要注意的点：

1. ServerSocket 和 Socket
2. InetAddress 类
3. socket.getInputStream() 和 socket.getOutputStream()
4. socket.getOutputStream() 这个输出流在完成输出后，需要有一个结束标记，可以用socket.shutdownOutput()，否则会一直等待继续输出
5. socket流在最后一起关闭

客户端代码：

public class Client { // 客户端public static void main(String[] args) throws IOException {// 创建连接服务端的socketSocket socket = new Socket(InetAddress.getLocalHost(), 8888);String path = "d:\\sx.jpg";// 读取客户端本地文件的输入流BufferedInputStream bis = new BufferedInputStream(new FileInputStream(path));// 传送文件的socket输出流OutputStream outputStream = socket.getOutputStream();int readByte = 0;byte[] buf = new byte[1024];// 边读入边输出while((readByte = bis.read(buf)) != -1 ){outputStream.write(buf,0,readByte);}// socket输出信息完毕后记得 shutdown// 否则会卡在这socket.shutdownOutput();// 接收服务端传来的接收状态的输入流InputStream inputStream = socket.getInputStream();while((readByte = inputStream.read(buf)) != -1){System.out.println(new String(buf,0,readByte));}// 闭流inputStream.close();outputStream.close();bis.close();socket.close();}
}

服务端代码：

public class Server { //服务端public static void main(String[] args) throws IOException {// 创建 serverSocketServerSocket serverSocket = new ServerSocket(8888);// 监听端口Socket socket = serverSocket.accept();String path = "d:\\sx2.jpg";// 创建输出流处理客户端传来的图片BufferedOutputStream bos = new BufferedOutputStream(new FileOutputStream(path));// socket输入流InputStream inputStream = socket.getInputStream();int readByte = 0;byte[] buf = new byte[1024];// 从socket输入流读取图片的字节数组，并同时写入到输出流中while((readByte = inputStream.read(buf)) != -1) {bos.write(buf,0,readByte);}// 不涉及socket的流，可以提前关闭bos.close();// 收到客户端的图片后，给客户端回送消息OutputStream outputStream = socket.getOutputStream();outputStream.write("服务端已收到图片".getBytes());// socket输出信息完毕后记得 shutdownsocket.shutdownOutput();// 关闭 socket相关的流，都要放最后关闭outputStream.close();inputStream.close();socket.close();serverSocket.close();}
}