1.logback介绍
logback是由log4j创始人设计的又一个开源日志组件。logback当前分成三个模块:logback-core,logback-classic和logback-access。logback-core是其它两个模块的基础模块。logback-classic是log4j的一个改良版本。此外logback-classic完整实现SLF4J API使你可以很方便地更换成其它日志系统如log4j或JDK14 Logging。logback-access访问模块与Servlet容器集成提供通过Http来访问日志的功能(用的少)。
2. maven依赖
<dependency> <groupId>org.slf4j</groupId> <artifactId>slf4j-api</artifactId> <version>1.7.21</version> </dependency> <dependency> <groupId>ch.qos.logback</groupId> <artifactId>logback-classic</artifactId> <version>1.1.7</version> </dependency> <dependency> <groupId>ch.qos.logback</groupId> <artifactId>logback-access</artifactId> <version>1.1.7</version> </dependency>
logback-classic包含了logback-core,不需要再单独引用了。
3. 配置和使用
1. 日志使用
我们使用org.slf4j.LoggerFactory,就可以直接使用日志了。
private static final Logger logger = LoggerFactory.getLogger(this.getClass());
使用:
@Controller
@RequestMapping(value = "")
public class IndexController extends BaseController {
/**
* Success
* @param response
* @throws IOException
*/
@RequestMapping(value = "")
@ResponseBody
public void hello(HttpServletResponse response) throws IOException {
logger.debug("DEBUG TEST 这个地方输出DEBUG级别的日志");
logger.info("INFO test 这个地方输出INFO级别的日志");
logger.error("ERROR test 这个地方输出ERROR级别的日志");
}
}
2. 在控制台输出特定级别的日志
logback的配置文件都放在/src/main/resource/文件夹下的logback.xml文件中。其中logback.xml文件就是logback的配置文件。只要将这个文件放置好了之后,系统会自动找到这个配置文件。
下面的配置中,我们输出特定的ERROR级别的日志:
<?xml version="1.0"?>
<configuration>
<!-- ch.qos.logback.core.ConsoleAppender 控制台输出 -->
<appender name="console" class="ch.qos.logback.core.ConsoleAppender">
<encoder charset="UTF-8">
<pattern>[%-5level] %d{HH:mm:ss.SSS} [%thread] %logger{36} - %msg%n</pattern>
</encoder>
</appender>
<!-- 日志级别 -->
<root>
<level value="error" />
<appender-ref ref="console" />
</root>
</configuration>
结果只在控制台输出ERROR级别的日志。
3. 设置输出多个级别的日志
<?xml version="1.0"?>
<configuration>
<!-- ch.qos.logback.core.ConsoleAppender 控制台输出 -->
<appender name="console" class="ch.qos.logback.core.ConsoleAppender">
<encoder>
<pattern>[%-5level] %d{HH:mm:ss.SSS} [%thread] %logger{36} - %msg%n</pattern>
</encoder>
</appender>
<!-- 日志级别 -->
<root>
<level value="error" />
<level value="info" />
<appender-ref ref="console" />
</root>
</configuration>
设置两个level,则可以输出 ERROR和INFO级别的日志了。
4. 设置文件日志(你懂得)
additivity="false"很少将这个属性设置为true
<?xml version="1.0" encoding="UTF-8"?> <configuration> <!-- ch.qos.logback.core.ConsoleAppender 控制台输出 --> <appender name="STDOUT" class="ch.qos.logback.core.ConsoleAppender"> <encoder charset="UTF-8"> <pattern>%d{yyyy-MM-dd HH:mm:ss.SSS} [%thread] %-5level %logger{36} - %msg%n</pattern> </encoder> </appender> <!-- ch.qos.logback.core.rolling.RollingFileAppender 文件日志输出 --> <appender name="INFO" class="ch.qos.logback.core.rolling.RollingFileAppender"> <file>${catalina.base}/logs/guide_info.log</file> <rollingPolicy class="ch.qos.logback.core.rolling.TimeBasedRollingPolicy"> <fileNamePattern>${catalina.base}/logs/guide_info.%d{yyyy-MM-dd}-%i.log</fileNamePattern> <maxHistory>30</maxHistory> <timeBasedFileNamingAndTriggeringPolicy class="ch.qos.logback.core.rolling.SizeAndTimeBasedFNATP"> <MaxFileSize>50MB</MaxFileSize> </timeBasedFileNamingAndTriggeringPolicy> </rollingPolicy> <encoder> <pattern>%d{yyyy-MM-dd HH:mm:ss.SSS} [%thread] %-5level %logger{36} - %msg%n</pattern> </encoder> </appender> <!-- ch.qos.logback.core.rolling.RollingFileAppender 异常日志输出 --> <appender name="ERROR" class="ch.qos.logback.core.rolling.RollingFileAppender"> <file>${catalina.base}/logs/guide_error.log</file> <rollingPolicy class="ch.qos.logback.core.rolling.TimeBasedRollingPolicy"> <fileNamePattern>${catalina.base}/logs/guide.%d{yyyy-MM-dd}-%i.log</fileNamePattern> <maxHistory>30</maxHistory> <timeBasedFileNamingAndTriggeringPolicy class="ch.qos.logback.core.rolling.SizeAndTimeBasedFNATP"> <MaxFileSize>50MB</MaxFileSize> </timeBasedFileNamingAndTriggeringPolicy> </rollingPolicy> <encoder> <pattern>%d{yyyy-MM-dd HH:mm:ss.SSS} [%thread] %-5level %logger{36} - %msg%n</pattern> </encoder> </appender> <!--打印info级别的日志--> <logger name="infoLog" level="info" additivity="false"> <appender-ref ref="INFO" /> </logger> <!--打印异常错误日志--> <logger name="errorLog" level="error" additivity="false"> <appender-ref ref="ERROR" /> </logger> <!-- 日志级别 --> <root level="debug"> <appender-ref ref="STDOUT" /> </root> </configuration>
public class Test { public static void main(String[] args) { Logger INFO_LOG = LoggerFactory.getLogger("infoLog"); Logger ERROR_LOG = LoggerFactory.getLogger("errorLog"); INFO_LOG.info("业务日志"); ERROR_LOG.error("异常日志"); } }
/** * Return a logger named according to the name parameter using the * statically bound {@link ILoggerFactory} instance. * * @param name * The name of the logger. * @return logger */ public static Logger getLogger(String name) { ILoggerFactory iLoggerFactory = getILoggerFactory(); return iLoggerFactory.getLogger(name); }
5. 精确设置每个包下面的日志
<logger name="com.xxx" additivity="false">
<level value="info" />
<appender-ref ref="file" />
<appender-ref ref="console" />
</logger>