My MainActivity class throws java.lang.ClassNotFoundException when extends ActionBarActivity

Question

I followed the instructions indicated in other threads on how to import external libraries, but after importing android-support-v7-appcompat.jar into the Referenced Libraries of my Android project (in ADT v.22.0.5) I get java.lang.ClassNotFoundException:

import android.os.Bundle;
import android.support.v7.app.ActionBar;
import android.support.v7.app.ActionBarActivity;
import android.view.Menu;

public class MainActivity extends ActionBarActivity {
    
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        
        ActionBar actionBar = getSupportActionBar();
        actionBar.setDisplayHomeAsUpEnabled(true);
        }
}

Can someone please shed some light?

enter image description here

Did you added v4 jar also? if not that should be add to project. — Pankaj Kumar, Sep 02 '13 at 05:06
see the link http://stackoverflow.com/questions/17440595/r-cannot-be-resolved-may-have-wrong-build-path-or-libraries-import/17440632#17440632 — Sunil Kumar, Sep 02 '13 at 05:06
The only other jars are: android.jar and android-support-v4.jar — Javide, Sep 02 '13 at 05:08
remove the v7 jar and checked the v4 jar in order and export and make clean and build project — Sunil Kumar, Sep 02 '13 at 05:17
ensure that android private libraries and other 3rd party libraries are checked in "Order and Export" tab. — Spring Breaker, Sep 02 '13 at 05:25
I fixed it following the instructions indicated in my answer. — Javide, Sep 02 '13 at 06:13

score 10 · Answer 1 · answered Sep 02 '13 at 05:49

10

Go the "Java Build Path" -> Order and export -> check all checkboxes -> clean -> build -> run

answered Sep 02 '13 at 05:49

Biraj Zalavadia

27,812
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I fixed it following the instructions indicated in my answer. – Javide Sep 02 '13 at 06:40
This was an easy fix for me. – Jacksonkr Aug 06 '14 at 19:14
nice! Thank you – Brewology Sep 15 '16 at 01:44

score 0 · Answer 2 · answered Sep 02 '13 at 05:51

0

You must add the class path to your new library.

You can see a file named .classpath, specify the path to your new library.

<classpathentry kind="lib" path="<path to your .jar file>"/>

answered Sep 02 '13 at 05:51

Dileep

5,254
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I fixed it following the instructions indicated in my answer. – Javide Sep 02 '13 at 06:13

score 0 · Accepted Answer · answered Sep 02 '13 at 06:11

0

I fixed it following these instructions:

answered Sep 02 '13 at 06:11

Javide

2,275
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My MainActivity class throws java.lang.ClassNotFoundException when extends ActionBarActivity

3 Answers3

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