Android HTTP-POST

Question

I am new to HTTP-POST. I have a site "http://otu-git.dyndns.ws/pvm_srv/echo_json.html" where I can put

    { 
        "USR":
        {   
            "fun":"validarUsuario",
            "txtUser":"123",
            "md5Passwd":"123"
        }
    }

and the response I get is

    {"success":"true","nombre":"test"}

I want to know how I can do this in my Android app. Can someone guide me ?

    DefaultHttpClient httpClient=new DefaultHttpClient();

    HttpPost httpPost =new HttpPost("http://otu-git.dyndns.ws/pvm_srv/echo_json.html");
    HttpResponse response;

    StringEntity se;

    JSONObject json =new JSONObject();
    try {
        json.put("fun", "validarUsuario");
        json.put("txtUser", "123");
        json.put("md5Passwd", "123");

        se=new StringEntity(json.toString());

        httpPost.setEntity(se);

        response=httpClient.execute(httpPost);

        Log.i(tag, "JSON "+response.toString());

    } catch (JSONException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    } catch (UnsupportedEncodingException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    } catch (ClientProtocolException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    } catch (IOException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }

This is my code. Can you please check if it is correct ? I have added the Internet permission for the app.

@Ngathet I am getting the following error

11-05 14:02:38.489: E/AndroidRuntime(8844): FATAL EXCEPTION: main
11-05 14:02:38.489: E/AndroidRuntime(8844): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.dhiraj.mpos/com.dhiraj.mpos.LoginActivity}: android.os.NetworkOnMainThreadException
11-05 14:02:38.489: E/AndroidRuntime(8844):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2049)
11-05 14:02:38.489: E/AndroidRuntime(8844):     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2083)
11-05 14:02:38.489: E/AndroidRuntime(8844):     at android.app.ActivityThread.access$600(ActivityThread.java:134)
11-05 14:02:38.489: E/AndroidRuntime(8844):     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1233)
11-05 14:02:38.489: E/AndroidRuntime(8844):     at android.os.Handler.dispatchMessage(Handler.java:99)
11-05 14:02:38.489: E/AndroidRuntime(8844):     at android.os.Looper.loop(Looper.java:137)
11-05 14:02:38.489: E/AndroidRuntime(8844):     at android.app.ActivityThread.main(ActivityThread.java:4697)
11-05 14:02:38.489: E/AndroidRuntime(8844):     at java.lang.reflect.Method.invokeNative(Native Method)
11-05 14:02:38.489: E/AndroidRuntime(8844):     at java.lang.reflect.Method.invoke(Method.java:511)
11-05 14:02:38.489: E/AndroidRuntime(8844):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:787)
11-05 14:02:38.489: E/AndroidRuntime(8844):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:554)
11-05 14:02:38.489: E/AndroidRuntime(8844):     at dalvik.system.NativeStart.main(Native Method)
11-05 14:02:38.489: E/AndroidRuntime(8844): Caused by: android.os.NetworkOnMainThreadException
11-05 14:02:38.489: E/AndroidRuntime(8844):     at android.os.StrictMode$AndroidBlockGuardPolicy.onNetwork(StrictMode.java:1119)
11-05 14:02:38.489: E/AndroidRuntime(8844):     at java.net.InetAddress.lookupHostByName(InetAddress.java:441)
11-05 14:02:38.489: E/AndroidRuntime(8844):     at java.net.InetAddress.getAllByNameImpl(InetAddress.java:243)
11-05 14:02:38.489: E/AndroidRuntime(8844):     at java.net.InetAddress.getAllByName(InetAddress.java:220)
11-05 14:02:38.489: E/AndroidRuntime(8844):     at org.apache.http.impl.conn.DefaultClientConnectionOperator.openConnection(DefaultClientConnectionOperator.java:137)
11-05 14:02:38.489: E/AndroidRuntime(8844):     at org.apache.http.impl.conn.AbstractPoolEntry.open(AbstractPoolEntry.java:164)
11-05 14:02:38.489: E/AndroidRuntime(8844):     at org.apache.http.impl.conn.AbstractPooledConnAdapter.open(AbstractPooledConnAdapter.java:119)
11-05 14:02:38.489: E/AndroidRuntime(8844):     at org.apache.http.impl.client.DefaultRequestDirector.execute(DefaultRequestDirector.java:360)
11-05 14:02:38.489: E/AndroidRuntime(8844):     at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:555)
11-05 14:02:38.489: E/AndroidRuntime(8844):     at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:487)
11-05 14:02:38.489: E/AndroidRuntime(8844):     at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:465)
11-05 14:02:38.489: E/AndroidRuntime(8844):     at com.dhiraj.mpos.LoginActivity.insert(LoginActivity.java:88)
11-05 14:02:38.489: E/AndroidRuntime(8844):     at com.dhiraj.mpos.LoginActivity.onCreate(LoginActivity.java:45)
11-05 14:02:38.489: E/AndroidRuntime(8844):     at android.app.Activity.performCreate(Activity.java:4539)
11-05 14:02:38.489: E/AndroidRuntime(8844):     at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1049)
11-05 14:02:38.489: E/AndroidRuntime(8844):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2013)

`

Answer 1

You need to create JSONObject first to request eg.

JSONObject obj = new JSONObject();

obj.put("fun", "validarUsuario");
obj.put( "txtUser",123);
obj.put( "md5Passwd",123);

And Use the follwing Metod to Get response by passing the above obj to YourJsonObj

public JSONObject insert(JSONObject YourJsonObj)
    {
            HttpPost postRequest = new HttpPost(YourURLString);

            StringEntity entity = new StringEntity(YourJsonObj.toString());
            entity.setContentType("application/json");

            postRequest.setHeader("Content-Type", "application/json");
            postRequest.setHeader("Accept", "application/json");
            postRequest.setEntity(entity);

            HttpResponse response = client.execute(postRequest);
            int status = response.getStatusLine().getStatusCode();

            if (status == 200) {
                HttpEntity e = response.getEntity();
                String data = EntityUtils.toString(e);
                JSONObject obj = new JSONObject(data);
                return obj;
            } else {
                return null;
            }
    }

Answer 2

http://loopj.com/android-async-http/

Use this client for your purpose .Its one of the best library for httpclient