java.io.IOException：服务器返回的HTTP响应代码：URL的400

Question

I want to download CSV file from URL. For that i am using HTTP URL Connection. While running the code, i am getting below error:

 java.io.IOException: Server returned HTTP response code: 400 for URL: https://twc.centercode.com/files/report.aspx/PLS Tracker.csv?t=GetElementFullCSV&r=0668821a036046ef9fde587c609e2c8f&e=47437d179bce477f936dcfdc470bf378
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(Unknown Source)

Please find below code:

        final int BUFFER_SIZE = 4096;  
        String fileURL = "https://twc.centercode.com/files/report.aspx/PLS Tracker.csv?t=GetElementFullCSV&r=0668821a036046ef9fde587c609e2c8f&e=47437d179bce477f936dcfdc470bf378";  
        String fileName = "EFTReportTest.csv";  
        String saveDir = "D:\\";  
        URL url = new URL(fileURL);  
        HttpURLConnection httpConn = (HttpURLConnection) url.openConnection();  
        int responseCode = httpConn.getResponseCode();

        if (responseCode == HttpURLConnection.HTTP_OK) {
        InputStream inputStream = httpConn.getInputStream();
        String saveFilePath = saveDir + "" + fileName;
        FileOutputStream outputStream = new FileOutputStream(saveFilePath);
        int bytesRead = -1;
        byte[] buffer = new byte[BUFFER_SIZE];
        while ((bytesRead = inputStream.read(buffer)) != -1) {
            outputStream.write(buffer, 0, bytesRead);
        }

        outputStream.close();
        inputStream.close();

        System.out.println("File downloaded");
      }
         else{
            System.out.println("No file to download. Server replied HTTP code: " + responseCode);
        }
        httpConn.disconnect();

Please let me know what i am doing wrong here.

Answer 1

HTML code 400 is "Bad request" (See here)

Basically, what you're sending to the server is invalid or not formatted in the way it's expecting. This could be due to user agent, security, etc. I don't know enough about the website in question to tell you how they expect it, you might want to check the site for any information about an API or likewise that you could use.