How to get values from EditText from a different Class in android?

Question

This is not the usual question everyone else has asked, I know how to get the value from EditText. I am creating a login/signup for my app, I want to have the user login data retrieved by one separate class/package and the user sign up data with a separate class/package. NOTE: this Class is not an activity but does extend AppCompatActivity to allow the use of findViewById.

This is the UserSignUpData.class with just one get-Method as it crashes start after

public class UserSignUpData extends AppCompatActivity {

    public String getSignUpFullName() {
        EditText et = (EditText) findViewById(R.id.signup_name); //NullPointerException
        String fn = et.getText().toString();
        return fn;
    }//end getSignUpFullName()

And I am calling the onClick(signup) method that I declared in the layout from the MainActivity.class like this

public class MainActivity extends AppCompatActivity {
    public void signUp(View v){
       UserSignUpData signUpData = new UserSignUpData();
       String name = signUpData.getSignUpFullName();
       Toast.makeText(MainActivity.this, ud.getSignUpFullName(), Toast.LENGTH_SHORT).show(); 
       //just to test if it works
    }

So I end up getting a NullPointerException which points to

EditText et = (EditText) findViewById(R.id.signup_name);

This is the error code:

FATAL EXCEPTION: main java.lang.IllegalStateException: Could not execute method for android:onClick
     at android.support.v7.app.AppCompatViewInflater$DeclaredOnClickListener.onClick(AppCompatViewInflater.java:293)
     at android.view.View.performClick(View.java:4240)
     at android.view.View$PerformClick.run(View.java:17721)
     at android.os.Handler.handleCallback(Handler.java:730)
     at android.os.Handler.dispatchMessage(Handler.java:92)
     at android.os.Looper.loop(Looper.java:137)
     at android.app.ActivityThread.main(ActivityThread.java:5103)
     at java.lang.reflect.Method.invokeNative(Native Method)
     at java.lang.reflect.Method.invoke(Method.java:525)
     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:737)
     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553)
     at dalvik.system.NativeStart.main(Native Method)
  Caused by: java.lang.reflect.InvocationTargetException
     at java.lang.reflect.Method.invokeNative(Native Method)
     at java.lang.reflect.Method.invoke(Method.java:525)
     at android.support.v7.app.AppCompatViewInflater$DeclaredOnClickListener.onClick(AppCompatViewInflater.java:288)
     at android.view.View.performClick(View.java:4240) 
     at android.view.View$PerformClick.run(View.java:17721) 
     at android.os.Handler.handleCallback(Handler.java:730) 
     at android.os.Handler.dispatchMessage(Handler.java:92) 
     at android.os.Looper.loop(Looper.java:137) 
     at android.app.ActivityThread.main(ActivityThread.java:5103) 
     at java.lang.reflect.Method.invokeNative(Native Method) 
     at java.lang.reflect.Method.invoke(Method.java:525) 
     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:737) 
     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553) 
     at dalvik.system.NativeStart.main(Native Method) 
  Caused by: java.lang.NullPointerException
     at android.support.v7.app.AppCompatDelegateImplBase.<init>(AppCompatDelegateImplBase.java:72)
     at android.support.v7.app.AppCompatDelegateImplV7.<init>(AppCompatDelegateImplV7.java:146)
     at android.support.v7.app.AppCompatDelegateImplV11.<init>(AppCompatDelegateImplV11.java:28)
     at android.support.v7.app.AppCompatDelegateImplV14.<init>(AppCompatDelegateImplV14.java:41)
     at android.support.v7.app.AppCompatDelegate.create(AppCompatDelegate.java:193)
     at android.support.v7.app.AppCompatDelegate.create(AppCompatDelegate.java:173)
     at android.support.v7.app.AppCompatActivity.getDelegate(AppCompatActivity.java:511)
     at android.support.v7.app.AppCompatActivity.findViewById(AppCompatActivity.java:183)
     at com.example.pc_charlie.loginapp.UserSignUpData.getSignUpFullName(UserSignUpData.java:12)
     at com.example.pc_charlie.loginapp.MainActivity.signUp(MainActivity.java:52)
     at java.lang.reflect.Method.invokeNative(Native Method) 
     at java.lang.reflect.Method.invoke(Method.java:525) 
     at android.support.v7.app.AppCompatViewInflater$DeclaredOnClickListener.onClick(AppCompatViewInflater.java:288) 
     at android.view.View.performClick(View.java:4240) 
     at android.view.View$PerformClick.run(View.java:17721) 
     at android.os.Handler.handleCallback(Handler.java:730) 
     at android.os.Handler.dispatchMessage(Handler.java:92) 
     at android.os.Looper.loop(Looper.java:137) 
     at android.app.ActivityThread.main(ActivityThread.java:5103) 
     at java.lang.reflect.Method.invokeNative(Native Method) 
     at java.lang.reflect.Method.invoke(Method.java:525) 
     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:737) 
     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553) 
     at dalvik.system.NativeStart.main(Native Method)

I could also be wrong about it being a NullPointerException, but its some error thats stopping the code from working. thanks

"does extend AppCompatActivity to allow the use of findViewById" -- I don't think you understand how `findViewById` works. You can't find views across other activities just like that. — OneCricketeer, Aug 09 '16 at 16:02

Viral Patel · Accepted Answer · 2016-08-09T18:01:15.260

1

If the class is not for an Activity. You should not extend activity.

I'm assuming you are trying to separate out the logic into another class.

In that case just pass the EditText as a parameter to the method getSignUpFullName as getSignUpFullName(EditText et) after instantiating it properly in the MainActivity. Do not try to find it in the UserSignUpData class.

edited Aug 09 '16 at 18:01

answered Aug 09 '16 at 15:57

Viral Patel

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That worked mate thanks :) I just got of a Java Spring project, so im still thinking in Java. – Sabbib Aug 09 '16 at 17:48

score 0 · Answer 2 · answered Aug 09 '16 at 16:08

Looks like you are just trying to pass data between classes. You don't need to find a view from a separate class, and a "data container" class probably shouldn't extend any Activity.

public class UserSignUpData {

    private String signUpFullName;

    public UserSignUpData(String fullName) {
        this.signUpFullName = fullName;
    }

    public String getSignUpFullName() { return this.signUpFullName };
}

public class MainActivity extends AppCompatActivity {
    public void signUp(View v){
       EditText et = (EditText) findViewById(R.id.signup_name);
       String name = et.getText().toString();

       UserSignUpData ud = new UserSignUpData(name);
       Toast.makeText(MainActivity.this, ud.getSignUpFullName(), Toast.LENGTH_SHORT).show(); 
       //just to test if it works
    }
}

How to get values from EditText from a different Class in android?

2 Answers2