在springboot中使用Mybatis Generator的两种方式

摘要：每个微服务仅关注于完成一件任务并很好地完成该任务。在一个微服务的开发过程中很可能只关注对单表的操作。本文将说到在的项目中如何去配置形式和配置类形式和使用以及生成代码的两种方式形式和注解形式，在中更推荐去使用注解的形式。

Mybatis Generator(MBG)是Mybatis的一个代码生成工具。MBG解决了对数据库操作有最大影响的一些CRUD操作，很大程度上提升开发效率。如果需要联合查询仍然需要手写sql。相信很多人都听说过微服务，各个微服务之间是松耦合的。每个微服务仅关注于完成一件任务并很好地完成该任务。在一个微服务的开发过程中很可能只关注对单表的操作。所以MBG在开发过程中可以快速的生成代码提升开发效率。

本文将说到在springboot的项目中如何去配置（XML形式和Java配置类形式）和使用MBG以及MBG生成代码的两种方式（XML形式和注解形式），在springboot中更推荐去使用注解的形式。

添加依赖

    
        org.mybatis.generator
        mybatis-generator-core
        1.3.5
    

2.XML配置

配置示例：在新建springboot项目的根目录下创建mbg.xml文件。

配置详解

生成代码：

public class TestMGB {
    public static void main(String[] args) throws IOException, XMLParserException, InvalidConfigurationException, SQLException, InterruptedException {
        List warnings =new ArrayList();
        boolean overwrite=true;
        File configFile=new File("mgb.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);
    }

}

3.Java配置示例
基于Java的配置是和上面的XML配置是相对应的。直接运行该示例即可生成数据表对于的pojo,mapper接口和一个sqlprovider Java类。

package com.mgb.test;

import java.util.ArrayList;
import java.util.List;

import org.mybatis.generator.api.MyBatisGenerator;
import org.mybatis.generator.config.CommentGeneratorConfiguration;
import org.mybatis.generator.config.Configuration;
import org.mybatis.generator.config.Context;
import org.mybatis.generator.config.JDBCConnectionConfiguration;
import org.mybatis.generator.config.JavaClientGeneratorConfiguration;
import org.mybatis.generator.config.JavaModelGeneratorConfiguration;
import org.mybatis.generator.config.JavaTypeResolverConfiguration;
import org.mybatis.generator.config.ModelType;
import org.mybatis.generator.config.PluginConfiguration;
import org.mybatis.generator.config.SqlMapGeneratorConfiguration;
import org.mybatis.generator.config.TableConfiguration;
import org.mybatis.generator.internal.DefaultShellCallback;

public class MGBConfig {
    public static void main(String[] args) throws Exception{
         //配置xml配置项
         List warnings = new ArrayList();
         boolean overwrite = true;
         Configuration config = new Configuration();
         Context context = new Context(ModelType.CONDITIONAL);
         context.setTargetRuntime("MyBatis3");
         context.setId("defaultContext");
         
        //自动识别数据库关键字，默认false，如果设置为true，
        //根据SqlReservedWords中定义的关键字列表；一般保留默认值，遇到数据库关键字（Java关键字），
        //使用columnOverride覆盖
         context.addProperty("autoDelimitKeywords","true");
         
        //生成的Java文件的编码
        context.addProperty("javaFileEncoding","utf-8");
        context.addProperty("beginningDelimiter","`");
        context.addProperty("endingDelimiter","`");
        //格式化java代码
        context.addProperty("javaFormatter","org.mybatis.generator.api.dom.DefaultJavaFormatter");
        //格式化xml代码
        context.addProperty("xmlFormatter","org.mybatis.generator.api.dom.DefaultXmlFormatter");
        //格式化信息
        PluginConfiguration pluginConfiguration = new PluginConfiguration();
        pluginConfiguration.setConfigurationType("org.mybatis.generator.plugins.SerializablePlugin");
        pluginConfiguration.setConfigurationType("org.mybatis.generator.plugins.ToStringPlugin");
        context.addPluginConfiguration(pluginConfiguration);
        
        //设置是否去除生成注释
        CommentGeneratorConfiguration commentGeneratorConfiguration = new CommentGeneratorConfiguration();
        commentGeneratorConfiguration.addProperty("suppressAllComments","true");
        //commentGeneratorConfiguration.addProperty("suppressDate","true");
        context.setCommentGeneratorConfiguration(commentGeneratorConfiguration);
    
        //设置连接数据库
        JDBCConnectionConfiguration jdbcConnectionConfiguration = new JDBCConnectionConfiguration();
        jdbcConnectionConfiguration.setDriverClass("com.mysql.jdbc.Driver");
        jdbcConnectionConfiguration.setConnectionURL("jdbc:mysql://localhost:3306/definesys");
        jdbcConnectionConfiguration.setPassword("welcome1");
        jdbcConnectionConfiguration.setUserId("root");
        context.setJdbcConnectionConfiguration(jdbcConnectionConfiguration);
        
        JavaTypeResolverConfiguration javaTypeResolverConfiguration = new JavaTypeResolverConfiguration();
        //是否使用bigDecimal， false可自动转化以下类型（Long, Integer, Short, etc.）
        javaTypeResolverConfiguration.addProperty("forceBigDecimals","false");
        context.setJavaTypeResolverConfiguration(javaTypeResolverConfiguration);
        
        //生成实体类的地址
        JavaModelGeneratorConfiguration javaModelGeneratorConfiguration = new JavaModelGeneratorConfiguration();
        javaModelGeneratorConfiguration.setTargetPackage("com.mgb.domain");
        javaModelGeneratorConfiguration.setTargetProject("src/main/java");
        javaModelGeneratorConfiguration.addProperty("enableSubPackages","true");
        javaModelGeneratorConfiguration.addProperty("trimStrings","true");
        context.setJavaModelGeneratorConfiguration(javaModelGeneratorConfiguration);
        
        //生成的xml的地址
        SqlMapGeneratorConfiguration sqlMapGeneratorConfiguration = new SqlMapGeneratorConfiguration();
        sqlMapGeneratorConfiguration.setTargetProject("src/main/java");
        sqlMapGeneratorConfiguration.setTargetPackage("com.mgb.mapper");
        sqlMapGeneratorConfiguration.addProperty("enableSubPackages","true");
        context.setSqlMapGeneratorConfiguration(sqlMapGeneratorConfiguration);
        
        //生成注解接口
        JavaClientGeneratorConfiguration javaClientGeneratorConfiguration = new JavaClientGeneratorConfiguration();
        javaClientGeneratorConfiguration.setTargetPackage("com.mgb.dao");
        javaClientGeneratorConfiguration.setTargetProject("src/main/java");
        //注解形式 ANNOTATEDMAPPER  xml形式 XMLMAPPER
        javaClientGeneratorConfiguration.setConfigurationType("ANNOTATEDMAPPER");
        javaClientGeneratorConfiguration.addProperty("enableSubPackages","true");
        context.setJavaClientGeneratorConfiguration(javaClientGeneratorConfiguration);
        
        TableConfiguration tableConfiguration = new TableConfiguration(context);
        tableConfiguration.setTableName("user_info");
        tableConfiguration.setCountByExampleStatementEnabled(true);
        tableConfiguration.setUpdateByExampleStatementEnabled(true);
        tableConfiguration.setDeleteByExampleStatementEnabled(true);
        tableConfiguration.setInsertStatementEnabled(true);
        tableConfiguration.setDeleteByPrimaryKeyStatementEnabled(true);        
        context.addTableConfiguration(tableConfiguration);
        
        config.addContext(context);
        DefaultShellCallback callback = new DefaultShellCallback(overwrite);
        MyBatisGenerator myBatisGenerator = new MyBatisGenerator(config, callback, warnings);
        myBatisGenerator.generate(null);
    }
    
}

package com.mgb.service;

import java.util.List;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import com.mgb.dao.UserInfoMapper;
import com.mgb.domain.UserInfo;
import com.mgb.domain.UserInfoExample;

@Service
public class UserService {
    @Autowired
    private UserInfoMapper userInfoMapper;
    
    /**
     * 按姓名查询
     * @param name
     * @return
     */
    public List getUserByName(String name){
        UserInfoExample uerInfoExample=new UserInfoExample();
        uerInfoExample.createCriteria().andNameEqualTo(name);
        return userInfoMapper.selectByExample(uerInfoExample);
    }
    
    /**
     * 有条件的insert
     * @param userInfo
     * @return
     */
    public Integer addUser(UserInfo userInfo) {
        return userInfoMapper.insertSelective(userInfo);
    }
    
    /**
     * 根据ID更新用户信息
     * @param userInfo
     * @return
     */
    public Integer updateUser(UserInfo userInfo) {
        return userInfoMapper.updateByPrimaryKey(userInfo);
    }
    
    /**
     * 根据ID删除用户
     * @param id
     * @return
     */
    public Integer deleteUserById(Integer id) {
        return userInfoMapper.deleteByPrimaryKey(id);
    }

}