Junit测试日志语句

Question

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

public class Foo {
    private final Logger log = LoggerFactory.getLogger(Foo.class);

    public String something() {
        log.info("doing foo test");
        return "test";
    }
}

public class FooTest {
    private Foo foo;

    @Before
    public void setUp() throws Exception {
        foo = new Foo();
    }

    @Test
    public void testSomething() {
        String result = foo.something();
        assertEquals(result,"test");
    }
}

public class FooTest {
    private Foo foo;
    @Mock private Appender appender;
    @Captor private ArgumentCaptor captor;

    @Before
    public void setUp() throws Exception {
        foo = new Foo();
        MockitoAnnotations.initMocks(this);
        Logger.getRootLogger().addAppender(appender);
    }

    @After
    public void tearDown() throws Exception {
        Logger.getRootLogger().removeAllAppenders();
    }

    @Test
    public void testSomething() {
        String result = foo.something();
        assertEquals(result,"test");
        verify(appender).doAppend(((LoggingEvent) captor.capture()));
        LoggingEvent loggingEvent = (LoggingEvent) captor.getValue();
        assertEquals(loggingEvent.getRenderedMessage(), "doing foo test");
    }
}

Wanted but not invoked:
appender.doAppend(<Capturing argument>);
-> at <package>.testSomething(FooTest.java:22)
Actually, there were zero interactions with this mock.

有没有更简单的方法来完成我想要的？如果这是最好的方法，那么我做错了什么？

Answer 1

当然可以！

• 创建您自己的自定义内存中单例appender类
• 修改测试记录器配置，以便除了要进行的所有其他日志记录之外，还记录到此追加程序
• clear()在每次测试期间清除它@begin
• 断言-在测试结束前正常测试它。

实际上，SLF4J已经有了一个实现，您可以查看它。