日志：

       记录事件发生过程，方便问题追溯，问题查找，注意中文乱码及日志级别

jar包引入：

<!-- log4j -->
<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-log4j</artifactId>
    <version>1.3.8.RELEASE</version>
</dependency>

<!--排除自带日志-->
<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-web</artifactId>
    <exclusions>
        <exclusion>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-logging</artifactId>
        </exclusion>
    </exclusions>
</dependency>

application.properties

#log4j
#logging.config=classpath:log4j.properties

log4j.properties

log4j.rootLogger=INFO, springboot, stdout

# Define all the appenders
# stdout
log4j.appender.stdout=org.apache.log4j.ConsoleAppender
log4j.appender.stdout.Target=System.out
log4j.appender.stdout.layout=org.apache.log4j.PatternLayout
log4j.appender.stdout.layout.ConversionPattern=%d{yyyy-MM-dd HH:mm:ss.SSS} %-5p [%c{1}] %m%n

log4j.appender.springboot=org.apache.log4j.DailyRollingFileAppender
log4j.appender.springboot.File=./logs/server.log
log4j.appender.springboot.Append=true
log4j.appender.springboot.DatePattern='.'yyyy-MM-dd
log4j.appender.springboot.layout=org.apache.log4j.PatternLayout
log4j.appender.springboot.layout.ConversionPattern=%d{yyyy-MM-dd HH:mm:ss.SSS} %-5p [%c] %m%n

使用：

import org.apache.log4j.Logger;

private final Logger logger = Logger.getLogger(当前类名.class);

logger.error("操作失败,msg," + e.getMessage());