Java将远程服务器上的文件经过本地服务器中转后输出至前端

浅浅的花香味﹌ 2022-06-16 02:42 355阅读 0赞

import java.io.IOException;
    import java.io.InputStream;
    import java.io.OutputStream;
    import java.net.HttpURLConnection;
    import java.net.URL;
    import javax.servlet.http.HttpServletResponse;

URL imgUrl = null;
    InputStream is = null;
    OutputStream outStream = null;
    HttpURLConnection httpUrl = null;
    try{
        imgUrl = new URL(filename);
        httpUrl = (HttpURLConnection) imgUrl.openConnection();
        httpUrl.connect();
        httpUrl.getInputStream();
        is = httpUrl.getInputStream();
    
        outStream = response.getOutputStream();
        response.setContentType("image/jpeg");
        //创建一个Buffer字符串
        byte[] buffer = new byte[1024];
        //每次读取的字符串长度，如果为-1，代表全部读取完毕
        int len = 0;
        //使用一个输入流从buffer里把数据读取出来
        while( (len=is.read(buffer)) != -1 ){
            //用输出流往buffer里写入数据，中间参数代表从哪个位置开始读，len代表读取的长度
            outStream.write(buffer, 0, len);
        }
    }catch (Exception e) {
        e.printStackTrace();
    }
    finally{
        if(is != null)
        {
            try {
                is.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        if(outStream != null) {
            try {
                outStream.flush();
                outStream.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        if(httpUrl != null) {
            httpUrl.disconnect();
        }
    }