {
        try {

            // Receive the serialized object
            byte[] buf = new byte[1024];
            DatagramPacket packet = new DatagramPacket(buf, buf.length);
            socket.receive(packet);
            System.out.println("SERVER: data received: ");

            // Display the serialized object. 
            byte[] data = packet.getData();
            System.out.println(Arrays.toString(data));

            ByteArrayInputStream in = new ByteArrayInputStream(data);
            ObjectInputStream is = new ObjectInputStream(in);
            try {
                Object obj = is.readObject();
                if (obj instanceof DatakNotification) {
                    System.out.println("Data notification received: ");
                } else if (obj instanceof DataChunk) {
                    System.out.println("Data Chunk received: ");
                }
                System.out.println(obj);
            } catch (ClassNotFoundException e) {
                e.printStackTrace();
            }
        } catch (IOException e) {
            e.printStackTrace();
            mRunning = false;
        }
    }
    socket.close();
}

在日志中，我看到如下。

第一个对象（标题）

SERVER: data received: 
[-84, -19, 0, 5, 115, 114, 0, 47, 99, 111, 109, 46, 99, 111, 110, 97, 46, 118, 105, 100, 101, 111, 99, 108, 105, 101, 11
0, 116, 46, 99, 104, 117, 110, 107, 103, 101, 110, 46, 66, 108, 111, 99, 107, 78, 111, 116, 105, 102, 105, 99, 97, 116, 
105, 111, 110, -41, 62, 52, -41, -16, 78, 119, 0, 2, 0, 5, 73, 0, 10, 109, 66, 108, 111, 99, 107, 83, 105, 122, 101, 73,
 0, 10, 109, 67, 104, 117, 110, 107, 83, 105, 122, 101, 73, 0, 14, 109, 76, 97, 115, 116, 67, 104, 117, 110, 107, 83, 10
5, 122, 101, 73, 0, 12, 109, 84, 111, 116, 97, 108, 67, 104, 117, 110, 107, 115, 76, 0, 8, 109, 66, 108, 111, 99, 107, 7
3, 100, 116, 0, 18, 76, 106, 97, 118, 97, 47, 108, 97, 110, 103, 47, 83, 116, 114, 105, 110, 103, 59, 120, 112, 0, 0, 10
1, 48, 0, 0, 4, 0, 0, 0, 1, 48, 0, 0, 0, 26, 116, 0, 36, 97, 53, 100, 48, 51, 54, 52, 55, 45, 54, 52, 51, 52, 45, 52, 55
, 98, 100, 45, 97, 101, 55, 51, 45, 55, 102, 57, 53, 49, 48, 52, 102, 55, 49, 98, 56, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,

收到阻止通知： Block Id：a5d03647-6434-47bd-ae73-7f95104f71b8块大小：25904块大小：1024最后块大小：304总块数：26

第二个对象（1K数据）

服务器：收到的数据： [-84，-19,0,5,115,114,0,39,99,111,109,46,99,111,110,97,46,118,105,100,101,111,99,108 ，105,101,11 0,116,46,99,104,117,110,107,103,101,110,46,68,97,116,97,67,104,117,110,107，-95，-44,27， 37，-39， - 34,12,17,2,0,5,73,0,7,109,76,101,110,103,116,104,90,0,7,10,10,77,97,114,107,101， 100,73,0,12,1 09,83,101,113,117,101,110,99,101,78,117,109,91,0,4,109,66,117,102,116,0,2,91,66,76， 0,8,109,6 7,104,117,110,107,73,100,116,0,18,76,106,97,118,97,47,108,97,110,103,47,83,116,114,105， 110,103 ，59,120,112,0,0,0,0,0,0,0,0,117,114,0,2,91,66，-84，-13,23，-8,6， 8,84，-32,2,0,0,120,112,0 ，0,4,0,70,76,86,1,1,0,0,0,9,0,0,0,0,18,0,0，-73,0,0,0,0， 0,0,0,2,0,10,111,110,77,101,11 6,97,68,97,116,97,8,0,0,0,8,0,100,117,114,97,116,105,111,110,0,0,0,0， 0,0,0,0,0,0,5,119 ＆LT; .....＆GT; -124，-7，-22，-22，-62,86,12,1,45,29，-126，-128,24,6，-48,96,3，-53，-15，-95 ，-24,48,31,1,10，-4,24,7 9，-63,41,68,6]

java.io.InvalidClassException: com.dataxfer.chunkgen.DataChunk; local class incompatible: stream classdesc serialVersionUID = -6785768889157546991, local class serialVersionUID = 2835159210520537273
    at java.io.ObjectStreamClass.initNonProxy(ObjectStreamClass.java:617)
    at java.io.ObjectInputStream.readNonProxyDesc(ObjectInputStream.java:1622)
    at java.io.ObjectInputStream.readClassDesc(ObjectInputStream.java:1517)
    at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:1771)
    at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1350)
    at java.io.ObjectInputStream.readObject(ObjectInputStream.java:370)
    at com.dataxfer.transceiver.LocalUdpReceiver.run(LocalUdpReceiver.java:62)

Answer 1

这意味着您的作家和读者的serialVersionUID不匹配。这是因为作者和读者的这个类的代码是不同的。

这意味着需要对读取的serialVersionUID进行硬编码以匹配编写器。

尝试设置

private static final long serialVersionUID = -6785768889157546991L;

仅当您未更改任何字段的类型或删除任何字段时，此操作才有效。

Java序列化二进制数据期间的InvalidClassException

1 个答案: