logback xml example

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。

下面就举例介绍一下如何在项目中使用logback:

1. Send logs to Console

所有的日志都将会重定向到控制台.

logback.xml

<?xml version="1.0" encoding="UTF-8"?>
<configuration>

    <appender name="STDOUT" class="ch.qos.logback.core.ConsoleAppender">
        <layout class="ch.qos.logback.classic.PatternLayout">
            <Pattern>
                %d{yyyy-MM-dd HH:mm:ss} [%thread] %-5level %logger{36} - %msg%n
            </Pattern>
        </layout>
    </appender>

    <logger name="com.mkyong.web" level="debug" additivity="false">
        <appender-ref ref="STDOUT" />
    </logger>

    <root level="error">
        <appender-ref ref="STDOUT" />
    </root>

</configuration>

2、Send logs to File

所有的日志将会重定向到c:/logs/debug.log文件中,而且这个日志文件将会每天归档或者当文件大小超过10MB的时候

logback.xml

<?xml version="1.0" encoding="UTF-8"?>
<configuration>

    <property name="DEV_HOME" value="c:/logs" />

    <appender name="FILE-AUDIT" class="ch.qos.logback.core.rolling.RollingFileAppender">
        <file>${DEV_HOME}/debug.log</file>
        <encoder class="ch.qos.logback.classic.encoder.PatternLayoutEncoder">
            <Pattern>
                %d{yyyy-MM-dd HH:mm:ss} - %msg%n
            </Pattern>
        </encoder>

        <rollingPolicy class="ch.qos.logback.core.rolling.TimeBasedRollingPolicy">
            <!-- rollover daily -->
            <fileNamePattern>${DEV_HOME}/archived/debug.%d{yyyy-MM-dd}.%i.log
                        </fileNamePattern>
            <timeBasedFileNamingAndTriggeringPolicy  class="ch.qos.logback.core.rolling.SizeAndTimeBasedFNATP">
                <maxFileSize>10MB</maxFileSize>
            </timeBasedFileNamingAndTriggeringPolicy>
        </rollingPolicy>

    </appender>

    <logger name="com.mkyong.web" level="debug" additivity="false">
        <appender-ref ref="FILE-AUDIT" />
    </logger>

    <root level="error">
        <appender-ref ref="FILE-AUDIT" />
    </root>

</configuration>

3. Send logs to Console and File

结合控制台与文件一起输出。

logback.xml

<?xml version="1.0" encoding="UTF-8"?>
<configuration>

    <property name="DEV_HOME" value="c:/logs" />

    <appender name="STDOUT" class="ch.qos.logback.core.ConsoleAppender">
        <layout class="ch.qos.logback.classic.PatternLayout">
            <Pattern>
                %d{yyyy-MM-dd HH:mm:ss} [%thread] %-5level %logger{36} - %msg%n
            </Pattern>
        </layout>
    </appender>

    <appender name="FILE-AUDIT" class="ch.qos.logback.core.rolling.RollingFileAppender">
        <file>${DEV_HOME}/debug.log</file>
        <encoder class="ch.qos.logback.classic.encoder.PatternLayoutEncoder">
            <Pattern>
                %d{yyyy-MM-dd HH:mm:ss} - %msg%n
            </Pattern>
        </encoder>

        <rollingPolicy class="ch.qos.logback.core.rolling.TimeBasedRollingPolicy">
            <!-- rollover daily -->
            <fileNamePattern>${DEV_HOME}/archived/debug.%d{yyyy-MM-dd}.%i.log
                        </fileNamePattern>
            <timeBasedFileNamingAndTriggeringPolicy  class="ch.qos.logback.core.rolling.SizeAndTimeBasedFNATP">
                <maxFileSize>10MB</maxFileSize>
            </timeBasedFileNamingAndTriggeringPolicy>
        </rollingPolicy>

    </appender>

    <appender name="FILE-ERROR" class="ch.qos.logback.core.rolling.RollingFileAppender">
        <file>${DEV_HOME}/error.log</file>
        <encoder class="ch.qos.logback.classic.encoder.PatternLayoutEncoder">
            <Pattern>
                %d{yyyy-MM-dd HH:mm:ss} - %msg%n
            </Pattern>
        </encoder>

        <rollingPolicy class="ch.qos.logback.core.rolling.TimeBasedRollingPolicy">
            <!-- rollover daily -->
            <fileNamePattern>${DEV_HOME}/archived/error.%d{yyyy-MM-dd}.%i.log
                        </fileNamePattern>
            <timeBasedFileNamingAndTriggeringPolicy  class="ch.qos.logback.core.rolling.SizeAndTimeBasedFNATP">
                <maxFileSize>10MB</maxFileSize>
            </timeBasedFileNamingAndTriggeringPolicy>
        </rollingPolicy>

    </appender>

    <!-- Send logs to both console and file audit -->
    <logger name="com.mkyong.web" level="debug" additivity="false">
        <appender-ref ref="FILE-AUDIT" />
        <appender-ref ref="STDOUT" />
    </logger>

    <root level="error">
        <appender-ref ref="FILE-ERROR" />
    </root>

</configuration>

4、SiftingAppender example

把日志输出到分开的日志文件中，这个日志文件名称通过MDC在运行时定义.

logback.xml

<?xml version="1.0" encoding="UTF-8"?>
<configuration>

    <property name="DEV_HOME" value="c:/logs" />

    <appender name="FILE-THREAD" class="ch.qos.logback.classic.sift.SiftingAppender">

          <discriminator>
        <key>logFileName</key>
        <defaultValue>head0</defaultValue>
      </discriminator>

      <sift>

        <appender name="FILE-${logFileName}" class="ch.qos.logback.core.rolling.RollingFileAppender">
            <file>${DEV_HOME}/${logFileName}.log</file>

            <encoder class="ch.qos.logback.classic.encoder.PatternLayoutEncoder">
                <Pattern>
                    %d{yyyy-MM-dd HH:mm:ss} [%thread] %level %logger{35} - %msg%n
                </Pattern>
            </encoder>

            <rollingPolicy  class="ch.qos.logback.core.rolling.FixedWindowRollingPolicy">
                <FileNamePattern>${DEV_HOME}/${logFileName}.%i.log.zip
                </FileNamePattern>
                <MinIndex>1</MinIndex>
                <MaxIndex>10</MaxIndex>
            </rollingPolicy>

            <triggeringPolicy  class="ch.qos.logback.core.rolling.SizeBasedTriggeringPolicy">
                <MaxFileSize>10MB</MaxFileSize>
            </triggeringPolicy>

        </appender>

      </sift>
    </appender>

    <logger name="com.mkyong.web" level="debug" additivity="false">
        <appender-ref ref="FILE-THREAD" />
    </logger>

    <root level="error">
        <appender-ref ref="FILE-THREAD" />
    </root>

</configuration>

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

//...
public void run() {

    MDC.put('logFileName',"head1");

    logger.debug("hello");

    MDC.remove('logFileName');

}

可以查看完全的例子: Logback SiftingAppender example.

5、Set log file name programmatically

以System.setProperty的方式以编程式的命名日志名称为${log.name}.

logback.xml

<?xml version="1.0" encoding="UTF-8"?>
<configuration>

    <property name="USER_HOME" value="/home/mkyong/ant/logs" />

    <appender name="FILE-ENGINE-ERROR" class="ch.qos.logback.core.FileAppender">
        <file>${USER_HOME}/${log.name}.error</file>
        <encoder>
            <pattern>%d{yyyy-MM-dd HH:mm:ss} [%thread] %-5level %logger{36} - %msg%n</pattern>
        </encoder>
    </appender>

    <appender name="FILE-ENGINE" class="ch.qos.logback.core.FileAppender">
        <file>${USER_HOME}/${log.name}.log</file>
        <encoder>
            <pattern>%d{yyyy-MM-dd HH:mm:ss} [%thread] %-5level %logger{35} - %msg%n</pattern>
        </encoder>
    </appender>

    <logger name="com.mkyong.core" level="debug" additivity="false">
        <appender-ref ref="FILE-ENGINE" />
    </logger>

    <root level="error">
        <appender-ref ref="FILE-ENGINE-ERROR" />
    </root>

</configuration>

TestRunApp.java

package com.mkyong.core;

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

public class TestRunApp {

    //No static,else log.name.IS_UNDEFINED.log
    private final Logger logger = LoggerFactory.getLogger(TestRunApp.class);

    public static void main(String[] args) {

        //Set this before the logger start.
        System.setProperty("log.name","abcdefg");

        TestRunApp obj = new TestRunApp();
        obj.start();

    }

    private void start() {

        logger.debug("------ Starting Ant------");
        //...
    }

}

and Output:

Debug log file path
/home/mkyong/ant/logs/abcdefg.log

Error log file path
/home/mkyong/ant/logs/abcdefg.error

可以查看完全的例子: [Logback – Set log file name programmatically](Logback – Set log file name programmatically)

官方网站:http://logback.qos.ch/manual/introduction.html
推荐阅读:logback 配置详解