我有以下logback.xml文件：
<configuration debug="true">
<appender name="STDOUT" class="ch.qos.logback.core.ConsoleAppender">
<encoder>
<pattern>%d{HH:mm:ss.SSS} [%thread] %-5level %logger{36} - %msg%n</pattern>
</encoder>
</appender>
<root level="debug">
<appender-ref ref="STDOUT" />
</root>
</configuration>现在，在发生特定事件时，我想以编程方式将root记录程序的级别从debug更改为error。我不能使用变量替换，这是强制性的，我必须在代码中执行此操作。
如何做呢 ？谢谢。
Answers:
试试这个：
import org.slf4j.LoggerFactory;
import ch.qos.logback.classic.Level;
import ch.qos.logback.classic.Logger;
Logger root = (Logger)LoggerFactory.getLogger(Logger.ROOT_LOGGER_NAME);
root.setLevel(Level.INFO);请注意，您还可以告诉logback定期扫描您的配置文件，如下所示：
<configuration scan="true" scanPeriod="30 seconds" >
...
</configuration> 使用logback 1.1.3，我必须执行以下操作（Scala代码）：
import ch.qos.logback.classic.Logger
import org.slf4j.LoggerFactory
...
val root: Logger = LoggerFactory.getLogger(org.slf4j.Logger.ROOT_LOGGER_NAME).asInstanceOf[Logger]我认为您可以使用MDC以编程方式更改日志记录级别。下面的代码是更改当前线程的日志记录级别的示例。这种方法不会创建对logback实现的依赖（SLF4J API包含MDC）。
<configuration>
<turboFilter class="ch.qos.logback.classic.turbo.DynamicThresholdFilter">
<Key>LOG_LEVEL</Key>
<DefaultThreshold>DEBUG</DefaultThreshold>
<MDCValueLevelPair>
<value>TRACE</value>
<level>TRACE</level>
</MDCValueLevelPair>
<MDCValueLevelPair>
<value>DEBUG</value>
<level>DEBUG</level>
</MDCValueLevelPair>
<MDCValueLevelPair>
<value>INFO</value>
<level>INFO</level>
</MDCValueLevelPair>
<MDCValueLevelPair>
<value>WARN</value>
<level>WARN</level>
</MDCValueLevelPair>
<MDCValueLevelPair>
<value>ERROR</value>
<level>ERROR</level>
</MDCValueLevelPair>
</turboFilter>
......
</configuration>MDC.put("LOG_LEVEL", "INFO");正如其他人指出的那样，您只需创建mockAppender一个LoggingEvent实例，然后创建一个实例，该实例实际上侦听内部注册/发生的日志记录事件mockAppender。
这是测试中的样子：
import org.slf4j.LoggerFactory;
import ch.qos.logback.classic.Level;
import ch.qos.logback.classic.Logger;
import ch.qos.logback.classic.spi.ILoggingEvent;
import ch.qos.logback.classic.spi.LoggingEvent;
import ch.qos.logback.core.Appender;
@RunWith(MockitoJUnitRunner.class)
public class TestLogEvent {
// your Logger
private Logger log = (Logger) LoggerFactory.getLogger(Logger.ROOT_LOGGER_NAME);
// here we mock the appender
@Mock
private Appender<ILoggingEvent> mockAppender;
// Captor is generic-ised with ch.qos.logback.classic.spi.LoggingEvent
@Captor
private ArgumentCaptor<LoggingEvent> captorLoggingEvent;
/**
* set up the test, runs before each test
*/
@Before
public void setUp() {
log.addAppender(mockAppender);
}
/**
* Always have this teardown otherwise we can stuff up our expectations.
* Besides, it's good coding practise
*/
@After
public void teardown() {
log.detachAppender(mockAppender);
}
// Assuming this is your method
public void yourMethod() {
log.info("hello world");
}
@Test
public void testYourLoggingEvent() {
//invoke your method
yourMethod();
// now verify our logging interaction
// essentially appending the event to mockAppender
verify(mockAppender, times(1)).doAppend(captorLoggingEvent.capture());
// Having a generic captor means we don't need to cast
final LoggingEvent loggingEvent = captorLoggingEvent.getValue();
// verify that info log level is called
assertThat(loggingEvent.getLevel(), is(Level.INFO));
// Check the message being logged is correct
assertThat(loggingEvent.getFormattedMessage(), containsString("hello world"));
}
}