CODEWITHSUNDEEP
javanetwork-programming
Stripies
Stripies

Reputation: 1267

ObjectInputStream giving strange results

Here is the code I am using.

Client:

public static void main(String[] args) throws IOException {
    Socket socket = new Socket("0.0.0.0", 5555);
    ObjectOutputStream out = new ObjectOutputStream(socket.getOutputStream());
    FileInputStream in = new FileInputStream("C:/Documents and Settings/Owner/Desktop/Client/README.txt");
    byte[] b = new byte[1024];
    int i = 0;
    i = in.read(b);
    out.writeInt(i);
    out.write(b, 0, i);
    out.flush();
    i = in.read(b);
    out.writeInt(i);
    out.write(b, 0, i);
    out.flush();
    out.close();
    in.close();
    socket.close();
}

Server:

public static void main(String[] args) throws IOException {
    ServerSocket ss = new ServerSocket(5555);
    Socket s = ss.accept();
    ObjectInputStream in = new ObjectInputStream(s.getInputStream());
    FileOutputStream fos = new FileOutputStream("C:/README.txt");
    int i = 0;
    i = in.readInt();
    System.out.println(i);
    byte[] bytes = new byte[i];
    in.read(bytes);
    i = in.readInt();
    System.out.println(i);
    byte[] bytes2 = new byte[i];
    in.read(bytes2);
    fos.write(bytes);
    fos.close();
    s.close();
    ss.close();
}

The file README.txt has ~2400 bytes in it. When I run this, the server outputs this.

1024

1869488225

It then throws a java.lang.OutOfMemoryError.

Can anybody tell me why it is reading 1869488225 instead of 1024?

Thanks

Upvotes: 1

Views: 167

Answers (1)

user207421
user207421

Reputation: 310860

in.read(bytes);
in.read(bytes2);

Here you are ignoring the return value of read and assuming that it fills the buffer. You should change read() to readFully() here, but in general you should never ignore a read() result. It can be -1 indicating EOS, or it can be any count from 1 up to the buffer size. If you inadvertently specify a zero length buffer it can even be zero.

Upvotes: 1

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