Eclipse Xml Incorrect Line Endings

android.content.ActivityNotFoundException: Unable to find explicit activity class {com.example.my_package/com.example.my_package.MainClass}; have you declared this activity in your AndroidManifest.xml?

Is MainClass.java in AndroidManifest as a activity ?
AndroidManifest.xml example

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="//schemas.android.com/apk/res/android"
      package="com.example.my_packag"
      android:versionCode="1"
      android:versionName="1.0">
    <uses-sdk android:minSdkVersion="7" />

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

    </application>
</manifest>

Multiple substitutions specified in non-positional format;did you mean to add the formatted="false" attribute?
Wiktionary, WiktionarySimple
location C:\documents\WiktionarySimple\res\values\strings.xml
Issue:

    <string name="template_user_agent">"%s/%s (Linux; Android)"</string>
    <string name="template_wotd_title">"Wiktionary:Word of the day/%s %s"</string>
    <string name="template_define_url">"//en.wiktionary.org/wiki/%s"</string>

Solution:

   <string name="template_user_agent" translatable="false">"%1$s/%2$s (Linux; Android)"</string>
    <string name="template_wotd_title">"Wiktionary:Word of the day/%1$s %2$s"</string>
    <string name="template_define_url" translatable="false">"//en.wiktionary.org/wiki/%s"</string>

Click Handler Android Java example source code. Open new class as activity and open URL in browser.
In layout.xml file:

 android:layout_height="wrap_content" android:onClick="@string/clickHandler">

In string.xml

myClickHandler

In MainClass.java file

	public void myClickHandler(View view) {
		switch (view.getId()) {
		// open new class as activity
		case R.id.btnOpenClass: {
				Intent pictureActivity = new Intent(getBaseContext(),
						MyClass.class);
				startActivity(pictureActivity);
		}
		break;			
			
		case R.id.btnAbout: {
			//aboutDialogCreate();
		}
			break;
			
		// open url	
		 case R.id.btnHome: {
		 String url = "//android.okhelp.cz/";
		 Intent i = new Intent(Intent.ACTION_VIEW);
		 i.setData(Uri.parse(url));
		 startActivity(i);
		 }break;

		}

	}// end myClickHandler

// listener .. if click on button will scrolling to mTextView bottom
private OnClickListener mButtonListener = new OnClickListener() {
	    public void onClick(View v) {
	      // do something when the button is clicked
	    int nBottom =	mTextView.getBottom();
	    hScrollView.scrollTo(0, nBottom);
	    }
	};

do while Java example

public class MainClass {
	public static void main(String[] arg) {
			String[] arrayOfString = { "Hello", "people", "hello", "world!" };
			int i = 0;
                        // first cycle is always executed
			do {
				System.out.println("Loop: " + i);
				System.out.println(arrayOfString[i]);
				i++;
				
			}while ( i == -1 );
	}
}
/*
Loop: 0
Hello
*/

public class MainClass {
	public static void main(String[] arg) {
			String[] arrayOfString = { "Hello", "people", "hello", "world!" };
			int i = 0;
			do {
				System.out.println("Loop: " + i);
				System.out.println(arrayOfString[i]);
				i++;
				
			}while ( i < arrayOfString.length );
	}
}
/*
Loop: 0
Hello
Loop: 1
people
Loop: 2
hello
Loop: 3
world!
*/

Admob testing on emulator issue.
Android Eclipse code warning:
setTesting(boolean) from the type AdRequest is deprecated
Solution:
adRequest.addTestDevice(AdRequest.TEST_EMULATOR);

AdView adView = new AdView(this, AdSize.BANNER, "a14d9..........");//MY_AD_UNIT_ID
AdRequest adRequest = new AdRequest();
		adRequest.setTesting(true); // deprecated

		adRequest.addTestDevice(AdRequest.TEST_EMULATOR); // OK
		adView.loadAd(adRequest);