JAVA之旅(三十三)

1、JAVA之旅（三十三）一.TCP说完UDP，我们就来说下我们应该重点掌握的TCP了TCP传输 Socket和ServiceSocket建立客户端和服务端建立连接后，通过Socket中的IO流进行数据的传输关闭Socket同样的，我们的客户端和服务端都是两个独立的应用我们通过查阅API文档发现，该对象在建立的时候，就可以去连接指定主机，因为tcp是面向连接的，所以在建立socket服务时，就要有服务存在，并成功连接，形成通路后，在该通道进行数据传输所以我们用代码来看下他的步骤客户端package com.lgl.hellojava;import java.io.IOException;impor

2、t java.io.InputStream;import java.io.OutputStream;import .ServerSocket;import .Socket;import .UnknownHostException;public class TcpClient public static void main(String args) try /1.创建客户端的服务，传地址和端口 Socket s = new Socket("192.168.1.102",10000); /2.为了发送数据，应该获得socket流中的输出流 OutputStream out =

3、s.getOutputStream(); out.write("你好".getBytes(); s.close(); catch (UnknownHostException e) / TODO Auto-generated catch block e.printStackTrace(); catch (IOException e) / TODO Auto-generated catch block e.printStackTrace(); 服务端package com.lgl.hellojava;import java.io.IOException;import java.

4、io.InputStream;import .ServerSocket;import .Socket;/* * 定义端点接收数据打印出来 * 服务端： * 1.建立服务端的socket服务，servicesocket,并监听一个端口 * 2.获取连接过来的客户端对象，通过accept方法，这个方法是阻塞的，没有连接就会等 * 3.客户端如果发过来数据，那么服务端要使用对应的客户端对象，并获取到该对象的读取流 * 4.关闭服务端（可选操作） * author LGL * */public class TcpService public static void main(String args)

5、try /1.建立连接，监听端口 ServerSocket ss = new ServerSocket(10000); /2.连接客户端对象 Socket accept = ss.accept(); /获取ip String ip = accept.getInetAddress().getHostAddress(); /3.获取客户端发送过来的数据 InputStream in = accept.getInputStream(); /4.开始读取 byte buf = new byte1024; int len = in.read(buf); System.out.println(new St

6、ring(buf,0,len); /5.关闭 ss.close(); catch (IOException e) / TODO Auto-generated catch block e.printStackTrace(); 二.TCP互相传输我们在来写一个实例去说明，他们的互访动作，这里为了写起来方便，就写在一个类中了package com.lgl.hellojava;import java.io.IOException;import java.io.InputStream;import java.io.OutputStream;import .ServerSocket;import .Soc

7、ket;import .UnknownHostException;/* * 客户端发送信息，服务端收到，反馈信息 * * author LGL * */public class Tcp public static void main(String args) try Socket s = new Socket("192.168.1.102", 10005); OutputStream out = s.getOutputStream(); out.write("我是客户端".getBytes(); InputStream in = s.getInputSt

8、ream(); byte buf = new byte1024; int len = in.read(buf); System.out.println(new String(buf, 0, len); s.close(); catch (UnknownHostException e) / TODO Auto-generated catch block e.printStackTrace(); catch (IOException e) / TODO Auto-generated catch block e.printStackTrace(); /* * 服务端 * author LGL * *

9、/class Server public static void main(String args) try ServerSocket ss = new ServerSocket(10005); Socket s = ss.accept(); InputStream in = s.getInputStream(); byte buf = new byte1024; int len = in.read(buf); System.out.println(new String(buf, 0, len); OutputStream out = s.getOutputStream(); out.writ

10、e("收到后反馈".getBytes(); s.close(); ss.close(); catch (IOException e) / TODO Auto-generated catch block e.printStackTrace(); 三.复制文件同样的这里也是使用的流，我们具体来看下怎么去操作，我们同样的，写在一个类中package com.lgl.socket;import java.io.BufferedReader;import java.io.FileReader;import java.io.FileWriter;import java.io.IOExc

11、eption;import java.io.InputStreamReader;import java.io.PrintWriter;import .ServerSocket;import .Socket;import .UnknownHostException;public class FileClient public static void main(String args) try Socket s = new Socket("192.168.1.102", 10006); BufferedReader bufr = new BufferedReader(new F

12、ileReader("test.txt"); PrintWriter pw = new PrintWriter(s.getOutputStream(), true); String line = null; while (line = bufr.readLine() != null) pw.println(line); pw.print("over"); BufferedReader bufIn = new BufferedReader(new InputStreamReader( s.getInputStream(); String str = buf

13、In.readLine(); System.out.println(str); bufr.close(); s.close(); catch (UnknownHostException e) / TODO Auto-generated catch block e.printStackTrace(); catch (IOException e) / TODO Auto-generated catch block e.printStackTrace(); class FileServer public static void main(String args) try ServerSocket s

14、s = new ServerSocket(10006); Socket s = ss.accept(); BufferedReader bufIn = new BufferedReader(new InputStreamReader( s.getInputStream(); PrintWriter out = new PrintWriter(new FileWriter("test1.txt"), true); String line = null; while (line = bufIn.readLine() != null) if ("over".e

15、quals(line) break; out.println(line); PrintWriter pw = new PrintWriter(s.getOutputStream(), true); pw.println("上传成功"); out.close(); s.close(); ss.close(); catch (IOException e) / TODO Auto-generated catch block e.printStackTrace(); 四.上传图片我们再来看下图片是怎么上传的，我们先来分析下步骤客户端1.服务端点2.读取客户端已有的图片数据3.通过s

16、ocket，发送给服务端4.读取服务端反馈的信息5.关闭资源* * 客户端 * * author LGL * */public class PicClient public static void main(String args) try Socket s = new Socket("192.168.1.102", 10009); FileInputStream fis = new FileInputStream("1.png"); OutputStream out = s.getOutputStream(); byte buf = new byte1

17、024; int len = 0; while (len = fis.read(buf) != -1) out.write(buf, 0, len); /告訴服务端数据写完 s.shutdownInput(); InputStream in = s.getInputStream(); byte bufn = new byte1024; int num = in.read(bufn); System.out.println(new String(bufn, 0, num); fis.close(); s.close(); catch (UnknownHostException e) / TODO

18、 Auto-generated catch block e.printStackTrace(); catch (IOException e) / TODO Auto-generated catch block e.printStackTrace(); 服务端直接看代码/* * 服務端 * author LGL * */class PicServer public static void main(String args) try ServerSocket ss = new ServerSocket(10009); Socket s = cept(); InputStream in = s.ge

19、tInputStream(); FileOutputStream fos = new FileOutputStream("2.png"); byte buf = new byte1024; int len = 0; while (len = in.read(buf) != -1) fos.write(buf, 0, len); OutputStream out = s.getOutputStream(); out.write("上传成功".getBytes(); fos.close(); s.close(); ss.close(); catch (IOE

20、xception e) / TODO Auto-generated catch block e.printStackTrace(); 其实跟I/O区别真不大，但是概念一定要了解清楚五.多并发上传多并发这个概念就是多人互动了，这对服务器的负荷还是有考究的，这里呢，我们就模拟一下，多人上传图片的场景，我们是怎么做的？我们还是在上传图片的那份代码上更改首先我们可以确定的是，这是服务端的代码这个服务端有个局限性，当A客户端连接之后，被服务端获取到，服务端就在执行代码了，这个时候如果B客户端连接只有等待，这就是我们需要多并发的原因了，为了让多个客户端同时连接，服务端最好就是讲每个客户端封装到一个单独的线

21、程中，这样就可以同时处理多个客户端请求如何定义线程？只要明确了每个客户端要在服务端执行的代码即可/* * 服務端 * * author LGL * */class PicServer public static void main(String args) try ServerSocket ss = new ServerSocket(10009); while (true) Socket s = ss.accept(); new Thread(new PicThread(s).start(); catch (IOException e) / TODO Auto-generated catch

22、block e.printStackTrace(); /* * 并发线程 * author LGL * */class PicThread implements Runnable private Socket s; public PicThread(Socket s) this.s = s; Override public void run() try String ip = s.getInetAddress().getHostAddress(); System.out.println("ip：" + ip); long millis = System.currentTim

23、eMillis(); File file = new File(millis + ".png"); InputStream in = s.getInputStream(); FileOutputStream fos = new FileOutputStream(file); byte buf = new byte1024; int len = 0; while (len = in.read(buf) != -1) fos.write(buf, 0, len); OutputStream out = s.getOutputStream(); out.write("上

24、传成功".getBytes(); fos.close(); s.close(); catch (Exception e) throw new RuntimeException("上传失败"); 其实我写的代码还是有点烂的，但是思想在就好，我们得先把思想学会了六.多并发登录上面说的多并发的上传，实在服务端端，现在我们来说下登录，是作用在客户端package com.lgl.socket;import java.io.BufferedReader;import java.io.FileReader;import java.io.IOException;import j

25、ava.io.InputStreamReader;import java.io.PrintWriter;import .ServerSocket;import .Socket;import .UnknownHostException;public class LoginClient public static void main(String args) try Socket s = new Socket("192.168.1.102", 10008); BufferedReader bufr = new BufferedReader(new InputStreamRead

26、er( System.in); PrintWriter out = new PrintWriter(s.getOutputStream(), true); BufferedReader bufIn = new BufferedReader(new InputStreamReader( s.getInputStream(); for (int i = 0; i < 3; i+) String line = bufr.readLine(); if (line = null) break; out.println(line); String info = bufIn.readLine(); S

27、ystem.out.println("info:" + info); if (info.contains("欢迎") break; bufr.close(); s.close(); catch (UnknownHostException e) / TODO Auto-generated catch block e.printStackTrace(); catch (IOException e) / TODO Auto-generated catch block e.printStackTrace(); /* * 服务端 * * author LGL * */class LoginServer public static void main(String args) try ServerSocket ss = new ServerSocket(10008); while (true) Socket s = ss.accept(); new Thread(new UserThread(s).start(); catch (IOException e) / TODO Auto-generated catch block e.printStackTrace(); /*