Question

I am fairly new to android programming and I’m working off an example from a book I purchased but the example app they are showing me how to make is coming up with bugs in it. Its very simple so far but I am getting the following error so far:

07-30 04:36:59.265: W/System.err(540): java.lang.ClassNotFoundException: com.sanbox.basicsstarter.LifeCycleTest
07-30 04:36:59.285: W/System.err(540):  at java.lang.Class.classForName(Native Method)
07-30 04:36:59.285: W/System.err(540):  at java.lang.Class.forName(Class.java:217)

My code is really on 3 seperate files the first is the main activity calling the AndroidBasicsStarterActivity:

package com.sandbox.basicsstarter;

import android.app.ListActivity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.os.Bundle;
import android.widget.ArrayAdapter;
import android.widget.ListView;
import android.util.Log;

public class AndroidBasicsStarterActivity extends ListActivity {
String tests[] = { "LifeCycleTest", "SingleTouchTest", "MultiTouchTest",
"KeyTest", "AccelerometerTest", "AssetsTest",
"ExternalStorageTest", "SoundPoolTest", "MediaPlayerTest",
"FullScreenTest", "RenderViewTest", "ShapeTest", "BitmapTest",
"FontTest", "SurfaceViewTest" };
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setListAdapter(new ArrayAdapter<String>(this,
    android.R.layout.simple_list_item_1, tests));
}

private void log(String text) {
    Log.d("LifeCycleTest ", text);
}

@Override
protected void onListItemClick(ListView list, View view, int position,
    long id) {
        super.onListItemClick(list, view, position, id);
        String testName = tests[position];
        log(testName);
    try {
        Class clazz = Class.forName("com.sanbox.basicsstarter." + testName);

        Intent intent = new Intent(this, clazz);
        startActivity(intent);
    } catch (ClassNotFoundException e) {
        e.printStackTrace();
    }
}
}

then the LifeCycleTest class:

package com.sandbox.basicsstarter;

import android.app.Activity;
import android.os.Bundle;
import android.util.Log;
import android.widget.TextView;

public class LifeCycleTest extends Activity {
StringBuilder builder = new StringBuilder();
TextView textView;
private void log(String text) {
    Log.d("LifeCycleTest", text);
    builder.append(text);
    builder.append('\n');
    textView.setText(builder.toString());
}
@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    textView = new TextView(this);
    textView.setText(builder.toString());
    setContentView(textView);
    log("created");
}
@Override
protected void onResume() {
    super.onResume();
    log("resumed");
}
@Override
protected void onPause() {
        super.onPause();
        log("paused");
    if (isFinishing()) {
        log("finishing");
    }
}
}

And lastly the manifest file:

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.sandbox.basicsstarter"
android:versionCode="1"
android:versionName="1.0" >

<uses-sdk android:minSdkVersion="15" />

<application
    android:icon="@drawable/ic_launcher"
    android:label="@string/app_name" >
    <activity
        android:name=".AndroidBasicsStarterActivity"
        android:label="@string/app_name" >
        <intent-filter>
            <action android:name="android.intent.action.MAIN" />

            <category android:name="android.intent.category.LAUNCHER" />
        </intent-filter>
    </activity>
    <activity android:label="Life Cycle Test"
        android:name=".LifeCycleTest"
        android:configChanges="keyboard|keyboardHidden|orientation" />
</application>

</manifest>

So can anyone help me figure out where my error is occuring? I already tried cleaning up the project but that did not resolve anything. Thanks so much for any possible ideas!

Answer 1

Do this to start the activity:

Intent intent = new Intent(this, LifeCycleTest.class);

There is no need to find the class using Class.forName

EDIT

The reason why it can’t find the class is because you have misspelled the package.

It should be com.sandbox.basicsstarter. You omitted the d in sandbox.