如何使用表单URL编码的auth basic发送发布请求

Question

在Java中，如何使用 application / x-www-form-urlencoded 和 Authorization Basic 发送请求。我总是得到响应服务器返回的HTTP响应代码：URL为400 Postman Headers image

Postman body image

我尝试了以下代码：

try{
            url=new URL("https://secure.URL target");
            conn=(HttpURLConnection)url.openConnection();
            conn.setRequestMethod("POST");
            conn.setDoOutput(true);
            conn.setRequestProperty("cache-control", "no-cache");
            conn.setRequestProperty("Authorization", "Basic" + authEncode);
            conn.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");

            String data=URLEncoder.encode("username","UTF-8")
                    +"="+ URLEncoder.encode(user, "UTF-8");
            data += "&" + URLEncoder.encode("password", "UTF-8") +"="
                    + URLEncoder.encode(pass, "UTF-8");
            data += "&" + URLEncoder.encode("grant_type", "UTF-8") +"="
                    + URLEncoder.encode(grant,"UTF-8");

            conn.connect();

            OutputStreamWriter wr=new OutputStreamWriter(conn.getOutputStream());
            wr.write(data);
            wr.flush();

            is=conn.getInputStream();
            BufferedReader br=new BufferedReader(new InputStreamReader(is,"UTF-8"),8);
            result=br.readLine();
            System.out.println(result);


        }catch(IOException e){
            e.printStackTrace();
        }finally{
            if(conn != null){
                conn.disconnect();
            }
        }
    }