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01-mybatis映射文件深入-动态sql概述和环境搭建(配置查看预处理的sql语句于查询过程中产生的sql查询语句日志)

发布时间：2025-01-29 23:25:14编辑：雪饮阅读（）

基于webapp骨架建立一个新module，如SpringProject2Module6
pom文件参考如：
<?xml version="1.0" encoding="UTF-8"?>

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
  <modelVersion>4.0.0</modelVersion>

  <groupId>org.example</groupId>
  <artifactId>SpringProject2Module6</artifactId>
  <version>1.0-SNAPSHOT</version>
  <packaging>war</packaging>

  <name>SpringProject2Module6 Maven Webapp</name>
  <!-- FIXME change it to the project's website -->
  <url>http://www.example.com</url>

  <properties>
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    <maven.compiler.source>8</maven.compiler.source>
    <maven.compiler.target>8</maven.compiler.target>
  </properties>

  <dependencies>
    <dependency>
      <groupId>mysql</groupId>
      <artifactId>mysql-connector-java</artifactId>
      <version>5.1.32</version>
    </dependency>
    <dependency>
      <groupId>org.mybatis</groupId>
      <artifactId>mybatis</artifactId>
      <version>3.4.6</version>
    </dependency>
    <dependency>
      <groupId>junit</groupId>
      <artifactId>junit</artifactId>
      <version>4.12</version>
      <scope>test</scope>
    </dependency>
    <dependency>
      <groupId>log4j</groupId>
      <artifactId>log4j</artifactId>
      <version>1.2.17</version>
    </dependency>
  </dependencies>


</project>
然后建立user类
package sp26.domain;

public class User {
    private int id;
    private String username;
    private String password;

    public int getId() {
        return id;
    }

    public void setId(int id) {
        this.id = id;
    }

    public String getUsername() {
        return username;
    }

    public void setUsername(String username) {
        this.username = username;
    }

    public String getPassword() {
        return password;
    }

    public void setPassword(String password) {
        this.password = password;
    }

    @Override
    public String toString() {
        return "User{" +
                "id=" + id +
                ", username='" + username + '\'' +
                ", password='" + password + '\'' +
                '}';
    }
}
然后建立UserMapper.java
package sp26.dao;


import sp26.domain.User;
import java.util.List;

public interface UserMapper {
    public List<User> findByCondition(User user);
}
然后建立src/main/resources/sp26/mapper/UserMapper.xml如：
<?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="sp26.dao.UserMapper">
    <!--查询操作-->
    <select id="findByCondition" parameterType="user" resultType="user">
        select * from user where id=#{id} and username=#{username} and password=#{password}
    </select>
</mapper>
然后建立src/main/resources/sqlMapConfig.xml如：
<?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>
    <!--通过properties标签加载外部properties文件-->
    <properties resource="jdbc.properties"/>
    <typeAliases>
        <typeAlias type="sp26.domain.User" alias="user"/>
    </typeAliases>
    <!--数据源环境-->
    <environments default="developement">
        <environment id="developement">
            <transactionManager type="JDBC"></transactionManager>
            <dataSource type="POOLED">
                <property name="driver" value="${jdbc.driver}"/>
                <property name="url" value="${jdbc.url}"/>
                <property name="username" value="${jdbc.username}"/>
                <property name="password" value="${jdbc.password}"/>
            </dataSource>
        </environment>
    </environments>
   

    <!--加载映射文件-->
    <mappers>
        <mapper resource="sp26/mapper/UserMapper.xml"></mapper>
    </mappers>

</configuration>
然后建立src/main/resources/jdbc.properties如：
jdbc.driver=com.mysql.jdbc.Driver
jdbc.url=jdbc:mysql://192.168.217.132/mybatis
jdbc.username=root
jdbc.password=1448169a3cb137d7
最后建立src/test/java/,并在src/test/java下面建立sp26这个package，然后在src/test/java/sp26下面建立测试类如MapperTest.java：
package sp26;

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 sp26.dao.UserMapper;
import sp26.domain.User;

import java.io.IOException;
import java.io.InputStream;
import java.util.List;

public class MapperTest {
    @Test
    public void test1() throws IOException {
        InputStream resourceAsStream= Resources.getResourceAsStream("sqlMapConfig.xml");
        SqlSessionFactory sqlSessionFactory=new SqlSessionFactoryBuilder().build(resourceAsStream);
        SqlSession sqlSession=sqlSessionFactory.openSession();
        UserMapper mapper=sqlSession.getMapper(UserMapper.class);

        User condition=new User();
        condition.setId(1);
        condition.setUsername("zhangsan");
        condition.setPassword("123");

        List<User> userList=mapper.findByCondition(condition);

        System.out.println(userList);
        sqlSession.close();
    }
}
然后再建立log4j.properties文件于src/main/resources/目录下，内容如：
### direct log messages to stdout ###
log4j.appender.stdout=org.apache.log4j.ConsoleAppender
log4j.appender.stdout.Target=System.out
log4j.appender.stdout.layout=org.apache.log4j.PatternLayout
log4j.appender.stdout.layout.ConversionPattern=%d{ABSOLUTE} %5p %c{1}:%L - %m%n

### direct messages to file mylog.log ###
log4j.appender.file=org.apache.log4j.FileAppender
log4j.appender.file.File=c:/mylog.log
log4j.appender.file.layout=org.apache.log4j.PatternLayout
log4j.appender.file.layout.ConversionPattern=%d{ABSOLUTE} %5p %c{1}:%L - %m%n

### set log levels - for more verbose logging change 'info' to 'debug' ###

log4j.rootLogger=debug, stdout
尤其最后一句
log4j.rootLogger=debug, stdout
这里的debug，原本是info，要修改info为debug，这样就可以查看到sql查询过程中的sql语句了。
虽然只是预处理语句，但是也能看到对于占位被填充的参数