Java源码：URL编程

Example 1 Below is a simple Java program which can get the hostname of a computer
from IP address. download now

Tips
1. Compile: javac GetHost
2. Run: java GetHost 111.111.111.1(your IP or others)
import java.io.*;
import java.net.*;
//
//
// GetHost.java
//
//
public class GetHost
{
public static void main (String arg[]){
if (arg.length=1){
InetAddress[] Inet;
int i=1;
try{
for (i=1;i=arg.length;i++){
Inet = InetAddress.getAllByName(arg[i-1]);
for (int j=1;j=Inet.length;j++){
System.out.print(Inet[j-1].toString());
System.out.print("");
}
}
}
catch(UnknownHostException e){
System.out.print("Unknown HostName!"+arg[i-1]);
}
}
else{
System.out.print("Usage java/jview GetIp ");
}
}
}

Example 2
download now
//GetHTML.java
/**
* This is a program which can read information from a web server.
* @version 1.0 2000/01/01
* @author jdeveloper
**/
import java.net.*;
import java.io.*;

public class GetHTML {
public static void main(String args[]){
if (args.length 1){
System.out.println("USAGE: java GetHTML httpaddress");
System.exit(1);
}
String sURLAddress = new String(args[0]);
URL url = null;
try{
url = new URL(sURLAddress);
}catch(MalformedURLException e){
System.err.println(e.toString());
System.exit(1);
}
try{
InputStream ins = url.openStream();
BufferedReader breader = new BufferedReader(new InputStreamReader(ins));
String info = breader.readLine();
while(info != null){
System.out.println(info);
info = breader.readLine();
}
}
catch(IOException e){
System.err.println(e.toString());
System.exit(1);
}
}
}