Mockito应用

import static org.mockito.Mockito.mock;
import static org.mockito.Mockito.when;

import org.junit.Assert;
import org.junit.Test;
import org.mockito.Mockito;

public class MockitoDemo {
	@Test
	public void mockitoTest() throws Exception {
		Service service = new Service();
		Dao dao = mock(Dao.class);// 相当于 new一个dao的模拟类
		service.setDao(dao);
		when(dao.update("1", "2")).thenReturn(2);
		Assert.assertEquals(2, service.update("1", "2"));

		// 方法的参数可以匹配任意值，Mockito.anyXXX() 和任意类 Mockito.any(clazz)
		when(dao.update(Mockito.anyString(), Mockito.any(String.class))).thenReturn(3);
		// 不能将确定值和模糊值混搭，这样会报错
		// when(dao.update("3", Mockito.any(String.class))).thenReturn(3);
		Assert.assertEquals(3, service.update("3", "4"));

		// 下面模拟抛异常
		when(dao.update("3", "4")).thenThrow(new RuntimeException());
		Assert.assertEquals(-1, service.update("3", "4"));

		// void方法抛异常
		Mockito.doThrow(new RuntimeException("测试")).when(dao).voidTest();
		try {
			service.voidTest();
		} catch (Exception e) {
			Assert.assertEquals("测试", e.getMessage());
		}

		// 不能模拟抛Exception类
		// when(dao.update("3", "4")).thenThrow(new Exception());

		// 同一方法不能多次模拟抛异常
		// when(dao.update("3", "4")).thenThrow(new NullPointerException());
		// Assert.assertEquals(-1, service.update("3", "4"));
	}
}

class Service {
	private Dao dao;

	public void setDao(Dao dao) {
		this.dao = dao;
	}

	public void voidTest() {
		dao.voidTest();
	}

	public int update(String a, String b) {
		int i = 0;
		try {
			i = dao.update(a, b);
		} catch (Exception e) {
			i = -1;
		}
		return i;
	}
}

class Dao {
	public void voidTest() {
	}

	public int update(String a, String b) {
		return 1;
	}
}

附上maven依赖
<dependency>
<groupId>org.mockito</groupId>
<artifactId>mockito-all</artifactId>
<version>1.8.5</version>
</dependency>