package cn.bl.net;

import java.io.InputStream;
import java.net.URL;

import org.junit.Test;

public class Demo1_URL {
  @Test
  public void test() {
    URL url;
    try {
      url = new URL("https:/
      System.out.println(url.toString());//也就是这个网址
      System.out.println(url.getPort());//没设置就返回-1
      System.out.println(url.getDefaultPort());//返回默认端口  --  443
      System.out.println(url.getProtocol());//https - 协议
      System.out.println(url.getHost());/
      
      InputStream in = url.openStream();//将网页的html读取出来了
      byte[]b = new byte[512];
      int len = -1;
      while((len = in.read(b)) !=-1) {
        System.out.println(new String(b, 0, len));
      }
    } catch (Exception e) {
      e.printStackTrace();
    }
  }
}
package cn.bl.net;

import java.io.IOException;
import java.net.MalformedURLException;
import java.net.URL;
import java.net.URLConnection;

import org.junit.Test;

public class Demo2_URLConnection {
  @Test
  public void test() {
    try {
      URL url = new URL
      URLConnection con = url.openConnection();
      System.out.println("返回资源文件的长度:"+con.getContentLength());
      System.out.println("返回资源文件的类型:"+con.getContentType());
    } catch (MalformedURLException e) {
      e.printStackTrace();
    } catch (IOException e) {
      e.printStackTrace();
    }
  }
}
package cn.bl.net;

import java.net.InetAddress;

import org.junit.Test;

public class Deom3_InetAddress {
  @Test
  public void test() throws Exception {
    InetAddress address = InetAddress.getByName
    System.out.println(address.getHostAddress());//39.96.132.69

    System.out.println(address.isSiteLocalAddress());//false
    System.out.println(address.getHostName());
  }
}