The use of Java reflection in Android

Reprint Please specify source: http://www.cnblogs.com/cnwutianhao/p/6606687.html

Java developers or Android developers often encounter such a problem, if we want to invoke a Class A private method B, and then used in Class C. The usual method of direct invocation is not feasible. Some people say that the private to the public will be finished, but everything has a solution, do not change to public.

Go to the Chase:

There is a code like this

 Public class extends appcompatactivity {    @Override    protectedvoid  onCreate (Bundle Savedinstancestate) {        super. OnCreate (savedinstancestate);        Setcontentview (r.layout.activity_main);        Method ();    }     Private void method () {    }}

Now we want to test the private method in mainactivity with JUnit.

If we want to test the private method in Mainactivity, the direct call is not working, then we use the Java Reflection (Reflect)

First, create a test file mainactivitytest, inherit Androidtestcase

 Public class extends Androidtestcase {}

Then, create the test class TestMethod

 Public void throws Exception {}

Full Test code

 Public class extends androidtestcase {    publicvoidthrows  Exception {        new  mainactivity ();         = Mainactivity. class. Getdeclaredmethod ("method");        Testmethod.setaccessible (true);        Testmethod.invoke (activity);}    }

At this point, we can use the private method in Mainactivity!

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The use of Java reflection in Android