Mybatis之日志

Mybatis

6、日志

6.1、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！

• SLF4J

• **LOG4J **

• LOG4J2

• JDK_LOGGING

• COMMONS_LOGGING

• **STDOUT_LOGGING **

• NO_LOGGING

• 在Mybatis中具体使用那个一日志实现，在设置中设定！

  • STDOUT_LOGGING标准日志输出。
  • 在mybatis核心配置文件中，配置我们的日志！

• "C:\Program Files\Java\jdk1.8.0_101\bin\java.exe" -ea -Didea.test.cyclic.buffer.size=1048576 "-javaagent:F:\IDEA\IntelliJ IDEA 
  PooledDataSource forcefully closed/removed all connections.
  PooledDataSource forcefully closed/removed all connections.
  PooledDataSource forcefully closed/removed all connections.
  PooledDataSource forcefully closed/removed all connections.
  Opening JDBC Connection
  Created connection 156545103.
  Setting autocommit to false on JDBC Connection [com.mysql.jdbc.JDBC4Connection@954b04f]
  ==>  Preparing: select * from user where id= ?; 
  ==> Parameters: 2(Integer)
  <==    Columns: id, name, pwd
  <==        Row: 2, 6, 6
  <==      Total: 1
  User{id=2, name='6', password='6'}
  Resetting autocommit to true on JDBC Connection [com.mysql.jdbc.JDBC4Connection@954b04f]
  Closing JDBC Connection [com.mysql.jdbc.JDBC4Connection@954b04f]
  Returned connection 156545103 to pool.
  Process finished with exit code 0
  

6.2、LOG4J

6.2.1、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、GUl组件。
• ]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。
• 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。

6.2.2、先导入log4j的包

•  <dependency>
      <groupId>log4j</groupId>
      <artifactId>log4j</artifactId>
      <version>1.2.17</version>
   </dependency>
  

•  ### set log levels ###
     log4j.rootLogger = DEBUG,Console,File
   
     ###  输出到控制台  ###
     log4j.appender.Console=org.apache.log4j.ConsoleAppender
     log4j.appender.Console.Target=System.out
     1og4j.appender.Console.Threshold=DEBUG
     log4j.appender.Console.layout=org.apache.log4j.PatternLayout
     log4j.appender.Console.layout.ConversionPattern=[%d{yy/MM/dd HH:mm:ss:SSS}]-%l:%m%n
   
     ### 输出到日志文件 ###
     log4j.appender.File=org.apache.log4j.RollingFileAppender 
     log4j.appender.File.File=${project}src\\main\\resources\\jcooling.log
     log4j.appender.File.MaxFileSize=10MB
     log4j.appender.File.Threshold=DEBUG
     log4j.appender.File.layout=org.apache.log4j.PatternLayout
     log4j.appender.File.layout.ConversionPattern=[%p][%d{yyyy-MM-dd HH\:mm\:ss,SSS}][%c]%m%n
   
     ### 日志输出级别 ###
     1og4j.logger.org.mybatis=DEBUG
     1og4j.logger.java.sq1=DEBUG
     1og4j.logger.java.sq1.Statement=DEBUG
     1og4j.logger.java.sql.ResultSet=DEBUG
     1og4j.logger.java.sq1.PreparedStatement=DEBUG
  
  

• 配置log4j为日志的实现。

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

6.2.3、log4j的使用

• 直接测试运行刚才的查询。

• [21/11/23 12:45:01:658]-org.apache.ibatis.logging.LogFactory.setImplementation(LogFactory.java:105):Logging initialized using 'class org.apache.ibatis.logging.log4j.Log4jImpl' adapter.
  [21/11/23 12:45:01:660]-org.apache.ibatis.logging.LogFactory.setImplementation(LogFactory.java:105):Logging initialized using 'class org.apache.ibatis.logging.log4j.Log4jImpl' adapter.
  [21/11/23 12:45:01:674]-org.apache.ibatis.datasource.pooled.PooledDataSource.forceCloseAll(PooledDataSource.java:353):PooledDataSource forcefully closed/removed all connections.
  [21/11/23 12:45:01:674]-org.apache.ibatis.datasource.pooled.PooledDataSource.forceCloseAll(PooledDataSource.java:353):PooledDataSource forcefully closed/removed all connections.
  [21/11/23 12:45:01:674]-org.apache.ibatis.datasource.pooled.PooledDataSource.forceCloseAll(PooledDataSource.java:353):PooledDataSource forcefully closed/removed all connections.
  [21/11/23 12:45:01:674]-org.apache.ibatis.datasource.pooled.PooledDataSource.forceCloseAll(PooledDataSource.java:353):PooledDataSource forcefully closed/removed all connections.
  [21/11/23 12:45:01:727]-org.apache.ibatis.transaction.jdbc.JdbcTransaction.openConnection(JdbcTransaction.java:136):Opening JDBC Connection
  [21/11/23 12:45:01:874]-org.apache.ibatis.datasource.pooled.PooledDataSource.popConnection(PooledDataSource.java:424):Created connection 852445367.
  [21/11/23 12:45:01:875]-org.apache.ibatis.transaction.jdbc.JdbcTransaction.setDesiredAutoCommit(JdbcTransaction.java:100):Setting autocommit to false on JDBC Connection [com.mysql.jdbc.JDBC4Connection@32cf48b7]
  [21/11/23 12:45:01:878]-org.apache.ibatis.logging.jdbc.BaseJdbcLogger.debug(BaseJdbcLogger.java:143):==>  Preparing: select * from user where id= ?; 
  [21/11/23 12:45:01:898]-org.apache.ibatis.logging.jdbc.BaseJdbcLogger.debug(BaseJdbcLogger.java:143):==> Parameters: 2(Integer)
  [21/11/23 12:45:01:910]-org.apache.ibatis.logging.jdbc.BaseJdbcLogger.debug(BaseJdbcLogger.java:143):<==      Total: 1
  User{id=2, name='6', password='6'}
  [21/11/23 12:45:01:911]-org.apache.ibatis.transaction.jdbc.JdbcTransaction.resetAutoCommit(JdbcTransaction.java:122):Resetting autocommit to true on JDBC Connection [com.mysql.jdbc.JDBC4Connection@32cf48b7]
  [21/11/23 12:45:01:911]-org.apache.ibatis.transaction.jdbc.JdbcTransaction.close(JdbcTransaction.java:90):Closing JDBC Connection [com.mysql.jdbc.JDBC4Connection@32cf48b7]
  [21/11/23 12:45:01:912]-org.apache.ibatis.datasource.pooled.PooledDataSource.pushConnection(PooledDataSource.java:381):Returned connection 852445367 to pool.
  
  Process finished with exit code 0
  

• 简单使用

  • 在要使用Log4j的类中，导入包 import org.apache.log4j.Logger。

  • 日志对象，参数为当前类的class。

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

  • 日志级别。

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