今天就来说一下我们如何在窗口中看到我们执行了sql语句，使用Log4j工具
第一步：首先我们创建一个Maven项目：
导入必须的依赖：
<dependencies>
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>8.0.20</version>
</dependency>
<!-- https://mvnrepository.com/artifact/org.mybatis/mybatis -->
<dependency>
<groupId>org.mybatis</groupId>
<artifactId>mybatis</artifactId>
<version>3.5.4</version>
</dependency>
<dependency>
<!-- 单元测试 -->
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>4.11</version>
<scope>test</scope>
</dependency>
<dependency>
<groupId>log4j</groupId>
<artifactId>log4j</artifactId>
<version>1.2.17</version>
</dependency>
//如果是web项目，要引入这个依赖
<dependency>
<groupId>org.apache.logging.log4j</groupId>
<artifactId>log4j-web</artifactId>
<version>2.13.3</version>
</dependency>
</dependencis>第二步：在resource文件下创建log4j配置文件和mybatis配置文件：
log4j.properties：
log4j.rootLogger=DEBUG,CONSOLE,file
#log4j.rootLogger=ERROR,ROLLING_FILE
log4j.logger.cn.siliang.dao=debug
log4j.logger.com.ibatis=debug
log4j.logger.com.ibatis.common.jdbc.SimpleDataSource=debug
log4j.logger.com.ibatis.common.jdbc.ScriptRunner=debug
log4j.logger.com.ibatis.sqlmap.engine.impl.SqlMapClientDelegate=debug
log4j.logger.java.sql.Connection=debug
log4j.logger.java.sql.Statement=debug
log4j.logger.java.sql.PreparedStatement=debug
log4j.logger.java.sql.ResultSet=debug
log4j.logger.org.tuckey.web.filters.urlrewrite.UrlRewriteFilter=debug
######################################################################################
# Console Appender \u65e5\u5fd7\u5728\u63a7\u5236\u8f93\u51fa\u914d\u7f6e
######################################################################################
log4j.appender.CONSOLE=org.apache.log4j.ConsoleAppender
log4j.appender.Threshold=error
log4j.appender.CONSOLE.Target=System.out
log4j.appender.CONSOLE.layout=org.apache.log4j.PatternLayout
log4j.appender.CONSOLE.layout.ConversionPattern= [%p] %d %c - %m%n
######################################################################################
# DailyRolling File \u6bcf\u5929\u4ea7\u751f\u4e00\u4e2a\u65e5\u5fd7\u6587\u4ef6\uff0c\u6587\u4ef6\u540d\u683c\u5f0f:log2009-09-11
######################################################################################
log4j.appender.file=org.apache.log4j.DailyRollingFileAppender
log4j.appender.file.DatePattern=yyyy-MM-dd
log4j.appender.file.File=log.log
log4j.appender.file.Append=true
log4j.appender.file.Threshold=error
log4j.appender.file.layout=org.apache.log4j.PatternLayout
log4j.appender.file.layout.ConversionPattern=%d{yyyy-M-d HH:mm:ss}%x[%5p](%F:%L)%m%n
log4j.logger.com.opensymphony.xwork2=error mybatis-config.xml文件配置：
<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE configuration
PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
"http://mybatis.org/dtd/mybatis-3-config.dtd">
<configuration>
<settings>
<setting name="logImpl" value="LOG4J"/>
<setting name="autoMappingBehavior" value="FULL"/>
</settings>
<environments default="development">
<environment id="development">
<transactionManager type="JDBC"/>
<dataSource type="POOLED">
<property name="driver" value="com.mysql.cj.jdbc.Driver"/>
<property name="url" value="jdbc:mysql://localhost:3306/mybatis?useSSL=true&characterEncoding=UTF-8&serverTimezone=UTC"/>
<property name="username" value="root"/>
<property name="password" value="123"/>
</dataSource>
</environment>
</environments>
<mappers>
<mapper resource="dao/UserMapper.xml"/>
</mappers>
</configuration>第三步：我们开始写实体 和 接口以及单元测试类
User实体：
package pojo;
import java.sql.DatabaseMetaData;
import java.sql.Date;
public class User {
private String id; //id
private String name; //姓名
private int age; //密码
private String email;
private Date create_time;
private Date update_time;
private int version;
public String getId() {
return id;
}
public void setId(String id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public int getAge() {
return age;
}
public void setAge(int age) {
this.age = age;
}
public String getEmail() {
return email;
}
public void setEmail(String email) {
this.email = email;
}
public Date getCreate_time() {
return create_time;
}
public void setCreate_time(Date create_time) {
this.create_time = create_time;
}
public Date getUpdate_time() {
return update_time;
}
public void setUpdate_time(Date update_time) {
this.update_time = update_time;
}
public int getVersion() {
return version;
}
public void setVersion(int version) {
this.version = version;
}
@Override
public String toString() {
return "User{" +
"id='" + id + '\'' +
", name='" + name + '\'' +
", age=" + age +
", email='" + email + '\'' +
", create_time=" + create_time +
", update_time=" + update_time +
", version=" + version +
'}';
}
}
UserMapper接口：
package dao;
import pojo.User;
import java.util.List;
public interface UserMapper {
List<User> selectUser();
}
UserMapper.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="dao.UserMapper">
<select id="selectUser" resultType="pojo.User">
select * from user
</select>
</mapper>添加一个myBatis的工具类：
public class MybatisUtils {
private static SqlSessionFactory sqlSessionFactory;
static {
try {
//使用mybatis获取sqlSessionFactory对象
String resource = "mybatis-config.xml";
InputStream inputStream = Resources.getResourceAsStream(resource);
sqlSessionFactory =
new SqlSessionFactoryBuilder().build(inputStream);
} catch (IOException e) {
e.printStackTrace();
}
}
//既然有了SqlSessionFactory，顾名思义，我们就可以从中获得SqlSession的失礼了
//SqlSession完全包含了面向数据库执行SQL命令所需的所有方法
public static SqlSession getSqlSession() {
return sqlSessionFactory.openSession();
}
}
单元测试：
public class UserTest {
@Test
public void test1(){
// 第一步：获得sqlsession对象
SqlSession sqlSession= MybatisUtils.getSqlSession();
// 方式一： 执行 sql
UserMapper userDao=sqlSession.getMapper(UserMapper.class);
List<User> userList=userDao.selectUser();
for(User user:userList){
System.out.println(user);
}
//关闭sqlSession
sqlSession.close();
}
}最终大功告成！ 运行结束之后我们可以看看日志：
