Mybatis学习笔记(十九)【mybatis逆向工程】

Contents

• 下载逆向工程
• 使用方法
  
  • 运行逆向工程
  • 生成代码配置文件
  • 执行生成程序
  • 使用生成的代码

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mybaits需要程序员自己编写sql语句,mybatis官方提供逆向工程,可以针对单表自动生成mybatis执行所需要的代码（mapper.java,mapper.xml、po..）

企业实际开发中，常用的逆向工程方式：由数据库的表生成java代码。

先附上官网链接：

• MyBatis Generator
• A code generator for MyBatis and iBATIS. - GitHub

下载逆向工程

这里其实可以添加Maven依赖的，因为跟着视频做的，所以我就建了个普通工程，直接添加了个lib文件夹，把要用的jar包直接copy进来了。

maven中央仓库MyBatis-Generator下载地址：【MyBatis Generator Core】

使用方法

运行逆向工程

根据官网说的（Running MyBatis Generator）：

Running MyBatis Generator

MyBatis Generator (MBG) can be run in the following ways:

• From the command prompt with an XML configuration
• As an Ant task with an XML configuration
• As a Maven Plugin
• From another Java program with an XML configuration
• From another Java program with a Java based configuration

还可以通过eclipse的插件生成代码

建议使用java程序方式，不依赖开发工具。

生成代码配置文件

<?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>    <context id="testTables" targetRuntime="MyBatis3">        <commentGenerator>            <!-- 是否去除自动生成的注释 true：是 ： false:否 -->            <property name="suppressAllComments" value="true" />        </commentGenerator>        <!--数据库连接的信息：驱动类、连接地址、用户名、密码 -->        <jdbcConnection driverClass="com.mysql.jdbc.Driver"            connectionURL="jdbc:mysql://120.25.162.238:3306/mybatis001?characterEncoding=utf-8"             userId="root"            password="123">        </jdbcConnection>        <!-- <jdbcConnection driverClass="oracle.jdbc.OracleDriver"            connectionURL="jdbc:oracle:thin:@127.0.0.1:1521:yycg"             userId="yycg"            password="yycg">        </jdbcConnection> -->        <!-- 默认false，把JDBC DECIMAL 和 NUMERIC 类型解析为 Integer，为 true时把JDBC DECIMAL 和             NUMERIC 类型解析为java.math.BigDecimal -->        <javaTypeResolver>            <property name="forceBigDecimals" value="false" />        </javaTypeResolver>        <!-- targetProject:生成PO类的位置 -->        <javaModelGenerator targetPackage="com.iot.ssm.po"            targetProject=".\src">            <!-- enableSubPackages:是否让schema作为包的后缀 -->            <property name="enableSubPackages" value="false" />            <!-- 从数据库返回的值被清理前后的空格 -->            <property name="trimStrings" value="true" />        </javaModelGenerator>        <!-- targetProject:mapper映射文件生成的位置 -->        <sqlMapGenerator targetPackage="com.iot.ssm.mapper"             targetProject=".\src">            <!-- enableSubPackages:是否让schema作为包的后缀 -->            <property name="enableSubPackages" value="false" />        </sqlMapGenerator>        <!-- targetPackage：mapper接口生成的位置 -->        <javaClientGenerator type="XMLMAPPER"            targetPackage="com.iot.ssm.mapper"             targetProject=".\src">            <!-- enableSubPackages:是否让schema作为包的后缀 -->            <property name="enableSubPackages" value="false" />        </javaClientGenerator>        <!-- 指定数据库表 -->        <table tableName="items"></table>        <table tableName="orders"></table>        <table tableName="orderdetail"></table>        <table tableName="user"></table>        <!-- <table schema="" tableName="sys_user"></table>        <table schema="" tableName="sys_role"></table>        <table schema="" tableName="sys_permission"></table>        <table schema="" tableName="sys_user_role"></table>        <table schema="" tableName="sys_role_permission"></table> -->        <!-- 有些表的字段需要指定java类型         <table schema="" tableName="">            <columnOverride column="" javaType="" />        </table> -->    </context></generatorConfiguration>

需要注意的位置：

• javaModelGenerator,生成PO类的位置
• sqlMapGenerator,mapper映射文件生成的位置
• javaClientGenerator,mapper接口生成的位置
• table,指定数据库表

执行生成程序

public void generator() throws Exception{    List<String> warnings = new ArrayList<String>();    boolean overwrite = true;    //指定逆向工程配置文件    File configFile = new File("generatorConfig.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);} 

日志输出：

2016-02-27 16:29:46,419 [main] DEBUG [org.mybatis.generator.internal.db.DatabaseIntrospector] - Retrieving column information for table "items"2016-02-27 16:29:46,477 [main] DEBUG [org.mybatis.generator.internal.db.DatabaseIntrospector] - Found column "id", data type 4, in table "mybatis001..items"2016-02-27 16:29:46,477 [main] DEBUG [org.mybatis.generator.internal.db.DatabaseIntrospector] - Found column "name", data type 12, in table "mybatis001..items"2016-02-27 16:29:46,477 [main] DEBUG [org.mybatis.generator.internal.db.DatabaseIntrospector] - Found column "price", data type 7, in table "mybatis001..items"2016-02-27 16:29:46,477 [main] DEBUG [org.mybatis.generator.internal.db.DatabaseIntrospector] - Found column "detail", data type -1, in table "mybatis001..items"2016-02-27 16:29:46,477 [main] DEBUG [org.mybatis.generator.internal.db.DatabaseIntrospector] - Found column "pic", data type 12, in table "mybatis001..items"2016-02-27 16:29:46,478 [main] DEBUG [org.mybatis.generator.internal.db.DatabaseIntrospector] - Found column "createtime", data type 93, in table "mybatis001..items"2016-02-27 16:29:46,503 [main] DEBUG [org.mybatis.generator.internal.db.DatabaseIntrospector] - Retrieving column information for table "orders"2016-02-27 16:29:46,551 [main] DEBUG [org.mybatis.generator.internal.db.DatabaseIntrospector] - Found column "id", data type 4, in table "mybatis001..orders"2016-02-27 16:29:46,551 [main] DEBUG [org.mybatis.generator.internal.db.DatabaseIntrospector] - Found column "user_id", data type 4, in table "mybatis001..orders"2016-02-27 16:29:46,551 [main] DEBUG [org.mybatis.generator.internal.db.DatabaseIntrospector] - Found column "number", data type 12, in table "mybatis001..orders"2016-02-27 16:29:46,551 [main] DEBUG [org.mybatis.generator.internal.db.DatabaseIntrospector] - Found column "createtime", data type 93, in table "mybatis001..orders"2016-02-27 16:29:46,551 [main] DEBUG [org.mybatis.generator.internal.db.DatabaseIntrospector] - Found column "note", data type 12, in table "mybatis001..orders"2016-02-27 16:29:46,577 [main] DEBUG [org.mybatis.generator.internal.db.DatabaseIntrospector] - Retrieving column information for table "orderdetail"2016-02-27 16:29:46,630 [main] DEBUG [org.mybatis.generator.internal.db.DatabaseIntrospector] - Found column "id", data type 4, in table "mybatis001..orderdetail"2016-02-27 16:29:46,630 [main] DEBUG [org.mybatis.generator.internal.db.DatabaseIntrospector] - Found column "orders_id", data type 4, in table "mybatis001..orderdetail"2016-02-27 16:29:46,631 [main] DEBUG [org.mybatis.generator.internal.db.DatabaseIntrospector] - Found column "items_id", data type 4, in table "mybatis001..orderdetail"2016-02-27 16:29:46,631 [main] DEBUG [org.mybatis.generator.internal.db.DatabaseIntrospector] - Found column "items_num", data type 4, in table "mybatis001..orderdetail"2016-02-27 16:29:46,656 [main] DEBUG [org.mybatis.generator.internal.db.DatabaseIntrospector] - Retrieving column information for table "user"2016-02-27 16:29:46,706 [main] DEBUG [org.mybatis.generator.internal.db.DatabaseIntrospector] - Found column "id", data type 4, in table "mybatis001..user"2016-02-27 16:29:46,706 [main] DEBUG [org.mybatis.generator.internal.db.DatabaseIntrospector] - Found column "username", data type 12, in table "mybatis001..user"2016-02-27 16:29:46,706 [main] DEBUG [org.mybatis.generator.internal.db.DatabaseIntrospector] - Found column "birthday", data type 91, in table "mybatis001..user"2016-02-27 16:29:46,706 [main] DEBUG [org.mybatis.generator.internal.db.DatabaseIntrospector] - Found column "sex", data type 1, in table "mybatis001..user"2016-02-27 16:29:46,706 [main] DEBUG [org.mybatis.generator.internal.db.DatabaseIntrospector] - Found column "address", data type 12, in table "mybatis001..user"

生成后的代码：

使用生成的代码

需要将生成工程中所生成的代码拷贝到自己的工程中。

测试ItemsMapper中的方法

package com.iot.ssm.mapper;import static org.junit.Assert.*;import java.util.Date;import java.util.List;import com.iot.ssm.po.Items;import com.iot.ssm.po.ItemsExample;import org.junit.Before;import org.junit.Test;import org.springframework.context.ApplicationContext;import org.springframework.context.support.ClassPathXmlApplicationContext;public class ItemsMapperTest {    private ApplicationContext applicationContext;    private ItemsMapper itemsMapper;    //在setUp这个方法得到spring容器    @Before    public void setUp() throws Exception {        applicationContext = new ClassPathXmlApplicationContext("classpath:spring/applicationContext.xml");        itemsMapper = (ItemsMapper) applicationContext.getBean("itemsMapper");    }    //根据主键删除     @Test    public void testDeleteByPrimaryKey() {    }    //插入    @Test    public void testInsert() {        //构造 items对象        Items items = new Items();        items.setName("手机");        items.setPrice(999f);        items.setCreatetime(new Date());        itemsMapper.insert(items);    }    //自定义条件查询    @Test    public void testSelectByExample() {        ItemsExample itemsExample = new ItemsExample();        //通过criteria构造查询条件        ItemsExample.Criteria criteria = itemsExample.createCriteria();        criteria.andNameEqualTo("笔记本");        //可能返回多条记录        List<Items> list = itemsMapper.selectByExample(itemsExample);        System.out.println(list);    }    //根据主键查询    @Test    public void testSelectByPrimaryKey() {        Items items = itemsMapper.selectByPrimaryKey(1);        System.out.println(items);    }    //更新数据    @Test    public void testUpdateByPrimaryKey() {        //对所有字段进行更新，需要先查询出来再更新        Items items = itemsMapper.selectByPrimaryKey(1);        items.setName("手机");        itemsMapper.updateByPrimaryKey(items);        //如果传入字段不空为才更新，在批量更新中使用此方法，不需要先查询再更新        //itemsMapper.updateByPrimaryKeySelective(record);    }}