eine Feder-Controller mit POST in Android-Ergebnis in einem Null-Parameter aufrufen

Question

I-Daten von diesem POST method oder durch die first answer auf diese Frage bin Entsendung, die Daten an eine Feder Servlet Posting konfiguriert mit:

@RequestMapping(value = "/insert", method = RequestMethod.POST, consumes = { MediaType.APPLICATION_JSON_VALUE }) 
@ResponseStatus(HttpStatus.OK) 
public @ResponseBody String insert(String a) { 

Das Servlet -Methode wird aufgerufen, aber der Parameter 'a' ist null. Warum?

bearbeiten: Die wichtigste Methode und die AsyncTask:

main-Methode

ServerCaller serverCaller = new ServerCaller(); 
     try { 
      serverCaller.execute(new URL("http://192.168.56.1:8080/SpringHibernateExample/insert")); 
     } 

AsyncTask

package com.test.insert; 

import java.io.BufferedReader; 
import java.io.IOException; 
import java.io.InputStream; 
import java.io.InputStreamReader; 
import java.io.UnsupportedEncodingException; 
import java.net.URL; 
import java.net.URLEncoder; 
import java.util.List; 

import org.apache.http.HttpResponse; 
import org.apache.http.NameValuePair; 
import org.apache.http.client.HttpClient; 
import org.apache.http.client.methods.HttpPost; 
import org.apache.http.entity.StringEntity; 
import org.apache.http.impl.client.DefaultHttpClient; 
import org.json.JSONObject; 

import android.os.AsyncTask; 

public class ServerCaller extends AsyncTask<URL, Integer, Long> { 
    @Override 
    protected Long doInBackground(URL... params1) { 
     try {    
      POST(params1[0].toString()); 
     } 
     catch (Exception e) { 
      Log.realException(e); 
      throw new RuntimeException(e); 
     } 

     return 22l; 
    } 

    private String getQuery(List<NameValuePair> params) throws UnsupportedEncodingException { 
     StringBuilder result = new StringBuilder(); 
     boolean first = true; 

     for (NameValuePair pair : params) { 
      if (first) 
       first = false; 
      else 
       result.append("&"); 

      result.append(URLEncoder.encode(pair.getName(), "UTF-8")); 
      result.append("="); 
      result.append(URLEncoder.encode(pair.getValue(), "UTF-8")); 
     } 

     return result.toString(); 
    } 

    public static String POST(String url) { 
     InputStream inputStream = null; 
     String result = ""; 
     try { 

      // 1. create HttpClient 
      HttpClient httpclient = new DefaultHttpClient(); 

      // 2. make POST request to the given URL 
      HttpPost httpPost = new HttpPost(url); 

      String json = ""; 

      // 3. build jsonObject 
      JSONObject jsonObject = new JSONObject(); 
      jsonObject.accumulate("name", "a"); 
      jsonObject.accumulate("country", "b"); 
      jsonObject.accumulate("twitter", "c"); 

      // 4. convert JSONObject to JSON to String 
      json = jsonObject.toString(); 

      // ** Alternative way to convert Person object to JSON string usin Jackson Lib 
      // ObjectMapper mapper = new ObjectMapper(); 
      // json = mapper.writeValueAsString(person); 

      // 5. set json to StringEntity 
      StringEntity se = new StringEntity(json); 

      // 6. set httpPost Entity 
      httpPost.setEntity(se); 

      // 7. Set some headers to inform server about the type of the content 
      httpPost.setHeader("Accept", "application/json"); 
      httpPost.setHeader("Content-type", "application/json"); 

      // 8. Execute POST request to the given URL 
      HttpResponse httpResponse = httpclient.execute(httpPost); 

      // 9. receive response as inputStream 
      inputStream = httpResponse.getEntity().getContent(); 

      // 10. convert inputstream to string 
      if (inputStream != null) 
       result = convertInputStreamToString(inputStream); 
      else 
       result = "Did not work!"; 

     } 
     catch (Exception e) { 
      Log.e(e.getLocalizedMessage()); 
     } 

     // 11. return result 
     return result; 
    } 

    private static String convertInputStreamToString(InputStream inputStream) throws IOException { 
     BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(inputStream)); 
     String line = ""; 
     String result = ""; 
     while ((line = bufferedReader.readLine()) != null) 
      result += line; 

     inputStream.close(); 
     return result; 

    } 
} 

Answer 1

Ich glaube, Sie ein Json-Objekt übergeben, aber sie tun nicht im Frühling abbilden. Im Frühjahr müssen Sie eine Klasse, dh Custom mit dem Namen Eigenschaften erstellen, Land, twitter

public class CustomClass{ 
    private String name; 
    private String country; 
    private String twitter; 

    //getters and setters should be here 
} 

dann der Code im Frühjahr wie diese

@RequestMapping(value = "/insert", method = RequestMethod.POST, consumes = { MediaType.APPLICATION_JSON_VALUE }) 
@ResponseStatus(HttpStatus.OK) 
public @ResponseBody String insert(@RequestBody CustomClass cs) { 
    cs.getName(); 

Lassen Sie mich, wenn dieser