JAVA学习笔记(五十八)- InetAddress类与URL

InetAddress类

/*
 * InetAddress类 
 */
public class Test07 {
    public static void main(String[] args) throws UnknownHostException {
        //获取本机的InetAddress实例 
        System.out.println("*******获取本机的InetAddress实例**********");
        InetAddress address1 = InetAddress.getLocalHost();
        System.out.println("主机名："+address1.getHostName());
        System.out.println("IP地址："+address1.getHostAddress());
        byte[] bytes=address1.getAddress();
        System.out.println("字节数组形式的IP地址："+Arrays.toString(bytes));//超过127则为负数，加256
        System.out.println(address1);


        //根据主机名获取指定主机的InetAddress实例
        System.out.println("*******根据主机名获取指定主机的InetAddress实例**********");
        //InetAddress address2=InetAddress.getByName("HE67B6DJBOID2DA");
        InetAddress address2=InetAddress.getByName("5.8.6.45");
        System.out.println(address2.getHostName());
        System.out.println(address2);

        //根据字节数组形式的IP地址来获取InetAddress实例
        System.out.println("**********根据字节数组形式的IP地址来获取InetAddress实例***********");
        byte[] bytes2={(byte)192,(byte)168,6,8};
        InetAddress address3=InetAddress.getByAddress(bytes2);
        System.out.println(address3.getHostName());
        System.out.println(address3);
    }
}

URL常用方法

/*
 * URL常用方法
 */
public class Test08 {
    public static void main(String[] args) throws MalformedURLException {
        URL baidu=new URL("http://www.baidu.com");
        URL url=new URL(baidu, "/index.html?username=tom&password=123#test");
        System.out.println("协议："+url.getProtocol());
        System.out.println("主机："+url.getHost());
        System.out.println("端口："+url.getPort());
        System.out.println("文件路径："+url.getPath());
        System.out.println("文件名："+url.getFile());
        System.out.println("相对路径："+url.getRef());
        System.out.println("查询："+url.getQuery());

    }
}

使用URL读取网页内容

import java.io.BufferedInputStream;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.MalformedURLException;
import java.net.URL;

/*
 * 使用URL读取网页内容
 */
public class Test01 {
    public static void main(String[] args) throws IOException {
        test02();
    }

    //读取网页资源
    public static void test01() throws IOException{
        URL url = new URL("http://localhost:8080/webTest/");
        InputStream is = url.openStream();// 获取URL对象所表示的资源的输入流
        BufferedReader br = new BufferedReader(new InputStreamReader(is));// 将字节输入流转换为字符输入流
        String str = br.readLine();
        while (str != null) {
            System.out.println(str);
            str = br.readLine();
        }
        br.close();
        is.close();
    }

    //读取FTP上的文件资源
    public static void test02() throws IOException{
        URL url=new URL("ftp://wbs14061:abc@172.16.1.11/资料/exe2.txt");
        System.out.println("协议："+url.getProtocol());
        System.out.println("主机："+url.getHost());
        System.out.println("端口："+url.getPort());
        System.out.println("文件路径："+url.getPath());
        System.out.println("文件名："+url.getFile());
        System.out.println("相对路径："+url.getRef());
        System.out.println("查询："+url.getQuery());
        InputStream is = url.openStream();// 获取URL对象所表示的资源的输入流
        BufferedReader br = new BufferedReader(new InputStreamReader(is));// 将字节输入流转换为字符输入流
        String str = br.readLine();
        while (str != null) {
            System.out.println(str);
            str = br.readLine();
        }
        br.close();
        is.close();
    }
}