从url中下载资源(目前测试只有照片,文件类的没有进行测试)

首先:是工具类:

public class DownLoadUtils {

    /**
     * 从网络Url中下载文件
     *
     * @param urlStr  url路径
     * @param fileName   文件的名称
     * @param savePath    保存的路径
     * @throws IOException
     */
    public static void downLoadFromUrl(String urlStr, String fileName, String savePath) throws IOException {
        URL url = new URL(urlStr);
        HttpURLConnection conn = (HttpURLConnection) url.openConnection();
        //设置超时间为3秒
        conn.setConnectTimeout(3 * 1000);
        //防止屏蔽程序抓取而返回403错误
        conn.setRequestProperty("User-Agent", "Mozilla/4.0 (compatible; MSIE 5.0; Windows NT; DigExt)");

        //得到输入流
        InputStream inputStream = conn.getInputStream();
        //获取自己数组
        byte[] getData = readInputStream(inputStream);

        //文件保存位置
        File saveDir = new File(savePath);
        if (!saveDir.exists()) {
            saveDir.mkdir();
        }
        File file = new File(saveDir + File.separator + fileName);
        FileOutputStream fos = new FileOutputStream(file);
        fos.write(getData);
        if (fos != null) {
            fos.close();
        }
        if (inputStream != null) {
            inputStream.close();
        }
        System.out.println("info:" + url + " download success");
    }

    /**
     * 从输入流中获取字节数组
     *
     * @param inputStream
     * @return
     * @throws IOException
     */
    public static byte[] readInputStream(InputStream inputStream) throws IOException {
        byte[] buffer = new byte[1024];
        int len = 0;
        ByteArrayOutputStream bos = new ByteArrayOutputStream();
        while ((len = inputStream.read(buffer)) != -1) {
            bos.write(buffer, 0, len);
        }
        bos.close();
        return bos.toByteArray();
    }

}

测试类为:

@RunWith(SpringRunner.class)
@SpringBootTest
public class DownLoadUrl {

    @Test
    public void downLoadUrlTest() {
        //这一部分代码时候将url存储在文本中.然后读取文本
//        File file=new File("C:\\Users\\yejianan\\Desktop\\chuanda.txt");
//        BufferedReader reader=null;
//        String temp=null;
//        int line=1;
//        PrintWriter pw = null;
//        try{
//            reader=new BufferedReader(new FileReader(file));
//            while((temp=reader.readLine())!=null){
//                //获取特定的url的字符串
//                //int index=temp.indexOf('h');
//                //String res=temp.substring(index);//res表示url
//                System.out.println("line"+line+":"+temp);
//                try{
//                    downLoadFromUrl(temp,line+".jpg","C:\\Users\\yejianan\\Desktop\\chuanda");
//                }catch (Exception e) {
//                    // TODO: handle exception
//                    System.out.println(e.toString());
//                }
//                line++;
//            }
//        }
//        catch(Exception e){
//            e.printStackTrace();
//        }
//        finally{
//            if(reader!=null){
//                try{
//                    reader.close();
//                }
//                catch(Exception e){
//                    e.printStackTrace();
//                }
//            }
//        }
//    }
        String urlstr = "https://timgsa.baidu.com/timg?image&quality=80&size=b9999_10000&sec=1569842044752&di=e4815e7d6d558d62a21acd4396d7eba6&imgtype=0&src=http%3A%2F%2Fphoto16.zastatic.com%2Fimages%2Fphoto%2F9085%2F36339245%2F1315565987101.jpg";

        try {
            downLoadFromUrl(urlstr, "3.jpg", "D:\\data\\img");
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

以上这个照片可以直接从网络中下载