URL网络编程

URL类常用方法

package java2;

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

public class URLTest {
    public static void main(String[] args) {
        URL url1 = null;
        try {
            url1 = new URL("https://www.bilibili.com/video/BV1Kb411W75N?p=586");
        } catch (MalformedURLException e) {
            e.printStackTrace();
        }
//        public String getProtocol( ) 获取该URL的协议名
        System.out.println(url1.getProtocol());//https
//        public String getHost( ) 获取该URL的主机名
        System.out.println(url1.getHost());//www.bilibili.com
//        public String getPort( ) 获取该URL的端口号
        System.out.println(url1.getPort());//-1
//        public String getPath( ) 获取该URL的文件路径
        System.out.println(url1.getPath());//  /video/BV1Kb411W75N
//        public String getFile( ) 获取该URL的文件名
        System.out.println(url1.getFile());//  /video/BV1Kb411W75N?p=586
//        public String getQuery( ) 获取该URL的查询名
        System.out.println(url1.getQuery());//p=586
    }
}

URL编程：从网络上下载一张图片到本地

package java2;

import javax.net.ssl.HttpsURLConnection;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.URL;

public class URLTest1 {
    public static void main(String[] args) {
        HttpsURLConnection urlConnection = null;
        InputStream is = null;
        FileOutputStream fos = null;
        try {
            URL url = new URL("https://ss3.bdstatic.com/70cFv8Sh_Q1YnxGkpoWK1HF6hhy/it/u=2271518174,2892241511&fm=11&gp=0.jpg");

            urlConnection = (HttpsURLConnection) url.openConnection();

            urlConnection.connect();

            is = urlConnection.getInputStream();
            fos = new FileOutputStream("day09\\百度图片.jpg");
            byte[] buffer = new byte[1024];
            int len;
            while ((len = is.read(buffer)) != -1){
                fos.write(buffer,0,len);
            }
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            if (fos != null)
                try {
                    fos.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            if (is != null)
                try {
                    is.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            if (urlConnection != null)
                urlConnection.disconnect();
        }
    }
}