在Android上實現Junit單元測試的四部曲

我們曾經和大家探討過全面剖析Java ME單元測試理念，其實在android上實現JUnit單元測試也不是很困難，主要是在配置文件和測試環境上將花費很長時間，下面從四步簡單講一下在android上實現Junit單元測試。

第一步：新建一個TestCase，記得要繼承androidTestCase，才能有getContext()來獲取當前的上下文變量，這在Android測試中很重要的，因為很多的android api都需要context。

Java代碼

   
public class TestMath extends androidTestCase {    
        
    private int i1;    
    private int i2;    
    static final String LOG_TAG = "MathTest";    
        
    @Override    
    protected void setUp() throws Exception {    
        i1 = 2;    
        i2 = 3;    
    }    
        
    public void testAdd() {    
        assertTrue("testAdd failed", ((i1 + i2) == 5));    
    }    
        
    public void testDec() {    
        assertTrue("testDec failed", ((i2 - i1) == 1));    
    }    
    
    @Override    
    protected void tearDown() throws Exception {    
        super.tearDown();    
    }    
    
    @Override    
    public void testandroidTestCaseSetupProperly() {    
        super.testandroidTestCaseSetupProperly();    
        //Log.d( LOG_TAG, "testandroidTestCaseSetupProperly" );    
    }    
    
}    

第二步：新建一個TestSuit，這個就繼承Junit的TestSuite就可以了，注意這裡是用的addTestSuite方法，一開始使用addTest方法就是不能成功。

Java代碼

   
public class ExampleSuite extends TestSuite {    
        
    public ExampleSuite() {    
        addTestSuite(TestMath.class);    
    }    
    
}    

第三步：新建一個Activity，用來啟動單元測試，並顯示測試結果。系統的androidTestRunner竟然什麼連個UI界面也沒有實現，這裡只是最簡單的實現了一個

Java代碼

public class TestActivity extends Activity {    
        
    private TextView resultVIEw;    
        
    private TextView barVIEw;    
        
    private TextView messageVIEw;    
        
    private Thread testRunnerThread;    
        
    private static final int SHOW_RESULT = 0;    
        
    private static final int ERROR_FIND = 1;    
    
    @Override    
    protected void onCreate(Bundle savedInstanceState) {    
        super.onCreate(savedInstanceState);    
        setContentVIEw(R.layout.main);    
        resultVIEw = (TextView)findViewById(R.id.ResultVIEw);    
        barVIEw = (TextView)findViewById(R.id.BarVIEw);    
        messageVIEw = (TextView)findViewById(R.id.MessageVIEw);    
        Button lunch = (Button)findVIEwById(R.id.LunchButton);    
        lunch.setOnClickListener(new VIEw.OnClickListener() {    
            @Override    
            public void onClick(VIEw v) {    
                startTest();    
            }    
        });    
    }    
        
    private void showMessage(String message) {    
        hander.sendMessage(hander.obtainMessage(ERROR_FIND, message));    
    }    
        
    private void showResult(String text) {    
        hander.sendMessage(hander.obtainMessage(SHOW_RESULT, text));    
    }    
        
    private synchronized void startTest() {    
        if (testRunnerThread != null    
                && testRunnerThread.isAlive()) {    
            testRunnerThread = null;    
        }    
        if (testRunnerThread == null) {    
            testRunnerThread = new Thread(new TestRunner(this));    
            testRunnerThread.start();    
        } else {    
            Toast.makeText(this,     
                    "Test is still running",     
                    Toast.LENGTH_SHORT).show();    
        }    
    }    
        
    public Handler hander = new Handler() {    
        public void handleMessage(Message msg) {    
            switch (msg.what) {    
                case SHOW_RESULT:    
                    resultVIEw.setText(msg.obj.toString());    
                    break;    
                case ERROR_FIND:    
                    messageVIEw.append(msg.obj.toString());    
                    barVIEw.setBackgroundColor(Color.RED);    
                    break;    
                default:    
                    break;    
            }    
        }    
    };    
        
    class TestRunner implements Runnable, TestListener {    
        
        private Activity parentActivity;    
            
        private int testCount;    
            
        private int errorCount;    
            
        private int failureCount;    
            
        public TestRunner(Activity parentActivity) {    
            this.parentActivity = parentActivity;    
        }    
    
        @Override    
        public void run() {    
            testCount = 0;    
            errorCount = 0;    
            failureCount = 0;    
                
            ExampleSuite suite = new ExampleSuite();    
            androidTestRunner testRunner = new androidTestRunner();    
            testRunner.setTest(suite);    
            testRunner.addTestListener(this);    
            testRunner.setContext(parentActivity);    
            testRunner.runTest();    
        }    
    
        @Override    
        public void addError(Test test, Throwable t) {    
            errorCount++;    
            showMessage(t.getMessage() + "\n");    
        }    
    
        @Override    
        public void addFailure(Test test, AssertionFailedError t) {    
            failureCount++;    
            showMessage(t.getMessage() + "\n");    
        }    
    
        @Override    
        public void endTest(Test test) {    
            showResult(getResult());    
        }    
    
        @Override    
        public void startTest(Test test) {    
            testCount++;    
        }    
            
        private String getResult() {    
            int successCount = testCount - failureCount - errorCount;    
            return "Test:" + testCount + " Success:" + successCount + " Failed:" + failureCount + " Error:" + errorCount;    
        }    
            
    }    
    
}    

第四步：修改androidManifest.XML,加入，不然會提示找不到androidTestRunner，這裡需要注意是這句話是放在applications下面的，我一開始也不知道，放錯了地方，浪費了不少時間

XML代碼

XML version="1.0" encoding="utf-8"?>      
<manifest XMLns:android="http://schemas.Android.com/apk/res/android"      
      package="com.test.sample"      
      android:versionCode="1"      
      android:versionName="1.0">      
    <application android:icon="@drawable/icon" android:label="@string/app_name" android:debuggable="true">      
        <activity android:name=".TestActivity"      
                  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>      
    <uses-sdk android:minSdkVersion="4" />      
manifest>