发送'+'字符utf-8，java App到servlet [重复]

Question

我正在尝试编写一个包含此类字符串的字节缓冲区 &field_Value=

kggsW9YizUuRpjB/RtppZImnC8SekMGAWGnCmw+wPMwn7fWJva0QbSK/Slt/DDsZ

通过 HttpURLConnection，但我收到 &field_Value=

kggsW9YizUuRpjB/RtppZImnC8SekMGAWGnCmw wPMwn7fWJva0QbSK/Slt/DDsZ

所以“+”是唯一不发送的字符。它发生在我所有包含“+”的字符串中。

您能告诉我如何对字符串进行编码或我做错了什么吗？

这是我的代码：

发件人：

url = new URL(url_globalApp);
        connection = (HttpURLConnection)url.openConnection();
        connection.setRequestMethod("POST");
        connection.setRequestProperty("Content-Type","application/x-www-form-urlencoded");

        connection.setRequestProperty("Content-Language", "en-US");  
        connection.setRequestProperty("Accept-Charset", "UTF-8"); 
        connection.setUseCaches (false);
        connection.setDoInput(true);
        connection.setDoOutput(true);

        //Send request
        DataOutputStream wr = new DataOutputStream (
                connection.getOutputStream ());
        //**************** first try ************//
        wr.write(pairs_1.getBytes("UTF-8"), 0, pairs_1.length());

        //**************** second try ************//
            //wr.writeBytes(new String(pairs_1.getBytes(),"UTF-8"));

        //**************** third try ************//
            //wr.writeUTF(pairs_1);
            wr.flush ();
            wr.close ();

小服务程序：

protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
    request.setCharacterEncoding("UTF-8");
    Map <String,String[]> parameters = request.getParameterMap();
    System.out.println(parameters.get("field_value_1")[0]);

Answer 1

查询参数的值必须经过 URL 编码。

网址编码

kggsW9YizUuRpjB/RtppZImnC8SekMGAWGnCmw+wPMwn7fWJva0QbSK/Slt/DDsZ

是

kggsW9YizUuRpjB%2FRtppZImnC8SekMGAWGnCmw%2BwPMwn7fWJva0QbSK%2FSlt%2FDDsZ

注意/ 是如何编码为%2F，而+ 是如何编码为%2B。

你可以通过调用来做到这一点

java.net.URLEncoder.encode("kggsW9YizUuRpjB/RtppZImnC8SekMGAWGnCmw+wPMwn7fWJva0QbSK/Slt/DDsZ", "UTF-8")