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，我想以编程方式将根记录器的级别从 debug 更改为 error。我不能使用变量替换，我必须在代码中这样做。
怎么做？谢谢。
【问题讨论】：
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(org.slf4j.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>
【讨论】：
我假设您正在使用 logback（来自配置文件）。
来自logback manual，我知道了
Logger rootLogger = LoggerFactory.getLogger(org.slf4j.Logger.ROOT_LOGGER_NAME);
也许这可以帮助您更改值？
【讨论】：
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]
【讨论】：
正如其他人所指出的，您只需创建mockAppender，然后创建一个LoggingEvent 实例，该实例基本上侦听在mockAppender 中注册/发生的日志事件。
这是它在测试中的样子：
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"));
}
}
【讨论】：
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");
【讨论】：
我好像成功了
org.jboss.logmanager.Logger logger = org.jboss.logmanager.Logger.getLogger("");
logger.setLevel(java.util.logging.Level.ALL);
然后从netty获取详细的日志记录，下面已经做到了
org.slf4j.impl.SimpleLogger.setLevel(org.slf4j.impl.SimpleLogger.TRACE);
【讨论】：
org.slf4j.impl.SimpleLogger 在当前 v1.7.30 中没有 setLevel()。
这是一个控制器
@RestController
@RequestMapping("/loggers")
public class LoggerConfigController {
private final static org.slf4j.Logger LOGGER = LoggerFactory.getLogger(PetController.class);
@GetMapping()
public List<LoggerDto> getAllLoggers() throws CoreException {
LoggerContext loggerContext = (LoggerContext) LoggerFactory.getILoggerFactory();
List<Logger> loggers = loggerContext.getLoggerList();
List<LoggerDto> loggerDtos = new ArrayList<>();
for (Logger logger : loggers) {
if (Objects.isNull(logger.getLevel())) {
continue;
}
LoggerDto dto = new LoggerDto(logger.getName(), logger.getLevel().levelStr);
loggerDtos.add(dto);
}
if (LOGGER.isDebugEnabled()) {
LOGGER.debug("All loggers retrieved. Total of {} loggers found", loggerDtos.size());
}
return loggerDtos;
}
@PutMapping
public boolean updateLoggerLevel(
@RequestParam String name,
@RequestParam String level
)throws CoreException {
LoggerContext loggerContext = (LoggerContext) LoggerFactory.getILoggerFactory();
Logger logger = loggerContext.getLogger(name);
if (Objects.nonNull(logger) && StringUtils.isNotBlank(level)) {
switch (level) {
case "INFO":
logger.setLevel(Level.INFO);
LOGGER.info("Logger [{}] updated to [{}]", name, level);
break;
case "DEBUG":
logger.setLevel(Level.DEBUG);
LOGGER.info("Logger [{}] updated to [{}]", name, level);
break;
case "ALL":
logger.setLevel(Level.ALL);
LOGGER.info("Logger [{}] updated to [{}]", name, level);
break;
case "OFF":
default:
logger.setLevel(Level.OFF);
LOGGER.info("Logger [{}] updated to [{}]", name, level);
}
}
return true;
}
}
【讨论】：