网络编程之TCP、UDP和URL
客户端
-
连接服务器Socket
-
发送消息
package com.yeyue.lesson2;
import java.io.IOException;
import java.io.OutputStream;
import java.net.InetAddress;
import java.net.InetSocketAddress;
import java.net.Socket;
import java.net.UnknownHostException;
public class TcpCliebtDemo01 {
public static void main(String[] args) {
Socket socket = null;
OutputStream os = null;
try {
//1、要知道服务器的地址，端口号
InetAddress serverIP = InetAddress.getByName("127.0.0.1");
int port = 9999;
//2、创建一个socket连接
socket = new Socket(serverIP,port);
//3、发送消息IO流
os = socket.getOutputStream();
os.write("你好啊，我的朋友！".getBytes());
} catch (Exception e) {
e.printStackTrace();
}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
-
建立服务的端口ServerSocket
-
等待客户的连接 accept
-
接收用的消息
package com.yeyue.lesson2;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.ServerSocket;
import java.net.Socket;
public class TcpServerDemo01 {
public static void main(String[] args) {
ServerSocket serverSocket = null;
Socket socket = null;
InputStream is = null;
ByteArrayOutputStream baos = null;
try {
//1、得有一个地址
serverSocket = new ServerSocket(9999);
while (true){
//2、等待客户端连接过来
socket = serverSocket.accept();
//3、读取客户端信息
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 {
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();
}
}
}
}
}
TCP实现文件上传
客户端
package com.yeyue.lesson2;
import java.io.*;
import java.net.InetAddress;
import java.net.Socket;
public class TcpCliebtDemo02 {
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
FileInputStream fis = new FileInputStream(new File("1.jpg"));
//4、写出文件
byte[] buffer = new byte[1024];
int len;
while ((len=fis.read(buffer))!=-1){
os.write(buffer,0,len);
}
//通知服务器我已经结束了
socket.shutdownOutput(); //我已经传输完了
//确认服务端接收完毕了才可以断开
InputStream inputStream = socket.getInputStream();
//String byte[]
ByteArrayOutputStream baos = new ByteArrayOutputStream();
byte[] buffer2 = new byte[1024];
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();
}
}
服务器
package com.yeyue.lesson2;
import java.io.*;
import java.net.ServerSocket;
import java.net.Socket;
public class TcpServerDemo02 {
public static void main(String[] args) throws Exception {
//1、创建服务器
ServerSocket serverSocket = new ServerSocket(9000);
//2、监听客户端的连接
Socket socket = serverSocket.accept(); //阻塞式监听，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("2.jpg"));
byte[] buffer = new byte[1024];
int len;
while ((len=is.read(buffer))!=-1){
fos.write(buffer,0,len);
}
//通知客户端接收完毕了
OutputStream os = socket.getOutputStream();
os.write("我接收完毕了，你可以断开了".getBytes());
//关闭资源
fos.close();
is.close();
socket.close();
serverSocket.close();
}
}
UDP发送消息
发送端
package com.yeyue.lesson3;
import com.sun.org.apache.xml.internal.dtm.ref.DTMNodeListBase;
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.InetAddress;
public class UdpClientDemo1 {
public static void main(String[] args) throws Exception {
//1、建立一个socket
DatagramSocket socket = new DatagramSocket();
//2、建个包
String msg = "你好啊，我的朋友";
//发送给谁
InetAddress localhost = InetAddress.getByName("localhost");
int port = 9000;
//数据，数据的起始，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.yeyue.lesson3;
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.SocketException;
//等待客户端的连接
public class UdpServerDemo01 {
public static void main(String[] args) throws Exception {
//开放端口
DatagramSocket socket = new DatagramSocket(9000);
//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();
}
}
自定义发送消息
发送端
package com.yeyue.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;
import java.nio.charset.Charset;
public class UdpSenderDemo01 {
public static void main(String[] args) throws Exception {
DatagramSocket socket = new DatagramSocket(8888);
//准备数据：控制台读取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));
String data1 = new String(datas,0,datas.length,"UTF-8");
System.out.println(data1);
socket.send(packet);
if (data.equals("bye")){
break;
}
}
socket.close();
}
}
接收端
package com.yeyue.chat;
import java.net.DatagramPacket;
import java.net.DatagramSocket;
public class UdpReceiveDemo01 {
public static void main(String[] args) throws Exception {
DatagramSocket socket = new DatagramSocket(6666);
while (true) {
//准备接收包裹
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, data.length);
System.out.println(receiveData);
System.out.println(data.length);
// for (int i = 0; i < data.length; i++) {
// System.out.println(data[i]);
// }
//断开连接 bye
if (receiveData.equals("bye")) {
break;
}
}
socket.close();
}
}
老师与学生对话
老师
package com.yeyue.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,"老师")).start();
}
}
学生
package com.yeyue.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();
}
}
发送服务器
package com.yeyue.chat;
import java.io.BufferedReader;
import java.io.IOException;
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();
}
}
接收服务器
package com.yeyue.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();
}
}
URL
统一的资源定位符：定位资源，定位互联网上的某一个资源
协议：//IP地址：端口/项目名/资源
实例
package com.yeyue.lesson4;
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/helloworld/index.jsp?username=yeyue&password=123");
System.out.println(url.getProtocol()); //协议
System.out.println(url.getHost()); // 主机IP
System.out.println(url.getPort()); //端口
System.out.println(url.getPath()); //全路径
System.out.println(url.getFile()); //文件
System.out.println(url.getQuery()); //参数
}
}
URL下载文件
package com.yeyue.lesson4;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.URL;
public class UrlDownLoad {
public static void main(String[] args) throws IOException {
//下载地址
URL url = new URL("https://webfs.ali.kugou.com/202107011721/73be3332d43d20451d1143678abe97d5/KGTX/CLTX001/270df47a81871158c5846debbfc573f1.mp3");
//链接到这个地址
HttpURLConnection urlConnection = (HttpURLConnection) url.openConnection();
InputStream inputStream = urlConnection.getInputStream();
FileOutputStream fos = new FileOutputStream("3f1.mp3");
byte[] buffer = new byte[1024];
int len;
while ((len=inputStream.read(buffer))!=-1){
fos.write(buffer,0,len);
}
fos.close();
inputStream.close();
urlConnection.disconnect();
}
}
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