从青铜到王者，如何从0到1搭建一个完善的日志系统

public class App {
   public static void main(String[] args) throws IOException {
 
       Enumeration<URL> resources = App.class.getClassLoader().getResources("org/slf4j/impl/StaticLoggerBinder.class");
       while(resources.hasMoreElements()) {
           URL path = resources.nextElement();
           System.out.println(path);
      }
  }
}

<!-- 日志输出级别 -->
   <root level="INFO">
       <appender-ref ref="STDOUT" />
       <appender-ref ref="FILE" />
   </root>

<!-- Slf4j 依赖 -->
       <dependency>
           <groupId>org.slf4j</groupId>
           <artifactId>slf4j-api</artifactId>
           <version>1.7.30</version>
       </dependency>
       <!-- logback 依赖 -->
       <dependency>
           <groupId>ch.qos.logback</groupId>
           <artifactId>logback-classic</artifactId>
           <version>1.2.3</version>
       </dependency>

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

   <!--自定义控制台日志格式-->
   <appender name="CONSOLE" class="ch.qos.logback.core.ConsoleAppender">
       <encoder charset="UTF-8">
           <pattern>[%d{yyyy-MM-dd HH:mm:ss.SSS}] %level [%thread] %file:%line - %msg%n</pattern>
           <charset>UTF-8</charset>
       </encoder>
   </appender>

   <!--系统INFO级别日志-滚动记录日志-->
   <appender name="SYS_INFO" class="ch.qos.logback.core.rolling.RollingFileAppender">
       <!--被写入的文件名，可以是相对目录，也可以是绝对目录，如果上级目录不存在会自动创建，没有默认值-->
       <File>sys_info.log</File>
       <!--如果是 true，日志被追加到文件结尾，如果是 false，清空现存文件，默认是true。-->
       <append>true</append>
       <!--级别过滤器（LevelFilter）,此处只打INFO级别的日志-->
       <filter class="ch.qos.logback.classic.filter.LevelFilter">
           <level>INFO</level>
           <!--下面2个属性表示匹配规定level的接受打印，不匹配的（即非INFO）拒绝打印-->
           <onMatch>ACCEPT</onMatch>
           <onMismatch>DENY</onMismatch>
       </filter>
       <!-- 最常用的滚动策略，它根据时间来制定滚动策略，既负责滚动也负责出发滚动-->
       <rollingPolicy class="ch.qos.logback.core.rolling.TimeBasedRollingPolicy">
           <!--设置滚动文件规则，如果直接使用 %d，默认格式是 yyyy-MM-dd-->
           <fileNamePattern>sys_info.log.%d</fileNamePattern>
           <!--保留30天的日志-->
           <maxHistory>30</maxHistory>
       </rollingPolicy>

       <encoder charset="UTF-8">
           <pattern>[%d{yyyy-MM-dd HH:mm:ss.SSS}] %level [%thread] %file:%line - %msg%n</pattern>
           <charset>UTF-8</charset>
       </encoder>
   </appender>

   <!--系统ERROR级别日志-滚动记录日志-->
   <appender name="SYS_ERROR" class="ch.qos.logback.core.rolling.RollingFileAppender">
       <File>sys_error.log</File>
       <append>true</append>
       <!--此处只打ERROR级别的日志-->
       <filter class="ch.qos.logback.classic.filter.LevelFilter">
           <level>ERROR</level>
           <onMatch>ACCEPT</onMatch>
           <onMismatch>DENY</onMismatch>
       </filter>
       <rollingPolicy class="ch.qos.logback.core.rolling.TimeBasedRollingPolicy">
           <fileNamePattern>sys_error.log.%d</fileNamePattern>
           <maxHistory>12</maxHistory>
       </rollingPolicy>

       <encoder charset="UTF-8">
           <pattern>[%d{yyyy-MM-dd HH:mm:ss.SSS}] %level [%thread] %file:%line - %msg%n</pattern>
           <charset>UTF-8</charset>
       </encoder>
   </appender>

   <!--不同业务逻辑的日志打印到不同文件，见下面2种业务日志-->

   <!--业务逻辑日志-->
   <appender name="game_Appender" class="ch.qos.logback.core.rolling.RollingFileAppender">
       <File>D:/log/yj-test/b1.log</File>
       <append>true</append>
       <filter class="ch.qos.logback.classic.filter.LevelFilter">
           <level>INFO</level>
           <onMatch>ACCEPT</onMatch>
           <onMismatch>DENY</onMismatch>
       </filter>
       <rollingPolicy class="ch.qos.logback.core.rolling.TimeBasedRollingPolicy">
           <fileNamePattern>D:/log/yj-test/b1.log.%d</fileNamePattern>
           <maxHistory>12</maxHistory>
       </rollingPolicy>
       <encoder charset="UTF-8">
           <pattern>[%d{yyyy-MM-dd HH:mm:ss.SSS}] %level [%thread] %file:%line - %msg%n</pattern>
           <charset>UTF-8</charset>
       </encoder>
   </appender>

   <!--战斗日志-->
   <appender name="fight_Appender" class="ch.qos.logback.core.rolling.RollingFileAppender">
       <File>D:/log/yj-test/b2.log</File>
       <append>true</append>
       <filter class="ch.qos.logback.classic.filter.LevelFilter">
           <level>INFO</level>
           <onMatch>ACCEPT</onMatch>
           <onMismatch>DENY</onMismatch>
       </filter>
       <rollingPolicy class="ch.qos.logback.core.rolling.TimeBasedRollingPolicy">
           <fileNamePattern>D:/log/yj-test/b2.log.%d</fileNamePattern>
           <maxHistory>12</maxHistory>
       </rollingPolicy>
       <encoder charset="UTF-8">
           <pattern>[%d{yyyy-MM-dd HH:mm:ss.SSS}] %level [%thread] %file:%line - %msg%n</pattern>
           <charset>UTF-8</charset>
       </encoder>
   </appender>

   <!-- additivity属性为false，表示此logger的打印信息不再向上级传递(注：该值默认为true，logger的日志信息会依次向上级传递，最高级logger为root，如果不加则至少打印2次，本身一次，root一次)-->
   <logger name="game" additivity="false" level="INFO">
       <appender-ref ref="CONSOLE"/>
   </logger>
   <logger name="fight" additivity="false" level="INFO">
       <appender-ref ref="fight_Appender"/>
   </logger>


   <!--info和error分开打印，注：ERROR > WARN > INFO > DEBUG > TRACE-->
   <root level="INFO">
       <appender-ref ref="CONSOLE"/>
       <appender-ref ref="SYS_INFO"/>
       <appender-ref ref="SYS_ERROR"/>
   </root>

</configuration>

package com.pdool.logdemo;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication
public class LogDemoApplication {

   public static void main(String[] args) {
       SpringApplication.run(LogDemoApplication.class, args);
       Logger logger = LoggerFactory.getLogger(LogDemoApplication.class);
       Logger gameLogger = LoggerFactory.getLogger("game");
       logger.error("ccccccccccccccc");
       gameLogger.error("bbbbbbbbbbb");
  }

}