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Trying to import data from my university parking api in Android

I am trying to acquire live parking information from an API which is provided by my university. I am able to get data when I run the java code. But when I put this code in the android studio, it is giving me an exception.
This is my manifest file:
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.parth.p4">
<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
<uses-permission android:name="android.permission.ACCESS_WIFI_STATE" />
<application
android:allowBackup="true"
android:icon="#mipmap/ic_launcher"
android:label="#string/app_name"
android:roundIcon="#mipmap/ic_launcher_round"
android:supportsRtl="true"
android:theme="#style/AppTheme">
<activity android:name=".MainActivity">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<activity android:name=".Check"></activity>
</application>
</manifest>
This is my file where I am running the java code:
package com.example.parth.p4;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.widget.TextView;
import java.net.URL;
import javax.xml.parsers.DocumentBuilderFactory;
import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
public class Check extends AppCompatActivity {
public TextView t;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_check);
try {
chk();
}catch (Exception e)
{
t.setText("Error");
}
}
private static Document loadTestDocument(String url) throws Exception {
DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
factory.setNamespaceAware(true);
return factory.newDocumentBuilder().parse(new URL(url).openStream());
}
public void chk() throws Exception {
t = (TextView)findViewById(R.id.textView2);
String carPoolSpacesAvailable;
Document doc = loadTestDocument("https://api.uow.edu.au/parking/data/?format=xml");
NodeList nodes1 = doc.getElementsByTagName("parks");
carPoolSpacesAvailable = nodes1.item(6).getFirstChild().getNodeValue();
t.setText(carPoolSpacesAvailable);
}
}
This is my xml file where I am trying to show the data in a textview.
<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".Check">
<TextView
android:id="#+id/textView2"
android:layout_width="44dp"
android:layout_height="23dp"
tools:layout_editor_absoluteX="331dp"
tools:layout_editor_absoluteY="16dp" />
</android.support.constraint.ConstraintLayout>
The output which I am getting is the error message which I have put in the catch block in the oncreate() method.Please help.

Make sure you are not making a network call on the MAIN UI Thread.
Try to call the chk() from background thread.
TextView t;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
t = (TextView)findViewById(R.id.textView2);
new DownloadFilesTask().execute();
}
// doInBackground is called from the background thread while the onPostExecute is called on the Main Thread.
private class DownloadFilesTask extends AsyncTask<Void, Void, String> {
String carPoolSpacesAvailable = null;
#Override
protected String doInBackground(Void... voids) {
DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
factory.setNamespaceAware(true);
try {
Document
doc = factory.newDocumentBuilder().parse(new URL("https://api.uow.edu.au/parking/data/?format=xml").openStream());
NodeList nodes1 = doc.getElementsByTagName("parks");
carPoolSpacesAvailable = nodes1.item(6).getFirstChild().getNodeValue();
} catch (SAXException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} catch (ParserConfigurationException e) {
e.printStackTrace();
}
return carPoolSpacesAvailable;
}
#Override
protected void onPostExecute(String s) {
super.onPostExecute(s);
if(s!=null){
t.setText(s);
}
}
}
Try this in your second activity.

Replace your code by writing:
try {
chk();
}catch (Exception e)
{
Log.e("Error : ", "" + e.getMessage());
t.setText("Error");
}
After this run it, check the Logat in Error section and post a screenshot of the exception here.

url.openConnection(); is not actually invoked

Im building a graduation project for my collage about "Smart Homes, Home Automation System" implemented with Arduion on a mock-up structure.
To have the full image, the Arduaio takes the pin number via a get request to switch on or of a specific home device.
its all cool when i send the HTTP request from any browser, but when i use the
openConnection();
method, it's like something never happens, but when i use it to get some data about the home rooms and its devices it's working greatly.
i already gave the app the permission to access the internet.
the code from a simple project i made just to solve this praticualy problem:
MainActivity.java
package com.bitsandbytes.xemma_pc.newprototype;
import android.os.AsyncTask;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import java.io.IOException;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;
public class MainActivity extends AppCompatActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Button button = (Button) findViewById(R.id.button);
button.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
new SendRequest().execute();
}
});
}
private static class SendRequest extends AsyncTask <Void,Void,Void>{
#Override
protected Void doInBackground(Void... params) {
HttpURLConnection httpURLConnection = null ;
URL url ;
try {
url = new URL("http://192.168.1.143/pin=13");
httpURLConnection = (HttpURLConnection) url.openConnection();
} catch (MalformedURLException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}finally {
httpURLConnection.disconnect();
}
return null;
}
}
}
activity_main.xml
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingBottom="#dimen/activity_vertical_margin"
android:paddingLeft="#dimen/activity_horizontal_margin"
android:paddingRight="#dimen/activity_horizontal_margin"
android:paddingTop="#dimen/activity_vertical_margin"
tools:context="com.bitsandbytes.xemma_pc.newprototype.MainActivity">
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textAppearance="?android:attr/textAppearanceLarge"
android:text="Press it to Test it"
android:id="#+id/textView"
android:layout_marginTop="154dp"
android:layout_alignParentTop="true"
android:layout_centerHorizontal="true" />
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Pin 13"
android:id="#+id/button"
android:layout_below="#+id/textView"
android:layout_centerHorizontal="true" />
</RelativeLayout>
AndroidManifist.xml
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.bitsandbytes.xemma_pc.newprototype">
<uses-permission android:name="android.permission.INTERNET"/>
<application
android:allowBackup="true"
android:icon="#mipmap/ic_launcher"
android:label="#string/app_name"
android:supportsRtl="true"
android:theme="#style/AppTheme">
<activity android:name=".MainActivity">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>
</manifest>
i appreciate the help and the tips in advance.
EDIT: thanks you guys for helping me, but what it really helped me was using the getResponseMessage() method, and it works greatly :D
i didn't have to use .connect method to get some JSON strings before, but it was working.
anyway, thanks for the help!

openConnection just parses the URL and creates the appropriate URLConnection subclass. Network I/O doesn't happen until you send or receive something.

You need to read the data and then network IO will occur.
String response = "";
HttpURLConnection conn = (HttpURLConnection) url.openConnection();
// Set Method here
conn.setRequestMethod("POST");
InputStreamReader in = new InputStreamReader(conn.getInputStream());
BufferedReader br = new BufferedReader(in);
String line= "";
while ((line= br.readLine()) != null) {
response += line;
}
conn.disconnect();

URL.openConnection() only returns a URLConnection to the specified resource.
You can open an actual connection to that resource by calling the connect() method of that particular URLConnection.
For example:
HttpURLConnection connection = (HttpURLConnection) someUrl.openConnection();
connection.connect();
Operations that require a connection (like getInputStream() or getOutputStream()) will implicitly call connect(), so explicitly calling it before such operations is not necessary:
HttpURLConnection connection = (HttpURLConnection) someUrl.openConnection();
connection.connect(); // this is redundant
connection.getInputStream(); // getInputStream() will call connect()

Network Requests return null - Android

i am working on a network communication project in android, but my app dose not work ! after some debugging, i find out that every network request has a null response from system.
i tried so many ways such as :
1) hard restart my phone
2) adding all network permissions to the manifest file
<uses-permission android:name="android.permission.ACCESS_WIFI_STATE"/>
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"/>
<uses-permission android:name="android.permission.INTERNET"/>
3) using local network ( my phone as a server )
4) letting all applications to connect to the network : setting > networked apps > ...
but ! nothing happened...
this is my similar problem link, but there is no answer in this topic:
can't connect to internet in ONLY in my android app. Each method to connect internet returns null
network is working on my phone because some apps like telegram and chrome are working well !
and there is a funny thing here, when i copy and past this code to the simple java project not android project, it works well !
because i wanted to find out where is the problem, i just copy 3 simple lines of codes to the simple android project, but still nothing happened!
manifest file:
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.dltests"
android:versionCode="1"
android:versionName="1.0" >
<uses-sdk
android:minSdkVersion="11"
android:targetSdkVersion="17" />
<uses-permission android:name="android.permission.INTERNET"/>
<application
android:allowBackup="true"
android:icon="#drawable/ic_launcher"
android:label="#string/app_name"
android:theme="#style/AppTheme" >
<activity
android:name=".MainActivity"
android:label="#string/title_activity_main" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>
</manifest>
layout file
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context="${relativePackage}.${activityClass}" >
<TextView
android:id="#+id/hello"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="#string/hello_world" />
</RelativeLayout>
source file
package com.example.dltests;
import java.net.HttpURLConnection;
import java.net.URL;
import android.app.Activity;
import android.os.Bundle;
import android.widget.TextView;
public class MainActivity extends Activity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
TextView mTextView = (TextView) findViewById(R.id.hello);
try
{
URL mUrl = new URL("http://192.168.1.53:8080/some.zip");
HttpURLConnection mHttpURLConnection = (HttpURLConnection) mUrl.openConnection();
mTextView.setText(mHttpURLConnection.getContentLength());
}
catch (Exception e)
{
mTextView.setText("ERROR: " + e.getMessage());
}
}
}
and the result is :
ERROR: null

Android bars you from networking in the UI thread. What you need to do it spawn a separate thread to do the networking for you. Then you need either a receiver or handler to post/update the UI with the data.
1 - Create a new class:
import android.os.Handler;
import android.os.Message;
public class GetData extends Thread
{
// Holds url that data is stored on
private URL url
// Sets the url value
public GetData(URL newUrl)
{
url = newUrl;
}
// Runs when the thread is launched
public void run()
{
// Opens connection
HttpURLConnection con = (HttpURLConnection) url.openConnection();
// Sends back to UI using a Message
Message msg = MainActivity.MainActivityInterface.obtainMessage(MainActivity.getAndUpdate);
msg.obj = con.getContentLength(); // Adds the data
HomeScreen.homeScreenInterface.sendMessage(msg);
}
}
2 - Create handler in activity so UI can be updated as well as launch worker thread
import java.net.HttpURLConnection;
import java.net.URL;
import android.app.Activity;
import android.os.Bundle;
import android.widget.TextView;
import android.os.Handler;
import android.os.Message;
public class MainActivity extends Activity {
// Holds activity instance
public static MainActivity currentInstance;
// Variable that allows us to separate messages for handler
public static final getAndUpdate = 0;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
currentInstance = this;
TextView mTextView = (TextView) findViewById(R.id.hello);
try
{
URL mUrl = new URL("http://192.168.1.53:8080/some.zip");
// Spawns worker thread
GetData gd = new GetData(mUrl);
gd.start();
}
catch (Exception e)
{
mTextView.setText("ERROR: " + e.getMessage());
}
}
// Deals with service responses
public static Handler MainActivityInterface = new Handler()
{
#Override
public void handleMessage(Message msg)
{
switch(msg.what)
{
case getAndUpdate:
currentInstance.mTextView.setText((String) msg.obj); // Gets message object and updates UI
break;
}
}
}
}
I hope this helps. Note that I have not tested it as I am very far away from my coding computer!

Insert data from android app into mySql database [closed]

Closed. This question needs debugging details. It is not currently accepting answers.
Edit the question to include desired behavior, a specific problem or error, and the shortest code necessary to reproduce the problem. This will help others answer the question.
Closed 8 years ago.
Improve this question
I've been following a youtube video which explain how to insert data from an android app to mySQL.
It doesn't work for me and I don't know what am I doing wrong. It just breaks as soon as I execute it. Not even loading the textViews and Buttons
This is my MainActivity:
package com.example.insertbbdd;
import java.io.IOException;
import java.io.InputStream;
import java.util.ArrayList;
import java.util.List;
import org.apache.http.HttpEntity;
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.app.Activity;
import android.os.Bundle;
import android.os.StrictMode;
import android.support.v4.app.Fragment;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;
public class MainActivity extends Activity {
EditText eName, eAge, eMail;
Button bSumbit;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main_activity);
StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder().permitAll().build();
StrictMode.setThreadPolicy(policy);
eName = (EditText) findViewById(R.id.editName);
eAge = (EditText) findViewById(R.id.editAge);
eMail = (EditText) findViewById(R.id.editMail);
bSumbit = (Button) findViewById(R.id.submitButton);
bSumbit.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
// TODO Auto-generated method stub
InputStream is = null;
String name = "" + eName.getText().toString();
String age = "" + eAge.getText().toString();
String email = "" + eMail.getText().toString();
List<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>(1);
nameValuePairs.add(new BasicNameValuePair("name", name));
nameValuePairs.add(new BasicNameValuePair("age", age));
nameValuePairs.add(new BasicNameValuePair("email", email));
try{
HttpClient httpClient = new DefaultHttpClient();
HttpPost httpPost = new HttpPost("http://accessibility.es/prueba/script.php");
httpPost.setEntity(new UrlEncodedFormEntity(nameValuePairs));
HttpResponse response = httpClient.execute(httpPost);
HttpEntity entity = response.getEntity();
is = entity.getContent();
String msg = "Data entered succesfully";
Toast.makeText(getApplicationContext(), msg, Toast.LENGTH_LONG).show();
}
catch(ClientProtocolException e){
Log.e("Client Protocol", "Log_tag");
e.printStackTrace();
}
catch(IOException e){
Log.e("Log tag", "IOException");
e.printStackTrace();
}
}
});
}
}
This is my main_activity.xml :
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/RelativeLayout1"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical" >
<Button
android:id="#+id/submitButton"
style="?android:attr/buttonStyleSmall"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignLeft="#+id/editName"
android:layout_alignParentBottom="true"
android:layout_marginBottom="130dp"
android:text="Button" />
<TextView
android:id="#+id/editMail"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_above="#+id/submitButton"
android:layout_alignRight="#+id/editName"
android:layout_marginBottom="54dp"
android:layout_marginRight="17dp"
android:text="Large Text"
android:textAppearance="?android:attr/textAppearanceLarge" />
<TextView
android:id="#+id/editAge"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_above="#+id/editMail"
android:layout_alignLeft="#+id/editMail"
android:layout_marginBottom="43dp"
android:text="Large Text"
android:textAppearance="?android:attr/textAppearanceLarge" />
<TextView
android:id="#+id/editName"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_above="#+id/editAge"
android:layout_alignParentLeft="true"
android:layout_marginBottom="35dp"
android:layout_marginLeft="90dp"
android:text="Large Text"
android:textAppearance="?android:attr/textAppearanceLarge" />
</RelativeLayout>
And this is my AndroidManifest:
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.insertbbdd"
android:versionCode="1"
android:versionName="1.0" >
<uses-sdk
android:minSdkVersion="14"
android:targetSdkVersion="21" />
<uses-permission android:name="android.permission.INTERNET"/>
<application
android:allowBackup="true"
android:icon="#drawable/ic_launcher"
android:label="#string/app_name"
android:theme="#style/AppTheme" >
<activity
android:name=".MainActivity"
android:label="#string/app_name" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>
</manifest>

I'm guessing you are getting the ClassCastException because you are trying to call (EditText) on a TextView.
change this :
TextView eName, eAge, eMail;
eName = (TextView) findViewById(R.id.editName);
eAge = (TextView) findViewById(R.id.editAge);
eMail = (TextView) findViewById(R.id.editMail);
bSumbit = (Button) findViewById(R.id.submitButton);
or change your xml tag from TextView to EditText.
<EditText />
NB: what is pointed by others is also correct. if you click your submit button you will get
android.os.NetworkOnMainThreadException
so you need to use either Handler or AsyncTask

You need to carry out any network operations such as HttpPost (or indeed any other slow operation) in a separate thread from the main UI thread, and then use a callback to update the UI back on the main thread later.
See http://developer.android.com/guide/components/processes-and-threads.html and http://developer.android.com/reference/android/os/AsyncTask.html for the main documentation. There are also numerous guides on the web eg http://www.vogella.com/tutorials/AndroidBackgroundProcessing/article.html

try this..
try{
new Thread(new Runnable() {
public void run() {
HttpClient httpClient = new DefaultHttpClient();
HttpPost httpPost = new HttpPost("http://accessibility.es/prueba/script.php");
httpPost.setEntity(new UrlEncodedFormEntity(nameValuePairs));
HttpResponse response = httpClient.execute(httpPost);
HttpEntity entity = response.getEntity();
is = entity.getContent();
String msg = "Data entered succesfully";
Toast.makeText(getApplicationContext(), msg, Toast.LENGTH_LONG).show();
}
catch(ClientProtocolException e){
Log.e("Client Protocol", "Log_tag");
e.printStackTrace();
}
catch(IOException e){
Log.e("Log tag", "IOException");
e.printStackTrace();
}
}
}).start();

display web page source in android app

This is my first project in android java. I am trying to get a page source and display it. (I will use this with json later.) I followed a tutorial on lynda.com but I can't get this to work. there is a edittext, textview, and a button in this app. the user enter a url and press the button and the app adds the source to the page. When I click the button nothing happen. how can I fix this.
Note i have the internet permission added already.
Main.java
package com.example.news;
import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.net.URL;
import java.net.URLConnection;
import android.os.Bundle;
import android.app.Activity;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
public class Main extends Activity {
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
final EditText et = (EditText) findViewById(R.id.editText1);
final Button b = (Button) findViewById(R.id.button1);
final TextView tv = (TextView) findViewById(R.id.textView1);
b.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
try{
URL url = null;
url = new URL(et.getText().toString());
URLConnection conn = url.openConnection();
BufferedReader reader = new BufferedReader(new InputStreamReader(conn.getInputStream()));
String line = "";
while((line = reader.readLine()) != null){
tv.append(line);
}
}catch(Exception e){
}
}
});
}
}
This is my manifest file
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.news"
android:versionCode="1"
android:versionName="1.0" >
<uses-sdk
android:minSdkVersion="7"
android:targetSdkVersion="18" />
<uses-permission android:name="android.permission.INTERNET"/>
<application
android:allowBackup="true"
android:icon="#drawable/ic_launcher"
android:label="#string/app_name"
android:theme="#style/AppTheme" >
<activity
android:name="com.example.news.Main"
android:label="#string/app_name" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>
</manifest>
I got this error: android.os.NetworkOnMainThreadException

You are using the Internet on Main Thread.
You should use the code in doInBackground().
class Abc extends ASyncTask<String, String, String>
{
public String doInBackground(String... params)
{
URL url = null;
url = new URL(et.getText().toString());
URLConnection conn = url.openConnection();
BufferedReader reader = new BufferedReader(new InputStreamReader(conn.getInputStream()));
String line = "";
while((line = reader.readLine()) != null){
tv.append(line);
}
}
And in OnClick
new Abc.execute();