网络编程
1.1 ip
package com.jf.lesson01;
import java.net.InetAddress;
import java.net.UnknownHostException;
public class TestInetAdress {
public static void main(String[] args) {
try {
InetAddress inetAddress1 = InetAddress.getByName("127.0.0.1");
System.out.println(inetAddress1);
InetAddress inetAddress2 = InetAddress.getByName("localhost");
System.out.println(inetAddress2);
InetAddress inetAddress3 = InetAddress.getLocalHost();
System.out.println(inetAddress3);
//查询网站ip地址
InetAddress inetAddress4 = InetAddress.getByName("www.baidu.com");
System.out.println(inetAddress4);
System.out.println(inetAddress4.getCanonicalHostName());
} catch (UnknownHostException e) {
throw new RuntimeException(e);
}
}
}
1.2 端口
端口表示计算机上的一个程序的进程
不同的进程有不同的端口号
被规定0~65535
单个协议下端口号不能冲突
端口分类
公共端口0~1023
HTTP:80
HTTPS:443
ssh:22
FTP:21
Telnet:23
程序注册端口：1024~49151，分配用户或者程序
Tomcat:8080
Mysql:3306
Oracle:1521
动态，私有：49152~65535
netstat -ano #查看所有的端口
netstat -ano|findstr "5900" #查看指定的端口
tasklist|findstr "" # 查看指定端口的进程
package com.jf.lesson01;
import java.net.InetSocketAddress;
public class TestInetSockAdress {
public static void main(String[] args) {
InetSocketAddress inetSocketAddress = new InetSocketAddress("127.0.0.1", 8080);
System.out.println(inetSocketAddress);
}
}
1.3通信协议
1.4 tcp/ip协议
客户端
1.连接服务器Socket
2.发送消息
package com.jf.lesson01.lesson02;
import java.io.IOException;
import java.io.OutputStream;
import java.net.InetAddress;
import java.net.Socket;
import java.net.UnknownHostException;
//客户端
public class TcpClientDemo01 {
public static void main(String[] args) {
Socket socket =null;
OutputStream os =null;
//1.要知道服务器的地址
try {
InetAddress ServerIp = InetAddress.getByName("127.0.0.1");
//2.端口号
int port =9999;
//3.创建一个socket连接
socket = new Socket(ServerIp,port);
//4.发送消息IO流
os = socket.getOutputStream();
os.write("你好，收到消息".getBytes());
} catch (Exception e) {
throw new RuntimeException(e);
}finally {
if(os!=null){
try {
os.close();
} catch (IOException e) {
e.printStackTrace();
}
}
if(socket!=null){
try {
socket.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
}
}
服务器
1.建立服务的端口ServerSocket
2.等到用户的连接accept();
3.接收用户的消息
package com.jf.lesson01.lesson02;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.ServerSocket;
import java.net.Socket;
//服务端
public class TcpServerDemo01 {
public static void main(String[] args) {
ServerSocket serverSocket =null;
Socket socket =null;
InputStream is =null;
ByteArrayOutputStream baos =null;
try {
//1.设置服务器的地址
serverSocket = new ServerSocket(9999);
//2.等待客户端连接
socket = serverSocket.accept();
//3.读取客户端的消息
is = socket.getInputStream();
//管道流
baos = new ByteArrayOutputStream();
byte[] buffer = new byte[1024];
int len;
while ((len=is.read(buffer))!=-1){
baos.write(buffer,0,len);
}
System.out.println(baos.toString());
} catch (IOException e) {
e.printStackTrace();
}finally {
//关闭资源
if(baos!=null){
try {
baos.close();
} catch (IOException e) {
e.printStackTrace();
}
}
if(is!=null){
try {
is.close();
} catch (IOException e) {
e.printStackTrace();
}
}
if(socket!=null){
try {
socket.close();
} catch (IOException e) {
e.printStackTrace();
}
}
if(serverSocket!=null){
try {
serverSocket.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
}
}
文件上传
package com.jf.lesson01.lesson02;
import java.io.*;
import java.net.ServerSocket;
import java.net.Socket;
public class TcpServerDemo02 {
public static void main(String[] args) throws Exception {
//1.创建服务
ServerSocket serverSocket = new ServerSocket(9000);
//2.监听客户端的连接
Socket socket = serverSocket.accept();//阻塞式连接，会一直等待客户端连接
//3.获取输入流
InputStream is = socket.getInputStream();
//4.文件输出
FileOutputStream fos = new FileOutputStream(new File("receive.jpg"));
byte[] buffer = new byte[1024];
int len;
while ((len=is.read(buffer))!=-1){
fos.write(buffer,0,len);
}
//通知客户端我接收完毕了
OutputStream os = socket.getOutputStream();
os.write("我接受完毕了".getBytes());
//关闭资源
fos.close();
is.close();
socket.close();
serverSocket.close();
}
}
package com.jf.lesson01.lesson02;
import java.io.*;
import java.net.InetAddress;
import java.net.Socket;
import java.net.UnknownHostException;
public class TcpClientDemo02 {
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 os = socket.getOutputStream();
//3.读取文件流
FileInputStream fis = new FileInputStream(new File("02.jpg"));
//4.写出文件
byte[] buffer = new byte[1024];
int len;
while ((len=fis.read(buffer))!=-1){
os.write(buffer,0,len);
}
//通知服务器，已经传输完了
socket.shutdownOutput();
//确定服务器接收完毕，才能断开连接
InputStream inputStream = socket.getInputStream();
//String byte[]
ByteArrayOutputStream baos = new ByteArrayOutputStream();
byte[] buffer2 = new byte[2014];
int len2;
while ((len2=inputStream.read(buffer2))!=-1){
baos.write(buffer2,0,len2);
}
System.out.println(baos.toString());
//5.关闭资源
baos.close();
inputStream.close();
fis.close();
os.close();
socket.close();
}
}
1.5 udp
发短信，不需要连接，需要知道对方的地址
发送端
package com.jf.lesson03;
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.InetAddress;
import java.net.SocketException;
//不需要连接服务器
public class UdpClientDemo01 {
public static void main(String[] args) throws Exception {
//1.建立一个Socket
DatagramSocket socket = new DatagramSocket();
//2.建立包
//发送给谁
InetAddress localhost = InetAddress.getByName("localhost");
int port =9090;
String msg="你好啊";
//数据，数据的长度起始，要发送给谁
DatagramPacket packet = new DatagramPacket(msg.getBytes(), 0, msg.getBytes().length, localhost, port);
//3.发送包
socket.send(packet);
//4.关闭流
socket.close();
}
}
接收端
package com.jf.lesson03;
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.SocketException;
public class UdpServerDemo01 {
public static void main(String[] args) throws Exception {
//开放端口
DatagramSocket socket = new DatagramSocket(9090);
//接收数据包
byte[] buffer = new byte[1024];
DatagramPacket packet = new DatagramPacket(buffer, 0, buffer.length);
socket.receive(packet);//阻塞接收
System.out.println(packet.getAddress().getHostAddress());
System.out.println(new String(packet.getData(),0,packet.getLength()));
//关闭连接
socket.close();
}
}
循环发送消息
package com.jf.chat;
import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.InetSocketAddress;
import java.net.SocketException;
public class UdpSenderDemo01 {
public static void main(String[] args) throws Exception {
DatagramSocket socket = new DatagramSocket(8888);
//准备数据 system.in
BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));
while (true){
String data = reader.readLine();
byte[] datas = data.getBytes();
DatagramPacket packet = new DatagramPacket(datas,0,datas.length,new InetSocketAddress("localhost",6666));
socket.send(packet);
if(data.equals("bye")){
break;
}
}
socket.close();
}
}
循环接收消息
package com.jf.chat;
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.SocketException;
public class UdpReceiveDemo01 {
public static void main(String[] args) throws Exception {
DatagramSocket socket = new DatagramSocket(6666);
while (true){
//准备接收的包裹
byte[] container = new byte[1024];
DatagramPacket packet = new DatagramPacket(container,0,container.length);
socket.receive(packet);//阻塞式接收包裹
//断开连接,bye
byte[] data = packet.getData();
String receivedata = new String(data, 0, packet.getLength());
System.out.println(receivedata);
if(receivedata.equals("bye")){
break;
}
}
socket.close();
}
}
咨询
package com.jf.chat;
import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.InetSocketAddress;
import java.net.SocketException;
public class TalkSend implements Runnable {
DatagramSocket socket =null;
BufferedReader reader =null;
private int fromPort;
private String toIP;
private int toPort;
public TalkSend(int fromPort, String toIP, int toPort) {
this.fromPort = fromPort;
this.toIP = toIP;
this.toPort = toPort;
try {
socket = new DatagramSocket(fromPort);
reader = new BufferedReader(new InputStreamReader(System.in));
} catch (SocketException e) {
e.printStackTrace();
}
}
@Override
public void run() {
while (true){
try{
String data = reader.readLine();
byte[] datas = data.getBytes();
DatagramPacket packet = new DatagramPacket(datas,0,datas.length,new InetSocketAddress(this.toIP,this.toPort));
socket.send(packet);
if(data.equals("bye")){
break;
}
}catch (Exception e){
e.printStackTrace();
}
}
socket.close();
}
}
package com.jf.chat;
import java.io.IOException;
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.SocketException;
public class TalkReceive implements Runnable{
DatagramSocket socket =null;
private int port;
private String msgFrom;
public TalkReceive(int port,String msgFrom) {
this.port = port;
this.msgFrom = msgFrom;
try {
socket = new DatagramSocket(port);
} catch (SocketException e) {
e.printStackTrace();
}
}
@Override
public void run() {
while (true){
try {
//准备接收的包裹
byte[] container = new byte[1024];
DatagramPacket packet = new DatagramPacket(container,0,container.length);
socket.receive(packet);//阻塞式接收包裹
//断开连接,bye
byte[] data = packet.getData();
String receivedata = new String(data, 0, packet.getLength());
System.out.println(msgFrom+":"+receivedata);
if(receivedata.equals("bye")){
break;
}
} catch (IOException e) {
e.printStackTrace();
}
}
socket.close();
}
}
package com.jf.chat;
public class TalkStudent {
public static void main(String[] args) {
//开启两个线程
new Thread(new TalkSend(7777,"localhost",9999)).start();
new Thread(new TalkReceive(8888,"老师")).start();
}
}
package com.jf.chat;
public class TalkTeacher {
public static void main(String[] args) {
//开启两个线程
new Thread(new TalkSend(5555,"localhost",8888)).start();
new Thread(new TalkReceive(9999,"学生")).start();
}
}
1.6 URL
统一资源定位符：定位资源的，定位互联网上的某一资源
URL下载资源
package com.jf.lesson04;
import javax.net.ssl.HttpsURLConnection;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;
import java.net.URLConnection;
public class URLDown {
public static void main(String[] args) throws IOException {
//1.下载地址
URL url = new URL("http://localhost:8080/jf/01.txt");
//2.连接这个地址
HttpURLConnection urlConnection = (HttpURLConnection) url.openConnection();
InputStream inputStream = urlConnection.getInputStream();
FileOutputStream fos = new FileOutputStream("01.txt");
byte[] buffer = new byte[1024];
int len;
while ((len=inputStream.read(buffer))!=-1){
fos.write(buffer,0,len);
}
fos.close();
inputStream.close();
urlConnection.disconnect();//断开连接
}
}
url
package com.jf.lesson04;标签：java,socket,编程,网络,new,import,net,public From： https://www.cnblogs.com/huangjiangfei/p/18333493
import com.sun.xml.internal.ws.api.model.wsdl.WSDLOutput;
import java.net.MalformedURLException;
import java.net.URL;
public class URLDemo01 {
public static void main(String[] args) throws MalformedURLException {
URL url = new URL("Http://localhost:8080/hello/index.jsp?username=jf&password=123");
System.out.println(url.getProtocol());//协议
System.out.println(url.getHost());//主机
System.out.println(url.getPort());//端口
System.out.println(url.getPath());//文件
System.out.println(url.getFile());//全路径
System.out.println(url.getQuery());//参数
}
}