java网络编程相关库

java.net.InetSocketAddress

java.net.SocketAddress

import java.net.SocketAddress;
import java.net.InetSocketAddress;
import java.nio.channels.SocketChannel;

// 连接
SocketAddress address = new InetSocketAddress("127.0.0.1", 11111);
int soTimeout = 60000;
SocketChannel channel = SocketChannel.open();
channel.socket().setSoTimeout(soTimeout);
channel.connect(address);

// 读
import java.nio.ByteBuffer;
import java.nio.ByteOrder;

Object readDataLock = new Object();
ByteBuffer readHeader = ByteBuffer.allocate(4).order(ByteOrder.BIG_ENDIAN);
synchronized (readDataLock) {
    readHeader.clear();
    while(readHeader.hasRemaining()){
        int  r = channel.read(readHeader);
        if (r == -1) { throw new IOException "end of stream when reading header" }
    }
    int bodyLen = readHeader.getInt(0);
    ByteBuffer bodyBuf = ByteBuffer.allocate(bodyLen).order(ByteOrder.BIG_ENDIAN);
    while(bodyBuf.hasRemaining()){
       int r = channel.read(bodyBuf);
    }
}

// 写
Object writeDataLock = new Object();
ByteBuffer writeHeader = ByteBuffer.allocate(4).order(ByteOrder.BIG_ENDIAN);
// body = Packet.newBuilder().setType().setBody(xx.toByteString).build().toByteArray();
synchronized(writeDataLock){
    writeHeader.clear();
    writeHeader.putInt(body.length);
    writeHeader.flip();
    channel.write(writeHeader);
    channel.write(ByteBuffer.wrap(body));
}