Develop Reference

android app crashing on start-up

I am new to android . I am troubling during 2 weeks with an simple android apps which I am developing. In my app , I am trying to fetch a simple text from php . But every time when I try to launch the app it crashed. My code is below
package com.example.test;
import java.io.IOException;
import org.apache.http.HttpResponse;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.util.EntityUtils;
import android.os.Bundle;
import android.app.Activity;
import android.view.Menu;
import android.widget.TextView;
public class MainActivity extends Activity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
HttpClient httpclient = new DefaultHttpClient();
HttpPost httppost = new HttpPost("http://logger.net46.net/android/hello.php");
try {
HttpResponse response = httpclient.execute(httppost);
final String str = EntityUtils.toString(response.getEntity());
TextView tv = (TextView) findViewById(R.id.textView1);
tv.setText(str);
}
catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
}
I can not finding out where is my problem. Please someone help me.

You are probably getting NetWorkOnMainThreadException. You should use a Thread or AsyncTask for making the http post request and update ui on the ui thread.
Example:
public class MainActivity extends Activity {
TextView tv;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
tv = (TextView) findViewById(R.id.textView1);
new TheTask().execute();
}
class TheTask extends AsyncTask<Void,Void,String>
{
#Override
protected String doInBackground(Void... params) {
String str = null;
try
{
HttpClient httpclient = new DefaultHttpClient();
HttpPost httppost = new HttpPost("http://logger.net46.net/android/hello.php");
HttpResponse response = httpclient.execute(httppost);
str = EntityUtils.toString(response.getEntity());
}
catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return str;
}
#Override
protected void onPostExecute(String result) {
// TODO Auto-generated method stub
super.onPostExecute(result);
tv.setText(result);
}
}
}
Snap

getByName in POST HTTP request

I'm trying to get the ip address of a host name then use it in the POST Http request URL i'm sending to
everything was working find and after adding the getByName line it suddenly crashed
So please help me and tell me exactly what could be the problem ?
Thank you in advance
Logindb.java
package com.example.loginad;
import java.net.InetAddress;
import java.util.ArrayList;
import java.util.List;
import org.apache.http.HttpResponse;
import org.apache.http.NameValuePair;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.HttpClient;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.message.BasicNameValuePair;
import android.os.AsyncTask;
import android.os.Bundle;
import android.os.Handler;
import android.app.Activity;
import android.content.Intent;
import android.view.Menu;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
import android.widget.Toast;
public class Logindb extends Activity {
Button login;
EditText u,p;
TextView res;
String result;
String x="mobile";
String host="";
Thread mBack;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.logindb);
login=(Button)findViewById(R.id.login);
u=(EditText)findViewById(R.id.u);
p=(EditText)findViewById(R.id.p);
res=(TextView)findViewById(R.id.res);
mBack = new Thread(new Runnable()
{
public void run()
{
try
{
InetAddress address=null;
address = InetAddress.getByName("Osama-PC");
host=address.getHostAddress();
}
catch(Exception e)
{
e.printStackTrace();
}
}
});
login.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
new MyAsyncTask().execute(u.getText().toString(),p.getText().toString());
}
});
}
private class MyAsyncTask extends AsyncTask<String, Integer, Boolean>{
#Override
protected Boolean doInBackground(String... params) {
// TODO Auto-generated method stub
boolean success = postData(params[0],params[1]);
return success;
}
protected void onPostExecute(Boolean localres){
if (localres){
res.setText("A Correct Username and Password");
}else{
res.setText("Incorrect Username or Password");
}
Toast.makeText(getApplicationContext(), "command sent", Toast.LENGTH_LONG).show();
}
protected void onProgressUpdate(Integer... progress){
//pb.setProgress(progress[0]);
//Toast.makeText(getApplicationContext(), "Done", Toast.LENGTH_LONG).show();
}
public Boolean postData(String a,String b) {
ArrayList<NameValuePair> postParameters = new ArrayList<NameValuePair>();
postParameters.add(new BasicNameValuePair("username", a));
postParameters.add(new BasicNameValuePair("password", b));
postParameters.add(new BasicNameValuePair("mobileid",x));
// String valid = "1";
String response = null;
try {
// Toast.makeText(getApplicationContext(), host.toString(), Toast.LENGTH_LONG).show();
response = CustomHttpClient.executeHttpPost("http://"+host+"/new/check.php",postParameters);
//now in result you will have the response from php file either 0 or 1.
result = response.toString();
// res = res.trim();
result = result.replaceAll("\\s+", "");
// error.setText(res);
} catch (Exception e) {
//res.setText(e.toString());
}
return "1".equals(result);
}
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.logindb, menu);
return true;
}
}

Line 130:
Change return null; to return false;
Or something smarter would be to change
if(result!=null)
{
return result.equals("1");
}
else
{
return null;
}
to
return "1".equals(result);

HttpResponse.execute() throws exception

I'm trying to develop a simple app that gets data from web service and displays it
It throws exception exactly when he calls response.execute(client)
package com.example.webbasedapp;
import java.io.BufferedReader;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.URI;
import org.apache.http.HttpResponse;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.DefaultHttpClient;
import android.util.Log;
public class GETMethods {
public String getInternetData() throws Exception{
BufferedReader in=null;
String Data=null;
try{
HttpClient client=new DefaultHttpClient();
URI web=new URI("http://www.mybringback.com/");
HttpGet request = new HttpGet();
request.setURI(web);
HttpResponse reponse=client.execute(request);
Log.v("response code", reponse.getStatusLine()
.getStatusCode() + "");
InputStream inp=reponse.getEntity().getContent();
in=new BufferedReader(new InputStreamReader(inp));
StringBuffer buf=new StringBuffer();
String l="";
String nl=System.getProperty("line.separator");
while((l=in.readLine())!=null){
buf.append(l+nl);
}
in.close();
Data=buf.toString();
return Data;
}finally{
if(in!=null){
try{
in.close();
return Data;
}catch (Exception e){
Log.d("error",e.toString());
}
}
}
}
}
And this is my main activity
package com.example.webbasedapp;
import android.app.Activity;
import android.os.Bundle;
import android.view.Menu;
import android.widget.TextView;
import android.widget.Toast;
public class Home extends Activity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_home);
TextView test = (TextView) findViewById(R.id.data);
GETMethods data = new GETMethods();
String d = null;
try {
d = data.getInternetData();
// test.setText(d);
} catch (Exception e) {
// TODO Auto-generated catch block
d = "bla";
Toast.makeText(this, e.getMessage(), Toast.LENGTH_SHORT).show();
// Log.d("testW",e.getMessage());
}
test.setText(d);
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.home, menu);
return true;
}
}

You are attempting to access the network on the UI thread which is not allowed due to potential hangup issues. Look into AysncTask and implement GETMethods as one of them. It will look something like this:
public class GETMethods extends AsyncTask<String, Void, String>{
protected void doInBackground(String... params){
YourNetworkCode
}
}

wrong in json parsing

please help me to find the error in this code.
I want to get some data from remote server (php & mysql) by json then parsing it
the problem is that result returns null but it is supposed to return name at this link :
http://codeincloud.tk/json_android_example.php
package com.shadatv.shada;
import java.io.IOException;
import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.util.EntityUtils;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import android.app.Activity;
import android.os.AsyncTask;
import android.os.Bundle;
import android.widget.TextView;
import android.widget.Toast;
public class canticlesActivity extends Activity {
TextView httpStuff;
HttpClient client;
JSONObject json;
final static String URL = "http://codeincloud.tk/json_android_example.php";
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.canticles);
httpStuff = (TextView) findViewById(R.id.textView1);
client = new DefaultHttpClient();
new Read().execute("name");
}
public JSONObject lastTweet() throws ClientProtocolException, IOException, JSONException {
StringBuilder url = new StringBuilder(URL);
HttpGet get = new HttpGet(url.toString());
HttpResponse r = client.execute(get);
int status = r.getStatusLine().getStatusCode();
if (status == 200) {
HttpEntity e = r.getEntity();
String data = EntityUtils.toString(e);
JSONArray timeline = new JSONArray(data);
JSONObject last = timeline.getJSONObject(0);
return last;
} else {
Toast.makeText(getBaseContext(), "error", Toast.LENGTH_SHORT);
return null;
}
}
public class Read extends AsyncTask<String, Integer, String>{
#Override
protected String doInBackground(String... params) {
// TODO Auto-generated method stub
try {
json = lastTweet();
return json.getString(params[0]);
} catch (ClientProtocolException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (JSONException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return null;
}
#Override
protected void onPostExecute(String result) {
// TODO Auto-generated method stub
Toast.makeText(getBaseContext(), "ahmed .. " + result, Toast.LENGTH_LONG).show();
httpStuff.setText(result);
}
}
}

parse current json String as :
HttpEntity e = r.getEntity();
String data = EntityUtils.toString(e);
// convert data to json object
JSONObject last =new JSONObject(data);
because current webservice retuning an JSONObject only instead of JSONArray

Your URL provides the following data:
{"name":"Froyo","version":"Android 2.2"}
The chunk of code parsing the JSON is the following:
JSONArray timeline = new JSONArray(data);
JSONObject last = timeline.getJSONObject(0);
That makes the assumption that the JSON document you're reading is an Array instead of an Object. (Either is valid JSON, but the document you're fetching is quite clearly an Object). Web service calls may not always be returning one or the other so you'll have to take care that you're parsing against the correct type.

copy and past now it is working.
i changed JSONObject last =new JSONObject(data);
because http://codeincloud.tk/json_android_example.php retuning an JSONObject
package com.shadatv.shada;
import java.io.IOException;
import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.util.EntityUtils;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import android.app.Activity;
import android.os.AsyncTask;
import android.os.Bundle;
import android.widget.TextView;
import android.widget.Toast;
public class canticlesActivity extends Activity {
TextView httpStuff;
HttpClient client;
JSONObject json;
final static String URL = "http://codeincloud.tk/json_android_example.php";
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.canticles);
httpStuff = (TextView) findViewById(R.id.textView1);
client = new DefaultHttpClient();
new Read().execute("name");
}
public JSONObject lastTweet() throws ClientProtocolException, IOException, JSONException {
StringBuilder url = new StringBuilder(URL);
HttpGet get = new HttpGet(url.toString());
HttpResponse r = client.execute(get);
int status = r.getStatusLine().getStatusCode();
if (status == 200) {
HttpEntity e = r.getEntity();
String data = EntityUtils.toString(e);
JSONObject last = new JSONObject(data);
return last;
} else {
Toast.makeText(getBaseContext(), "error", Toast.LENGTH_SHORT);
return null;
}
}
public class Read extends AsyncTask<String, Integer, String>{
#Override
protected String doInBackground(String... params) {
// TODO Auto-generated method stub
try {
json = lastTweet();
return json.getString(params[0]);
} catch (ClientProtocolException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (JSONException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return null;
}
#Override
protected void onPostExecute(String result) {
// TODO Auto-generated method stub
Toast.makeText(getBaseContext(), "ahmed .. " + result, Toast.LENGTH_LONG).show();
httpStuff.setText(result);
}
}
}

Better to use GSON Library which is much simpler then doing manual parsing.
Link for the library is : http://code.google.com/p/google-gson/

Not getting the output

I'm trying to get the data from the database for which I created a php file. It returns the name as the reply to the call. the website it Ensignweb
the program code goes like this.
The php file is like this
<?php
$connect = mysql_connect("localhost","databasename","password");
mysql_select_db("ews_app");
$query = mysql_query("select name from comment");
if(!empty($query)){
if(mysql_num_rows($query)>0){
WHILE($row=mysql_fetch_array($query)):
$comment = array();
$comment["name"] = $row['name'];
echo "$comment<br>";
echo json_encode($comment);
echo "<br>";
endwhile;
}
}
?>
The java code goes like this:
import java.io.IOException;
import java.io.Reader;
import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.util.EntityUtils;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import android.app.Activity;
import android.os.AsyncTask;
import android.os.Bundle;
import android.view.Menu;
import android.widget.TextView;
import android.widget.Toast;
public class MainActivity extends Activity {
TextView httpStuff;
HttpClient client;
JSONObject json;
final static String URL = "http://www.ensignweb.com/sandbox/app/comment11.php";
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
httpStuff = (TextView) findViewById(R.id.data);
client = new DefaultHttpClient();
new Read().execute("name");
}
public JSONObject lastTweet() throws ClientProtocolException,IOException,JSONException{
StringBuilder url = new StringBuilder(URL);
HttpGet get = new HttpGet(url.toString());
HttpResponse r = client.execute(get);
int status = r.getStatusLine().getStatusCode();//return 200 if execution is success
if(status==200){
HttpEntity e = r.getEntity();
String data = EntityUtils.toString(e);
JSONArray timeline = new JSONArray(data);
JSONObject last = timeline.getJSONObject(0);
return last;
}else{
Toast.makeText(MainActivity.this, "error", Toast.LENGTH_LONG);
return null;
}
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
getMenuInflater().inflate(R.menu.activity_main, menu);
return true;
}
public class Read extends AsyncTask<String, Integer, String>{
#Override
protected String doInBackground(String... params) {
// TODO Auto-generated method stub
try {
json = lastTweet();
return json.toString();
} catch (ClientProtocolException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (JSONException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return null;
}
#Override
protected void onPostExecute(String result) {
// TODO Auto-generated method stub
httpStuff.setText(result);
}
}
}
But It is not displaying the json reply. I'm stucked in it from past few days.
Please help me out of it. I really need it.