ObjectInputStream的readObject读一个HashMap怎么总出错

Question

hashmapexception

Answer 1

        HashMap<String, String> map=new HashMap<String,String>();
        map.put("name", "kwj");
        ByteArrayOutputStream bout = new ByteArrayOutputStream();
        ObjectOutputStream oout = new ObjectOutputStream(bout);
        oout.writeObject(map);
        oout.flush();
        
        ByteArrayInputStream bin = new ByteArrayInputStream(bout.toByteArray());
        System.out.println(bin.available());
        byte[] b = new byte[bin.available()];
        bin.read(b);
        HashMap<String, String> m1 = (HashMap<String, String>)(new ObjectInputStream(new ByteArrayInputStream(b)).readObject());
        System.out.println(m1.get("name"));

Answer 2

// 也可以
//        String str=baos.toString("GBK");
//        byte[] byte_array=str.getBytes("GBK");
        byte[] byte_array = baos.toByteArray();

Answer 3

1楼那个是对的，但是
// 也可以
//        String str=baos.toString("GBK");
//        byte[] byte_array=str.getBytes("GBK");
        byte[] byte_array = baos.toByteArray();
这个用这个运行的时候就会出错
Exception in thread "main" java.io.EOFException
at java.io.ObjectInputStream$PeekInputStream.readFully(ObjectInputStream.java:2325)
at java.io.ObjectInputStream$BlockDataInputStream.readUTFBody(ObjectInputStream.java:3063)
at java.io.ObjectInputStream$BlockDataInputStream.readUTF(ObjectInputStream.java:2864)
at java.io.ObjectInputStream.readUTF(ObjectInputStream.java:1072)
at java.io.ObjectStreamClass.readNonProxy(ObjectStreamClass.java:704)
at java.io.ObjectInputStream.readClassDescriptor(ObjectInputStream.java:830)
at java.io.ObjectInputStream.readNonProxyDesc(ObjectInputStream.java:1601)
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 udpchat.Test.main(Test.java:23)

Answer 4

bout.toByteArray()这个得到的字节数组和 
String str=baos.toString("GBK");
//        byte[] byte_array=str.getBytes("GBK");
        byte[] byte_array = baos.toByteArray();
这个得到的不一样