Java多线程和网络编程项目

Megan package MultiTCP;import java.io.DataOutputStream;import java.io.IOException;import .ServerSocket;import .Socket;/*** 必须先启动再连接* 1、创建服务器指定端口ServerSocket(int port)* 2、接收客户端的连接阻塞式* 3、发送数据+接收数据** 接收多个客户端*/@SuppressWarnings("all")public class MultiServer {public static void main(String[] args) throws IOException {//1、创建服务器指定端口ServerSocket server = new ServerSocket(8888);while(true)//死循环一个accept 一个客户端{//2、接收客户端的连接Socket socket = server.accept();System.out.println("一个客户端建立连接");//2、发送数据String msg = "欢迎使用";//3、输出流/*BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(socket.getOutputStream()));bw.write(msg);bw.newLine();//一定要加行结束符，不然读不到数据bw.flush();*/DataOutputStream dos = new DataOutputStream(socket.getOutputStream());dos.writeUTF(msg);dos.flush();}}}package MultiTCP;import java.io.DataInputStream;import java.io.IOException;import .Socket;import .UnknownHostException;/*** 1、创建客户端必须指定服务器+端口此时就在连接* Socket(String host,int port)* 2、接收数据+发送数据*/@SuppressWarnings("all")public class Client {public static void main(String[] args) throws UnknownHostException, IOException { //1、创建客户端必须指定服务器+端口此时就在连接Socket client = new Socket("localhost",8888);//2、接收数据/*BufferedReader br = new BufferedReader(new InputStreamReader(client.getInputStream()));String echo = br.readLine();//阻塞式方法System.out.println(echo);*/DataInputStream dis = new DataInputStream(client.getInputStream());String echo = dis.readUTF();System.out.println(echo);}}以上代码存在的问题服务器为一个客户端发送数据完毕才能连接下一个客户端。

因此，为了解决上述的问题，我们需要为服务器端创建多线程操作。

首先我们需要为聊天室添加发送数据和接收数据。

package CSNet;import java.io.DataInputStream;import java.io.DataOutputStream;import java.io.IOException;import .ServerSocket;import .Socket;/*** 创建服务器*/@SuppressWarnings("all")public class Server {public static void main(String[] args) throws IOException {ServerSocket server = new ServerSocket(9999);Socket client = server.accept();//写出数据//输入流DataInputStream dis = new DataInputStream(client.getInputStream());String msg = dis.readUTF();System.out.println("服务器收到"+msg);//输出流DataOutputStream dos = new DataOutputStream(client.getOutputStream());dos.writeUTF("服务器发送给客户端"+msg);dos.flush();}}package CSNet;import java.io.BufferedReader;import java.io.DataInputStream;import java.io.DataOutputStream;import java.io.IOException;import java.io.InputStreamReader;import .Socket;import .UnknownHostException;/*** 创建客户端：发送数据+接收数据* 写出数据：输出流* 读取数据：输入流* 输入流与输出流在同一个线程内，因此我们应该让输入流与输出流彼此独立*/@SuppressWarnings("all")public class Client {public static void main(String[] args) throws UnknownHostException, IOException { Socket client = new Socket("localhost",9999);//控制台的输入流BufferedReader console = new BufferedReader(new InputStreamReader(System.in));DataOutputStream dos = new DataOutputStream(client.getOutputStream());DataInputStream dis = new DataInputStream(client.getInputStream());while(true){String info = console.readLine();//输出流dos.writeUTF(info);dos.flush();//输入流String msg = dis.readUTF();System.out.println(msg);}}}以上的代码存在输入流与输出流在同一个线程内问题，因此我们应该让输入流与输出流彼此独立。

接下来我们是需要实现多线程，让输入流与输出流分离。

对客户端实现多线程。

客户端发送数据package ThreadNet;import java.io.BufferedReader;import java.io.DataOutputStream;import java.io.IOException;import java.io.InputStreamReader;import .Socket;/*** 发送数据线程：用于发送数据*/public class Send implements Runnable{//控制台的输入流private BufferedReader console;//管道的数据输出流private DataOutputStream dos;//控制线程标识private boolean isRunning = true;//初始化public Send() {console = new BufferedReader(new InputStreamReader(System.in));}public Send(Socket client){this();try {dos = new DataOutputStream(client.getOutputStream());} catch (IOException e) {}}//1、从控制台接收数据private String getMsgFromConsole(){try {return console.readLine();} catch (IOException e) {}return "";}/*** 1、从控制台接收数据* 2、发送数据*/public void send(){String msg = getMsgFromConsole();try {if(null!=msg&& !msg.equals("")){dos.writeUTF(msg);dos.flush();//强制刷新}} catch (IOException e) {isRunning = false;//发送失败，提示关闭线程CloseUtil.closeAll(dos,console);//如果不能发送成功，直接关闭流。

}}@Overridepublic void run() {//线程体while(isRunning){send();}}}客户端接收数据package ThreadNet;import java.io.DataInputStream;import java.io.IOException;import .Socket;/*** 接收线程：用于接收数据*/public class Receive implements Runnable{//管道的数据输入流private DataInputStream dis ;//线程标识private boolean isRunning = true;public Receive() {}public Receive(Socket client) {try {dis = new DataInputStream(client.getInputStream());} catch (IOException e) {isRunning = false;CloseUtil.closeAll(dis);}}//接收数据的方法public String receive(){String msg = "";try {msg = dis.readUTF();} catch (IOException e) {isRunning = false;CloseUtil.closeAll(dis);}return msg;}@Overridepublic void run() {//线程体while(isRunning){System.out.println(receive());}}}客户端package ThreadNet;import java.io.IOException;import .Socket;import .UnknownHostException;/*** 创建客户端：发送数据+接收数据* 写出数据：输出流* 读取数据：输入流* 输入流与输出流在同一个线程内应该独立出来*/public class Client {public static void main(String[] args) throws UnknownHostException, IOException { Socket client = new Socket("localhost",9999);new Thread(new Send(client)).start();//一条路径new Thread(new Receive(client)).start();//一条路径}}服务器package ThreadNet;import java.io.DataInputStream;import java.io.DataOutputStream;import java.io.IOException;import .ServerSocket;import .Socket;/*** 创建服务器*/public class Server {public static void main(String[] args) throws IOException {ServerSocket server = new ServerSocket(9999);while(true){Socket client = server.accept();//写出数据//输入流DataInputStream dis = new DataInputStream(client.getInputStream());//输出流DataOutputStream dos = new DataOutputStream(client.getOutputStream());while(true){String msg = dis.readUTF();//System.out.println(msg);dos.writeUTF("服务器收到数据并返回"+msg);dos.flush();}}}}关闭流package ThreadNet;import java.io.Closeable;import java.io.IOException;/*** 关闭流的方法*/public class CloseUtil {public static void closeAll(Closeable ... io){for(Closeable temp:io){if(null==temp){try {temp.close();} catch (IOException e) {e.printStackTrace();}}}}}这个方仍然存在问题，服务器端只能够一个一个的接收，必须要等到上一条执行完，才能进入下一条，存在所谓的先后顺序，并不具备多线程的功能。