Mybatis上路_06-使用Java自动生成

1.编写Generator执行配置文件:

            generatorConfigation.xml。注意配置数据库驱动包的绝对路径。

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<?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>
    <!-- 数据库驱动包,使用绝对路径 -->
    <classPathEntry location="c:/mysql-connector-java-5.1.22-bin.jar" />
  
    <!-- 环境配置 **************************************************
        id="自定义的配置名称"
        targetRuntime="MyBatis版本" -->
    <context id="MySqlTables" targetRuntime="MyBatis3" >
    
        <!-- 数据库  ===============================================
            driverClass="驱动"
            connectionURL="数据库url"
            userId="用户"
            password="密码" -->
        <jdbcConnection
            driverClass="com.mysql.jdbc.Driver"
            connectionURL="jdbc:mysql://127.0.0.1:3306/db_mybatis" 
            userId="root"
            password="root">  
        </jdbcConnection>
 
        <!-- Java数据类型分离器,数据类型转换 =====================
            property 属性
                name="强迫双精度"
                value="不" -->
        <javaTypeResolver>
            <property name="forceBigDecimals" value="false" />
        </javaTypeResolver>
  
        <!-- Java模型生成器 =======================================
            targetPackage="生成文件的目标路径"
            targetProject="已存在的项目包"
                enableSubPackages-可以省略对应约束名,true-是的,可以省略tb_generator
                trimString-验证字符串,true-是的 -->
        <javaModelGenerator
                targetPackage="cn.cvu.test.model"
                targetProject="src">
            <property name="enableSubPackages" value="false" />
            <property name="trimStrings" value="true" />
        </javaModelGenerator>
  
        <!-- sql映射文件生成器 =======================================
            targetPackage="生成文件的目标路径"
            targetProject="已存在的项目包"
                enableSubPackages-可以省略对应约束名,true-是的,可以省略tb_generator -->
        <sqlMapGenerator
                targetPackage="cn.cvu.test.xml"
                targetProject="src">
            <property name="enableSubPackages" value="false" />
        </sqlMapGenerator>
  
        <!-- java委托对象DAO生成器,接口 =============================
            type=""
            targetPackage="生成文件的目标路径"
            targetProject="已存在的项目包"
                enableSubPackages-可以省略对应约束名,true-是的,可以省略tb_generator -->
        <javaClientGenerator
                type="XMLMAPPER"
                targetPackage="cn.cvu.test.dao"
                targetProject="src">
            <property name="enableSubPackages" value="false" />
        </javaClientGenerator>
        
        <!-- 表单,已存在,根据此表生成其它文件 =======================
            tableName="已有的表单名称"
            domainObjetctName="对应生成的文件名前缀" -->
        <table tableName="tb_generator" domainObjectName="Eminem">
            <!-- useActualColumnNames-使用真实列名 ,
                 true-嗯。如果false,则由columnOverride节点控制  -->
            <property name="useActualColumnNames" value="true" />
            
            <!-- 标识列
                column="列名" sqlStatement="某种数据库语言" identity="作为主键" -->
            <generatedKey column="id" sqlStatement="MySql" identity="true" />
            
            <!-- 覆盖项,当property name="useActualColumnNames" value="true"时。
                column="被覆盖值的列名" property="用来覆盖的对应的java类的属性" -->
            <columnOverride column="name" property="generName" />
  
        </table>
        
    </context>
 
</generatorConfiguration>

2.在MyEclipse中建空web项目:

            将配置文件放到src里。加入generator的jar文件。

            

3.编写并执行Java程序:

            

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package cn.cvu.test.build;
  
import java.io.File;
import java.util.ArrayList;
import java.util.List;
import org.junit.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;
  
public class TestGenerateWithJava {
  
    @Test
    public void testBuild() throws Exception {
                // 信息缓存
                List<String> warnings = new ArrayList<String>();
                // 覆盖已有的重名文件
                boolean overwrite = true;
                // 准备 配置文件
                File configFile = new File("F:/myeclipse_workspace/generator/src/generatorConfigation.xml");
                // 1.创建 配置解析器
                ConfigurationParser parser = new ConfigurationParser(warnings);
                // 2.获取 配置信息
                Configuration config = parser.parseConfiguration(configFile);
                // 3.创建 默认命令解释调回器
                DefaultShellCallback callback = new DefaultShellCallback(overwrite);
                // 4.创建 mybatis的生成器
                MyBatisGenerator myBatisGenerator = new MyBatisGenerator(config, callback, warnings);
                // 5.执行,关闭生成器
        myBatisGenerator.generate(null);
    }
}

4.查看并修改生成的文件:

            选中src,按F5刷新,可以看到新文件已经创建:

            

            修改报错的EmineMapper.java文件,去除注解:

            



5.测试,使用生成的文件查询:

1)导入MyBatis的jar包:

                mybatis-3.2.2.jar 
                mybatis-generator-core-1.3.2.jar 
                mysql-connector-java-5.1.22-bin.jar 

2)创建MyBatis的xml配置文件:

                上面我们注释掉了自动生成的注解代码,在src新建一个xml配置文件,mybatisConfigation.xml:

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<?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>
    <environments default="development">
        <environment id="development">
            <transactionManager type="JDBC" />
            <dataSource type="POOLED">
                <property name="driver" value="com.mysql.jdbc.Driver" />
                <property name="url" value="jdbc:mysql://127.0.0.1:3306/db_mybatis" />
                <property name="username" value="root" />
                <property name="password" value="root" />
            </dataSource>
        </environment>
    </environments>
 
    <mappers>
        <!-- 引入MBG生成器创建的映射文件 -->
        <mapper resource="cn/cvu/test/xml/EminemMapper.xml" />
    </mappers>
</configuration>

3)Java测试代码:

                创建测试类cn.cvu.test.dotest.TestDoGeneratorWithJava :

                

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package cn.cvu.test.dotest;
 
import java.io.Reader;
import java.util.List;
import org.apache.ibatis.io.Resources;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;
import org.junit.Test;
import cn.cvu.test.dao.EminemMapper;
import cn.cvu.test.model.Eminem;
import cn.cvu.test.model.EminemExample;
import cn.cvu.test.model.EminemExample.Criteria;
 
public class TestDoGeneratorWithJava {
 
    @Test
    public void testQuery() throws Exception {
 
        // 创建SQL会话:
        Reader reader = Resources.getResourceAsReader("mybatisConfigation.xml");
        SqlSession session = new SqlSessionFactoryBuilder().build(reader).openSession();
 
        // 创建查询实例:
        EminemExample eminemExample = new EminemExample();
 
        // 获取映射实体:
        EminemMapper mapper = session.getMapper(EminemMapper.class);
 
        // 利用实体通过实例查询全部条目
        List<Eminem> eminems = mapper.selectByExample(eminemExample);
        System.out.println("ID name notes ");
        for (Eminem eminem : eminems) {
                System.out.println(eminem.getId()+
                                " "+eminem.getGenerName()+
                                " "+eminem.getNotes());
        }
        session.close();
    }
}
 

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原文地址:https://www.cnblogs.com/a757956132/p/4380103.html