<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
 package="com.lee0000.test"
 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=".JUintTestActivity"
   android:label="@string/app_name" >
   <intent-filter>
    <action android:name="android.intent.action.MAIN" />
    <category android:name="android.intent.category.LAUNCHER" />
   </intent-filter>
  </activity>
 <uses-library android:name="android.test.runner" />  
 </application>
 <instrumentation 
  android:name="android.test.InstrumentationTestRunner"
  android:targetPackage="com.lee0000.test" android:label="Tests"/> 
</manifest> 

public class testclass {
 public void str(String s){
  System.out.println(s.substring(6));
 }
 public int add(int a,int b){
  return a+b;
 }
} 

import junit.framework.Assert;
import android.test.AndroidTestCase;
public class Test extends AndroidTestCase{
 public void teststr() throws Exception{
  testclass tc = new testclass();
  tc.str("null");
 }
 public void testadd(){
  testclass tc = new testclass();
  int t = tc.add(1, 2);
  Assert.assertEquals(3, t);
 }
}