一、TCP与UDP
TCP（Transmission Control Protocol，传输控制协议）协议：负责将要传输的文件分段 进行传输，一般用于建立会话 ，其基本特性是可靠传输 、流量控制，所谓三握手、四挥手也是基于TCP协议的
UDP（User Data Protocol，用户数据报协议）协议：一个数据包就能够完成数据通信 ，数据包不分段 ，不需要建立会话 ，不需要流量控制 ，属于不可靠传输 ， 屏幕广播 、多播 、广播都是基于UDP协议
二、TCP实现数据上传
1、TCP服务端
package com.tcpip;
import java.io.File;
import java.io.FileOutputStream;
import java.io.InputStream;
import java.net.ServerSocket;
import java.net.Socket;
public class TcpServerTest {
public static void main(String[] args) throws Exception {
//1、创建服务
ServerSocket serverSocket = new ServerSocket(9000);
//2、监听客户端连接
Socket socket = serverSocket.accept();
//3、获取输入流
InputStream is = socket.getInputStream();
//4、文件输出
FileOutputStream fos = new FileOutputStream(new File("copy.png"));
byte[] buffer = new byte[1024];
int len;
while ((len=is.read(buffer))!=-1){
fos.write(buffer,0,len);
}
//5、关闭资源
fos.close();
is.close();
socket.close();
serverSocket.close();
}
}
2、TCP客户端
package com.tcpip;
import java.io.File;
import java.io.FileInputStream;
import java.io.OutputStream;
import java.net.InetAddress;
import java.net.Socket;
public class TcpClientTest {
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("01.png"));
//4、写入文件
byte[] buffer = new byte[1024];
int len;
while ((len=fis.read(buffer))!=-1){
os.write(buffer,0,len);
}
//5.关闭资源
fis.close();
os.close();
socket.close();
}
}
3、测试
三、UDP实现数据上传
1、UDP接收端
package com.tcpip;
import java.net.DatagramPacket;
import java.net.DatagramSocket;
public class UdpServerTest {
public static void main(String[] args) throws Exception {
//1、开放端口
DatagramSocket socket = new DatagramSocket(9090);
//2、接收数据包
byte[] buffer = new byte[1024];
DatagramPacket packet = new DatagramPacket(buffer,0,buffer.length);
socket.receive(packet);
System.out.println(new String(packet.getData(),0,packet.getData().length));
//3、关闭连接
socket.close();
}
}
2、UDP发送端
package com.tcpip;
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.InetAddress;
public class UdpClientTest {
public static void main(String[] args) throws Exception {
//1、建立一个socket
DatagramSocket socket = new DatagramSocket();
//2、建个包
String msg = "UDP 测试";
InetAddress localhost = InetAddress.getByName("localhost");
int port = 9090;
DatagramPacket packet = new DatagramPacket(msg.getBytes(),0,msg.getBytes().length,localhost,port);
//3、发送包
socket.send(packet);
//4、关闭资源
socket.close();
}
}
3、测试
四、UDP实现多线程在线咨询
1、发送端
package com.tcpip;
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();
}
}
@Override
public void run() {
while (true){
String data = null;
try {
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 (IOException e) {
e.printStackTrace();
}
}
socket.close();
}
}
2、接收端
package com.tcpip;
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 {
//准备接收包裹
byte[] container = new byte[1024];
DatagramPacket packet = new DatagramPacket(container,0,container.length);
//阻塞式接收包裹
socket.receive(packet);
//断开连接bye
byte[] data = packet.getData();
String receiveData = new String(data,0,data.length);
System.out.println(msgFrom + ":" + receiveData);
if(receiveData.equals("bye")){
break;
}
} catch (IOException e) {
e.printStackTrace();
}
}
socket.close();
}
}
3、学生
package com.tcpip;
public class TalkStudent {
public static void main(String[] args) {
new Thread(new TalkSend(7777,"localhost",9999)).start();
new Thread(new TalkReceive(8888,"老师")).start();
}
}
4、老师
package com.tcpip;
public class TalkTeacher {
public static void main(String[] args) {
new Thread(new TalkSend(5555,"localhost",8888)).start();
new Thread(new TalkReceive(9999,"学生")).start();
}
}
5、开始聊天啦，模拟请假
五、Java下载URL网络资源（图片、音乐、视频、电影）
一、前言
今天学习了一下FTP/IP的相关知识，发现一个强大的功能，用Java下载URL网络资源，据说收费的也能下！ 学编程真好，Java真好。
二、代码实例
package com.tcpip;
import java.io.FileOutputStream;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.URL;
public class UrlDown {
public static void main(String[] args) throws Exception {
URL url = new URL("https://vodkgeyttp8.vod.126.net/cloudmusic/776e/core/e166/8847b8c0360e7e3314cf773848e943cd.mp4?wsSecret=ebc2bc0c17347de34a5b1246c3be0b34&wsTime=1598776625");
HttpURLConnection urlConnection = (HttpURLConnection) url.openConnection();
InputStream is = urlConnection.getInputStream();
FileOutputStream fos = new FileOutputStream("FOR LOVE.mp4");
byte[] buffer = new byte[1024];
int len;
while ((len=is.read(buffer))!=-1){
fos.write(buffer,0,len);
}
fos.close();
is.close();
urlConnection.disconnect();
}
}
三、执行效果
1、搜索网络资源URL
2、代码下载效果
3、视频播放
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