java网络编程
导读：Socket编程1基础知识协议 端口号(辨别不同应用 TCP/IP协议是目前世界上应用最广泛的协议是以TCP为基础的不同层次上多个协议的集合也称：TCP/IP协议族 或 TCP/IP协议栈TCP:Transmission Control P...
Socket编程
1基础知识
协议 端口号(辨别不同应用)
TCP/IP协议
是目前世界上应用最广泛的协议
是以TCP为基础的不同层次上多个协议的集合
也称：TCP/IP协议族 或 TCP/IP协议栈
TCP:Transmission Control Protocol 传输控制协议
IP: Internet Protocol 互联网协议
IP地址
为实现网络中不同计算机之间的通信，每台机器都必须有唯一的标识—-IP地址
IP地址格式：数字型：192.168.1.10
端口
1、用来区分不同应用程序，每个应用都会有个端口号
2、端口的范围065535,其中01023为系统保留
3、IP地址和端口号组成了所谓的Socket,Socket是网络上运行的程序之间双向通信链路的终结点，是TCP和UDP的基础。
4、常见协议端口号 http:80 ftp:21 telnet:23
JAVA中的网络支持
针对网络通信的不同层次，java提供的网络功能有四大类
1、InetAddress:用于标识网络上的硬件资源
2、Socket:使用TCP协议实现网络通信的Socket相关的类
3、Datagram:使用UDP协议，将数据保留在数据报中，通过网络进行通信
InetAddress类
1、InetAddress类用于标识网络上的硬件资源，表示互联网协议(IP)地址
public void inetAddressTest() throws Exception{
//获取本机的InetAddressTest实例
InetAddress localHost = InetAddress.getLocalHost();
System.out.println("计算机名："+localHost.getHostName());
System.out.println("ip地址："+localHost.getHostAddress());
//获取字节数组形式的IP地址
System.out.println(Arrays.toString(localHost.getAddress()));
System.out.println(localHost);
//根据机器名 获取InetAddress实例
InetAddress byName = InetAddress.getByName("SONGPC");
System.out.println(byName);
//根据ip地址获取实例信息
InetAddress address = InetAddress.getByName("192.168.43.52");
System.out.println(address);
}
Socket编程
TCP协议是面向连接、可靠的、有序的，以字节流的方式发送数据
基于TCP协议实现网络通信的类
>
客户端的Socket类
>
>
服务器端的ServerSocket类Socket通讯的模型
Socket通信实现步骤
1.创建ServerSocket和Socket
2.打开连接到Socket的输入/输出流
3.按照协议对Socket进行读/写操作
4.关闭输入输出流、关闭Socket
服务器端：
1.创建ServerSocket对象，绑定监听端口
2.通过accept()方法监听客户端请求
3.连接通过后，通过输入流读取客户端发送的请求信息
4.通过输出流向客户端发送相应信息
5.关闭相关资源
//1.创建服务器端的Socket,指定绑定的端口，并监听此端口
ServerSocket serverSocket=new ServerSocket(8000);
//2.调用accept()监听，等待客户端的连接
System.out.println("服务器:启动，等待客户端的连接***");
//连接成功后创建socket
Socket socket = serverSocket.accept();
System.out.println("服务器:客户端已经连接成功！");
//3.获取输入流，用来读取客户端发送信息
InputStream is = socket.getInputStream();
OutputStream outputStream = socket.getOutputStream();
//包装成高效字符流
BufferedReader br=new BufferedReader(new InputStreamReader(is));
String len="";
while((len=br.readLine())!=null){
System.out.println("服务端："+len);
}
(用完一个关闭一个 不然回阻塞)
socket.shutdownInput();
//4.获取输出流相应客户端请求
PrintWriter pw=new PrintWriter(outputStream);
//包装成打印了
pw.write("欢迎你。。。");
pw.flush();
socket.shutdownOutput();
//关闭资源
pw.close();
outputStream.close();
br.close();
is.close();
socket.close();
serverSocket.close();
客户端：
1.创建Socket对象，指定需要连接的服务器的地址和端口号
2.连接建立后，通过输出流向服务器端发送请求信息
3.通过输入流获取服务器端响应的信息
4.关闭相关资源
//1.创建客户端Socket,指定服务器端的地址和端口号
Socket socket=new Socket("localhost", 8000);
//2.获取输出流，用来向服务器端发送信息
OutputStream outputStream = socket.getOutputStream();
PrintWriter pw=new PrintWriter(outputStream);
//3.获取输入流获取服务器端的相应
InputStream inputStream = socket.getInputStream();
pw.write("用户名：admin;
密码：123");
pw.flush();
//关闭输出流(用完一个关闭一个 不然回阻塞)
socket.shutdownOutput();
BufferedReader br=new BufferedReader(new InputStreamReader(inputStream));
String len="";
while((len=br.readLine())!=null){
System.out.println("客户端:"+len);
}
socket.shutdownInput();
//关闭资源
br.close();
pw.close();
outputStream.close();
socket.close();
多线程服务器
应用多线程来实现服务器与多客户端之间的通信
基本步骤
1.服务器创建ServerSocket，循环调用accept()等待客户端连接
2.客户端创建一个socket并请求和服务器端连接
3.服务器端接受客户端请求，创建socket与该客户端建立专线连接
4.建立连接两个socket在一个单独的线程上对话
5.服务器端继续等待新的连接
服务器线程类ServerThread
public class ServerThread implements Runnable {
private Socket socket;
public ServerThread(Socket socket) {
this.socket = socket;
}
@Override
public void run() {
while (true)
{
InputStream is = null;
try {
is = socket.getInputStream();
}
catch (IOException e) {
e.printStackTrace();
}
OutputStream os = null;
try {
os = socket.getOutputStream();
}
catch (IOException e) {
e.printStackTrace();
}
DataInputStream dataInputStream = new DataInputStream(is);
DataOutputStream dataOutputStream = new DataOutputStream(os);
String string = null;
try {
string = dataInputStream.readUTF();
}
catch (IOException e) {
e.printStackTrace();
}
System.out.println(string);
try {
dataOutputStream.writeUTF(string);
if(string.equals("byebye"))
{
System.out.println("客户端下线了，我也退出了");
break;
}
}
catch (IOException e) {
e.printStackTrace();
}
}
}
}
服务器端
public class SimpleSocketServer {
public static void main(String[] args) throws IOException {
ServerSocket serverSocket = new ServerSocket(6666);
System.out.println("服务器启动");
while (true)
{
Socket socket = serverSocket.accept();
//监听，等待客户端连接上来
InetAddress inetAddress= socket.getInetAddress();
//得到客户端的地址信息
System.out.println("客户端："+ inetAddress.getHostAddress() + "连接上来了");
ServerThread serverThread = new ServerThread(socket);
new Thread(serverThread).start();
}
}
}
客户端线程
public class ClientThread implements Runnable{
private Socket socket;
public ClientThread(Socket socket) {
this.socket = socket;
}
@Override
public void run() {
while (true)
{
try {
InputStream inputStream = socket.getInputStream();
DataInputStream dataInputStream = new DataInputStream(inputStream);
String response = dataInputStream.readUTF();
//阻塞
System.out.println("服务器回应：" + response);
if(response.equals("byebye"))
{
System.out.println("退出");
break;
}
}
catch (IOException e) {
e.printStackTrace();
}
}
}
}
客户端
public class TcpClient {
// public static boolean isDead = false;
public static void main(String[] args) throws IOException {
Socket socket = new Socket("127.0.0.1",6666);
ClientThread clientThread = new ClientThread(socket);
Thread child = new Thread(clientThread);
child.start();
OutputStream os = socket.getOutputStream();
DataOutputStream dataOutputStream = new DataOutputStream(os);
Scanner scanner = new Scanner(System.in);
System.out.println("请输入要发给服务器的信息：byebye 退出");
while (scanner.hasNext())//阻塞在此处，等待用户在控制台的输入
{
String string = scanner.nextLine();
dataOutputStream.writeUTF(string);
if(string.equals("byebye"))
{
break;
}
System.out.println("请输入要发给服务器的信息：byebye 退出");
}
}
}
6.UDP编程
UDP协议(用户数据报协议)是无连接、不可靠、无序的
UDP协议以数据报作为数据传输的载体
进行数据传输时，首先需要将要传输的数据定义成数据报（Datagram），在数据报中指明数据要达到的Socket(主机地址和端口号)，然后再将数据报发送出去
相关操作类
DatagramPacket:表示数据报包
DatagramSocket:进行端到端通信的类
服务器端实现步骤
1.创建DatagramSocket,指定端口号
2.创建DatagramPacket
3.接受客户端发送的数据信息
4.读取数据
package com.andgo.udp通信;
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.InetAddress;
import java.net.SocketException;
import java.net.UnknownHostException;
/**
* UDP服务端
* @author Administrator
*/
public class UDPServer {
/**
* 1.创建DatagramSocket,指定端口号
2.创建DatagramPacket
3.接受客户端发送的数据信息
4.读取数据
* @param args
* @throws UnknownHostException
* @throws SocketException
*/
public static void main(String[] args) throws Exception {
/*
*实现了接收数据
*/
//0.创建本机的address
//InetAddress address = InetAddress.getLocalHost();
// 1.创建DatagramSocket,指定端口号
DatagramSocket socket=new DatagramSocket(8888);
//2.创建DatagramPacket，用于接收客户端发送来的数据
byte[] data=new byte[1024];
DatagramPacket packet=new DatagramPacket(data, data.length);
//3.接收客户端发送的数
System.out.println("服务器端已经启动，等待接收数据");
socket.receive(packet);
//此方法在接收到数据报之前会一直阻塞
//4.读取数据
String info=new String(data, 0, packet.getLength());
System.out.println("服务器接收到："+info);
/*
*向客户端响应数据
*/
//1.定义客户端的地址、端口号、数据
InetAddress address=packet.getAddress();
int port=packet.getPort();
byte[] bs="欢迎。。。。".getBytes();
//2.创建数据报，包含响应的数据信息
DatagramPacket packet2=new DatagramPacket(bs, bs.length, address, port);
//3.向客户端发送数据
socket.send(packet2);
//4.关闭资源
socket.close();
}
}
客户端实现步骤
1.定义发送数据
2.创建DatagramPacket,包含将要发送的信息
3.创建DatagramSocket
4.发送数据
package com.andgo.udp通信;
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.InetAddress;
import java.net.UnknownHostException;
/**
* UDP客户端
* @author Administrator
*
*/
public class UDPClient {
/**
* 1.定义发送数据
2.创建DatagramPacket,包含将要发送的信息
3.创建DatagramSocket
4.发送数据
* @param args
* @throws Exception
*/
public static void main(String[] args) throws Exception {
/*
*向服务器端发送数据
*/
//1.定义服务器的地址，端口号、数据
InetAddress address=InetAddress.getByName("localhost");
int port=8888;
byte[] data="用户名：admin;
密码：123".getBytes();
//2.创建数据报，包含发送的数据
DatagramPacket packet=new DatagramPacket(data, data.length, address, port);
//3.创建DatagramSocket
DatagramSocket socket=new DatagramSocket();
//4.向服务器端发送数据
socket.send(packet);
/*
*接收服务器端响应的数据
*/
//1.创建DatagramPacket，用于接收服务器端响应的数据
byte[] bs=new byte[1024];
DatagramPacket packet2=new DatagramPacket(bs, bs.length);
//2.接收服务器端响应的数据
socket.receive(packet2);
//3.读取数据
String reply=new String(bs, 0, packet2.getLength());
System.out.println("客户端："+reply);
//4.关闭资源
socket.close();
}
}
多线程UDP服务器
UDPServerThread
package com.andgo.udp通信多线程实现;
import java.io.IOException;
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.InetAddress;
import java.net.Socket;
public class UDPServerThread extends Thread{
private byte[] data;
private DatagramPacket packet;
private DatagramSocket socket;
public UDPServerThread(byte[] data, DatagramPacket packet, DatagramSocket socket) {
this.data = data;
this.packet = packet;
this.socket = socket;
}
@Override
public void run() {
//4.读取数据
String info=new String(data, 0, packet.getLength());
System.out.println("服务器接收到："+info);
/*
*向客户端响应数据
*/
//1.定义客户端的地址、端口号、数据
InetAddress address=packet.getAddress();
int port=packet.getPort();
byte[] bs="欢迎。。。。".getBytes();
//2.创建数据报，包含响应的数据信息
DatagramPacket packet2=new DatagramPacket(bs, bs.length, address, port);
//3.向客户端发送数据
try {
socket.send(packet2);
}
catch (IOException e) {
System.out.println("数据发送异常");
e.printStackTrace();
}
//4.关闭资源
//socket.close();
//UDP中用同一个socket发送和接受数据 ，datagramPaket包含了数据、端口、地址信息(用于区分和发送到哪里)
}
}
UDPServer
package com.andgo.udp通信多线程实现;
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.InetAddress;
import java.net.SocketException;
import java.net.UnknownHostException;
/**
* UDP服务端
* @author Administrator
*
*/
public class UDPServer {
/**
* 1.创建DatagramSocket,指定端口号
2.创建DatagramPacket
3.接受客户端发送的数据信息
4.读取数据
* @param args
* @throws UnknownHostException
* @throws SocketException
*/
public static void main(String[] args) throws Exception {
/*
*实现了接收数据
*/
//0.创建本机的address
//InetAddress address = InetAddress.getLocalHost();
// 1.创建DatagramSocket,指定端口号
DatagramSocket socket=new DatagramSocket(8888);
//2.创建DatagramPacket，用于接收客户端发送来的数据
byte[] data=new byte[1024];
DatagramPacket packet=new DatagramPacket(data, data.length);
//3.接收客户端发送的数
System.out.println("服务器端已经启动，等待接收数据");
while(true){
socket.receive(packet);
//此方法在接收到数据报之前会一直阻塞
UDPServerThread thread=new UDPServerThread(data, packet, socket);
thread.run();
}
}
}
UDPClient
package com.andgo.udp通信多线程实现;
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.InetAddress;
import java.net.UnknownHostException;
/**
* UDP客户端
* @author Administrator
*
*/
public class UDPClient {
/**
* 1.定义发送数据
2.创建DatagramPacket,包含将要发送的信息
3.创建DatagramSocket
4.发送数据
* @param args
* @throws Exception
*/
public static void main(String[] args) throws Exception {
/*
*向服务器端发送数据
*/
//1.定义服务器的地址，端口号、数据
InetAddress address=InetAddress.getByName("localhost");
int port=8888;
byte[] data="用户名：admissn;
密码：123sssss".getBytes();
//2.创建数据报，包含发送的数据
DatagramPacket packet=new DatagramPacket(data, data.length, address, port);
//3.创建DatagramSocket
DatagramSocket socket=new DatagramSocket();
//4.向服务器端发送数据
socket.send(packet);
/*
*接收服务器端响应的数据
*/
//1.创建DatagramPacket，用于接收服务器端响应的数据
byte[] bs=new byte[1024];
DatagramPacket packet2=new DatagramPacket(bs, bs.length);
//2.接收服务器端响应的数据
socket.receive(packet2);
//3.读取数据
String reply=new String(bs, 0, packet2.getLength());
System.out.println("客户端："+reply);
//4.关闭资源
socket.close()
}
}
基于socket公共聊天室的实现
1.客户端
TcpClient.java
package com.company;
import java.io.*;
import java.net.Socket;
import java.util.Scanner;
/**
* Created by ttc on 2018/6/12.
*/
public class TcpClient {
public static void helpList() {
System.out.println("提示：进入聊天室，默认公聊!!");
System.out.println("/B 用户在线列表，用户#信息 私聊，/C 查看聊天记录，/0 退出系统");
}
// public static boolean isDead = false;
public static void main(String[] args) throws IOException {
Scanner scanner = new Scanner(System.in);
System.out.println("请输入服务器ip地址");
String strIP = scanner.nextLine();
Socket socket = new Socket(strIP,6666);
System.out.println("请输入你的名字");
String username = scanner.nextLine();
ClientThread clientThread = new ClientThread(socket,username);
Thread child = new Thread(clientThread);
child.start();
OutputStream os = socket.getOutputStream();
DataOutputStream dataOutputStream = new DataOutputStream(os);
dataOutputStream.writeUTF(username);
System.out.println("欢迎进入聊天室，需要帮助请输入/A");
while (scanner.hasNext())//阻塞在此处，等待用户在控制台的输入
{
String string = scanner.nextLine();
if(string.equalsIgnoreCase("/A"))
{
helpList();
}
else if(string.equalsIgnoreCase("/C"))
{
//读取聊天记录
File file = new File(username+".txt");
FileReader fileReader = new FileReader(file);
BufferedReader bufferedReader = new BufferedReader(fileReader);
String msg = bufferedReader.readLine();
while (msg != null)
{
System.out.println(msg);
msg = bufferedReader.readLine();
}
fileReader.close();
bufferedReader.close();
}
else if(string.equalsIgnoreCase("/0"))
{
System.exit(0);
}
else
{
dataOutputStream.writeUTF(string);
//将信息发送给服务器
}
}
}
}
ClientThread.java
package com.company;
import java.io.*;
import java.net.Socket;
import java.net.SocketException;
import java.util.Date;
/**
* Created by ttc on 2018/6/12.
*/
public class ClientThread implements Runnable{
private Socket socket;
private String username;
public ClientThread(Socket socket,String username) {
this.username = username;
this.socket = socket;
}
private void writeToFile(String msg)
{
File file = new File(username + ".txt");
try {
FileWriter fileWriter = new FileWriter(file,true);
BufferedWriter bufferedWriter = new BufferedWriter(fileWriter);
Date date = new Date();
bufferedWriter.newLine();
bufferedWriter.write(date.toLocaleString() + ":" + msg);
bufferedWriter.flush();
fileWriter.close();
bufferedWriter.close();
}
catch (IOException e) {
e.printStackTrace();
}
}
@Override
public void run() {
while (true)
{
try {
InputStream inputStream = socket.getInputStream();
DataInputStream dataInputStream = new DataInputStream(inputStream);
String response = dataInputStream.readUTF();
//阻塞
System.out.println(response);
writeToFile(response);
}
catch (SocketException e)
{
//1.关闭socket
try {
socket.close();
}
catch (IOException e1) {
e1.printStackTrace();
}
//2.退出
System.out.println("服务断开~~~~~~~");
System.exit(0);
}
catch (IOException e) {
e.printStackTrace();
}
}
}
}
2.服务端
SimpleSocketServer.java
package com.company;
import java.io.*;
import java.net.InetAddress;
import java.net.ServerSocket;
import java.net.Socket;
import java.util.Collections;
import java.util.HashMap;
import java.util.Map;
/**
* Created by ttc on 2018/6/12.
*/
public class SimpleSocketServer {
static MapString,Socket>
name2Client = Collections.synchronizedMap(new HashMap>
());
public static void main(String[] args) throws IOException {
ServerSocket serverSocket = new ServerSocket(6666);
System.out.println("服务器启动");
while (true)
{
Socket socket = serverSocket.accept();
//监听，等待客户端连接上来
InetAddress inetAddress= socket.getInetAddress();
//得到客户端的地址信息
System.out.println("客户端："+ inetAddress.getHostAddress() + "连接上来了");
//读取客户端的用户名
InputStream inputStream = socket.getInputStream();
DataInputStream dataInputStream = new DataInputStream(inputStream);
String client_name = dataInputStream.readUTF();
//阻塞
name2Client.put(client_name,socket);
ServerThread serverThread = new ServerThread(socket,client_name);
new Thread(serverThread).start();
}
}
}
ServerThread.java
package com.company;
import java.io.*;
import java.net.Socket;
import java.net.SocketException;
import java.util.Map;
/**
* Created by ttc on 2018/6/12.
*/
public class ServerThread implements Runnable {
private String client_name;
private Socket socket;
public ServerThread(Socket socket,String client_name) {
this.client_name = client_name;
this.socket = socket;
}
//广播消息给所有在线用户
public void send_msg_to_all_clients(String message) throws IOException {
for(Map.EntryString,Socket>
entry : SimpleSocketServer.name2Client.entrySet())
{
Socket socket = entry.getValue();
OutputStream outputStream = socket.getOutputStream();
DataOutputStream dataOutputStream = new DataOutputStream(outputStream);
dataOutputStream.writeUTF(message);
}
}
@Override
public void run() {
try {
send_msg_to_all_clients(client_name + "上线了");
}
catch (IOException e) {
e.printStackTrace();
}
//不断的读取，服务的客户端发过来的信息
while (true)
{
InputStream is = null;
try {
is = socket.getInputStream();
}
catch (IOException e) {
e.printStackTrace();
}
DataInputStream dataInputStream = new DataInputStream(is);
String string = null;
try {
string = dataInputStream.readUTF();
String[] info = string.split("#");
if(info.length == 2)//私聊
{
String target_user = info[0];
String msg = info[1];
if(target_user.equals(client_name))
{
OutputStream outputStream2 = socket.getOutputStream();
DataOutputStream dataOutputStream2 = new DataOutputStream(outputStream2);
dataOutputStream2.writeUTF("不能自己和自己聊天");
}
else if(SimpleSocketServer.name2Client.containsKey(target_user))//是当前在线用户的话
{
//把消息发送给该用户
Socket targer_socket = SimpleSocketServer.name2Client.get(target_user);
OutputStream outputStream = targer_socket.getOutputStream();
DataOutputStream dataOutputStream = new DataOutputStream(outputStream);
dataOutputStream.writeUTF(client_name + "对你说："+ msg);
//同时回应发信息的用户
OutputStream outputStream2 = socket.getOutputStream();
DataOutputStream dataOutputStream2 = new DataOutputStream(outputStream2);
dataOutputStream2.writeUTF("你对"+target_user+"说："+msg);
}
else
{
//回应用户，用户名有误
//同时回应发信息的用户
OutputStream outputStream2 = socket.getOutputStream();
DataOutputStream dataOutputStream2 = new DataOutputStream(outputStream2);
dataOutputStream2.writeUTF("用户名有误。");
}
}
else if(string.equalsIgnoreCase("/B"))//获取在线用户列表
{
OutputStream outputStream = socket.getOutputStream();
DataOutputStream dataOutputStream = new DataOutputStream(outputStream);
dataOutputStream.writeUTF("当前在线用户列表：");
for (Map.EntryString, Socket>
entry : SimpleSocketServer.name2Client.entrySet()) {
dataOutputStream.writeUTF(entry.getKey());
}
}
else
{
send_msg_to_all_clients(client_name + "说：" + string);
}
}
catch (SocketException e)
{
//1.关闭对应的socket
try {
socket.close();
}
catch (IOException e1) {
e1.printStackTrace();
}
//2.把客户端从map中移除
SimpleSocketServer.name2Client.remove(client_name);
System.out.println(client_name + "退出了");
//3.本线程结束
return;
}
catch (IOException e) {
e.printStackTrace();
}
}
}
}
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