HTTP POST Anfrage mit JSON String in JAVA

Question

Ich muss eine http Post Anfrage mit einem JSON String, den ich bereits generiert habe, machen. Ich habe versucht, verschiedene zwei verschiedene Methoden:

1.HttpURLConnection 
2.HttpClient 

aber ich habe das gleiche „unerwünschte“ resultieren aus beiden. Mein Code bisher mit HttpURLConnection ist:

public static void SaveWorkflow() throws IOException { 
    URL url = null; 
    url = new URL(myURLgoeshere); 
    HttpURLConnection urlConn = null; 
    urlConn = (HttpURLConnection) url.openConnection(); 
    urlConn.setDoInput (true); 
    urlConn.setDoOutput (true); 
    urlConn.setRequestMethod("POST"); 
    urlConn.setRequestProperty("Content-Type", "application/json"); 
    urlConn.connect(); 

    DataOutputStream output = null; 
    DataInputStream input = null; 
    output = new DataOutputStream(urlConn.getOutputStream()); 

       /*Construct the POST data.*/ 
    String content = generatedJSONString; 

    /* Send the request data.*/ 
    output.writeBytes(content); 
    output.flush(); 
    output.close(); 

    /* Get response data.*/ 
    String response = null; 
    input = new DataInputStream (urlConn.getInputStream()); 
    while (null != ((response = input.readLine()))) { 
     System.out.println(response); 
     input.close(); 
    } 
} 

Mein Code bisher mit Httpclient ist:

public static void SaveWorkflow() { 
    try { 

     HttpClient httpClient = new DefaultHttpClient(); 
     HttpPost postRequest = new HttpPost(myUrlgoeshere); 
     StringEntity input = new StringEntity(generatedJSONString); 
     input.setContentType("application/json;charset=UTF-8"); 
     postRequest.setEntity(input); 
     input.setContentEncoding(new BasicHeader(HTTP.CONTENT_TYPE,"application/json;charset=UTF-8")); 
     postRequest.setHeader("Accept", "application/json"); 
     postRequest.setEntity(input); 

     HttpResponse response = httpClient.execute(postRequest); 

     BufferedReader br = new BufferedReader(
         new InputStreamReader((response.getEntity().getContent()))); 

     String output; 

     while ((output = br.readLine()) != null) { 
      System.out.println(output); 
     } 

     httpClient.getConnectionManager().shutdown(); 

    } catch (MalformedURLException e) { 

     e.printStackTrace(); 

    } catch (IOException e) { 

     e.printStackTrace(); 

    } 
} 

Wo JsonString erzeugt wird, wie folgt aus:

{"description":"prova_Process","modelgroup":"","modified":"false"} 

Die Antwort bekomme ich ist:

{"response":false,"message":"Error in saving the model. A JSONObject text must begin with '{' at 1 [character 2 line 1]","ids":[]} 

Irgendeine Idee bitte?

Answer 1

Schließlich schaffte ich die Lösung für mein Problem zu finden ...

public static void SaveWorkFlow() throws IOException 
    { 
     CloseableHttpClient httpClient = HttpClients.createDefault(); 
     HttpPost post = new HttpPost(myURLgoesHERE); 
     List<NameValuePair> params = new ArrayList<>(); 
     params.add(new BasicNameValuePair("task", "savemodel")); 
     params.add(new BasicNameValuePair("code", generatedJSONString)); 
     CloseableHttpResponse response = null; 
     Scanner in = null; 
     try 
     { 
      post.setEntity(new UrlEncodedFormEntity(params)); 
      response = httpClient.execute(post); 
      // System.out.println(response.getStatusLine()); 
      HttpEntity entity = response.getEntity(); 
      in = new Scanner(entity.getContent()); 
      while (in.hasNext()) 
      { 
       System.out.println(in.next()); 

      } 
      EntityUtils.consume(entity); 
     } finally 
     { 
      in.close(); 
      response.close(); 
     } 
    } 

Answer 2

Eine andere Möglichkeit, dies zu erreichen, wie unten dargestellt ist:

public static void makePostJsonRequest(String jsonString) 
{ 
    HttpClient httpClient = new DefaultHttpClient(); 
    try { 
     HttpPost postRequest = new HttpPost("Ur_URL"); 
     postRequest.setHeader("Content-type", "application/json"); 
     StringEntity entity = new StringEntity(jsonString); 

     postRequest.setEntity(entity); 

     long startTime = System.currentTimeMillis(); 
     HttpResponse response = httpClient.execute(postRequest); 
     long elapsedTime = System.currentTimeMillis() - startTime; 
     //System.out.println("Time taken : "+elapsedTime+"ms"); 

     InputStream is = response.getEntity().getContent(); 
     Reader reader = new InputStreamReader(is); 
     BufferedReader bufferedReader = new BufferedReader(reader); 
     StringBuilder builder = new StringBuilder(); 
     while (true) { 
      try { 
       String line = bufferedReader.readLine(); 
       if (line != null) { 
        builder.append(line); 
       } else { 
        break; 
       } 
      } catch (Exception e) { 
       e.printStackTrace(); 
      } 
     } 
     //System.out.println(builder.toString()); 
     //System.out.println("****************"); 
    } catch (Exception ex) { 
     ex.printStackTrace(); 
    } 
}