如果 add 方法是静态的，则没有得到答案，否则非静态 add 方法正在工作

Question

SimpleA.java 类是目标类。如果 add 方法是非静态的，我必须模拟 SimpleB.java 类的 getList 方法，它工作正常，但它显示静态 add 方法有问题

SimpleA.java

     import java.util.ArrayList;
        public class SimpleA {
                private   static  SimpleB obj1  ;

            public  static int add(){
                ArrayList<Integer> arr1 =  obj1.getList1();
                ArrayList<Integer> arr2 =  obj1.getList2();


                int res=0;

                for(Integer val : arr1){

                    res+=val;
                }
                for(Integer val1 : arr2){
                    res+=val1;
                }

                return res;


            }
        }

        SimpleB.java

        import java.util.ArrayList;
        import java.util.Iterator;


        public class SimpleB {

            public   ArrayList<Integer> getList1(){
                System.out.println("inside class SimpleB and getlist1");
                ArrayList<Integer> lst1 = new ArrayList<Integer>();
                lst1.add(10);
                lst1.add(20);
                return lst1;
            }
            public   ArrayList<Integer> getList2(){
                System.out.println("inside class SimpleB and getlist2");
                ArrayList<Integer>  lst2 = new ArrayList<Integer>();
                lst2.add(30);
                lst2.add(40);
                return lst2;
            }
        }

SimpleATest.java

这是测试类，我正在测试 SimpleA.java 类

        import java.lang.reflect.Field;
        import java.util.ArrayList;

        import org.easymock.EasyMock;
        import org.junit.After;
        import org.junit.Before;
        import org.junit.Test;
        import org.junit.runner.RunWith;
        import org.powermock.api.easymock.PowerMock;
        import org.powermock.api.mockito.PowerMockito;
        import org.powermock.core.classloader.annotations.PrepareForTest;
        import org.powermock.modules.junit4.PowerMockRunner;
        import org.powermock.reflect.Whitebox;



        @RunWith(PowerMockRunner.class)
        @PrepareForTest({SimpleA.class})

        public class SimpleATest {
                  SimpleA simpleA1;
                  SimpleB mockSample;




            @Before
            public  void setUp(){
                ArrayList<Integer> lst = new ArrayList<Integer>();
                lst.add(30);
                lst.add(40);
                lst.add(100);

                simpleA1 = new SimpleA();

                mockSample = PowerMock.createMock(SimpleB.class);
                PowerMock.mockStatic(SimpleA.class);
                EasyMock.expect(mockSample.getList1()).andReturn(lst);
                EasyMock.expect(mockSample.getList2()).andReturn(lst);
                PowerMock.replay(mockSample);

                Whitebox.setInternalState(simpleA1,mockSample);




                System.out.println("Init method is invoked");
            }

            @Test
            public void testAdd(){
                int res = simpleA1.add();
                System.out.println("res = "+res);

            }

            @After
            public void destroy(){
                System.out.println("Destroy method is invoked");
            }




        }

Answer 1

我过去曾见过这种行为。解决方法是首先在静态方法上设置默认答案，然后填写行为：

@RunWith(PowerMockRunner.class)
@PrepareForTest(MyClassWithStaticMethods.class)
public testClass{

    @Test
    public void testSomething(){
        // this prepares the class; all static methods get a default return value (in this case type Object is returned and the default returned object is null)
        PowerMockito.mockStatic(MyClassWithStaticMethods.class, new Answer<Object>() 
        {
            @Override
            public Object answer(InvocationOnMock invocation) throws Throwable {
                return null;
            }
        });

        //Now the class is prepared, we can just change the behaviour of the static method in the way we would like.
        String in = "example input string";
        String out = "example output string";

        // after preparing the class, you can override a specific static method. For this example we use the matchers, could also have used Matchers.any(String.class) or any other matcher combination as long as it maps on the method.
        PowerMockito.when(MyClassWithStaticMethods.staticMethod(Matchers.eq(in))).thenReturn(out);
    }
    //..body
}