使用带有 mockito 的 powermock 的空指针异常

Question

我正在尝试使用 Powermock 和 Mockito 编写 JUnit 测试用例。我正在从下面的测试用例中调用一个方法。这个方法反过来从method1调用，然后调用method2。我已经添加了@RunWith 和@PrepareForTest 注释。

//这是我的测试类：

package com.company.Abc.helpdesk.service;

import static org.junit.Assert.*;

import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.cfg.AnnotationConfiguration;
import org.junit.After;
import org.junit.Before;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.mockito.Mockito;
import org.powermock.api.mockito.PowerMockito;
import org.powermock.core.classloader.annotations.PrepareForTest;
import org.powermock.modules.junit4.PowerMockRunner;

import com.company.vtest.login.dao.AbcDAO;
import com.company.vtest.login.entity.Login;

import static org.mockito.Mockito.*;

import static org.powermock.api.mockito.PowerMockito.when;

/**
 * @author Joginder
 * 
 */
@RunWith(PowerMockRunner.class)
@PrepareForTest({ Session.class })
public class AdminServicesTestNikhil {

    @Test
    public void testRegisterNewAdmin() {
        // Declare variables to be passed as params
        Login rna = new Login(8005, "admin");

        // Mock classes

        AbcDAO mockDAO = mock(AbcDAO.class);
        PowerMockito.mockStatic(Session.class);

        // Mock method calls

        when(AbcDAO.getSession()).thenReturn(any(Session.class));

        // Call test method
        AdminServices adminServices = new AdminServices();
        assertEquals(adminServices.registerNewAdmin(rna), 0);

        // Verify method calls

        // Verify results
        fail("Not yet implemented");
    }

}


//here is the private method: 

private static SessionFactory buildSessionFactory() {
        // build session factory;
        // Read from cfg
        SessionFactory sessionFactory;
        sessionFactory = new AnnotationConfiguration()
                .addAnnotatedClass(com.company.Abc.login.entity.Login.class)
                .addAnnotatedClass(
                        com.company.Abc.assessment.entity.CreatedAsmnt.class)
                .addAnnotatedClass(
                        com.company.Abc.assessment.entity.QuesPerAsmnt.class)
                .addAnnotatedClass(
                        com.company.Abc.assessment.entity.AnsOptions.class)
                .addAnnotatedClass(
                        com.company.Abc.assessment.entity.TestTaker.class)
                .addAnnotatedClass(
                        com.company.Abc.question.entity.QuestionBank.class)
                .addAnnotatedClass(
                        com.company.Abc.question.entity.QuestionDetails.class)
                .addAnnotatedClass(
                        com.company.Abc.question.entity.AnswerDetails.class)
                .addAnnotatedClass(
                        com.company.Abc.assessment.entity.PanelRetrieval.class)
                .addAnnotatedClass(
                        com.company.Abc.assessment.entity.ViewQA.class)
                .addAnnotatedClass(
                        com.company.Abc.question.entity.Master.class)
                .addAnnotatedClass(
                        com.company.Abc.question.entity.MasterT.class)
                .addAnnotatedClass(
                        com.company.vtest.question.entity.MasterForm.class)
                .addAnnotatedClass(ResultAnnotated.class)
                .addAnnotatedClass(Candidate.class)
                .addAnnotatedClass(AssessmentTaken.class)
                .addAnnotatedClass(Section.class)
                .addAnnotatedClass(SelTechInfo.class)
                .addAnnotatedClass(AsmntSchedule.class).configure()

                .buildSessionFactory();

        return sessionFactory;

    }

错误跟踪：

java.lang.NullPointerException
    at com.company.Abc.login.dao.AbcDAO.getSession(AbcDAO.java:83)
    at com.company.Abc.helpdesk.service.AdminServicesTest.testRegisterNewAdmin(AdminServicesTest.java:54)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
    at java.lang.reflect.Method.invoke(Unknown Source)
    at org.junit.internal.runners.TestMethod.invoke(TestMethod.java:66)
    at org.powermock.modules.junit4.internal.impl.PowerMockJUnit44RunnerDelegateImpl$PowerMockJUnit44MethodRunner.runTestMethod(PowerMockJUnit44RunnerDelegateImpl.java:310)
    at org.junit.internal.runners.MethodRoadie$2.run(MethodRoadie.java:86)
    at org.junit.internal.runners.MethodRoadie.runBeforesThenTestThenAfters(MethodRoadie.java:94)
    at org.powermock.modules.junit4.internal.impl.PowerMockJUnit44RunnerDelegateImpl$PowerMockJUnit44MethodRunner.executeTest(PowerMockJUnit44RunnerDelegateImpl.java:294)
    at org.powermock.modules.junit4.internal.impl.PowerMockJUnit47RunnerDelegateImpl$PowerMockJUnit47MethodRunner.executeTestInSuper(PowerMockJUnit47RunnerDelegateImpl.java:127)
    at org.powermock.modules.junit4.internal.impl.PowerMockJUnit47RunnerDelegateImpl$PowerMockJUnit47MethodRunner.executeTest(PowerMockJUnit47RunnerDelegateImpl.java:82)
    at org.powermock.modules.junit4.internal.impl.PowerMockJUnit44RunnerDelegateImpl$PowerMockJUnit44MethodRunner.runBeforesThenTestThenAfters(PowerMockJUnit44RunnerDelegateImpl.java:282)
    at org.junit.internal.runners.MethodRoadie.runTest(MethodRoadie.java:84)
    at org.junit.internal.runners.MethodRoadie.run(MethodRoadie.java:49)
    at org.powermock.modules.junit4.internal.impl.PowerMockJUnit44RunnerDelegateImpl.invokeTestMethod(PowerMockJUnit44RunnerDelegateImpl.java:207)
    at org.powermock.modules.junit4.internal.impl.PowerMockJUnit44RunnerDelegateImpl.runMethods(PowerMockJUnit44RunnerDelegateImpl.java:146)
    at org.powermock.modules.junit4.internal.impl.PowerMockJUnit44RunnerDelegateImpl$1.run(PowerMockJUnit44RunnerDelegateImpl.java:120)
    at org.junit.internal.runners.ClassRoadie.runUnprotected(ClassRoadie.java:34)
    at org.junit.internal.runners.ClassRoadie.runProtected(ClassRoadie.java:44)
    at org.powermock.modules.junit4.internal.impl.PowerMockJUnit44RunnerDelegateImpl.run(PowerMockJUnit44RunnerDelegateImpl.java:122)
    at org.powermock.modules.junit4.common.internal.impl.JUnit4TestSuiteChunkerImpl.run(JUnit4TestSuiteChunkerImpl.java:106)
    at org.powermock.modules.junit4.common.internal.impl.AbstractCommonPowerMockRunner.run(AbstractCommonPowerMockRunner.java:53)
    at org.powermock.modules.junit4.PowerMockRunner.run(PowerMockRunner.java:59)
    at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:50)
    at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:467)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:683)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:390)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:197)

Answer 1

代替when(AbcDAO.getSession()).thenReturn(any(Session.class));，执行 Session mockedSession = mock(Session.class); when(AbcDAO.getSession()).thenReturn(mockedSession);

any() 只是一个模式匹配器。 mock() 将使用给定的类创建一个模拟对象。

Answer 2

公共类 AbcDAO {

private static SessionFactory sessionFactory=null; 
private static Session session;
public static Connection con = null;



private static SessionFactory buildSessionFactory() {
    // build session factory;
    // Read from cfg
    SessionFactory sessionFactory;
    sessionFactory = new AnnotationConfiguration()
            .addAnnotatedClass(com.company.Abc.login.entity.Login.class)
            .addAnnotatedClass(
                    com.company.Abc.assessment.entity.CreatedAsmnt.class)
            .addAnnotatedClass(
                    com.company.Abc.assessment.entity.QuesPerAsmnt.class)
            .addAnnotatedClass(
                    com.company.Abc.assessment.entity.AnsOptions.class)
            .addAnnotatedClass(
                    com.company.Abc.assessment.entity.TestTaker.class)
            .addAnnotatedClass(
                    com.company.Abc.question.entity.QuestionBank.class)
            .addAnnotatedClass(
                    com.company.Abc.question.entity.QuestionDetails.class)
            .addAnnotatedClass(
                    com.company.Abc.question.entity.AnswerDetails.class)
            .addAnnotatedClass(
                    com.company.Abc.assessment.entity.PanelRetrieval.class)
            .addAnnotatedClass(
                    com.company.Abc.assessment.entity.ViewQA.class)
            .addAnnotatedClass(
                    com.company.Abc.question.entity.Master.class)
            .addAnnotatedClass(
                    com.company.Abc.question.entity.MasterT.class)
            .addAnnotatedClass(
                    com.company.vtest.question.entity.MasterForm.class)
            .addAnnotatedClass(ResultAnnotated.class)
            .addAnnotatedClass(Candidate.class)
            .addAnnotatedClass(AssessmentTaken.class)
            .addAnnotatedClass(Section.class)
            .addAnnotatedClass(SelTechInfo.class)
            .addAnnotatedClass(AsmntSchedule.class).configure()

            .buildSessionFactory();

    return sessionFactory;

}

静态SessionFactory sessionFactory;

public static Session getSession() throws HibernateException {

    // sessionFactory = AbcDAO.buildSessionFactory();

    try {
        if (sessionFactory != null)
            session = sessionFactory.getCurrentSession();
        else {
            sessionFactory = AbcDAO.buildSessionFactory();
            session = sessionFactory.openSession();
        }
    } catch (org.hibernate.HibernateException he) {

        session = sessionFactory.openSession();
    }
    return session;

}

public void save(Object object) {
    session.beginTransaction();
    session.save(object);
    session.close();
}

Answer 3

Session mockSession = mock(Session.class);
// Mock a static method as below
PowerMockito.mockStatic(AbcDAO.class); 
when(AbcDAO.getSession()).thenReturn(mockSession);

如果您在 adminServices.registerNewAdmin() 中调用会话对象的任何方法 在上面的 mockSession 对象上设置所需的期望。