JUnit用于try和catch块覆盖

Question

我试图为下面的代码编写一个JUnit，但我不知道如何覆盖用catch block语句编写的代码。请任何人为下面的代码编写一个示例JUnit。

这里我不想讨论任何异常，而是想讨论使用Mockito在catch块中编写的代码行。

public Product getProductLookUpData() {

        Product product = null;
        try{
            // Try to get value from cacheable method
            product = productCacheDao.getProductLookUpData();
            .....//statements
        } catch (Exception ex) {
            // getting value from db
            product = productDao.getIpacMetricCodeLookUpData();
            ....//statements
        }

        return product;
    }

Answer 1

您可以模拟productcachedao和productdao并检查在测试用例中调用这些方法的次数。您可以使用这些模拟对象模拟异常抛出，如下所示：

when(mockObject.method(any())).thenThrow(new IllegalStateException());

所以，对于你的情况，我会做这样的事情：

import org.junit.Assert;
import org.junit.Before;
import org.junit.Test;

import static org.mockito.Mockito.*;

public class ProductTest {
    private static final Product CACHED_PRODUCT = new Product("some parameters for cached product");
    private static final Product DB_PRODUCT = new Product("some parameters for DB product");

    private ProductService service;
    private ProductDao productDaoMock;
    private ProductCacheDao productCacheDaoMock;

    @Before
    public void setup() {
        service = new ProductService();
        productDaoMock = mock(ProdoctDao.class);
        service.setProductDao(productDaoMock);

        productCacheDaoMock = mock(ProdoctCacheDao.class);
        service.setProductCacheDao(productCacheDaoMock);
    }

    @Test
    public void testCache() {
        when(productCacheDaoMock.getProductLookUpData(any())).thenReturn(CACHED_PRODUCT);

        final Product product = service.getProductLookUpData();

        Assert.assertEquals(CACHED_PRODUCT, product);
        verify(productCacheDaoMock, times(1)).getProductLookUpData(any());
        verify(productDaoMock, never()).getIpacMetricCodeLookUpData(any());
    }

    @Test
    public void testDB() {
        when(productCacheDaoMock.getProductLookUpData(any())).thenThrow(new IllegalStateException());
        when(productDaoMock.getIpacMetricCodeLookUpData(any())).thenReturn(DB_PRODUCT);

        final Product product = service.getProductLookUpData();

        Assert.assertEquals(DB_PRODUCT, product);
        verify(productCacheDaoMock, times(1)).getProductLookUpData(any());
        verify(productDaoMock, times(1)).getIpacMetricCodeLookUpData(any());
    }
}