SpringBoot学习(1) - 日志

 package com.study.spring_boot_log;

 import org.springframework.boot.SpringApplication;
 import org.springframework.boot.autoconfigure.SpringBootApplication;
 import org.springframework.boot.autoconfigure.websocket.WebSocketAutoConfiguration;
 import org.springframework.context.ConfigurableApplicationContext;

 import com.study.spring_boot_log.dao.UserDao;
 import com.study.spring_boot_log.service.UserService;
 @SpringBootApplication(exclude=WebSocketAutoConfiguration.class)
 public class App {
     public static void main(String[] args) {
         ConfigurableApplicationContext context = SpringApplication.run(App.class,args);
         context.getBean(UserDao.class).log();
         System.out.println("===================");
         context.getBean(UserService.class).log();

         context.close();
     }
 }

pom.xml:

 <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
     xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>

     <groupId>com.study.springboot</groupId>
     <artifactId>spring-boot-log</artifactId>
     <version>1.0.0</version>
     <packaging>jar</packaging>

     <name>spring-boot-log</name>
     <url>http://maven.apache.org</url>

     <properties>
         <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
     </properties>

     <dependencyManagement>
         <dependencies>
             <dependency>
                 <groupId>org.springframework.boot</groupId>
                 <artifactId>spring-boot-dependencies</artifactId>
                 <version>1.5.3.RELEASE</version>
                 <scope>import</scope>
                 <type>pom</type>
             </dependency>
         </dependencies>
     </dependencyManagement>

     <dependencies>
         <dependency>
             <groupId>org.springframework.boot</groupId>
             <artifactId>spring-boot-starter</artifactId>
         </dependency>
     </dependencies>
 </project>

 package com.study.spring_boot_log.dao;

 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 import org.springframework.stereotype.Component;

 @Component
 public class UserDao {
     private Logger log = LoggerFactory.getLogger(UserDao.class);
     public void log() {
         log.debug("user dao debug log");
         log.info("user dao info log");
         log.warn("user dao warn log");
         log.error("user dao error log");
     }
 }

 package com.study.spring_boot_log.service;

 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 import org.springframework.stereotype.Component;

 @Component
 public class UserService {
     private Logger log = LoggerFactory.getLogger(UserService.class);
     public void log() {
         log.debug("user service debug log");
         log.info("user service info log");
         log.warn("user service warn log");
         log.error("user service error log");
     }
 }

springboot默认 的日志级别是info
可以通过logging.level.*=debug配置项设置，*可以是包，也可以是某个类。

也可以在Run Configurations中配置 --debug，或者SpringApplication.run(App.class,“--debug=true”)。这两种debug只会是springboot默认，自定义的类不会debug。

日志级别有：TRACE,DEBUG,INFO,WARN,ERROR,FATA,OFF
日志级别配置成OFF，表示关闭日志输出

logging.file 指定日志文件路径名字
logging.path 指定日志目录(此时的日志名字为spring.log)
日志文件输出，文件的大小10M之后，就会分割

logging.pattern.console 配置控制台输出日志的pattern
logging.file.console 配置日志文件输出日志的pattern

application.properties

 logging.level.com.study.spring_boot_log.dao.UserDao=off
 logging.level.com.study.spring_boot_log.service.UserService=DEBUG

 logging.file=D:/ivy/mylog
 logging.path=D:/ivy/mylogs

 logging.pattern.console=%-20(%d{yyyy-MM-dd} [%thread]) %-5level %logger{80} - %msg%n
 logging.file.console=%-20(%d{yyyy-MM-dd HH:mm:ss.SSS} [%thread]) %-5level %logger{80} - %msg%n

springboot 默认支持logback
也就是说，只需要在classpath下放一个logback.xml，logback-spring.xml的文件，即可定制日志的输出

logback-spring.xml或logback.xml：

 <?xml version="1.0" encoding="UTF-8"?>
 <configuration>
   <appender name="consoleLog" class="ch.qos.logback.core.ConsoleAppender">
     <layout class="ch.qos.logback.classic.PatternLayout">
       <pattern>%-20(%d{yyyy-MM-dd HH:mm:ss.SSS} [%thread]) %-5level %logger{80} - %msg%n</pattern>
     </layout>
   </appender>  

   <root level="debug">
     <appender-ref ref="consoleLog" />
   </root>
 </configuration>

使用其他的日志组件的步骤：
1.排除默认的日志组件：spring-boot-starter-logging
2.加入新的日志路径依赖
3.把相应的配置文件放在classpath下

log4j2.xml：

 <?xml version="1.0" encoding="UTF-8"?>
 <configuration>
     <appenders>
         <Console name="console" target="SYSTEM_OUT" follow="true">
           <PatternLayout pattern="%d{yyyy-MM-dd} [%thread] %-5level %logger{80} - %msg%n"/>
         </Console>
    </appenders>
    <loggers>
     <root level="DEBUG">
       <appender-ref ref="console"/>
     </root>
   </loggers>
 </configuration>