mybatis的学习和使用--日志配置(3)

关于 mybatis的日志配置，在官网上已经有详细的配置说明，http://www.mybatis.org/mybatis-3/zh/logging.html   在调试mybatis的代码有着很大的用处。

我的样例代码路径是： https://github.com/wangjiuong/MybatisDemo/tree/master/ExampleMyBatisLogConfig

 

运行com.wang.MyBatis.app的main函数，

    public static void main(String[] args) {
        insertUser();
        // deleteUser();
        selectUserById();

        selectUserById();
        // selectAllUser();
    }

    /**
     * 新增用户
     */
    private static void insertUser() {
        SqlSession session = DBTools.getSession();
        UserMapper mapper = session.getMapper(UserMapper.class);
        UserBean user = new UserBean("懿", "1314520", 7000.0);
        try {
            mapper.insertUser(user);
            System.out.println(user.toString());
            session.commit();
        } catch (Exception e) {
            e.printStackTrace();
            session.rollback();
        }
    }

 

selectUserById的函数如下：

    /**
     * 根据id查询用户
     */
    private static void selectUserById() {
        SqlSession session = DBTools.getSession();
        UserMapper mapper = session.getMapper(UserMapper.class);
        try {
            UserBean user = mapper.selectUserById(12);
            mapper.selectUserById(12);
            mapper.selectUserById(12);
            if (null != user) {
                System.out.println(user.toString());
            }
            session.commit();
        } catch (Exception e) {
            e.printStackTrace();
            session.rollback();
        }
    }

 

 

日志输出如下：

2017-04-04 23:08:21,496 DEBUG [com.wang.MyBatis.model.UserMapper.insertUser] -==>  Preparing: insert into t_user (username,password,account) values (?,?,?) 
  2017-04-04 23:08:21,558 DEBUG [com.wang.MyBatis.model.UserMapper.insertUser] -==> Parameters: 懿(String), 1314520(String), 7000.0(Double)
  2017-04-04 23:08:21,568 DEBUG [com.wang.MyBatis.model.UserMapper.insertUser] -<==    Updates: 1
  UserBean [id=9196, username=懿, password=1314520, account=7000.0]
2017-04-04 23:08:21,585 DEBUG [com.wang.MyBatis.model.UserMapper.selectUserById] -==>  Preparing: select * from t_user where id=? 
  org.apache.ibatis.logging.jdbc.PreparedStatementLogger@543788f3
2017-04-04 23:08:21,586 DEBUG [com.wang.MyBatis.model.UserMapper.selectUserById] -==> Parameters: 12(Integer)
  2017-04-04 23:08:21,612 DEBUG [com.wang.MyBatis.model.UserMapper.selectUserById] -<==      Total: 0
  2017-04-04 23:08:21,622 DEBUG [com.wang.MyBatis.model.UserMapper.selectUserById] -==>  Preparing: select * from t_user where id=? 
  org.apache.ibatis.logging.jdbc.PreparedStatementLogger@15b3e5b
2017-04-04 23:08:21,622 DEBUG [com.wang.MyBatis.model.UserMapper.selectUserById] -==> Parameters: 12(Integer)
  2017-04-04 23:08:21,626 DEBUG [com.wang.MyBatis.model.UserMapper.selectUserById] -<==      Total: 0

 

从日志输出可以看出，示例代码中没有开启二级缓存，mybatis的二级缓存的配置涉及到两项配置，1个是mapper.xml 配置，一个是setting中的配置，我们修改配置开启二级缓存配置：

UserMapper.xml配置修改如下：

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org/DTD Mapper 3.0" "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.wang.MyBatis.model.UserMapper">
    <cache/>
    ***************************

 

mybatis.cfg.xml中cacheEnabled修改为true,

        <setting name="cacheEnabled" value="true" />

在运行测试代码，日志显示如下：

2017-04-04 23:35:10,221 DEBUG [com.wang.MyBatis.model.UserMapper.insertUser] -==>  Preparing: insert into t_user (username,password,account) values (?,?,?) 
  2017-04-04 23:35:10,283 DEBUG [com.wang.MyBatis.model.UserMapper.insertUser] -==> Parameters: 懿(String), 1314520(String), 7000.0(Double)
  2017-04-04 23:35:10,283 DEBUG [com.wang.MyBatis.model.UserMapper.insertUser] -<==    Updates: 1
  UserBean [id=9204, username=懿, password=1314520, account=7000.0]
2017-04-04 23:35:10,299 DEBUG [com.wang.MyBatis.model.UserMapper] -Cache Hit Ratio [com.wang.MyBatis.model.UserMapper]: 0.0
  2017-04-04 23:35:10,314 DEBUG [com.wang.MyBatis.model.UserMapper.selectUserById] -==>  Preparing: select * from t_user where id=? 
  org.apache.ibatis.logging.jdbc.PreparedStatementLogger@6d3af739
2017-04-04 23:35:10,314 DEBUG [com.wang.MyBatis.model.UserMapper.selectUserById] -==> Parameters: 12(Integer)
  2017-04-04 23:35:10,345 DEBUG [com.wang.MyBatis.model.UserMapper.selectUserById] -<==      Total: 0
  2017-04-04 23:35:10,345 DEBUG [com.wang.MyBatis.model.UserMapper] -Cache Hit Ratio [com.wang.MyBatis.model.UserMapper]: 0.0
  2017-04-04 23:35:10,345 DEBUG [com.wang.MyBatis.model.UserMapper] -Cache Hit Ratio [com.wang.MyBatis.model.UserMapper]: 0.0
  2017-04-04 23:35:10,361 DEBUG [com.wang.MyBatis.model.UserMapper] -Cache Hit Ratio [com.wang.MyBatis.model.UserMapper]: 0.25
  2017-04-04 23:35:10,361 DEBUG [com.wang.MyBatis.model.UserMapper] -Cache Hit Ratio [com.wang.MyBatis.model.UserMapper]: 0.4
  2017-04-04 23:35:10,361 DEBUG [com.wang.MyBatis.model.UserMapper] -Cache Hit Ratio [com.wang.MyBatis.model.UserMapper]: 0.5
  

从日志看出，二级缓存生效，在同一个mapper.xml的不同session之间，缓存生效。