mybatis学习（五、日志）

五、日志

1.日志工厂

如果一个数据库操作出现了异常，我们需要排错，日志就是最好的助手

曾经：sout、debug

现在：日志工厂

设置名 描述 有效值 默认值
logImpl 指定 MyBatis 所用日志的具体实现，未指定时将自动查找。 SLF4J | LOG4J | LOG4J2 | JDK_LOGGING | COMMONS_LOGGING | STDOUT_LOGGING | NO_LOGGING 未设置
  • SLF4J
  • LOG4J 【掌握】
  • LOG4J2
  • JDK_LOGGING
  • COMMONS_LOGGING
  • STDOUT_LOGGING 【掌握】
  • NO_LOGGING

在mybatis中具体用哪一个日志实现，在日志中设定。

STDOUT_LOGGING标准日志输出

在mybatis核心配置文件中的配置

<settings>
    <setting name="logImpl" value="STDOUT_LOGGING"/>
</settings>

控制台中得到的日志

Opening JDBC Connection
Created connection 1684015092.
Setting autocommit to false on JDBC Connection [com.mysql.jdbc.JDBC4Connection@646007f4]
==>  Preparing: select * from mybatis.user where id=? 
==> Parameters: 3(Integer)
<==    Columns: id, name, pwd
<==        Row: 3, 王二, 123456
<==      Total: 1
User{id=3, name='王二', password='123456'}
Resetting autocommit to true on JDBC Connection [com.mysql.jdbc.JDBC4Connection@646007f4]
Closing JDBC Connection [com.mysql.jdbc.JDBC4Connection@646007f4]
Returned connection 1684015092 to pool.

2.log4j

什么是log4j？

  • Log4j是Apache的一个开源项目，通过使用Log4j，我们可以控制日志信息输送的目的地是控制台、文件、GUI组件，甚至是套接口服务器、NT的事件记录器、UNIX Syslog守护进程等；
  • 我们也可以控制每一条日志的输出格式；
  • 通过定义每一条日志信息的级别，我们能够更加细致地控制日志的生成过程；
  • 可以通过一个配置文件来灵活地进行配置，而不需要修改应用的代码。

  1. 先导入log4j的包

    <!-- https://mvnrepository.com/artifact/log4j/log4j -->
<dependency>
    <groupId>log4j</groupId>
    <artifactId>log4j</artifactId>
    <version>1.2.17</version>
</dependency>

  2. log4j.properties

    ### 设置###
log4j.rootLogger = debug,stdout,D,E

### 输出信息到控制抬 ###
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 = [%-5p] %d{yyyy-MM-dd HH:mm:ss,SSS} method:%l%n%m%n

### 输出DEBUG 级别以上的日志到=./logs/error.log ###
log4j.appender.D = org.apache.log4j.DailyRollingFileAppender
log4j.appender.D.File = ./logs/log.log
log4j.appender.D.Append = true
log4j.appender.D.Threshold = DEBUG 
log4j.appender.D.layout = org.apache.log4j.PatternLayout
log4j.appender.D.layout.ConversionPattern = %-d{yyyy-MM-dd HH:mm:ss}  [ %t:%r ] - [ %p ]  %m%n

### 输出ERROR 级别以上的日志到=./logs/error.log ###
log4j.appender.E = org.apache.log4j.DailyRollingFileAppender
log4j.appender.E.File =./logs/error.log 
log4j.appender.E.Append = true
log4j.appender.E.Threshold = ERROR 
log4j.appender.E.layout = org.apache.log4j.PatternLayout
log4j.appender.E.layout.ConversionPattern = %-d{yyyy-MM-dd HH:mm:ss}  [ %t:%r ] - [ %p ]  %m%n

  3. 配置log4j为日志的实现

    <settings>
    <setting name="logImpl" value="LOG4J"/>
</settings>

  4. log4j的使用

    直接执行：

    [DEBUG] 2020-02-08 21:42:08,766 method:org.apache.ibatis.logging.LogFactory.setImplementation(LogFactory.java:105)
Logging initialized using 'class org.apache.ibatis.logging.log4j.Log4jImpl' adapter.
[DEBUG] 2020-02-08 21:42:08,771 method:org.apache.ibatis.logging.LogFactory.setImplementation(LogFactory.java:105)
Logging initialized using 'class org.apache.ibatis.logging.log4j.Log4jImpl' adapter.
[DEBUG] 2020-02-08 21:42:08,813 method:org.apache.ibatis.datasource.pooled.PooledDataSource.forceCloseAll(PooledDataSource.java:353)
PooledDataSource forcefully closed/removed all connections.
[DEBUG] 2020-02-08 21:42:08,814 method:org.apache.ibatis.datasource.pooled.PooledDataSource.forceCloseAll(PooledDataSource.java:353)
PooledDataSource forcefully closed/removed all connections.
[DEBUG] 2020-02-08 21:42:08,814 method:org.apache.ibatis.datasource.pooled.PooledDataSource.forceCloseAll(PooledDataSource.java:353)
PooledDataSource forcefully closed/removed all connections.
[DEBUG] 2020-02-08 21:42:08,815 method:org.apache.ibatis.datasource.pooled.PooledDataSource.forceCloseAll(PooledDataSource.java:353)
PooledDataSource forcefully closed/removed all connections.
[DEBUG] 2020-02-08 21:42:08,899 method:org.apache.ibatis.transaction.jdbc.JdbcTransaction.openConnection(JdbcTransaction.java:136)
Opening JDBC Connection
[DEBUG] 2020-02-08 21:42:09,354 method:org.apache.ibatis.datasource.pooled.PooledDataSource.popConnection(PooledDataSource.java:424)
Created connection 225290371.
[DEBUG] 2020-02-08 21:42:09,355 method:org.apache.ibatis.transaction.jdbc.JdbcTransaction.setDesiredAutoCommit(JdbcTransaction.java:100)
Setting autocommit to false on JDBC Connection [com.mysql.jdbc.JDBC4Connection@d6da883]
[DEBUG] 2020-02-08 21:42:09,359 method:org.apache.ibatis.logging.jdbc.BaseJdbcLogger.debug(BaseJdbcLogger.java:143)
==>  Preparing: select * from mybatis.user where id=? 
[DEBUG] 2020-02-08 21:42:09,383 method:org.apache.ibatis.logging.jdbc.BaseJdbcLogger.debug(BaseJdbcLogger.java:143)
==> Parameters: 3(Integer)
[DEBUG] 2020-02-08 21:42:09,587 method:org.apache.ibatis.logging.jdbc.BaseJdbcLogger.debug(BaseJdbcLogger.java:143)
<==      Total: 1
User{id=3, name='王二', password='123456'}
[DEBUG] 2020-02-08 21:42:09,589 method:org.apache.ibatis.transaction.jdbc.JdbcTransaction.resetAutoCommit(JdbcTransaction.java:122)
Resetting autocommit to true on JDBC Connection [com.mysql.jdbc.JDBC4Connection@d6da883]
[DEBUG] 2020-02-08 21:42:09,590 method:org.apache.ibatis.transaction.jdbc.JdbcTransaction.close(JdbcTransaction.java:90)
Closing JDBC Connection [com.mysql.jdbc.JDBC4Connection@d6da883]
[DEBUG] 2020-02-08 21:42:09,592 method:org.apache.ibatis.datasource.pooled.PooledDataSource.pushConnection(PooledDataSource.java:381)
Returned connection 225290371 to pool.

简单使用

  1. 在要使用log4j的类中导入包：import org.apache.log4j.Logger;

  2. 日志对象，参数为当前类的class：

     static Logger logger = Logger.getLogger(UserMapperTest.class);

  3. 编写测试类(常用日志级别)：

    @Test
public void testLog4j(){
    logger.info("info：进入了test4j");
    logger.debug("debug：进入了test4j");
    logger.error("error：进入了test4j");
}

    [INFO ] 2020-02-08 21:55:46,475 method:com.lzt.dao.UserMapperTest.testLog4j(UserMapperTest.java:38)
info：进入了test4j
[DEBUG] 2020-02-08 21:55:46,478 method:com.lzt.dao.UserMapperTest.testLog4j(UserMapperTest.java:39)
debug：进入了test4j
[ERROR] 2020-02-08 21:55:46,478 method:com.lzt.dao.UserMapperTest.testLog4j(UserMapperTest.java:40)
error：进入了test4j
posted @ 2021-03-02 09:05  HoneyOneD  阅读(116)  评论(0)    收藏  举报