client:  package com.xiao.socket;      import java.io.ByteArrayOutputStream;  import java.io.FileInputStream;  import java.io.InputStream;  import java.io.OutputStream;  import java.net.InetAddress;  import java.net.Socket;    public class Client1 {      public static void main(String[] args) throws Exception {          //1.创建一个socket连接          Socket socket = new Socket(InetAddress.getByName("127.0.0.1"),9000);          //2.创建一个输出流          OutputStream outputStream = socket.getOutputStream();          //3.读取文件          FileInputStream fileInputStream = new FileInputStream("D:\\照片\\xiao.jpg");          byte[] buffer = new byte[1024];          int lenth;          while ((lenth=fileInputStream.read(buffer))!=-1){          outputStream.write(buffer,0,lenth);          }          //通知服务器，我已经结束了          socket.shutdownOutput();          //确认服务器接收完毕，才能够断开连接          InputStream inputStream = socket.getInputStream();          ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream();          byte[] buffer1 = new byte[1024];          int lenth1;          while ((lenth1=inputStream.read(buffer1))!=-1){              byteArrayOutputStream.write(buffer1,0,lenth1);          }          System.out.println(byteArrayOutputStream.toString());          fileInputStream.close();          outputStream.close();          socket.close();      }  }

server:  package com.xiao.socket;    import java.io.FileOutputStream;  import java.io.IOException;  import java.io.InputStream;  import java.io.OutputStream;  import java.net.ServerSocket;  import java.net.Socket;    public class Server1 {      public static void main(String[] args) throws Exception {          //1.先创建一个端口号          ServerSocket serverSocket = new ServerSocket(9000);          //2.等待连接          Socket socket = serverSocket.accept();//阻塞式监听，会一直等待客户端连接          //3.获取输入流          InputStream inputStream = socket.getInputStream();          FileOutputStream fileOutputStream = new FileOutputStream("receive.jpg");          byte[] buffer = new byte[1024];          int lenth;          while((lenth=inputStream.read(buffer))!=-1){              fileOutputStream.write(buffer,0,lenth);          }          //通知客户端我接收完毕          OutputStream outputStream = socket.getOutputStream();          outputStream.write("我接收完毕".getBytes());            fileOutputStream.close();          inputStream.close();          socket.close();      }  }