Program pauses on initializing object input stream in Java

问题

While running debugger, the program pauses on initializing object streams from server main input output streams. Following is the code :

 public TFileReader(Client cli)throws Exception{
    this.cli = cli;
    fileSock = new Socket(cli.ServerIp(), cli.FilePort());
    fobjIn = new ObjectInputStream(fileSock.getInputStream());
    fobjOut = new ObjectOutputStream(fileSock.getOutputStream());
    fobjOut.flush();

}

 @Override
public void run(){

    try{
            System.out.println("file reader thread online");

            fobjOut.writeObject(cli.Name());
            fobjOut.flush();
           String per = (String) fobjIn.readObject();
            System.out.println(per+"video filing...");
            if(!per.equals("OKF"))
            {
                    throw new Exception("Error In retriving video.");
            }

It pauses on fobjIn and do not go to execute fobjOut although fobjIn it passes from fobjIn breakpoint but do not hit out breakpoint.

回答1:

I would keep it simple like this

public TFileReader(Client cli) throws IOException {
    this.cli = cli;
    socket = new Socket(cli.ServerIp(), cli.FilePort());
    out = new ObjectOutputStream(socket.getOutputStream());
    out.flush();
    in = new ObjectInputStream(socket.getInputStream());
}

public void writeObject(Object o) throw IOException {
    out.writeObject(o);
    out.reset();
    out.flush();
}

public <T> T readObject() throw IOException {
    return (T) in.readObject();
}

public void close() throws IOException {
    in.close();
    out.close();
    socket.close();
}

回答2:

The problem is that ObjectInputStream pre-reads data on initialization.

The preferred solution is at Java Creating a new ObjectInputStream Blocks: always initialize your ObjectOutputStream before initializing your ObjectInputStream, so that the "handshake" that the two use internally can be initiated.

When you don't control all the code and cannot change the order, consider delaying the OIS initialization until data is available (InputStream.available or mark/read/reset on a buffered stream wrapping it, etc).

来源：https://stackoverflow.com/questions/14551211/program-pauses-on-initializing-object-input-stream-in-java

标签

java

sockets

stream

objectinputstream