Question

我有一个将单例实现为

的类

public class UMR {

private static UMR umr =  new UMR();

private MR mr;

private UMR(){
    this.mr = MR.getInstance();
}

public static UMR getInstance() {
    return umr;
}

}

这是我的测试方法代码

@Test
public void test(){

    suppress(constructor(UMR.class));   

    mockStatic(UMR.class);

    UMR umr = PowerMockito.mock(UMR.class);

    when(UMR.getInstance()).thenReturn(umr);    

    System.out.println("End");

}

使用和导入注释：

import static org.powermock.api.mockito.PowerMockito.mockStatic;
import static org.powermock.api.mockito.PowerMockito.when;
import static org.powermock.api.support.membermodification.MemberMatcher.constructor;
import static org.powermock.api.support.membermodification.MemberModifier.suppress;

import org.junit.Test;
import org.junit.runner.RunWith;
import org.powermock.api.mockito.PowerMockito;
import org.powermock.core.classloader.annotations.PrepareForTest;
import org.powermock.modules.junit4.PowerMockRunner;

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

我不希望调用私有构造函数，但即使在第一个语句中成功压缩构造函数后它仍然会调用构造函数。

如果我做错了，请建议。

Answer 1

在构造函数被抑制之前调用此行中的构造函数。

SELECT st.StudentLastName, stc.CourseDate, c.CourseTitle,
   CASE WHEN stc.CourseDate IN (
      SELECT AbsenceDate FROM FactAbsence WHERE studentID = stc.StudentID
   ) THEN'missing'
   ELSE 'attended'
   END date_info
FROM dimStudent st JOIN
   factStudentCourse stc ON st.StudentID = stc.StudentID JOIN
   dimCourse c ON stc.CourseID=c.CourseID
ORDER BY stc.CourseDate DESC;

在这种情况下，您必须使用private static UMR umr = new UMR()。

Answer 2

你可以转向懒惰的初始单身模式吗？

public class UMR {
    private static UMR umr;

    private MR mr;

    private UMR(){
        this.mr = MR.getInstance();
    }

    public static UMR getInstance() {
        // double locked lazy initializing singleton
        if (umr==null) {
            synchronized(UMR.class) {
                // when we get here, another thread may have already beaten us
                // to the init
                if(umr==null) {
                    // singleton is made here on first use via the getInstance
                    // as opposed to the original example where the singleton
                    // is made when anything uses the type
                    umr = new UMR();
                }
            }
        }
        return umr;
    }
}

构造函数抑制不使用PowerMock + Mockito

2 个答案: