JavaEE——Mybatis（14）--MyBatis逆向工程

MyBatis Generator：
• 简称MBG，是一个专门为MyBatis框架使用者定制的代码生成器，可以快速的根据表生成对应的映射文件，接口，以及bean类。支持基本的增删改查，以及QBC风格的条件查询。但是表连接、存储过程等这些复杂sql的定义需要我们手工编写
• 官方文档地址
http://www.mybatis.org/generator/
• 官方工程地址
https://github.com/mybatis/generator/releases

导入

在中找到如何使用

在XML Configuration File Reference中有实例

 

 mbg.xml

targetRuntime="MyBatis3Simple":生成简单版的CRUD
MyBatis3:豪华版

 

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE generatorConfiguration
        PUBLIC "-//mybatis.org//DTD MyBatis Generator Configuration 1.0//EN"
        "http://mybatis.org/dtd/mybatis-generator-config_1_0.dtd">

<generatorConfiguration>
    <!--<classPathEntry location="/Program Files/IBM/SQLLIB/java/db2java.zip" />-->

    <context id="DB2Tables" targetRuntime="MyBatis3Simple">
        <!--jdbcConnection:指定如何连接到目标数据库-->
        <jdbcConnection driverClass="com.mysql.jdbc.Driver"
                        connectionURL="jdbc:mysql://localhost:3306/db_person"
                        userId="root"
                        password="1234">
        </jdbcConnection>

        <javaTypeResolver >
            <property name="forceBigDecimals" value="false" />
        </javaTypeResolver>

        <!--javaModelGenerator:指定JavaBean的生成策略
        targetPackage="test.model"：目标包名
	    targetProject="\MBGTestProject\src"：目标工程，生成的是bean.Student类-->
        <javaModelGenerator targetPackage="bean"
                            targetProject=".\src">
            <property name="enableSubPackages" value="true" />
            <property name="trimStrings" value="true" />
        </javaModelGenerator>

        <!--sqlMapGenerator: sql映射生成策略，生成的是conf/dao/StudentMapper.xml-->
        <sqlMapGenerator targetPackage="dao"
                         targetProject=".\src\conf">
            <property name="enableSubPackages" value="true" />
        </sqlMapGenerator>

        <!--javaClientGenerator:指定mapper接口所在的位置，生成的是dao.StudentMapper接口-->
        <javaClientGenerator type="XMLMAPPER" targetPackage="dao"
                             targetProject=".\src">
            <property name="enableSubPackages" value="true" />
        </javaClientGenerator>

        <!--指定要逆向分析哪些表:根据表要创建JavaBean-->
        <table tableName="student" domainObjectName="Student"></table>
        <table tableName="grade" domainObjectName="Grade"></table>
        
    </context>
</generatorConfiguration>

　　

　　

运行mbg

@Test
    public void testMbg() throws Exception {
        List<String> warnings = new ArrayList<String>();
        boolean overwrite = true;
        File configFile = new File("mbg.xml");
        ConfigurationParser cp = new ConfigurationParser(warnings);
        Configuration config = cp.parseConfiguration(configFile);
        DefaultShellCallback callback = new DefaultShellCallback(overwrite);
        MyBatisGenerator myBatisGenerator = new MyBatisGenerator(config, callback, warnings);
        myBatisGenerator.generate(null);
    }

　　

 生成结果：

测试：

package test;

import bean.Student;
import dao.StudentMapper;
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.jupiter.api.Test;
import org.mybatis.generator.api.MyBatisGenerator;
import org.mybatis.generator.config.Configuration;
import org.mybatis.generator.config.xml.ConfigurationParser;
import org.mybatis.generator.internal.DefaultShellCallback;

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


public class Mybatis_mbgTest {


    public SqlSessionFactory getSqlSessionFactory() throws IOException {
        String resource = "conf/mybatis_config.xml";
        InputStream inputStream = Resources.getResourceAsStream(resource);
        return new SqlSessionFactoryBuilder().build(inputStream);
    }

    @Test
    public void testMbg() throws Exception {
        List<String> warnings = new ArrayList<String>();
        boolean overwrite = true;
        File configFile = new File("mbg.xml");
        ConfigurationParser cp = new ConfigurationParser(warnings);
        Configuration config = cp.parseConfiguration(configFile);
        DefaultShellCallback callback = new DefaultShellCallback(overwrite);
        MyBatisGenerator myBatisGenerator = new MyBatisGenerator(config, callback, warnings);
        myBatisGenerator.generate(null);
    }

    @Test
    public void testSimple() throws IOException {
        SqlSessionFactory sqlsessionFactory = getSqlSessionFactory();
        SqlSession openSession = sqlsessionFactory.openSession();

        try{
            StudentMapper studentMapper = openSession.getMapper( StudentMapper.class );
            List<Student> students = studentMapper.selectAll();
            for(Student student : students){
                System.out.println(student.getId());
            }
        }finally {
            openSession.close();
        }
    }
}

　　

其中conf/mybatis_config.xml

<?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>

    <!--引入外部properties配置文件-->
    <properties resource="conf\dbconfig.properties"></properties>

    <environments default="development">
        <environment id="development">
            <transactionManager type="JDBC"/>
            <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>
    <mappers>
        <mapper resource="conf\dao\StudentMapper.xml"/>
    </mappers>
</configuration>

　　

conf/dbconfig.properties

jdbc.driver=com.mysql.jdbc.Driver
jdbc.url=jdbc:mysql://127.0.0.1:3306/db_person
jdbc.username=root
jdbc.password=1234

　　

带条件复杂查询

@Test
	public void testMyBatis3() throws IOException{
		SqlSessionFactory sqlSessionFactory = getSqlSessionFactory();
		SqlSession openSession = sqlSessionFactory.openSession();
		try{
			EmployeeMapper mapper = openSession.getMapper(EmployeeMapper.class);
			//xxxExample就是封装查询条件的
			//1、查询所有
			//List<Employee> emps = mapper.selectByExample(null);
			//2、查询员工名字中有e字母的，和员工性别是1的
			//封装员工查询条件的example
			EmployeeExample example = new EmployeeExample();
			//创建一个Criteria，这个Criteria就是拼装查询条件
			//select id, last_name, email, gender, d_id from tbl_employee 
			//WHERE ( last_name like ? and gender = ? ) or email like "%e%"
			Criteria criteria = example.createCriteria();
			criteria.andLastNameLike("%e%");
			criteria.andGenderEqualTo("1");
			
			Criteria criteria2 = example.createCriteria();
			criteria2.andEmailLike("%e%");
			example.or(criteria2);
			
			List<Employee> list = mapper.selectByExample(example);
			for (Employee employee : list) {
				System.out.println(employee.getId());
			}
			
		}finally{
			openSession.close();
		}
	}