Java狂神说网络编程笔记
- IP
import java.net.InetAddress;
import java.net.UnknownHostException;
public class Hello {
//
// 测试IP
public static void main(String[] args) {
try {
//返回主机
InetAddress inetAddress = InetAddress.getByName("127.0.0.1");
System.out.println(inetAddress);
InetAddress inetAddress2 = InetAddress.getByName("localhost");
System.out.println(inetAddress);
InetAddress inetAddress3 = InetAddress.getLocalHost();
System.out.println(inetAddress);
//返回网站地址
InetAddress inetAddress1 = InetAddress.getByName("www.baidu.com");
System.out.println(inetAddress1);
//常用方法
//System.out.println(inetAddress1.getAddress());
System.out.println(inetAddress1.getCanonicalHostName()); //规范名,
System.out.println(inetAddress1.getHostAddress());//ip
System.out.println(inetAddress2.getHostName());//域名
} catch (UnknownHostException e) {
e.printStackTrace();
}
}
}
- 一些命令
import java.net.InetSocketAddress;
public class Hello {
//
public static void main(String[] args) {
InetSocketAddress inetSocketAddress = new InetSocketAddress("127.0.0.1",8080);
InetSocketAddress inetSocketAddress1 = new InetSocketAddress("localhost",8080);
System.out.println(inetSocketAddress);
System.out.println(inetSocketAddress1);
System.out.println(inetSocketAddress.getAddress()); //返回IP
System.out.println(inetSocketAddress.getHostName()); //返回名字
System.out.println(inetSocketAddress.getPort()); //返回端口
}
}
- 通信协议
package kssManyThread;
import java.io.IOException;
import java.io.OutputStream;
import java.net.InetAddress;
import java.net.Socket;
import java.nio.charset.StandardCharsets;
//客户端
public class day1 {
public static void main(String[] args) throws IOException {
//1.要知道服务器的地址
InetAddress ServerIp = InetAddress.getByName("127.0.0.1");
//2.端口号
int port = 9999;
//3.创建一个socket连接
Socket socket = new Socket(ServerIp, port);
//4.发送消息 IO流
OutputStream outputStream = socket.getOutputStream();
outputStream.write("你好,欢迎狂神说Java".getBytes(StandardCharsets.UTF_8));
if(outputStream!=null){
outputStream.close();
}
if (socket!=null){
socket.close();
}
}
}
package kssManyThread;
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 day2 {
public static void main(String[] args) throws IOException {
//1.我得有一个地址
ServerSocket serverSocket = new ServerSocket(9999);
//2.等待客户端连接过来
Socket socket = serverSocket.accept();
//3.读取客户端的消息
InputStream is = socket.getInputStream();
//管道流
ByteArrayOutputStream 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());
if (baos!=null){
baos.close();
}
if (is!=null){
is.close();
}
if (socket!=null) {
socket.close();
}
if (serverSocket!=null) {
serverSocket.close();
}
}
}
- 发送图片（文件）
package kssManyThread;
import java.io.*;
import java.net.InetAddress;
import java.net.Socket;
import java.nio.charset.StandardCharsets;
//客户端
public class day1 {
public static void main(String[] args) throws IOException {
//1.要知道服务器的地址
InetAddress ServerIp = InetAddress.getByName("127.0.0.1");
//2.端口号
int port = 9999;
//3.创建一个socket连接
Socket socket = new Socket(ServerIp, port);
//4.发送消息 IO流
OutputStream outputStream = socket.getOutputStream();
//读取文件
FileInputStream fis = new FileInputStream(new File("E:\\idea\\WorkerSystem\\src\\Worker\\t01369c7b27429f28cb.jpg"));
byte[] buffer = new byte[1024];
int len;
while((len=fis.read())!=-1){
outputStream.write(buffer,0,len);
}
//通知服务器,我已经结束了
socket.shutdownOutput();
InputStream inputStream = socket.getInputStream();
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());
if(outputStream!=null){
outputStream.close();
}
if (socket!=null){
socket.close();
}
}
}
package kssManyThread;
import java.io.*;
import java.net.ServerSocket;
import java.net.Socket;
import java.nio.charset.StandardCharsets;
//服务端
public class day2 {
public static void main(String[] args) throws IOException {
//1.我得有一个地址
ServerSocket serverSocket = new ServerSocket(9999);
//2.等待客户端连接过来
Socket socket = serverSocket.accept();
//3.读取客户端的消息
InputStream is = socket.getInputStream();
//文件输出
FileOutputStream fos = new FileOutputStream(new File("re.jpg"));
byte[] buffer = new byte[1024];
int len;
while ((len=is.read(buffer))!=-1){
fos.write(buffer,0,len);
}
//通知客户端我接受完毕了
OutputStream os = socket.getOutputStream();
os.write("我接受完毕了".getBytes(StandardCharsets.UTF_8));
if (fos!=null){
fos.close();
}
if (is!=null){
is.close();
}
if (socket!=null) {
socket.close();
}
if (serverSocket!=null) {
serverSocket.close();
}
}
}
- UDP案例
kage kssManyThread;
import java.io.IOException;
import java.net.*;
import java.nio.charset.StandardCharsets;
//UDP不需要连接服务器
public class day1 {
public static void main(String[] args) throws IOException {
//1.建立一个socket
DatagramSocket socket = new DatagramSocket();
//2.建立包
String message = "你好啊,服务器";
//发送给谁
InetAddress localhost = InetAddress.getByName("localhost");
int port = 9090;
DatagramPacket packet = new DatagramPacket(message.getBytes(StandardCharsets.UTF_8), 0, message.getBytes(StandardCharsets.UTF_8).length,localhost,port );
//3.发送包
socket.send(packet);
//4.关闭流
socket.close();
}
}
package kssManyThread;
import java.net.DatagramPacket;
import java.net.DatagramSocket;
public class day2 {
public static void main(String[] args) throws Exception {
//开放端口
DatagramSocket socket = new DatagramSocket(9090);
//接受数据包
byte[] buffer = new byte[1024];
DatagramPacket packet = new DatagramPacket(buffer, 0, buffer.length);//接受
socket.receive(packet);
System.out.println(new String(packet.getData()));
//关闭链接
socket.close();
}
}
- 模拟两个人在聊天
package kssManyThread;
import java.io.IOException;
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.SocketException;
//接受的线程
public class day2 implements Runnable{
DatagramSocket socket = null;
private int port;
private String msgFrom;
public day2(int port,String msgFrom) throws SocketException {
this.port = port;
this.msgFrom = msgFrom;
socket = new DatagramSocket(port);
}
@Override
public void run() {
while (true) {
try {
byte[] container = new byte[1024];
DatagramPacket packet = new DatagramPacket(container, 0, container.length);
socket.receive(packet);
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();
}
}
package kssManyThread;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.net.*;
import java.nio.charset.StandardCharsets;
//发送的线程
public class day1 implements Runnable {
DatagramSocket socket = null;
BufferedReader reader = null;
private int fromPort;
private String toIP;
private int toPort;
public day1(int fromPort, String toIP, int toPort) throws SocketException {
this.fromPort = fromPort;
this.toIP = toIP;
this.toPort = toPort;
socket = new DatagramSocket(fromPort);
reader = new BufferedReader(new InputStreamReader(System.in));
}
@Override
public void run() {
while (true){
try {
String data = reader.readLine();
byte[] datas = data.getBytes(StandardCharsets.UTF_8);
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();
}
}
package kssManyThread;
import java.net.SocketException;
public class Talk {
public static void main(String[] args) throws SocketException {
//开启两个线程
new Thread(new day1(7777,"localhost",9999)).start();
new Thread(new day2(8888,"老师")).start();
}
}
package kssManyThread;
import java.net.SocketException;
public class Talk2 {
public static void main(String[] args) throws SocketException {
//开启两个线程
new Thread(new day1(5555,"localhost",8888)).start();
new Thread(new day2(9999,"学生")).start();
}
}
- 下载网络资源(试了个图片，不能干坏事对吧？)
package kssManyThread;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;
public class last {
public static void main(String[] args) throws IOException {
//1.下载地址
URL url = new URL("");//自己去想
//2.连接到这个资源HTTP
HttpURLConnection urlConnection = (HttpURLConnection) url.openConnection();
InputStream inputStream = urlConnection.getInputStream();
FileOutputStream fos = new FileOutputStream("图标.png");//看你下载什么文件
byte[] buffer = new byte[1024];
int len;
while((len=inputStream.read(buffer))!=-1){
fos.write(buffer,0,len);
}
fos.close();
inputStream.close();
urlConnection.disconnect();
}
}