一、在Mybatis中使用日誌的步驟
以第一個Mybatis程序爲例，介紹Mybatis中日誌的使用。
第一步：創建log4j.properties文件
通常情況下此文件放置在和src同級下的config文件夾。
第二步：寫入配置信息
# Global logging configuration
log4j.rootLogger=info, stdout
# MyBatis logging configuration...
log4j.logger.org.mybatis.example.BlogMapper=TRACE
# Console output...
log4j.appender.stdout=org.apache.log4j.ConsoleAppender
log4j.appender.stdout.layout=org.apache.log4j.PatternLayout
log4j.appender.stdout.layout.ConversionPattern=%5p [%t] - %m%n
關於log4j.rootLogger屬性：
- 真正的項目上線時使用：log4j.rootLogger=info
- 測試階段：log4j.rootLogger=debug
二、日誌分析
執行第一個Mybatis程序後，打印出的日誌如下：
DEBUG [main] - Logging initialized using 'class org.apache.ibatis.logging.slf4j.Slf4jImpl' adapter.
DEBUG [main] - PooledDataSource forcefully closed/removed all connections.
DEBUG [main] - PooledDataSource forcefully closed/removed all connections.
DEBUG [main] - PooledDataSource forcefully closed/removed all connections.
DEBUG [main] - PooledDataSource forcefully closed/removed all connections.
DEBUG [main] - Opening JDBC Connection
DEBUG [main] - Created connection 1969003420.
DEBUG [main] - Setting autocommit to false on JDBC Connection [com.mysql.jdbc.JDBC4Connection@755c9b9c]
DEBUG [main] - ==> Preparing: SELECT id,username as name,sex,address,birthday FROM user WHERE id = ?;
DEBUG [main] - ==> Parameters: 1(Integer)
DEBUG [main] - <== Total: 1
1,冬雨,女,北京,2020-02-06
DEBUG [main] - Resetting autocommit to true on JDBC Connection [com.mysql.jdbc.JDBC4Connection@755c9b9c]
DEBUG [main] - Closing JDBC Connection [com.mysql.jdbc.JDBC4Connection@755c9b9c]
DEBUG [main] - Returned connection 1969003420 to pool.
| 日誌信息 | 日誌分析 |
|---|---|
| Opening JDBC Connection | 打開JDBC鏈接 |
| Created connection 1969003420. | 創建連接 |
| Setting autocommit to false on JDBC Connection | 事務自動提交失敗 |
| Preparing: SELECT id,username as name,sex,address,birthday FROM user WHERE id = ?; | sql語句 |
