Andriod Studio:E/AndroidRuntime: FATAL EXCEPTION: main

Question

please solve this issue I am a beginner in android development I don't know what the issue is.

Process: com.example.myapplicationofexarth, PID: 2703 java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.myapplicationofexarth/com.example.myapplicationofexarth.MainActivity}: java.lang.ClassCastException: android.support.constraint.ConstraintLayout cannot be cast to android.widget.TextView at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2913) at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3048) at android.app.servertransaction.LaunchActivityItem.execute(LaunchActivityItem.java:78) at android.app.servertransaction.TransactionExecutor.executeCallbacks(TransactionExecutor.java:108) at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:68) at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1808) at android.os.Handler.dispatchMessage(Handler.java:106) at android.os.Looper.loop(Looper.java:193) at android.app.ActivityThread.main(ActivityThread.java:6669) at java.lang.re flect.Method.invoke(Native Method) at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:493) at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:858) Caused by: java.lang.ClassCastException: android.support.constraint.ConstraintLayout cannot be cast to android.widget.TextView at com.example.myapplicationofexarth.MainActivity.onCreate(MainActivity.java:15) at android.app.Activity.performCreate(Activity.java:7136) at android.app.Activity.performCreate(Activity.java:7127) at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1271) at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2893)

MainActivity.Java

package com.example.myapplicationofexarth;

import android.graphics.Color;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.widget.TextView;

public class MainActivity extends AppCompatActivity {
    TextView text;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        text=(TextView)findViewById(R.id.textexample);
        text.setTextColor(Color.RED);
    }
}

Answer 1

looking at the error message I'd say you've probably given the R.Id.textexample to the constraint layout instead of the TextView by accident.

check the Id of the textView in the xml layout.