如何在套接字通道中发送和接收序列化对象

Question

我想通过套接字通道传输序列化对象。 我想将“嗨朋友”字符串作为序列化对象，然后将此对象写入套接字通道，而在另一端我想读取相同的对象并检索数据。

我想使用 Java SocketChannel 完成所有这些事情。这个怎么做？ 我已经尝试如下，但在接收方没有得到任何数据。

private static void writeObject(Object obj, SelectionKey selectionKey) {
    ObjectOutputStream oos;
    try {
        SocketChannel channel = (SocketChannel) selectionKey.channel();
        oos = new ObjectOutputStream(Channels.newOutputStream(channel));

        oos.writeObject(obj);
    } catch (IOException ex) {
        ex.printStackTrace();
    }
}

private static Object readObject(SelectionKey selectionKey) {
    ObjectInputStream ois;
    Object obj = new Object();
    SocketChannel channel = (SocketChannel) selectionKey.channel();
    try {
        ois = new ObjectInputStream(Channels.newInputStream(channel));
        obj = ois.readObject();
    } catch (Exception ex) {
        ex.printStackTrace();
    }
    return obj;
}

Answer 1

您的 SocketChannel 处理似乎不完整，请参阅这个 complete SocketChannels 传输字节的示例：

/*
 * Writer
 */
import java.io.IOException;
import java.io.ObjectOutputStream;
import java.net.InetSocketAddress;
import java.nio.channels.ServerSocketChannel;
import java.nio.channels.SocketChannel;

public class Sender {
    public static void main(String[] args) throws IOException {
        System.out.println("Sender Start");

        ServerSocketChannel ssChannel = ServerSocketChannel.open();
        ssChannel.configureBlocking(true);
        int port = 12345;
        ssChannel.socket().bind(new InetSocketAddress(port));

        String obj ="testtext";
        while (true) {
            SocketChannel sChannel = ssChannel.accept();

            ObjectOutputStream  oos = new 
                      ObjectOutputStream(sChannel.socket().getOutputStream());
            oos.writeObject(obj);
            oos.close();

            System.out.println("Connection ended");
        }
    }
}

还有读者

/*
 * Reader
 */
import java.io.IOException;
import java.io.ObjectInputStream;
import java.net.InetSocketAddress;
import java.nio.channels.SocketChannel;

public class Receiver {
    public static void main(String[] args) 
    throws IOException, ClassNotFoundException {
        System.out.println("Receiver Start");

        SocketChannel sChannel = SocketChannel.open();
        sChannel.configureBlocking(true);
        if (sChannel.connect(new InetSocketAddress("localhost", 12345))) {

            ObjectInputStream ois = 
                     new ObjectInputStream(sChannel.socket().getInputStream());

            String s = (String)ois.readObject();
            System.out.println("String is: '" + s + "'");
        }

        System.out.println("End Receiver");
    }
}

当您首先启动服务器，然后是接收器时，您将获得以下输出：

服务器的控制台

Sender Start
Connection ended

接收者的控制台

Receiver Start
String is: 'testtext'
End Receiver

这不是最好的解决方案，但遵循您使用Java的ServerSocketChannel