URL下载网络资源

什么是URL？
- 统一资源定位符，定位互联网上的某个资源

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

public class UrlDemp {
    public static void main(String[] args) throws Exception{
        //1.下载地址
        URL url = new URL("资源的地址");
        //2.连接到这个资源
        HttpURLConnection urlConnection = (HttpURLConnection) url.openConnection();
        InputStream inputStream = urlConnection.getInputStream();
        FileOutputStream fos = new FileOutputStream("music");
        byte[] buffer = new byte[1024];
        int len;
        while(( len =inputStream.read(buffer)) != -1){
            //写出这个数据
            fos.write(buffer,0,len);
        }
        //关闭资源
        fos.close();
        inputStream.close();
        urlConnection.disconnect();

    }

}