SpringMVC项目添加日志

谁践踏了优雅 2022-05-27 04:37 221阅读 0赞

在项目中日志信息真的是不容忽视，我继续跟进我之前的项目，现在开始来添加日志了，首先看一下错误信息

11-Apr-2018 17:24:05.786 INFO \[RMI TCP Connection(3)-127.0.0.1\] org.apache.jasper.servlet.TldScanner.scanJars At least one JAR was scanned for TLDs yet contained no TLDs. Enable debug logging for this logger for a complete list of JARs that were scanned but no TLDs were found in them. Skipping unneeded JARs during scanning can improve startup time and JSP compilation time.  
SLF4J: Failed to load class "org.slf4j.impl.StaticLoggerBinder".  
SLF4J: Defaulting to no-operation (NOP) logger implementation  
SLF4J: See http://www.slf4j.org/codes.html\#StaticLoggerBinder for further details.

MLog initialization issue: slf4j found no binding or threatened to use its (dangerously silent) NOPLogger. We consider the slf4j library not found.

直接不看了，只看主要的，那为啥要贴出来？贴出来搜索引擎才能在你贴错误信息的时候能搜出我写的啊

直接看这一段，SLF4J: Failed to load class "org.slf4j.impl.StaticLoggerBinder".

他的意思是这个包SLF4J没有找到org.slf4j.impl.StaticLoggerBinder这个类，也就是说我们确少依赖，所以我们添加依赖就行了，我们在gradle里面加上这样的几段，等待gradle的更新，然后我们重启tomcat再来看看

compile group: 'org.slf4j', name: 'slf4j-api', version: '1.7.25'
        compile group: 'org.slf4j', name: 'slf4j-log4j12', version: '1.7.25'
        compile group: 'org.slf4j', name: 'jcl-over-slf4j', version: '1.7.25'
        compile group: 'org.slf4j', name: 'jul-to-slf4j', version: '1.7.25'

现在我们发现控制台的日志信息改了

11-Apr-2018 17:31:37.126 INFO \[RMI TCP Connection(3)-127.0.0.1\] org.apache.jasper.servlet.TldScanner.scanJars At least one JAR was scanned for TLDs yet contained no TLDs. Enable debug logging for this logger for a complete list of JARs that were scanned but no TLDs were found in them. Skipping unneeded JARs during scanning can improve startup time and JSP compilation time.

log4j:WARN No appenders could be found for logger (org.springframework.web.context.ContextLoader).  
log4j:WARN Please initialize the log4j system properly.

log4j:WARN See http://logging.apache.org/log4j/1.2/faq.html\#noconfig for more info.

现在我们来看这一段log4j:WARN Please initialize the log4j system properly.

他的意思是要使用这个东西我们还需要对他进行配置，ok，我们现在就来配置他

我们在reresources文件夹下面新建一个 log4j.properties 文件，这个文件名是固定的，所以就不要想着改啦，文件地址也是classpath的地址，所以也不要想着变啦，当然你可以选择改掉它里面的配置去实现这样的功能

在里面加上下面的这些东西，这些只是一些很简单的基本的配置，这里我也不做详细的解释了，需要更详细的配置可以参考[log4j详细配置][log4j]，这篇文章对里面的配置写的很清楚，感兴趣的可以去看看

### set log levels ###
    log4j.rootLogger=INFO , console , debug , error
    ### console ###
    log4j.appender.console=org.apache.log4j.ConsoleAppender
    log4j.appender.console.Target=System.out
    log4j.appender.console.layout=org.apache.log4j.PatternLayout
    log4j.appender.console.layout.ConversionPattern=%-d{yyyy-MM-dd HH\:mm\:ss} [%p]-[%c] %m%n
    ### log file ###
    log4j.appender.debug=org.apache.log4j.DailyRollingFileAppender
    log4j.appender.debug.File=log.log
    log4j.appender.debug.Append=true
    log4j.appender.debug.Threshold=INFO
    log4j.appender.debug.layout=org.apache.log4j.PatternLayout
    log4j.appender.debug.layout.ConversionPattern=%-d{yyyy-MM-dd HH\:mm\:ss} [%p]-[%c] %m%n
    ### exception ###
    log4j.appender.error=org.apache.log4j.DailyRollingFileAppender
    log4j.appender.error.File=error-log.log
    log4j.appender.error.Append=true
    log4j.appender.error.Threshold=ERROR
    log4j.appender.error.layout=org.apache.log4j.PatternLayout
    log4j.appender.error.layout.ConversionPattern=%-d{yyyy-MM-dd HH\:mm\:ss} [%p]-[%c] %m%n
    ###需要声明，然后下方才可以使druid sql输出，否则会抛出log4j.error.key not found
    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{ISO8601} %l %c%n%p: %m%n
    ### druid sql ###
    log4j.logger.druid.sql=warn,stdout
    log4j.logger.druid.sql.DataSource=warn,stdout
    log4j.logger.druid.sql.Connection=warn,stdout
    log4j.logger.druid.sql.Statement=warn,stdout
    log4j.logger.druid.sql.ResultSet=warn,stdout

到这里我们的配置已经完成，我们需要对他进行测试才行，我就很懒，还是在我之前的Controller立面进行测试了，我现在是在跟进我的项目，实现这个功能和解决问题，大家如果感兴趣的话可以去GitHub下载我的项目[GitHub传送门][GitHub]

import org.apache.log4j.Logger;//导入这个包
        private final static Logger logger = Logger.getLogger (IndexController.class);//这个里面传入的类就是本类
        @RequestMapping("home")
        public String home() {
            //调用什么方法就是表示日志的级别
            logger.info("this.info-log");
            logger.error("this.error-log");
            logger.debug("this.debug-log");
            logger.trace("this.trace-log");
            return "home";
        }

![70][]

弄完之后，启动tomcat，敲入地址然后看控制台输出的日志信息

![70 1][]

可以看到我写了四个日志输出但是只打印出来了两条信息，这个是因为配置的日志级别，我配置的是INFO，他只输出INFO和ERROR级别的日志

到现在为止我们的日志也就完成了，有什么不正确的欢迎前来指导

转载请标明出处：https://blog.csdn.net/qq\_33733799/article/details/79899929

[log4j]: https://blog.csdn.net/dr_guo/article/details/50718063
[GitHub]: https://github.com/XiaoHang233/Practice.git
[70]: /images/20220527/2f0a18c7791441e9be40e9796ad1af47.png
[70 1]: /images/20220527/485c3c0bbbb4443592a4680c36d92ba7.png