I have my login page where i have my login So it means i have a button for the Login and an clickable text for the redirection to the register page. My button works fine but when I'm clicking my clickable text Unable to start activity ComponentInfo error shows.
MainActivity.class
package com.example.kun.carkila;
import android.content.Intent;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
import android.widget.Toast;
import com.kosalgeek.genasync12.AsyncResponse;
import com.kosalgeek.genasync12.PostResponseAsyncTask;
import java.util.HashMap;
public class MainActivity extends AppCompatActivity {
final String LOG = "MainActivity";
Button btnLogin;
EditText etUsername, etPassword;
TextView tvRegister;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
etUsername = (EditText) findViewById(R.id.etUsername);
etPassword = (EditText) findViewById(R.id.etPassword);
btnLogin = (Button) findViewById(R.id.btnLogin);
tvRegister = (TextView) findViewById(R.id.tvRegister);
btnLogin.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
HashMap postData = new HashMap();
String username = etUsername.getText().toString();
String password = etPassword.getText().toString();
postData.put("username", username);
postData.put("password", password);
PostResponseAsyncTask task1 = new PostResponseAsyncTask(MainActivity.this, postData,
new AsyncResponse() {
@Override
public void processFinish(String s) {
if (s.contains("renterowner")) {
Toast.makeText(MainActivity.this, "Renter Login Successful!", Toast.LENGTH_SHORT).show();
Intent in = new Intent(MainActivity.this, ListActivity.class);
startActivity(in);
} else if (s.contains("ownerrenter")) {
Toast.makeText(MainActivity.this, "Owner Login Successful!", Toast.LENGTH_SHORT).show();
Intent in = new Intent(MainActivity.this, ownerhome.class);
startActivity(in);
} else {
Toast.makeText(MainActivity.this, "Login Failed!", Toast.LENGTH_SHORT).show();
}
}
});
task1.execute("http://carkila.esy.es/authenticate.php");
}
});
tvRegister.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Intent in = new Intent(MainActivity.this, RegisterActivity.class);
startActivity(in);
}
});
}
}
My Register class is still empty though but still I cant manage to go there by clicking my textview. Thanks for the help. :)
content_main.xml
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout 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"
android:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
app:layout_behavior="@string/appbar_scrolling_view_behavior"
tools:context="com.example.kun.carkila.MainActivity"
tools:showIn="@layout/activity_main">
<EditText
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/etUsername"
android:layout_alignParentTop="true"
android:layout_alignParentRight="true"
android:layout_alignParentEnd="true"
android:layout_alignParentLeft="true"
android:layout_alignParentStart="true"
android:hint="Username" />
<EditText
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:inputType="textPassword"
android:ems="10"
android:id="@+id/etPassword"
android:layout_below="@+id/etUsername"
android:layout_alignParentRight="true"
android:layout_alignParentEnd="true"
android:layout_alignParentLeft="true"
android:layout_alignParentStart="true"
android:hint="Password" />
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Login"
android:id="@+id/btnLogin"
android:layout_below="@+id/etPassword"
android:layout_centerHorizontal="true" />
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Register"
android:id="@+id/tvRegister"
android:layout_below="@+id/btnLogin"
android:layout_centerHorizontal="true"
/>
</RelativeLayout>
Manifest ##
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
package="com.example.kun.carkila">
<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
<application
android:allowBackup="true"
android:icon="@mipmap/ic_launcher"
android:label="@string/app_name"
android:supportsRtl="true"
android:theme="@style/AppTheme"
tools:replace="@android:icon">
<activity
android:name=".MainActivity"
android:label="@string/app_name"
android:theme="@style/AppTheme.NoActionBar">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<activity
android:name=".ListActivity"
android:label="@string/title_activity_list"
android:theme="@style/AppTheme.NoActionBar" />
<activity
android:name=".DetailActivity"
android:label="@string/title_activity_detail"
android:parentActivityName=".ListActivity"
android:theme="@style/AppTheme.NoActionBar">
<meta-data
android:name="android.support.PARENT_ACTIVITY"
android:value="com.example.kun.carkila.ListActivity" />
</activity>
<activity
android:name=".InsertActivity"
android:label="@string/title_activity_insert"
android:parentActivityName=".ListActivity"
android:theme="@style/AppTheme.NoActionBar">
<meta-data
android:name="android.support.PARENT_ACTIVITY"
android:value="com.example.kun.carkila.ListActivity" />
</activity>
<activity
android:name=".ownerhome"
android:label="@string/title_activity_ownerhome"
android:theme="@style/AppTheme.NoActionBar" />
<activity
android:name=".RegisterActivity"
android:label="@string/title_activity_register"
android:parentActivityName=".MainActivity"
android:theme="@style/AppTheme.NoActionBar">
<meta-data
android:name="android.support.PARENT_ACTIVITY"
android:value="com.example.kun.carkila.MainActivity" />
</activity>
</application>
</manifest>
Error
07-18 00:18:18.282 24312-24312/? E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.example.kun.carkila, PID: 24312
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.kun.carkila/com.example.kun.carkila.RegisterActivity}: java.lang.NullPointerException
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2195)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2245)
at android.app.ActivityThread.access$800(ActivityThread.java:135)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1196)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:136)
at android.app.ActivityThread.main(ActivityThread.java:5021)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:515)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:827)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:643)
at dalvik.system.NativeStart.main(Native Method)
Caused by: java.lang.NullPointerException
at com.example.kun.carkila.RegisterActivity.onCreate(RegisterActivity.java:20)
at android.app.Activity.performCreate(Activity.java:5231)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1090)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2159)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2245)
at android.app.ActivityThread.access$800(ActivityThread.java:135)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1196)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:136)
at android.app.ActivityThread.main(ActivityThread.java:5021)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:515)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:827)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:643)
at dalvik.system.NativeStart.main(Native Method)
RegisterActivity.class
package com.example.kun.carkila;
import android.os.Bundle;
import android.support.design.widget.FloatingActionButton;
import android.support.design.widget.Snackbar;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;
import android.view.View;
public class RegisterActivity extends AppCompatActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_register);
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab);
fab.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
Snackbar.make(view, "Replace with your own action", Snackbar.LENGTH_LONG)
.setAction("Action", null).show();
}
});
getSupportActionBar().setDisplayHomeAsUpEnabled(true);
}
}
