利用TCP 客户端

首先盲写的一个传输文件的方法，但测试发现了一个非常不容易发现的问题，这里先说明一下。

错误的代码如下：

 1 package com.TCP.java; 2  3 import java.io.File; 4 import java.io.FileInputStream; 5 import java.io.FileNotFoundException; 6 import java.io.FileOutputStream; 7 import java.io.IOException; 8 import java.io.InputStream; 9 import java.io.OutputStream; 10 import java.net.InetAddress; 11 import java.net.ServerSocket; 12 import java.net.Socket; 13  14 import org.junit.Test; 15  16 //从客户端发送文件给服务端，服务端保存到本地。并返回“发送成功”给客户端。并关闭相应的连接。 17 public class TestTCP3 { 18   //客户端 19   @Test 20   public void client(){ 21     Socket socket = null; 22     OutputStream os = null; 23     FileInputStream fis = null; 24     InputStream is = null; 25     try { 26       //创建一个Socket的对象 27       socket = new Socket(InetAddress.getByName("192.168.1.101"),9090); 28       //从本地获取一个文件发送给服务端 29       os = socket.getOutputStream(); 30       fis = new FileInputStream(new File("findLei.jpg")); 31       byte[] b = new byte[1024]; 32       int length; 33       while((length = fis.read(b)) != -1){ 34         os.write(b,0,length); 35       } 36       socket.shutdownOutput(); 37       //接收来自服务端的信息 38       is = socket.getInputStream(); 39       byte[] b1 = new byte[1024]; 40       int length1; 41       while((length1 = is.read(b1)) != -1){ 42         String str = new String(b1,0,length1); 43         System.out.println(str); 44       } 45     }catch (IOException e) { 46       e.printStackTrace(); 47     } 48     finally{ 49       //关闭相应的流和Socket对象 50       if(is != null){ 51         try { 52           is.close(); 53         } catch (IOException e) { 54           e.printStackTrace(); 55         } 56       } 57       if(fis != null){ 58         try { 59           fis.close(); 60         } catch (IOException e) { 61           e.printStackTrace(); 62         } 63       } 64       if(os != null){ 65         try { 66           os.close(); 67         } catch (IOException e) { 68           e.printStackTrace(); 69         } 70       } 71       if(socket != null){ 72         try { 73           socket.close(); 74         } catch (IOException e) { 75           e.printStackTrace(); 76         } 77       } 78     } 79   } 80    81   //服务端 82   @Test 83   public void server(){ 84     ServerSocket ss = null; 85     Socket s = null; 86     InputStream is = null; 87     FileOutputStream fos = null; 88     OutputStream os = null; 89     try { 90       //创建一个ServerSocket的对象 91       ss = new ServerSocket(9090); 92       //调用accept()方法，返回一个Socket对象 93       s = ss.accept(); 94       //将从客户端发送的信息保存到本地 95       is = s.getInputStream(); 96       fos = new FileOutputStream("D:/Test"); 97 //      Random random = new Random(); 98 //      fos = new FileOutputStream("D:/Test/" + String.valueOf(random.nextInt(90)) + ".jpg"); 99 //      fos = new FileOutputStream("find2.jpg");100       byte[] b = new byte[1024];101       int length;102       while((length = is.read(b)) != -1){103         fos.write(b, 0, length);104       }105       //发送接收成功的消息106       os = s.getOutputStream();107       os.write("接收成功".getBytes());108     } catch (FileNotFoundException e) {109       e.printStackTrace();110     } catch (IOException e) {111       e.printStackTrace();112     }113     finally{114       //关闭相应的流及ServerSocket，Socket对象115       if(os != null){116         try {117           os.close();118         } catch (IOException e) {119           e.printStackTrace();120         }121       }122       if(fos != null){123         try {124           fos.close();125         } catch (IOException e) {126           e.printStackTrace();127         }128       }129       if(is != null){130         try {131           is.close();132         } catch (IOException e) {133           e.printStackTrace();134         }135       }136       if(s != null){137         try {138           s.close();139         } catch (IOException e) {140           e.printStackTrace();141         }142       }143       if(ss != null){144         try {145           ss.close();146         } catch (IOException e) {147           e.printStackTrace();148         }149       }150     }151   }152 }

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原标题：利用TCP 客户端

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