Log4j2获取记录事件

Question

我试图将一个小的测试用例（确保我们的日志记录按预期工作）从log4j-1.6迁移到log4j-2.6。我们正在做的是传递映射并将其记录在Debug级别下，并验证loggingEvent是否为Debug并为预期的呈现消息进行断言。我们正在这样做

   final ArgumentCaptor<LoggingEvent> loggingEventCaptor = ArgumentCaptor.forClass(LoggingEvent.class);

    verify(mockAppender).doAppend(loggingEventCaptor.capture());
    final LoggingEvent loggingEvent = loggingEventCaptor.getValue();

    assertEquals(Level.DEBUG, loggingEvent.getLevel());
    assertEquals("ExpectedMessage", loggingEvent.getRenderedMessage());

但后来知道，appender和loggingEvents不在log4j2中。但我找不到实现这一目标的方法。log4j2是否可以？

Answer 1

经过长时间的研究，我解决了这样的问题。在tst和src lik的属性文件中添加了自定义的附加程序

<?xml version="1.0" encoding="UTF-8"?>
<Configuration package="log4j.test" status="WARN">
<Appenders>
    <Console name="Console" target="SYSTEM_OUT">
        <PatternLayout pattern="%d{HH:mm:ss.SSS} [%t] %-5level %logger{36} - %msg%n"/>
    </Console>
</Appenders>
<Loggers>
    <Logger name="log4j.test.Log4jTest" level="debug">
        <AppenderRef ref="Console"/>
    </Logger>
    <Root level="debug">
        <AppenderRef ref="Console"/>
    </Root>
</Loggers>
</Configuration>

在这里，我将日志级别设置为Debug，并编写了一个自定义附加程序，该附加程序实际上已经创建了附加程序，并设置和获取日志消息

@Plugin(name = "TestAppender", category = "Core", elementType = "apender", printObject = true)
public class TestAppender extends AbstractAppender {

    private List<String> messages = new ArrayList<String>();

    protected TestAppender(String name, Filter filter, Layout<? extends Serializable> layout) {
        super(name, filter, layout);
    }

    @Override
    public void append(LogEvent event) {
        getMessages().add(event.getMessage().toString());
    }

    public static TestAppender createAppender(@PluginAttribute("name") String name,
            @PluginElement("Layout") Layout<? extends Serializable> layout, 
            @PluginElement("Filter") final Filter filter,
            @PluginAttribute("otherAttribute") String otherAttribute) {
        if (name == null) {
            LOGGER.error("No name provided for TestAppender");
            return null;
        }
        if (layout == null) {
            layout = PatternLayout.createDefaultLayout();
        }
        return new TestAppender(name, filter, layout);
    }

    public List<String> getMessages() {
        return messages;
    }

    public void setMessages(List<String> messages) {
        this.messages = messages;
    }    
}

在我的实际测试中，我在设置方法中初始化并附加了一个附加程序

   @Before
    public void setUp() {
        org.apache.logging.log4j.core.Logger logger = (org.apache.logging.log4j.core.Logger) LogManager.getRootLogger();
        PatternLayout layout = PatternLayout.createLayout("%d{HH:mm:ss.SSS} [%t] %-5level %logger{1} - %msg%n%ex",
                null, null, null, Charset.forName("GBK"), false, true, null, null);
        testAppender = TestAppender.createAppender("TestAppender", layout, null, "true");
        testAppender.start();
        logger.getContext().getConfiguration().addLoggerAppender(logger, testAppender);
    }

并以此方式断言。

   assertEquals(Level.DEBUG, LogManager.getRootLogger().getLevel());
    assertEquals(
            "[Request headers: [{key: one, values: [one1, one2]}, {key: two, values: []}, {key: three, values: [three]}]]",
            testAppender.getMessages().toString());

这是一个漫长的过程。但这对我有用。经过长时间的研究，我想到了这一点。我正在寻找更好，更简单的方法来执行此操作（如果有）。

注意：我根据目的从多个博客复制了此代码。