在Android上实现Junit单元测试的四部曲。

下面从四步简单讲一下在Android上实现Junit单元测试。

第一步：新建一个TestCase，记得要继承androidTestCase，才能有getContext()来获取当前的上下文变量，这在Android测试中很重要的，因为很多的Android api都需要context。

Java代码

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：新建一个TestSuit，这个就继承Junit的TestSuite就可以了，注意这里是用的addTestSuite方法，一开始使用addTest方法就是不能成功。

Java代码

public class ExampleSuite extends TestSuite {

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

}

第三步：新建一个Activity，用来启动单元测试，并显示测试结果。系统的AndroidTestRunner竟然什么连个UI界面也没有实现，这里只是最简单的实现了一个

Java代码

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，不然会提示找不到AndroidTestRunner，这里需要注意是这句话是放在applications下面的，我一开始也不知道，放错了地方，浪费了不少时间

Xml代码

xml version="1.0" encoding="utf-8"?>
<manifest xmlns: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>