spring-boot集成PageHelper和通用Mapper

前提条件：已经集成mybatis

代码生成步骤：

1. 添加依赖

   <dependency>
       <groupId>tk.mybatis</groupId>
       <artifactId>mapper-spring-boot-starter</artifactId>
       <version>1.1.4</version>
   </dependency>
   <dependency>
       <groupId>org.mybatis.generator</groupId>
       <artifactId>mybatis-generator-core</artifactId>
       <version>1.3.6</version>
   </dependency>

2. 创建一个拥有main方法的类，代码如下

   package com.ghaien.generator;
   
   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 sun.nio.cs.Surrogate.Generator;
   
   import java.util.ArrayList;
   import java.util.List;
   
   public class GeneratorMain {
       /**
        * 代码生成器
        * @param args
        * @throws Exception
        */
       public static void main(String[] args) throws Exception {
           List<String> warnings = new ArrayList<>();
           boolean overwrite = true;
           ConfigurationParser cp = new ConfigurationParser(warnings);
           Configuration config = cp.parseConfiguration(
                     Generator.class.getResourceAsStream("/generator/generatorConfig.xml"));
           DefaultShellCallback callback = new DefaultShellCallback(overwrite);
           MyBatisGenerator myBatisGenerator = new MyBatisGenerator(config, callback, warnings);
           myBatisGenerator.generate(null);
       }
   }

3. 在上面代码中对应的目录下创建generatorConfig.xml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="Mysql" targetRuntime="MyBatis3Simple" defaultModelType="flat">
   
           <plugin type="tk.mybatis.mapper.generator.MapperPlugin">
               <property name="mappers" value="tk.mybatis.mapper.common.Mapper"/>
               <!-- caseSensitive默认false，当数据库表名区分大小写时，可以将该属性设置为true -->
               <property name="caseSensitive" value="true"/>
           </plugin>
   
           <jdbcConnection driverClass="com.mysql.jdbc.Driver"
                           connectionURL="jdbc:mysql://localhost:3306/test"
                           userId="root"
                           password="1234">
           </jdbcConnection>
           <!--生成的实体类的存储路径和包名-->
           <javaModelGenerator targetPackage="com.ghaien.dao.pojo.vo" 
                targetProject="E:\document\IdeaProjects\spring-boot-demo\src\main\java"/>
           <!--生成的*Mapper.xml文件的存储位置-->
           <sqlMapGenerator targetPackage="mapper"  
                targetProject="E:\document\IdeaProjects\spring-boot-demo\src\main\resources"/>
           <!--生成的*Mapper.java文件的存储位置和包名-->
           <javaClientGenerator targetPackage="com.ghaien.dao.mapper" 
                targetProject="E:\document\IdeaProjects\spring-boot-demo\src\main\java" type="XMLMAPPER" />
           <!--对应数据库中表名（可以使用"%" 对应所有表）-->
           <table tableName="user" >
               <!--该表有一个id自增的主键，在生成实体类的时候会根据该配置生成相应的注解-->
               <generatedKey column="id" sqlStatement="Mysql" identity="true"/>
           </table>
       </context>
   </generatorConfiguration>

   以上配置可根据具体的需求进行配置

4. 执行main方法

集成步骤：

1. 添加依赖

   <dependency>
       <groupId>tk.mybatis</groupId>
       <artifactId>mapper-spring-boot-starter</artifactId>
       <version>1.1.4</version>
   </dependency>
   <dependency>
       <groupId>com.github.pagehelper</groupId>
       <artifactId>pagehelper-spring-boot-starter</artifactId>
       <version>1.2.1</version>
   </dependency>

2. application.properties中增加如下配置

   ##mapper
   ##mappers 多个接口时逗号隔开
   mapper.mappers=com.ghaien.utils.mapper.BaseMapper
   mapper.not-empty=false
   mapper.identity=MYSQL
   #
   ##pagehelper
   pagehelper.helperDialect=mysql
   pagehelper.reasonable=true
   pagehelper.supportMethodsArguments=true
   pagehelper.params=count=countSql

3. 将生成的*Mapper.xml文件移动到application.properties中mybatis.mapperLocations对用的目录下，随意移动生成的实体类位置
4. 创建BaseMapper(命名随意)接口，位置跟配置文件中的mapper.mappers对应，代码如下

   package com.ghaien.utils.mapper;
   
   import tk.mybatis.mapper.common.Mapper;
   import tk.mybatis.mapper.common.MySqlMapper;
   
   public interface BaseMapper<T> extends Mapper<T>, MySqlMapper<T> {
   }

   修改生成的*Mapper.java文件，使其继承BaseMapper，并移动到@MapperScan能扫描到的路径下，代码如下

   package com.ghaien.dao.mapper;
   
   import com.ghaien.dao.pojo.vo.User;
   import org.apache.ibatis.annotations.Param;
   import tk.mybatis.mapper.common.BaseMapper;
   
   public interface UserMapper extends BaseMapper<User> {
       /**
        * 测试UserMapper.xml文件路径是否正确
        * @param id
        * @return
        */
       User queryById(@Param("id") Long id);
   }

   注意：BaseMapper不能被@MapperScan扫描到

5. 测试是否成功集成，代码如下

   package com.ghaien.dao.mapper;
   
   import com.ghaien.dao.pojo.vo.User;
   import com.github.pagehelper.Page;
   import com.github.pagehelper.PageHelper;
   import org.junit.Test;
   import org.junit.runner.RunWith;
   import org.slf4j.Logger;
   import org.slf4j.LoggerFactory;
   import org.springframework.beans.factory.annotation.Autowired;
   import org.springframework.boot.test.context.SpringBootTest;
   import org.springframework.test.context.junit4.SpringRunner;
   
   import java.util.List;
   
   /**
    * Created by ghaien on 2018/1/29.
    */
   @SpringBootTest
   @RunWith(SpringRunner.class)
   public class UserMapperTest {
   
       @Autowired
       private UserMapper userMapper;
   
       private Logger log = LoggerFactory.getLogger(this.getClass());
   
       @Test
       public void testQueryByPage() {
   //        PageHelper.startPage(2, 1);
   //        List<User> users = userMapper.selectAll();
   //        for (User user : users) {
   //            log.info("userName = " + user.getUserName());
   //        }
   
           Page<User> page = PageHelper.startPage(2, 1).doSelectPage(() -> {
               userMapper.selectAll();
           });
           for (User user : page) {
               log.info("userName = " + user.getUserName());
           }
       }
   
   }

   以上两种方法最后输出的结果是一致的，若想查看sql语句只需在配置文件中增加如下配置即可

   logging.level.com.ghaien.dao=debug

完整代码