[开发测试]PowerMock测试私有方法和属性

第一章 PowerMock单元模拟测试框架简介

第二章 PowerMock模拟功能异常

在实际工作中是否碰到,当某些方法或属性定为私有的,是比较重要的功能点需要用单元测试验证。在不改变代码的情况下，如何验证？对了，使用PowerMock轻松解决。PowerMock的诞生就为了解决其他单元测试框架不能解决的问题。工作中多做本地单元测试，可以有效提前发现问题并及时处理，最后做到每个功能"0"bug，代码的质量也有了保障。这段时间连续发了几遍关于PowerMock文章，是个人学习的总结分享，而学PowerMock的原因，是在一次读spring源码时发现spring每一个模块必定会有单元测试类(如下图)，经典框架都怎么做了，所以也跟着学了。 下面分享测试方法。

spring-beans源码单元测试案例示意图

一 PowerMock测试类普通私有方法和静态私有方法。

1 PowerMock功能调用

PowerMock.when(Object instance, String methodName, Object... arguments)

PowerMockito.verifyPrivate(Object instance).invoke(, String methodName, Object... arguments);

2 被测试普通私有方法和静态私有方法demo

package powerMock;
public class OrderService {
    private  OrderDao orderDao;
    public void setOrderDao(OrderDao orderDao) {
        this.orderDao = orderDao;
    }
    public OrderService(OrderDao orderDao) {
        this.orderDao = orderDao;
    }
  //普通私有方法
  private int update1(){
      try{
          orderDao.update();
      }catch (Exception e){
          e.printStackTrace();
      }
      return 1;
  }
  //静态私有方法
  private static void updateById(){
        System.out.println("updateById");
   }
  
  //静态带参私有方法
  private static void updateById(String param){
        System.out.println("updateById:" +param);
    }
  
  //测试静态带参数和返回值的方法
   private static int updateByIdWithResult(String param){
        System.out.println("updateByIdWithResult:" +param);
        return 0;
    }
}

3 测试普通私有方法和静态私有方法demo

package powerMock;

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;

@RunWith(PowerMockRunner.class)
@PrepareForTest({StringUtils.class})
public class TestOrderService {
   //测试普通私有方法
    @Test
    public void testPrivateMethod(){
        OrderDao orderDao=PowerMockito.mock(OrderDao.class);
        OrderService  orderService=new OrderService(orderDao);
        OrderService  spy=PowerMockito.spy(orderService);
        try {
            PowerMockito.when(spy, "update1",new Object[]{});
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
   //测试普通私有方法另一种方法
   @Test
    public void testPrivateMethod1(){
        OrderDao orderDao=new OrderDao();
        OrderService  orderService=new OrderService(orderDao);
        try {
            PowerMockito.verifyPrivate(orderService).invoke("update1",new Object[]{});
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
    
     //测试静态私有方法
    @Test
    public void testPrivateStaticMethod(){
        OrderDao orderDao=new OrderDao();
        OrderService  orderService=new OrderService(orderDao);
        try {
            PowerMockito.verifyPrivate(orderService).invoke("updateById",new Object[]{});
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
    
    //测试静态私有方法带参数
    @Test
    public void testPrivateStaticMethodWithParameter(){
        OrderDao orderDao=new OrderDao();
        OrderService  orderService=new OrderService(orderDao);
        try {
            PowerMockito.verifyPrivate(orderService).invoke("updateById",new Object[]{"1"});
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
     //测试静态私有方法带参数
    @Test
    public void testPrivateStaticMethodWithParameterResult(){
        OrderDao orderDao=new OrderDao();
        OrderService  orderService=new OrderService(orderDao);
        try {
            PowerMockito.verifyPrivate(orderService).invoke("updateByIdWithResult",new Object[]{"1"});
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

}

二 PowerMock测试类普通私有成员属性和静态私有成员属性

1 PowerMock功能调用

PowerMockito.field(Class<?> declaringClass, String fieldName).set(Object obj, Object value)

2 被测试普通私有成员属性和静态私有成员属性demo

package powerMock;
public class OrderService {
  private  OrderDao orderDao;
  private Integer param;
  private static  Integer result;

    public void setOrderDao(OrderDao orderDao) {
        this.orderDao = orderDao;
    }
   public OrderService(OrderDao orderDao) {
        this.orderDao = orderDao;
   }
  public void showPrivateFild(){
      System.out.println("showPrivateFild:"+param);
  }
  
    public  static  void showPrivateStaticFild(){
        System.out.println("showPrivateStaticFild:"+result);
    }
}

3 普通私有成员属性和静态私有成员属性demo

package powerMock;

import com.fast.common.core.utils.StringUtils;
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 static org.junit.Assert.assertEquals;
@RunWith(PowerMockRunner.class)
@PrepareForTest({StringUtils.class})
public class TestOrderService {

    //测试普通私有成员属性
    @Test
    public void testShowPrivateFild(){
        OrderDao orderDao=PowerMockito.mock(OrderDao.class);
        OrderService  orderService=new OrderService(orderDao);
        try {
            PowerMockito.field(OrderService.class,"param").set(orderService,2);
            orderService.showPrivateFild();
        } catch (IllegalAccessException e) {
            e.printStackTrace();
        }
    }
  
 //测试普通私有静态成员属性跟上面的一样
    @Test
    public void testShowPrivateStaticFild(){
        OrderDao orderDao=PowerMockito.mock(OrderDao.class);
        OrderService  orderService=new OrderService(orderDao);
        try {
            PowerMockito.field(OrderService.class,"result").set(orderService,2);
            orderService.showPrivateStaticFild();
        } catch (IllegalAccessException e) {
            e.printStackTrace();
        }
    }
}

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