一、代码

URLTest类

package com.day0321_1;

import java.net.MalformedURLException;
import java.net.URL;

/**
 * URL网络编程
 * 1、URL统一资源定义符，对应着互联网的某一资源地址
 * 2.格式：
 * http://localhost:8080/examples/beauty.jpg?username=Tom&password=123
 * 协议    主机名     端口号   资源地址             参数列表
 */
public class URLTest {

    public static void main(String[] args) {
        try {
            URL url1=new URL("http://localhost:8080/examples/beauty.jpg?username=Tom&password=123");

            //public String getProtocol() //获取该URL的协议名
            System.out.println(url1.getProtocol());
            //public String getHost() //获取该URL的主机名
            System.out.println(url1.getHost());
            //public String getPort() //获取该URL的端口号
            System.out.println(url1.getPort());
            //public String getPath() //获取该URL的文件路径
            System.out.println(url1.getPath());
            //public String getFile() //获取该URL的文件名
            System.out.println(url1.getFile());
            //public String getQuery() //获取该URL的查询名
            System.out.println(url1.getQuery());



        } catch (MalformedURLException e) {
            e.printStackTrace();
        }

    }

}

URLTest1 类

package com.day0321_1;

import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.URL;

public class URLTest1 {

    public static void main(String[] args) {


        HttpURLConnection urlConnection= null;
        InputStream is = null;
        FileOutputStream fos= null;
        try {
            URL url=new URL("http://localhost:8080/examples/beauty.jpg");

            urlConnection = (HttpURLConnection) url.openConnection();

            urlConnection.connect();

            is = urlConnection.getInputStream();
            fos = new FileOutputStream("新图片2.png");

            byte[] buffer=new byte[1024];
            int len;
            while((len= is.read(buffer))!=-1){
                fos.write(buffer,0,len);
            }

            System.out.println("图片下载完成");
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            //关闭资源
            if(is!=null){
                try {
                    is.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }

            if(fos!=null){
                try {
                    fos.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }

            if(urlConnection!=null){
                try {
                    urlConnection.disconnect();
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }

        }




    }
}

二、图片