Robotium调用getActivity()导致程序挂起的方法

1. 问题背景的叙述性说明

需要直接用在工作中没有项目的源代码robotium测试目标android平台launcher，该平台的基础上，当前日期的版本号android 4.4.2。之前我用来验证的可行性，同时android4.4.2测试手机htc incredable s针对一个仅仅有apk的notepad应用做过相同的验证，在測试手机上执行全然没有问题。该測试代码例如以下：

package com.example.android.notepad.tryout;

import com.robotium.solo.Solo;

import android.test.ActivityInstrumentationTestCase2;
import android.widget.TextView;
import android.app.Activity;

@SuppressWarnings("rawtypes")
public class NotePadTest extends ActivityInstrumentationTestCase2{

private static Solo solo = null;
public Activity activity;

private static final int NUMBER_TOTAL_CASES = 2;
private static int run = 0;

private static Class<?

> launchActivityClass;
//相应re-sign.jar生成出来的信息框里的两个值
private static String mainActiviy = "com.example.android.notepad.NotesList";
private static String packageName = "com.example.android.notepad";

static {

try {

launchActivityClass = Class.forName(mainActiviy);

} catch (ClassNotFoundException e) {

throw new RuntimeException(e);

}

}

@SuppressWarnings("unchecked")
public NotePadTest() {
super(packageName, launchActivityClass);
}

@Override
public void setUp() throws Exception {
//setUp() is run before a test case is started.
//This is where the solo object is created.
super.setUp();
//The variable solo has to be static, since every time after a case's finished, this class TCCreateNote would be re-instantiated
// which would lead to soto to re-instantiated to be null if it's not set as static
//TextView title = (TextView)getActivity().findViewById(Ref.id.title);

if(solo == null) {

NotePadTest.solo = new Solo(getInstrumentation(),getActivity());

}
}

@Override
public void tearDown() throws Exception {
//Check whether it's the last case executed.
run += countTestCases();
if(run >= NUMBER_TOTAL_CASES) {
solo.finishOpenedActivities();
}
}

public void testAddNoteCNTitle() throws Exception {
//Thread.sleep(5000);
solo.clickOnMenuItem("Add note");
solo.enterText(0, "中文标签笔记");
solo.clickOnMenuItem("Save");
solo.clickInList(0);
solo.clearEditText(0);
solo.enterText(0, "Text 1");
solo.clickOnMenuItem("Save");
solo.assertCurrentActivity("Expected NotesList Activity", "NotesList");

solo.clickLongOnText("中文标签笔记");
solo.clickOnText("Delete");

}

public void testAddNoteEngTitle() throws Exception {
solo.clickOnMenuItem("Add note");
solo.enterText(0, "English Title Note");
solo.clickOnMenuItem("Save");
solo.clickInList(0);
solo.clearEditText(0);
solo.enterText(0, "Text 1");
solo.clickOnMenuItem("Save");
solo.assertCurrentActivity("Expected NotesList Activity", "NotesList");

solo.clickLongOnText("English Title Note");
solo.clickOnText("Delete");
}
}

但在工作的測试目标平台launcher中使用相同的方法去setup并执行简单的測试时碰到问题：測试程序一直挂起没有返回，程序挂起在下面getaActivity()方法（因是公司代码。故以notepad測试代码代替之）：

@Override
public void setUp() throws Exception {
//setUp() is run before a test case is started.
//This is where the solo object is created.
super.setUp();
//The variable solo has to be static, since every time after a case's finished, this class TCCreateNote would be re-instantiated
// which would lead to soto to re-instantiated to be null if it's not set as static

if(solo == null) {
NotePadTest.solo = new Solo(getInstrumentation(),getActivity());
}
}

当时一直怀疑是否系统launcher的robotium初始化和setup方法跟普通的apk不一样，google上有历史文章描写叙述getActivity()在Android 2.xx.xx上确实有这个问题，但后来的版本号已经解决，而本人使用的时当前最的4.4.2，所以不应该还存在这样的问题。

针对这个思路去尝试找解决的方法终无果。

2.问题分析

既然是getActvity()方法出现故障。而该方法原有的bug也已经在最新的版本号fixed。在google无所获的情况下也仅仅能剩下分析源代码这条路了。由于是自己刚在backbook上搭建的自己主动化研究平台。为了节省时间。当时没有下载android的对应源代码，仅仅有sdk。所以第一步必须是先在项目中配置使用上android的源代码，其理与配置javadoc相近，请查看本人之前的一篇文章《How
to Configure Javadoc for Robotium Library》，这里不做累术。

增加源代码后调试分析。终于程序挂起在android.test.InstrumentationTestCase中的launchActivityWithIntent方法中,下面是eclipse中的调试截图演示样例：



下面是该方法的完整代码片段：

/**
* Utility method for launching an activity with a specific Intent.
*
* <p><b>NOTE:</b> The parameter <i>pkg</i> must refer to the package identifier of the
* package hosting the activity to be launched, which is specified in the AndroidManifest.xml
* file.  This is not necessarily the same as the java package name.
*
* @param pkg The package hosting the activity to be launched.
* @param activityCls The activity class to launch.
* @param intent The intent to launch with
* @return The activity, or null if non launched.
*/
@SuppressWarnings("unchecked")
public final <T extends Activity> T launchActivityWithIntent(
String pkg,
Class<T> activityCls,
Intent intent) {
intent.setClassName(pkg, activityCls.getName());
intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
T activity = (T) getInstrumentation().startActivitySync(intent);
getInstrumentation().waitForIdleSync();
return activity;
}

导致挂起的位置是里面的getInstrumentation().waitForIdleSync()方法，到了这里再代码跟踪进去看到的就是android.app.instrumentation这个基类里面:

/**
* Synchronously wait for the application to be idle.  Can not be called
* from the main application thread -- use {@link #start} to execute
* instrumentation in its own thread.
*/
public void waitForIdleSync() {
validateNotAppThread();
Idler idler = new Idler(null);
mMessageQueue.addIdleHandler(idler);
mThread.getHandler().post(new EmptyRunnable());
idler.waitForIdle();
}

这里依照本人的理解做的事情大概例如以下：

首先确保调用这种方法的来源不是application的主线程
然后把当前等待application变成idle的请求放到消息队列中
最后等待app在处理全然部事件达到idle状态的时候返回

看到这里我幡然领悟。在目标平台上面我们有一个天气预报的功能。在不停的发送事件给application（也就是launcher）来更新当前的天气情况。所以一直没有达到idle的状态。这样这个函数也就一直没有返回而挂起了。而在本人的測试手机上測试的notepad这个apk，一进去的launchable activity就是idle的。所以不会碰到这个问题。

带着这个思路在调整googlekeyword在stackoverflow中找到了国外同行碰到的一个类似的问题：http://stackoverflow.com/questions/20860832/why-does-getactivity-block-during-junit-test-when-custom-imageview-calls-start
这里总结下本人研究过程中了解到的robotium初始化solo的时候new Solo(getInstrumentation(),getActivity())中getActivity所做的事情：

假设目标activity没有起来。那么启动该activity并放在前台
假设目标activity已经起来，那么直接放在前台等待被測试
假设该该activity所属application在自己主动不停的接受事件，直接调用getActivity会由于一直等待application变成idle状态而挂起

3. 解决方法

本人依照项目中的目标測试launcher的实际情况想到的解决方法是在初始化solo的时候不去调用getActivity()这个InstrumentationTestCase2的方法：

solo = new Solo(getInstrumentation());

由于我们的launcher在robotium在kill掉原来的launcher进程的时候就会自己主动起来，所以并不须要手动的去getActivity()去启动。这样的方法在不能启动起来的apk如notepad上面就不行，不信你去掉getActivity()的调用，保证notepad不会启动或者放到前台。可是假设你在開始測试前先把notepad手动起来并放到前台，測试还是会正常进行的。比方下面的验证性代码：

package com.example.android.notepad.tryout;

import com.robotium.solo.Solo;

import android.test.ActivityInstrumentationTestCase2;
import android.widget.TextView;
import android.app.Activity;

@SuppressWarnings("rawtypes")
public class NotePadTest extends ActivityInstrumentationTestCase2{

private static Solo solo = null;
public Activity activity;

private static final int NUMBER_TOTAL_CASES = 2;
private static int run = 0;

private static Class<?> launchActivityClass;
//相应re-sign.jar生成出来的信息框里的两个值
private static String mainActiviy = "com.example.android.notepad.NotesList";
private static String packageName = "com.example.android.notepad";

static {

try {

launchActivityClass = Class.forName(mainActiviy);

} catch (ClassNotFoundException e) {

throw new RuntimeException(e);

}

}

@SuppressWarnings("unchecked")
public NotePadTest() {
super(packageName, launchActivityClass);
}

@Override
public void setUp() throws Exception {
//setUp() is run before a test case is started.
//This is where the solo object is created.
super.setUp();
//The variable solo has to be static, since every time after a case's finished, this class TCCreateNote would be re-instantiated
// which would lead to soto to re-instantiated to be null if it's not set as static
//TextView title = (TextView)getActivity().findViewById(Ref.id.title);

if(solo == null) {

NotePadTest.solo = new Solo(getInstrumentation());//, getActivity());

}
}

@Override
public void tearDown() throws Exception {
//Check whether it's the last case executed.
run += countTestCases();
if(run >= NUMBER_TOTAL_CASES) {
solo.finishOpenedActivities();
}
}

public void testAddNoteCNTitle() throws Exception {
//getActivity();
Thread.sleep(5000);
solo.clickOnMenuItem("Add note");
solo.enterText(0, "中文标签笔记");
solo.clickOnMenuItem("Save");
solo.clickInList(0);
solo.clearEditText(0);
solo.enterText(0, "Text 1");
solo.clickOnMenuItem("Save");
solo.assertCurrentActivity("Expected NotesList Activity", "NotesList");

solo.clickLongOnText("中文标签笔记");
solo.clickOnText("Delete");

}
}

初始化solo的时候和testcase里面都没有去调用getActivity(),可是在testcase開始前先睡眠5秒。假设在这5秒的过程中你手动把notepad给启动起来，那么睡眠时间过后測试会继续正常执行。

刚才stackoverflow上提到的另外一个方法是重写getActivity()这个IntrumentationTestCase2的方法（注意我们全部的robotium測试类都是继承于该class的):

@Override
public MyActivity getActivity() {
if (mActivity == null) {
Intent intent = new Intent(getInstrumentation().getTargetContext(), MyActivity.class);
intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
// register activity that need to be monitored.
monitor = getInstrumentation().addMonitor(MyActivity.class.getName(), null, false);
getInstrumentation().getTargetContext().startActivity(intent);
mActivity = (MyActivity) getInstrumentation().waitForMonitor(monitor);
setActivity(mActivity);
}
return mActivity;
}

鉴于本人如今仅仅是做前期的可行性研究，够用就好。且周末手头上也没有目标机器在手进行验证，所以有兴趣的朋友就自己去尝试下吧。

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