Android

1 打印线程id

Thread.currentThread().getId()

2 打印堆栈

Log.info(Log.getStackTraceString(new Throwable()));

3.天气访问接口

接口地址：http://www.weather.com.cn/data/sk/101010100.htmlhttp://www.weather.com.cn/data/cityinfo/101010100.htmlhttp://m.weather.com.cn/data/101010100.html

4豆瓣250连接

https://api.douban.com/v2/movie/top250?start=0&count=10

5 判断当前是否允许横竖屏切换

private boolean isAutoRotateOn(Context context) {        return android.provider.Settings.System.getInt(context.getContentResolver(),        Settings.System.ACCELEROMETER_ROTATION, 0) == 1 ;    }

6 Fragment&ViewPager
I encountered the similar issue as you, after several hours research, I found the issue. If your ViewPager is created inside the Fragment, you need to use getChildFragmentManager() for the FragmentPagerAdapter, rather than getFragmentManager().

So your setupViewPager() method should look like this.

private void setupViewPager(ViewPager viewPager) {    ViewPagerAdapter adapter = new ViewPagerAdapter(getChildFragmentManager());    adapter.addFrag(new Courses(), "IT");    adapter.addFrag(new CoursesBussiness(), "Business");    viewPager.setAdapter(adapter);}

The root cause of the issue is you embeded Fragments inside the Fragment, that’s why it will throw the exception.

java.lang.IllegalStateException: FragmentManager is already executing transactions

According to the Google’s docs:

You can now embed fragments inside fragments. This is useful for a variety of situations in which you want to place dynamic and re-usable UI components into a UI component that is itself dynamic and re-usable. For example, if you use ViewPager to create fragments that swipe left and right and consume a majority of the screen space, you can now insert fragments into each fragment page. To nest a fragment, simply call getChildFragmentManager() on the Fragment in which you want to add a fragment. This returns a FragmentManager that you can use like you normally do from the top-level activity to create fragment transactions.