网络编程及三大协议（TCP + UDP + Http）
网络编程及三大协议（TCP + UDP + Http）
一、网络编程
1.计算机网络
是指将地理位置不同的具有独立功能的多台计算机及其外部设备，通过通信线路连接起来，在网络操作系统，网络管理软件及网络通信协议的管理和协调下，实现资源共享和信息传递的计算机系统。
2.网络编程
实现多台计算机之间实现数据的共享和传递，网络应用程序主要组成为：
网络编程+IO流+多线程
3.网络编程三要素
网络通讯的模型：请求-响应，客户端-服务端
三要素：IP地址，端口，协议（数据传输的规则）
1.IP地址
1.1.IP地址：网络中计算机的唯一标识（IP地址是一个32位的二进制数据，为了方便，将一个字节的二进制转换为一个十进制的数据）
1.2.IP地址的组成：网络号段+主机段
1.3.1.A类IP地址:第一段号码为网络号码，剩下的三段号码为本地计算机的号码
----可以配置256256256台主机1.3.2.B类IP地址:前二段号码为网络号码，剩下的二段号码为本地计算机的号码
C类IP地址:前三段号码为网络号码，剩下的一段号码为本地计算机的号码补充：
A类地址的表示范围为：0.0.0.0~126.255.255.255，默认网络屏蔽为：255.0.0.0；A类地址分配给规模特别大的网络使用。A类网络用第一组数字表示网络本身的地址，后面三组数字作为连接于网络上的主机的地址。分配给具有大量主机（直接个人用户）而局域网络个数较少的大型网络。例如IBM公司的网络。B类地址的表示范围为：128.0.0.0~191.255.255.255，默认网络屏蔽为：255.255.0.0；
C类地址的表示范围为：192.0.0.0~223.255.255.255，默认网络屏蔽为：255.255.255.0；C类地址分配给小型网络，如一般的局域网和校园网，它可连接的主机数量是最少的，采用把所属的用户分为若干的网段进行管理。
2.端口号
正在运行的程序的标识
A:每个网络程序都会至少有一个逻辑端口
B:用于标识进程的逻辑地址，不同进程的标识不同
C:有效端口：065535，其中01024系统使用或保留端口。
a) 80
b) ftp:23
c) www.baidu.com:80
- 通过第三方工具可以查看
注意：端口与协议有关：TCP和UDP的端口互不相干，同一个协议的端口不能重复，不同协议的可以重复
TCP:10086
UDP:10086
3.协议
通信规则，就是数据的传输规则
TCP、UDP都是传输层的协议
TCP建立连接，形成传输数据的通道；在连接中进行大数据量传输；通过三次握手完成连接，是可靠协议；必须建立连接，效率会稍低，例如：打电话
UDP将数据源和目的封装到数据包中，不需要建立连接；每个数据报的大小在限制在64k；因无连接，是不可靠协议；不需要建立连接，速度快：例如发短信
4.InetAddress – 主机类
import java.net.InetAddress;
import java.net.UnknownHostException;
public class Test01 {
public static void main(String[] args) throws UnknownHostException {
//获取到指定域名的服务器IP地址
// InetAddress byName = InetAddress.getByName("www.baidu.com");
// System.out.println(byName);//14.215.177.39
//获取到指定域名的所有服务器 IPd地址
// InetAddress[] allByName = InetAddress.getAllByName("www.baidu.com");
// for (InetAddress inetAddress : allByName) {
// System.out.println(inetAddress);
// }
//获取到本机的IP地址
InetAddress localHost = InetAddress.getLocalHost();
System.out.println(localHost);
}
}
二、TCP协议
Scoket也叫套接字，其表示的是IP地址和端口号的组合。
网络编程主要就是指Socket编程，网络间的通信其实就是Socket间的通信，数据就通过IO流在两个Scoket间进行传递。
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintStream;
import java.net.Socket;
import java.net.UnknownHostException;
//客户端
public class Client {
//注意：关闭流等于关闭Socket
public static void main(String[] args) throws UnknownHostException, IOException {
//武松
Socket socket = new Socket("127.0.0.001", 8888);
//1.向服务端发送消息
PrintStream ps = new PrintStream(socket.getOutputStream());
ps.println("武松：小二，上好酒好菜！");
//4.接收来自服务端的消息
BufferedReader br = new BufferedReader(new InputStreamReader(socket.getInputStream(), "GBK"));
String readLine = br.readLine();
System.out.println(readLine);
//关闭资源
ps.close();
br.close();
socket.close();
}
}
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintStream;
import java.net.ServerSocket;
import java.net.Socket;
//服务端
public class Server {
public static void main(String[] args) throws IOException {
//客栈掌柜
ServerSocket server = new ServerSocket(8888);
System.out.println("等待端连接中...");
//店小二
//accept()是线程阻塞的方法，客户端和服务端连接成功后才会生成一个Socket对象
Socket socket = server.accept();
System.out.println("欢迎光临，客人来了~~~");
//2.接收来自客户端的消息
BufferedReader br = new BufferedReader(new InputStreamReader(socket.getInputStream(),"GBK"));
String readLine = br.readLine();
System.out.println(readLine);
//3.向客户端发送消息
PrintStream ps = new PrintStream(socket.getOutputStream());
ps.println("店小二：好的，您请坐！");
//关闭资源
br.close();
ps.close();
socket.close();
server.close();
}
}
1.TCP案例之 传输文件
import java.io.FileInputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.net.Socket;
import java.net.UnknownHostException;
public class Client {
public static void main(String[] args) throws UnknownHostException, IOException {
Socket socket = new Socket("127.0.0.002", 6666);
//客户端读取源文件，通过Socket提供的输出流向服务端传输数据即可
FileInputStream fis = new FileInputStream("测试视频.mp4");
OutputStream os = socket.getOutputStream();
byte[] b = new byte[1024];
int len;
while ((len = fis.read(b)) != -1) {
os.write(b, 0, len);
}
fis.close();
os.close();
socket.close();
}
}
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.ServerSocket;
import java.net.Socket;
public class Server {
public static void main(String[] args) throws IOException {
ServerSocket server = new ServerSocket(6666);
Socket socket = server.accept();
//通过Socket提供过的输入流接收来自客户端的数据，并写入到本地文件中
InputStream is = socket.getInputStream();
FileOutputStream fos = new FileOutputStream("copy.mp4");
byte[] b = new byte[1024];
int len;
while ((len = is.read(b)) != -1) {
fos.write(b, 0, len);
}
is.close();
fos.close();
socket.close();
server.close();
}
}
2.TCP协议 之 一对一聊天
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintStream;
import java.net.Socket;
import java.net.UnknownHostException;
import java.util.Scanner;
public class Client {
public static void main(String[] args) throws UnknownHostException, IOException {
Socket socket = new Socket("127.0.0.001", 5555);
Scanner scan = new Scanner(System.in);
PrintStream ps = new PrintStream(socket.getOutputStream());
BufferedReader br = new BufferedReader(new InputStreamReader(socket.getInputStream(),"GBK"));
while (true) {
ps.println("小小：" + scan.next());
String readLine = br.readLine();
System.out.println(readLine);
}
}
}
3.TCP协议 之 优化一对一聊天
import java.io.IOException;
import java.io.PrintStream;
import java.net.Socket;
import java.net.UnknownHostException;
import java.util.Scanner;
public class Client {
public static void main(String[] args) throws UnknownHostException, IOException {
Socket socket = new Socket("127.0.0.1",5010);
new ReceiveThread(socket).start();
Scanner scan = new Scanner(System.in);
PrintStream ps = new PrintStream(socket.getOutputStream());
while (true) {
ps.println("刘备：" + scan.next());
}
}
}
import java.io.IOException;
import java.io.PrintStream;
import java.net.ServerSocket;
import java.net.Socket;
import java.util.Scanner;
public class Server {
public static void main(String[] args) throws IOException {
ServerSocket server = new ServerSocket(5010);
Socket socket = server.accept();
new ReceiveThread(socket).start();
Scanner scan = new Scanner(System.in);
PrintStream ps = new PrintStream(socket.getOutputStream());
while (true) {
ps.println("张飞：" + scan.next());
}
}
}
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.net.Socket;
public class ReceiveThread extends Thread{
private Socket socket;
public ReceiveThread(Socket socket) {
this.socket = socket;
}
@Override
public void run() {
try {
BufferedReader br = new BufferedReader(new InputStreamReader(socket.getInputStream(), "GBK"));
while (true) {
String readLine = br.readLine();
System.out.println(readLine);
}
} catch (IOException e) {
e.printStackTrace();
}
}
}
4.TCP协议 之 群聊
import java.io.IOException;
import java.io.PrintStream;
import java.net.Socket;
import java.net.UnknownHostException;
import java.util.Scanner;
public class Client {
public static void main(String[] args) throws UnknownHostException, IOException {
Socket socket = new Socket("127.0.0.1", 4563);
new ReceiveThread(socket).start();
Scanner scan = new Scanner(System.in);
PrintStream ps = new PrintStream(socket.getOutputStream());
while (true) {
ps.println("关羽：" + scan.next());
}
}
}
import java.io.IOException;
import java.net.ServerSocket;
import java.net.Socket;
import java.util.concurrent.ConcurrentHashMap;
public class Server {
public static final ConcurrentHashMap<String, Socket> map = new ConcurrentHashMap<>();
public static void main(String[] args) throws IOException {
ServerSocket server = new ServerSocket(4563);
while (true) {
Socket socket = server.accept();
//获取客户端的IP地址
String ip = socket.getInetAddress().toString();
System.out.println(ip);
//将IP地址和Socket对象存入Map中
map.put(ip,socket);
//此线程 -- 接收当前Socket的消息，并发送给其他Socket
new ServerThread(socket).start();
}
}
}
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.net.Socket;
public class ReceiveThread extends Thread{
private Socket socket;
public ReceiveThread(Socket socket) {
this.socket = socket;
}
@Override
public void run() {
try {
BufferedReader br = new BufferedReader(new InputStreamReader(socket.getInputStream(),"GBK"));
while (true) {
String readLine = br.readLine();
System.out.println(readLine);
}
} catch (IOException e) {
e.printStackTrace();
}
}
}
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintStream;
import java.io.UnsupportedEncodingException;
import java.net.Socket;
import java.util.Map.Entry;
import java.util.Set;
import java.util.concurrent.ConcurrentHashMap;
public class ServerThread extends Thread{
private Socket socket;
public ServerThread(Socket socket) {
this.socket = socket;
}
@Override
public void run() {
//接收当前Socket的消息，并发送给其他Socket
try {
BufferedReader br = new BufferedReader(new InputStreamReader(socket.getInputStream(),"GBK"));
while (true) {
String readLine = br.readLine();
System.out.println(readLine);
ConcurrentHashMap<String, Socket> map = Server.map;
Set<Entry<String,Socket>> entrySet = map.entrySet();
for (Entry<String, Socket> entry : entrySet) {
String ip = entry.getKey();
Socket value = entry.getValue();
if (!socket.getInetAddress().toString().equals(ip)) {
PrintStream ps = new PrintStream(value.getOutputStream());
ps.println(readLine);
}
}
}
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
}
四、UDP协议
1.简介
UDP（User Datagram Protocol）用户数据报包协议，UDP和TCP位于同一层-传输层，但它对于数据包的顺序错误或重发没有TCP可靠；UDP是一种面向无连接的通信协议。UDP向应用程序提供一种发送封装的原始IP数据报的方法，并且发送时无需建立连接，不保证可靠数据的传输
UDP — 发短信
TCP — 打电话
import java.net.DatagramSocket;
import java.net.SocketException;
public class Client01 {
public static void main(String[] args) throws SocketException {
DatagramSocket socket = new DatagramSocket(8808);
new ReceiveThread(socket).start();
new SendThread(socket, "127.0.0.1", 9099, "马超").start();
}
}
import java.net.DatagramSocket;
import java.net.SocketException;
public class Client02 {
public static void main(String[] args) throws SocketException {
DatagramSocket socket = new DatagramSocket(9099);
new ReceiveThread(socket).start();
new SendThread(socket, "127.0.0.1", 8808, "吕布").start();
}
}
import java.io.IOException;
import java.net.DatagramPacket;
import java.net.DatagramSocket;
public class ReceiveThread extends Thread{
private DatagramSocket socket;
public ReceiveThread(DatagramSocket socket) {
this.socket = socket;
}
@Override
public void run() {
while (true) {
try {
//数据容器
byte[] buf = new byte[1024];
//数据报包
DatagramPacket dp = new DatagramPacket(buf, 0, buf.length);
//接收数据报包
socket.receive(dp);
//打印
System.out.println(new String(buf).trim());
} catch (IOException e) {
e.printStackTrace();
}
}
}
}
import java.io.IOException;
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.UnknownHostException;
import java.util.Scanner;
public class SendThread extends Thread{
private DatagramSocket socket;
private String ip;
private int port;
private String name;
public SendThread(DatagramSocket socket, String ip, int port, String name) {
this.socket = socket;
this.ip = ip;
this.port = port;
this.name = name;
}
@Override
public void run() {
Scanner scan = new Scanner(System.in);
while (true) {
try {
//数据
byte[] buf = (name + ":" + scan.next()).getBytes();
//数据报包
DatagramPacket dp = new DatagramPacket(buf, 0, buf.length);
//发送数据报包
socket.send(dp);
} catch (UnknownHostException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
}
}
2.TCP VS UDP
| TCP | UDP | |
|---|---|---|
| 是否连接 | 面向连接 | 无面向连接 |
| 传输可靠性 | 可靠 | 不可靠 |
| 应用场合 | 传输大量数据 | 少量数据 |
| 速度 | 慢 | 快 |
五、Http协议
1.Http案例之获取来电归属地
import java.io.IOException;
import java.io.InputStreamReader;
import java.net.URL;
import javax.net.ssl.HttpsURLConnection;
public class Test01 {
public static void main(String[] args) throws IOException {
//获取链接地址
URL url = new URL("https://cx.shouji.360.cn/phonearea.php?number=15879090133");
//获取连接对象
HttpsURLConnection huc = (HttpsURLConnection) url.openConnection();
//设置参数
//设置请求方式
huc.setRequestMethod("GET");
//允许使用输入流
huc.setDoInput(true);
//允许使用输出流
huc.setDoOutput(true);
//设置连接超时时间
huc.setConnectTimeout(5000);
//设置读取超时时间
huc.setReadTimeout(5200);
//获取响应状态码
int responseCode = huc.getResponseCode();
if (responseCode == HttpsURLConnection.HTTP_OK) {//响应成功
InputStreamReader isr = new InputStreamReader(huc.getInputStream(), "UTF-8");
char[] c = new char[1024];
int len;
while ((len = isr.read(c)) != -1) {
System.out.println(new String(c, 0, len));
}
isr.close();
}else if(responseCode == HttpsURLConnection.HTTP_NOT_FOUND){
System.out.println("报错了 --- 页面未找到");
}
}
}
2.Http案例之获取快递
import java.io.IOException;
import java.io.InputStreamReader;
import java.net.URL;
import javax.net.ssl.HttpsURLConnection;
public class test02 {
public static void main(String[] args) throws IOException {
//获取地址
URL url = new URL("https://www.kuaidi100.com/?type=zhongtong&postid=78624759493002");
//获取连接对象
HttpsURLConnection huc = (HttpsURLConnection) url.openConnection();
//设置参数
//设置请求方式
huc.setRequestMethod("GET");
//允许使用输入流
huc.setDoInput(true);
//允许使用输出流
huc.setDoOutput(true);
//设置连接超时时间
huc.setConnectTimeout(5200);
//设置读取超时时间
huc.setReadTimeout(5000);
//获取响应状态码
int responseCode = huc.getResponseCode();
if (responseCode == HttpsURLConnection.HTTP_OK) {//响应成功
InputStreamReader isr = new InputStreamReader(huc.getInputStream(),"UTF-8");
char[] c = new char[1024];
int len;
while ((len = isr.read(c)) != -1) {
System.out.println(new String(c, 0, len));
}
isr.close();
} else if(responseCode == HttpsURLConnection.HTTP_NOT_FOUND){
System.out.println("报错了 --- 页面未找到");
}
}
}
3.Http案例之下载图片
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.URL;
import javax.net.ssl.HttpsURLConnection;
public class Test03 {
public static void main(String[] args) throws IOException {
//获取连接地址
URL url = new URL("https://ts1.cn.mm.bing.net/th/id/R-C.f27d775447d9f4ab7c71bbe5f8e38831?rik=4ISLL%2fsQWoSY8g&riu=http%3a%2f%2fimg95.699pic.com%2fphoto%2f40014%2f9369.jpg_wh860.jpg&ehk=S%2bDyu%2bhUKhk%2foLxQ6D7fO350Z%2fkmlDrRz5sM5J1QrCk%3d&risl=&pid=ImgRaw&r=0");
//获取连接对象
HttpsURLConnection huc = (HttpsURLConnection) url.openConnection();
//设置参数
//设置请求方式
huc.setRequestMethod("GET");
//允许使用输入流
huc.setDoInput(true);
//允许使用输出流
huc.setDoOutput(true);
//设置连接超时时间
huc.setConnectTimeout(5200);
//设置读取超时时间
huc.setReadTimeout(5000);
//获取响应状态码
int responseCode = huc.getResponseCode();
if (responseCode == HttpsURLConnection.HTTP_OK) {
InputStream is = huc.getInputStream();
FileOutputStream fos = new FileOutputStream("冲击的力量.jpg");
byte[] b = new byte[1024];
int len;
while ((len = is.read(b)) != -1) {
fos.write(b, 0, len);
}
is.close();
fos.close();
}else if (responseCode == HttpsURLConnection.HTTP_NOT_FOUND) {
System.out.println("报错了 --- 页面未找到");
}
}
}