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package com.example.alex.askii;
import android.content.Intent;
import android.support.v7.app.AppCompatActivity;
import android.graphics.Color;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;
import java.sql.DriverManager;
import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
//Alex Levin
public class Login extends AppCompatActivity {
Button login;
Button signUp;
EditText userNameET;
EditText passWordET;
DatabaseHelper helper = new DatabaseHelper(this);
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_login);
login = (Button)findViewById(R.id.Login);
signUp = (Button)findViewById(R.id.signUp);
userNameET = (EditText)findViewById(R.id.username);
passWordET = (EditText)findViewById(R.id.password);
login.setOnClickListener(new View.OnClickListener(){
@Override
public void onClick(View v){
//get text valiues
String userName = userNameET.getText().toString();
String passWord = passWordET.getText().toString();
//Query in java the username
String actualPassword = helper.searchPass(userName);
//If Correct
if(passWord.equals(actualPassword)){
Toast.makeText(getApplicationContext(),
"Redirecting...", Toast.LENGTH_SHORT).show();
/*
Intent i = new Intent(mainActivity.this, display.class);
i.putExtra("UserName", str);
startActivity(i)
Example code to go to next activity ^^
*/
}else{
Toast.makeText(getApplicationContext(), "Invalid Username Or Password", Toast.LENGTH_SHORT).show();
}
}
});
signUp.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Intent i = new Intent(Login.this, signUP.class);
startActivity(i);
}
});
}
}
<?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="com.example.alex.askii.Login">
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Askii Login"
android:textSize = "30dp"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintRight_toRightOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintVertical_bias="0.033"
tools:layout_constraintRight_creator="1"
tools:layout_constraintLeft_creator="1" />
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text= "Username:"
android:textSize="20dp"
app:layout_constraintRight_toLeftOf="@+id/username"
tools:layout_constraintRight_creator="1"
tools:layout_constraintBottom_creator="1"
app:layout_constraintBottom_toBottomOf="@+id/username"
android:layout_marginEnd="7dp"
android:layout_marginBottom="4dp"
android:layout_marginRight="7dp" />
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text= "Password:"
android:textSize="20dp"
android:id="@+id/textView"
tools:layout_constraintBottom_creator="1"
android:layout_marginStart="16dp"
app:layout_constraintBottom_toBottomOf="parent"
tools:layout_constraintLeft_creator="1"
android:layout_marginBottom="169dp"
app:layout_constraintLeft_toLeftOf="parent"
android:layout_marginLeft="16dp" />
<Button xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/Login"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Login"
android:onClick="login"
tools:layout_constraintRight_creator="1"
tools:layout_constraintBottom_creator="1"
app:layout_constraintBottom_toBottomOf="parent"
android:layout_marginEnd="84dp"
app:layout_constraintRight_toRightOf="parent"
android:layout_marginBottom="88dp"
android:layout_marginRight="130dp" />
<EditText
android:id="@+id/password"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:ems="10"
android:inputType="textPassword"
tools:layout_constraintRight_creator="1"
app:layout_constraintRight_toRightOf="@+id/username"
app:layout_constraintBaseline_toBaselineOf="@+id/textView"
tools:layout_constraintBaseline_creator="1"
tools:layout_constraintLeft_creator="1"
app:layout_constraintLeft_toLeftOf="@+id/username" />
<EditText
android:id="@+id/username"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:ems="10"
android:inputType="textPersonName"
android:text="Enter Username"
tools:layout_constraintBottom_creator="1"
app:layout_constraintBottom_toTopOf="@+id/password"
android:layout_marginStart="11dp"
tools:layout_constraintLeft_creator="1"
android:layout_marginBottom="20dp"
app:layout_constraintLeft_toRightOf="@+id/textView"
android:layout_marginLeft="11dp" />
<Button xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/signUp"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Sign Up"
tools:layout_constraintRight_creator="1"
tools:layout_constraintBottom_creator="1"
app:layout_constraintBottom_toBottomOf="parent"
android:layout_marginEnd="84dp"
app:layout_constraintRight_toRightOf="parent"
android:layout_marginRight="216dp"
android:layout_marginBottom="47dp" />
</android.support.constraint.ConstraintLayout>
package com.example.alex.askii;
import android.app.Activity;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;
/**
* Created by Alex on 12/30/2017.
*/
public class signUP extends AppCompatActivity{
@Override
protected void onCreate(Bundle savedInstanceState){
super.onCreate(savedInstanceState);
setContentView(R.layout.signup);
}
Button signUpOnPage = (Button)findViewById(R.id.signUpOnPage);
public void onSignUpOnPage(View v){
if(v.getId() == R.id.signUpOnPage){
EditText userName = (EditText)findViewById(R.id.newUserName);
EditText passWord = (EditText)findViewById(R.id.newPassWord);
EditText confPassword = (EditText)findViewById(R.id.newUserName);
String userNameString = userName.getText().toString();
String passWordString = passWord.getText().toString();
String confPasswordString = confPassword.getText().toString();
if(!passWordString.equals(confPasswordString)){
Toast check = Toast.makeText(signUP.this, "Passwords Don't Match", Toast.LENGTH_SHORT);
check.show();
}
}
}
}
Aus irgendeinem Grunde, den ichFehler mit neuem Vorsatz ANDROID STUDIO
12-30 02:39:59.308 1969-1969/com.example.alex.askii E/AndroidRuntime: FATAL EXCEPTION: main
java.lang.RuntimeException: Unable to instantiate activity ComponentInfo{com.example.alex.askii/com.example.alex.askii.signUP}: java.lang.NullPointerException
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1880)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1981)
at android.app.ActivityThread.access$600(ActivityThread.java:123)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1147)
at android.os.Handler.dispatchMessage(Handler.java:99)
at android.os.Looper.loop(Looper.java:137)
at android.app.ActivityThread.main(ActivityThread.java:4424)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:511)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:784)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:551)
at dalvik.system.NativeStart.main(Native Method)
Caused by: java.lang.NullPointerException
at android.support.v7.app.AppCompatDelegateImplBase.<init>(AppCompatDelegateImplBase.java:118)
at android.support.v7.app.AppCompatDelegateImplV9.<init>(AppCompatDelegateImplV9.java:152)
at android.support.v7.app.AppCompatDelegateImplV11.<init>(AppCompatDelegateImplV11.java:29)
at android.support.v7.app.AppCompatDelegateImplV14.<init>(AppCompatDelegateImplV14.java:53)
at android.support.v7.app.AppCompatDelegate.create(AppCompatDelegate.java:204)
at android.support.v7.app.AppCompatDelegate.create(AppCompatDelegate.java:184)
at android.support.v7.app.AppCompatActivity.getDelegate(AppCompatActivity.java:518)
at android.support.v7.app.AppCompatActivity.findViewById(AppCompatActivity.java:189)
at com.example.alex.askii.signUP.<init>(signUP.java:16)
at java.lang.Class.newInstanceImpl(Native Method)
at java.lang.Class.newInstance(Class.java:1319)
at android.app.Instrumentation.newActivity(Instrumentation.java:1023)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1871)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1981)
at android.app.ActivityThread.access$600(ActivityThread.java:123)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1147)
at android.os.Handler.dispatchMessage(Handler.java:99)
at android.os.Looper.loop(Looper.java:137)
at android.app.ActivityThread.main(ActivityThread.java:4424)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:511)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:784)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:551)
at dalvik.system.NativeStart.main(Native Method)
Ich bin wirklich nicht sicher, die folgende Störung erhalten, warum dies vielleicht geschieht, ist es etwas falsch mit meinen Manifesten, aber ich bezweifle es, weil die Manifest wurde automatisch generiert. Bitte helfen Sie, ich kann die Antwort nicht online finden, weil es scheint, als ob ich alles online richtig verfolgt habe. Dies ist der letzte Ort, an dem ich um Hilfe kam. Ich bin jetzt so frustriert!
Es tut mir leid, wie das ist eine exakte Kopie von jemand elses Fragen? Ich bin sicher, dass Leute ähnliche Probleme gehabt haben, die ich angeschaut habe! Aus irgendeinem Grund funktioniert es einfach nicht für mich! Deshalb habe ich um Hilfe gebeten! –