URL----网络资源定位指针
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.InetAddress;
import java.net.MalformedURLException;
import java.net.URL;
import java.net.URLConnection;
import java.util.Date;
import org.junit.Test;
public class UrlDemo {
@Test//URL
public void t1(){
try {
URL url=new URL("http://www.hncu.net");
InputStream in=url.openStream();
BufferedReader bf=new BufferedReader(new InputStreamReader(in));
String str="";
while((str=bf.readLine())!=null){
System.out.println(str);
}
bf.close();
} catch (MalformedURLException e) {
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
@Test//URLConnection ---响应头信息
public void t2(){
try {
URL url=new URL("http://www.hncu.net");
URLConnection con=url.openConnection();
String code=con.getContentEncoding();
System.out.println("code:"+code);
int len=con.getContentLength();
System.out.println("len:"+len);
Date d=new Date(con.getLastModified());
System.out.println(d.toString());
// con.setDoOutput(true);
// OutputStream out = con.getOutputStream();
// for(int i=0;i<10000;i++){
// out.write(i);
// }
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
@Test//IP地址的封装类:InetAddress
public void t3() throws IOException{
InetAddress ip=InetAddress.getByName("www.hncu.net");
System.out.println(ip.getHostAddress());
System.out.println(ip.getHostName());
}
}
package cn.hncu.udp.hello;
import java.io.IOException;
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.InetAddress;
public class UdpSendDemo {
/*
* UDP编程就两个类：DatagramPacket，DatagramSocket 发送: 创建一个数据包 DatagramPacket dp =
* new DatagramPacket(数据+IP+端口);
*
* 创建一个UDP的socket //可以指定端口，也可由系统随机分配 DatagramSocket s = new
* DatagramSocket();
*
* s.send(dp);//发送出去 ※※※入口※※※
*
* 数据包DatagramPacket类的构造方法分成两类： 1)有地址参数(通常是Ip地址)的就是用于发送的 2)没地址参数的就是用于接收的
*/
public static void main(String[] args) throws IOException {
byte buf[] = "hello,world!".getBytes();
DatagramPacket dp = new DatagramPacket(buf, buf.length,
InetAddress.getByName("127.0.0.1"), 10001);
DatagramSocket s = new DatagramSocket();//发送时可以不指定端口号
s.send(dp);// 入口
s.close();
}
}
package cn.hncu.udp.hello;
import java.io.IOException;
import java.net.DatagramPacket;
import java.net.DatagramSocket;
public class UdpReceiveDemo {
/*
* UDP编程就两个类：DatagramPacket，DatagramSocket
* 接收:
* 创建一个数据包
* DatagramPacket dp = new DatagramPacket(缓存);
*
* 创建一个UDP的socket //必须指定发送方数据包中给的端口号
* DatagramSocket ds = new DatagramSocket(发送方数据包中指定的端口号);
*
* ds.receive(dp);//数据收到dp中 //※※※※
*
从dp中把真正的数据解析出来 //※※※※
*/
public static void main(String[] args) throws IOException {
byte buf[]=new byte[1024];
DatagramPacket dp=new DatagramPacket(buf, buf.length);
DatagramSocket ds=new DatagramSocket(10001);
ds.receive(dp);
//从dp中解析数据
String ip=dp.getAddress().getHostAddress();
int port=dp.getPort();
byte data[]=dp.getData();
String text=new String(data,0,dp.getLength());
System.out.println(ip+":"+port+"--->"+text);
ds.close();
}
}
package cn.hncu.udp.chat.v1;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.InetAddress;
import java.net.SocketException;
public class UDPChat1 {
public static void main(String[] args) {
DatagramSocket sendDs = null;
DatagramSocket receiveDs = null;
try {
sendDs = new DatagramSocket(10002);
receiveDs = new DatagramSocket(10003);
new Thread(new Send(sendDs)).start();// 发
new Thread(new Receive(receiveDs)).start();// 收
} catch (SocketException e) {
e.printStackTrace();
}
}
}
class Send implements Runnable {
private DatagramSocket ds;
public Send(DatagramSocket ds) {
this.ds = ds;
}
@Override
public void run() {
try {
BufferedReader br = new BufferedReader(new InputStreamReader(
System.in));
String str = "";
while ((str = br.readLine()) != null) {
byte buf[] = str.getBytes();
DatagramPacket dp = new DatagramPacket(buf, buf.length,
InetAddress.getByName("127.0.0.1"), 10001);
ds.send(dp);
}
ds.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
class Receive implements Runnable {
private DatagramSocket ds;
public Receive(DatagramSocket ds) {
this.ds = ds;
}
@Override
public void run() {
try {
byte buf[] = new byte[1024];
while (true) {
DatagramPacket dp = new DatagramPacket(buf, buf.length);
ds.receive(dp);
// 解析数据
String ip = dp.getAddress().getHostAddress();
String text = new String(dp.getData(), 0, dp.getLength());
System.out.println(ip + ":" + text);
if ("over".equals(text)) {
break;
}
}
System.out.println("离线了.....");
ds.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
package cn.hncu.udp.chat.v2;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.InetAddress;
import java.net.SocketException;
public class UDPChat2 {
public static void main(String[] args) {
try {
DatagramSocket sendDs = new DatagramSocket(10000);
DatagramSocket receiveDs = new DatagramSocket(10001);
new Thread(new Send(sendDs)).start();// 发
new Thread(new Receive(receiveDs)).start();// 收
} catch (SocketException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
class Send implements Runnable {
private DatagramSocket ds;
public Send(DatagramSocket ds) {
this.ds = ds;
}
@Override
public void run() {
// System.in字节流 --> 转换流 --> 字符流 --> 缓存流
try {
BufferedReader br = new BufferedReader(new InputStreamReader(
System.in));
String str = "";
while ((str = br.readLine()) != null) {
byte buf[] = str.getBytes();
DatagramPacket dp = new DatagramPacket(buf, buf.length,
InetAddress.getByName("127.0.0.1"), 10003);
ds.send(dp);
}
ds.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
class Receive implements Runnable {
private DatagramSocket ds;
public Receive(DatagramSocket ds) {
this.ds = ds;
}
@Override
public void run() {
try {
while (true) {
byte buf[] = new byte[1024];
DatagramPacket dp = new DatagramPacket(buf, buf.length);
ds.receive(dp);
// 从dp中解析数据
String ip = dp.getAddress().getHostAddress();
String text = new String(dp.getData(), 0, dp.getLength());
System.out.println(ip + ":" + text);
if ("over".equals(text)) {
break;
}
}
System.out.println("离线了。。。。");
ds.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
