Java-網路程式設計程式碼
阿新 • • 發佈：2022-04-13
InetAddress關鍵字
為了方便我們獲取和操作IP地址，java提供了一個類InetAddress 供我們使用
- 確定主機名稱的IP地址。public static InetAddress getByName(String host)
- 獲取此IP地址的主機名。String getHostName()
- 返回文字顯示中的IP地址字串,String getHostAddress()。
程式碼如下：
public class InetAddressDemo { public static void main(String[] args) { //public static InetAddress getByName(String host) throws UnknownHostException // 確定主機名稱的IP地址。 InetAddress addressName = null; try { addressName = InetAddress.getByName("192.168.10.147"); System.out.println(addressName); } catch (UnknownHostException e) { e.printStackTrace(); } //String getHostName() //獲取此IP地址的主機名。 String hostName = addressName.getHostName(); System.out.println(hostName); //String getHostAddress() //返回文字顯示中的IP地址字串。 String hostAddress = addressName.getHostAddress(); System.out.println(hostAddress); //static InetAddress getLocalHost() //返回本地主機的地址。 try { InetAddress localHost = addressName.getLocalHost(); System.out.println(localHost); } catch (UnknownHostException e) { e.printStackTrace(); } } }
UDP 協議建立連線
UDP協議傳送資料的步驟：
- 1.建立傳送端的Socket物件
- 2.建立資料，並將資料打包
- 3.呼叫Socket物件中的一個辦法，將資料包傳送出去
- 4.釋放資源，關閉Socket物件
public class SendDemo1 { public static void main(String[] args) { //建立傳送端的Socket物件 //DatagramSocket() //構造資料報套接字並將其繫結到本地主機上的任何可用埠。 DatagramSocket ds = null; try { ds = new DatagramSocket(); } catch (SocketException e) { e.printStackTrace(); } //將資料轉成位元組陣列 byte[] bytes = "雲想衣裳花想容".getBytes(); //獲取位元組陣列的長度 int len = bytes.length; //IP地址，（你要傳送給誰的ip地址） InetAddress address = null; try { address = InetAddress.getByName("192.168.10.147"); } catch (UnknownHostException e) { e.printStackTrace(); } //指定接收的資料埠 int port = 10086; //建立一個數據包 //DatagramPacket(byte[] buf, int length, InetAddress address, int port) //構造用於傳送長度的分組的資料報包 length指定主機上到指定的埠號。 DatagramPacket datagramPacket = new DatagramPacket(bytes, len, address, port); //void send(DatagramPacket p) //從此套接字傳送資料報包。 try { ds.send(datagramPacket); } catch (IOException e) { e.printStackTrace(); } //釋放資源，關閉Socket物件 ds.close(); } }
UDP接收端程式碼步驟
- 1.接收端的Socket物件
- 2.建立一個數據包（用來接收資料的容器）
- 3.呼叫Socket物件中的方法來接收資料
- 4.解析資料包，列印在控制檯上
- 5.釋放資源
- 注意：接收端不能重複啟動
public class ReceiveDemo1 { public static void main(String[] args) { //建立接收端的Socket物件 //DatagramSocket(int port) //建構函式報套接字並將其繫結到本地主機的指定埠 DatagramSocket ds = null; try { ds= new DatagramSocket(10086); } catch (SocketException e) { e.printStackTrace(); } //建立一個數據包（用來接收資料的容器） //DatagramPacket(byte[] buf,int length) //構造一個 DatagramPacket 用於接收資料包length byte[] bytes = new byte[1024]; int len = bytes.length; DatagramPacket dp = new DatagramPacket(bytes, len); //呼叫Socket物件中的方法來接收資料 //void receive(DatagramPacket P) try { ds.receive(dp); // 阻塞方法 } catch (IOException e) { e.printStackTrace(); } InetAddress address = dp.getAddress(); String ip = address.getHostAddress(); String hostName = address.getHostName(); //解析資料包，列印到控制檯上 //byte[] getData() //返回資料緩衝區 byte[] data = dp.getData(); int length = dp.getLength();//獲取實際長度 String s = new String(data,0,length); System.out.println(hostName+"，IP地址為："+ip+"傳送的內容為："+s); //釋放資源 ds.close(); } }
通過迴圈改進，程式碼如下
傳送端：
package com.bigdat.java.day28.udpcoding;
import java.io.IOException;
import java.net.*;
import java.util.Scanner;
public class SendDemo2 {
public static void main(String[] args) {
while(true){
DatagramSocket ds = null;
//傳送端傳送資料
try {
ds = new DatagramSocket();
} catch (SocketException e) {
e.printStackTrace();
}
//建立一個輸入物件
Scanner scanner = new Scanner(System.in);
String next = scanner.next();
if("886".equals(next)){
break;
}else{
byte[] bytes = next.getBytes();
int length = bytes.length;
InetAddress address = null;
try {
address = InetAddress.getByName("192.168.10.147");
} catch (UnknownHostException e) {
e.printStackTrace();
}
int port = 10086;
DatagramPacket datagramPacket = new DatagramPacket(bytes,length,address,port);
try {
ds.send(datagramPacket);
} catch (IOException e) {
e.printStackTrace();
}
//關閉資源
//ds.close();
}
}
}
}
接收端：
package com.bigdat.java.day28.udpcoding;
import java.io.IOException;
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.InetAddress;
import java.net.SocketException;
public class ReceiveDemo2 {
public static void main(String[] args) {
//建立接收物件
DatagramSocket ds = null;
try {
ds = new DatagramSocket(10086);
} catch (SocketException e) {
e.printStackTrace();
}
System.out.println("====================接收端開始接收資料：=======================");
while(true){
//建立一個DatagramPacket 類的物件建立一個容器
byte[] bytes = new byte[1024];
int length = bytes.length;
DatagramPacket dp = new DatagramPacket(bytes,length );
//呼叫Socket方法receive 方法接收資料
try {
ds.receive(dp); // 阻塞資料包
} catch (IOException e) {
e.printStackTrace();
}
InetAddress address = dp.getAddress();
String hostName = address.getHostName(); //IP地址對應主機名
String hostAddress = address.getHostAddress();//IP 地址
byte[] data = dp.getData();
int length1 = data.length;
String s = new String(data, 0, length1);
System.out.println(hostName+",IP地址為："+hostAddress+"傳送的資訊為："+s);
}
}
}
TCP協議建立連線
TCP協議傳送資料的步驟：
- 1.建立客戶端的Socket物件
這一步一旦成功就證明連線成功- 2.獲取通道中的輸出流物件，寫資料
- 3.釋放資源
客戶端程式碼
public class ClientDemo1 {
public static void main(String[] args) throws Exception {
//此構造方法較為繁瑣，一般不用
//Socket(InetAddress address, int port)
//建立流套接字並將其連線到指定IP地址的指定埠號。
//Socket socket = new Socket(InetAddress.getByName("192.168.10.147\""),10086);
//Socket(String host, int port)
//建立流套接字並將其連線到指定的主機上的指定埠
Socket socket = new Socket("192.168.10.147", 10086);
//獲取通道中的輸出流物件，寫資料
while(true){
Scanner scanner = new Scanner(System.in);
String next = scanner.next();
if("886".equals(next)){
break;
}else{
OutputStream outputStream = socket.getOutputStream();
outputStream.write(next.getBytes());
}
}
//釋放資源
socket.close();
}
}
伺服器端程式碼：
public class ClientDemo1 {
public static void main(String[] args) throws Exception {
//此構造方法較為繁瑣，一般不用
//Socket(InetAddress address, int port)
//建立流套接字並將其連線到指定IP地址的指定埠號。
//Socket socket = new Socket(InetAddress.getByName("192.168.10.147\""),10086);
//Socket(String host, int port)
//建立流套接字並將其連線到指定的主機上的指定埠
Socket socket = new Socket("192.168.10.147", 10086);
//獲取通道中的輸出流物件，寫資料
while(true){
Scanner scanner = new Scanner(System.in);
String next = scanner.next();
if("886".equals(next)){
break;
}else{
OutputStream outputStream = socket.getOutputStream();
outputStream.write(next.getBytes());
}
}
//釋放資源
socket.close();
}
}
改進（客戶端傳送資料後，伺服器端有返回值）
客戶端
package com.bigdat.java.day28.tcpcoding;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.Socket;
import java.util.Scanner;
public class ClientDemo2 {
public static void main(String[] args) {
Socket socket = null;
try {
socket = new Socket("192.168.10.147",19999 );
} catch (IOException e) {
e.printStackTrace();
}
while(true){
Scanner scanner = new Scanner(System.in);
String next = scanner.next();
if("886".equals(next)){
System.out.println("連線已斷開...");
break;
}else{
OutputStream outputStream = null;
InputStream inputStream = null;
try {
outputStream = socket.getOutputStream();
inputStream = socket.getInputStream();
} catch (IOException e) {
e.printStackTrace();
}
try {
outputStream.write(next.getBytes());
} catch (IOException e) {
e.printStackTrace();
}
byte[] bytes = new byte[1024];
int length = 0;
try {
length = inputStream.read(bytes);
} catch (IOException e) {
e.printStackTrace();
}
String s = new String(bytes, 0, length);
System.out.println("伺服器返回的訊息是："+s);
}
}
}
}
伺服器端
package com.bigdat.java.day28.tcpcoding;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.InetAddress;
import java.net.ServerSocket;
import java.net.Socket;
public class ServerDemo2 {
public static void main(String[] args) {
ServerSocket sSocket = null;
try {
sSocket = new ServerSocket(19999);
} catch (IOException e) {
e.printStackTrace();
}
Socket accept = null;
try {
accept = sSocket.accept();
} catch (IOException e) {
e.printStackTrace();
}
while(true){
OutputStream outputStream = null;
InputStream inputStream = null;
try {
outputStream = accept.getOutputStream();
inputStream = accept.getInputStream();
} catch (IOException e) {
e.printStackTrace();
}
byte[] bytes = new byte[1024];
int len =0;
try {
len = inputStream.read(bytes);
} catch (IOException e) {
e.printStackTrace();
}
String s = new String(bytes, 0, len);
InetAddress inetAddress = accept.getInetAddress();
String hostName = inetAddress.getHostName();
String hostAddress = inetAddress.getHostAddress();
System.out.println(hostName+",IP地址為："+hostAddress+"客戶端上傳的資訊是："+s);
try {
outputStream.write("伺服器端已經接收到！！！".getBytes());
} catch (IOException e) {
e.printStackTrace();
}
}
}
}