MyBatis | 使用log4j在控制台输出SQL语句

我们在使用MyBatis时候想看看其发送的SQL语句，可以使用log4j-1.2.17.jar和log4j.properties来显示。

1.下载log4j-1.2.17.jar

点此进入官网下载，然后选择对应的版本：

2.在项目中添加jar包

下载完成后解压该压缩包，得到以下：

将该jar包加入项目中。

3.配置log4j.properties文件

加入如下的配置：

log4j.rootLogger=DEBUG, Console

#Console
log4j.appender.Console=org.apache.log4j.ConsoleAppender
log4j.appender.Console.layout=org.apache.log4j.PatternLayout
log4j.appender.Console.layout.ConversionPattern=%d [%t] %-5p [%c] - %m%n

log4j.logger.java.sql.ResultSet=INFO
log4j.logger.org.apache=INFO
log4j.logger.java.sql.Connection=DEBUG
log4j.logger.java.sql.Statement=DEBUG
log4j.logger.java.sql.PreparedStatement=DEBUG 

4.测试

EmployeeMapperPlus.xml文件：

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper
        PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.cerr.mybatis.dao.EmployeeMapperPlus">
    <resultMap id="myEmp" type="com.cerr.mybatis.Employee">
        <id column="id" property="id"/>
        <result column="last_name" property="lastName"/>
        <result column="email" property="email"/>
        <result column="gender" property="gender"/>
    </resultMap>
    <select id="getEmpById" resultMap="myEmp">
        select * from tb1_employee where id = #{id}
    </select>
</mapper>

EmployeeMapperPlus接口：

package com.cerr.mybatis.dao;
import com.cerr.mybatis.Employee;
public interface EmployeeMapperPlus {
    public Employee getEmpById(Integer id);
}

Employee实体类：

package com.cerr.mybatis;
public class Employee {
    private Integer id;
    private String lastName;
    private String email;
    private String gender;
    private Department department;
    public Integer getId() {
        return id;
    }
    public void setId(Integer id) {
        this.id = id;
    }
    public String getLastName() {
        return lastName;
    }
    public void setLastName(String lastName) {
        this.lastName = lastName;
    }
    public String getEmail() {
        return email;
    }
    public void setEmail(String email) {
        this.email = email;
    }
    public String getGender() {
        return gender;
    }
    public void setGender(String gender) {
        this.gender = gender;
    }
    public Department getDepartment() {
        return department;
    }
    public void setDepartment(Department department) {
        this.department = department;
    }
    @Override
    public String toString() {
        return "Employee{" +
                "id=" + id +
                ", lastName='" + lastName + '\'' +
                ", email='" + email + '\'' +
                ", gender='" + gender + '\'' +
                ", department=" + department +
                '}';
    }
    public Employee(Integer id, String lastName, String email, String gender) {
        this.id = id;
        this.lastName = lastName;
        this.email = email;
        this.gender = gender;
    }
    public Employee() {
    }
}

测试方法：

package com.cerr.mybatis;
import com.cerr.mybatis.dao.EmployeeMapper;
import com.cerr.mybatis.dao.EmployeeMapperAnnotation;
import com.cerr.mybatis.dao.EmployeeMapperPlus;
import org.apache.ibatis.io.Resources;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;
import org.junit.Test;
import java.io.IOException;
import java.io.InputStream;
import java.util.HashMap;
import java.util.Map;
public class MyBatisTest {
    //获取SQLSessionFactory
    public SqlSessionFactory getSqlSessionFactory() throws IOException {
        String resource = "mybatis-config.xml";
        InputStream inputStream = Resources.getResourceAsStream(resource);
        return new SqlSessionFactoryBuilder().build(inputStream);
    }
    @Test
    public void test() throws IOException {
        SqlSessionFactory sqlSessionFactory = getSqlSessionFactory();
        SqlSession sqlSession = sqlSessionFactory.openSession();
        try {
            EmployeeMapperPlus mapper = sqlSession.getMapper(EmployeeMapperPlus.class);
            Employee employee = mapper.getEmpById(1);
            System.out.println(employee);
        }finally {
            //关闭
            sqlSession.close();
        }
    }
}

在控制台中打印了sql信息：