Spring Boot系列六 Spring boot集成mybatis、分页插件pagehelper

1. 概述

本文的内容包括如下内容：

1. Spring Boot集成mybatis
2. Spring Boot集成pagehelper分页插件，定义分页的相关类
3. 实现工具类：model转dto，实现数据层和传输层的解耦
4. 完整展示了从浏览器输入URL，并从数据库操作数据的完整流程

2. Spring Boot集成Mybatis

2.1. pom.xml

mybatis和数据库的相关的jar

<!-- druid --><dependency>    <groupId>com.alibaba</groupId>    <artifactId>druid</artifactId>    <version>1.0.31</version></dependency><!-- Spring Boot集成mybatis --><dependency>    <groupId>org.mybatis.spring.boot</groupId>    <artifactId>mybatis-spring-boot-starter</artifactId>    <version>1.3.1</version></dependency><!-- https://mvnrepository.com/artifact/mysql/mysql-connector-java --><dependency>    <groupId>mysql</groupId>    <artifactId>mysql-connector-java</artifactId>    <version>6.0.6</version></dependency>

2.2. Mapper java类和xml及Model

测试表sql如下

CREATE TABLE `test`.`test` (  `id` INT NOT NULL,  `age` INT NULL,  `name` VARCHAR(45) NULL,  PRIMARY KEY (`id`),  UNIQUE INDEX `id_UNIQUE` (`id` ASC));

表对应Model类: com.hry.spring.mybatis.model.TestModel

public class TestModel {    private Integer id;    private Integer age;    private String name;   // set/get略}

配置Mapper类： com.hry.spring.mybatis.mapper.TestMapper

public interface TestMapper {    int deleteByPrimaryKey(Integer id);    int insert(TestModel record);    int insertSelective(TestModel record);    TestModel selectByPrimaryKey(Integer id);    List<TestModel> selectAll();    int updateByPrimaryKeySelective(TestModel record);    int updateByPrimaryKey(TestModel record);}

配置Mapper xml: TestMapper.xml

<?xml version="1.0" encoding="UTF-8"?><!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd"><mapper namespace="com.hry.spring.mybatis.mapper.TestMapper"> <resultMap id="BaseResultMap" type="com.hry.spring.mybatis.model.TestModel">   <id column="id" jdbcType="INTEGER" property="id" />   <result column="age" jdbcType="INTEGER" property="age" />   <result column="name" jdbcType="VARCHAR" property="name" /> </resultMap> <sql id="Base_Column_List">   id, age, name </sql> <select id="selectByPrimaryKey" parameterType="java.lang.Integer" resultMap="BaseResultMap">   select    <include refid="Base_Column_List" />   from test   where id = #{id,jdbcType=INTEGER} </select> <select id="selectAll"  resultMap="BaseResultMap">   select   <include refid="Base_Column_List" />   from test     order by id desc </select> <delete id="deleteByPrimaryKey" parameterType="java.lang.Integer">   delete from test   where id = #{id,jdbcType=INTEGER} </delete> <insert id="insert" parameterType="com.hry.spring.mybatis.model.TestModel">   insert into test (id, age, name,      )   values (#{id,jdbcType=INTEGER}, #{age,jdbcType=INTEGER}, #{name,jdbcType=VARCHAR}    ) </insert> <insert id="insertSelective" parameterType="com.hry.spring.mybatis.model.TestModel">   insert into test   <trim prefix="(" suffix=")" suffixOverrides=",">     <if test="id != null">       id,     </if>     <if test="age != null">       age,     </if>     <if test="name != null">       name,     </if>   </trim>   <trim prefix="values (" suffix=")" suffixOverrides=",">     <if test="id != null">       #{id,jdbcType=INTEGER},     </if>     <if test="age != null">       #{age,jdbcType=INTEGER},     </if>     <if test="name != null">       #{name,jdbcType=VARCHAR},     </if>   </trim> </insert> <update id="updateByPrimaryKeySelective" parameterType="com.hry.spring.mybatis.model.TestModel">   update test   <set>     <if test="age != null">       age = #{age,jdbcType=INTEGER},     </if>     <if test="name != null">       name = #{name,jdbcType=VARCHAR},     </if>   </set>   where id = #{id,jdbcType=INTEGER} </update> <update id="updateByPrimaryKey" parameterType="com.hry.spring.mybatis.model.TestModel">   update test   set age = #{age,jdbcType=INTEGER},     name = #{name,jdbcType=VARCHAR}   where id = #{id,jdbcType=INTEGER} </update></mapper>

2.3. mybatis配置

spring_mybatis.xml
spring.datasource.url的值配置在application.yml

<!-- ### 配置数据源 begin ###--><bean id="dataSource" class="com.alibaba.druid.pool.DruidDataSource" init-method="init" destroy-method="close">   <!-- 基本属性 url、user、password -->  <property name="url" value="${spring.datasource.url}" />  <property name="username" value="${spring.datasource.username}" />  <property name="password" value="${spring.datasource.password}" />  <property name="driverClassName" value="${spring.datasource.driverClassName}" />  <!-- 配置初始化大小、最小、最大 -->  <property name="initialSize" value="${spring.datasource.initialSize:5}" />  <property name="minIdle" value="${spring.datasource.minIdle:5}" />   <property name="maxActive" value="${spring.datasource.maxActive:20}" />  <!-- 配置获取连接等待超时的时间 -->  <property name="maxWait" value="${spring.datasource.maxWait:30000}" />  <!-- 配置间隔多久才进行一次检测，检测需要关闭的空闲连接，单位是毫秒 -->  <property name="timeBetweenEvictionRunsMillis" value="${spring.datasource.timeBetweenEvictionRunsMillis}" />  <!-- 配置一个连接在池中最小生存的时间，单位是毫秒 -->  <property name="minEvictableIdleTimeMillis" value="${spring.datasource.minEvictableIdleTimeMillis}" />  <property name="validationQuery" value="${spring.datasource.validationQuery}" />  <property name="testWhileIdle" value="${spring.datasource.testWhileIdle}" />  <property name="testOnBorrow" value="${spring.datasource.testOnBorrow}" />  <property name="testOnReturn" value="${spring.datasource.testOnReturn}" />  <!-- 打开PSCache，并且指定每个连接上PSCache的大小 -->  <property name="poolPreparedStatements" value="${spring.datasource.poolPreparedStatements}" />  <property name="maxPoolPreparedStatementPerConnectionSize" value="${spring.datasource.maxPoolPreparedStatementPerConnectionSize}" />  <!-- 配置监控统计拦截的filters -->  <property name="filters" value="${spring.datasource.filters}" />  <property name="connectionProperties" value="{spring.datasource.connectionProperties}" /></bean><!-- ### 配置数据源  end ###--><!-- ### Mybatis和事务配置  begin ###--><bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">    <property name="dataSource" ref="dataSource"/>    <!-- 配置扫描Mapper XML的位置 -->    <property name="mapperLocations" value="classpath:com/hry/spring/mybatis/mapper/*.xml"/>    <!-- 配置mybatis配置文件的位置 -->    <property name="configLocation" value="classpath:config/spring/mybatis_config.xml"/></bean><!-- 配置扫描Mapper接口的包路径 --><bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">    <property name="basePackage" value="com.hry.spring.mybatis.mapper"/>    <property name="sqlSessionFactoryBeanName" value="sqlSessionFactory"/></bean><!-- 事务配置 --><bean id="transactionManager"      class="org.springframework.jdbc.datasource.DataSourceTransactionManager"      p:dataSource-ref="dataSource"/><tx:advice id="txAdvice" transaction-manager="transactionManager" >    <tx:attributes>        <tx:method name="add*" propagation="REQUIRED" />    <tx:method name="create*" propagation="REQUIRED" />    <tx:method name="save*" propagation="REQUIRED" />        <tx:method name="insert*" propagation="REQUIRED" />    <tx:method name="update*" propagation="REQUIRED" />    <tx:method name="batch*" propagation="REQUIRED" />    <tx:method name="del*" propagation="REQUIRED" />    <tx:method name="get*" propagation="SUPPORTS" read-only="true" />    <tx:method name="find*" propagation="SUPPORTS" read-only="true" />        <tx:method name="*" read-only="true"/>    </tx:attributes></tx:advice><aop:config >    <aop:pointcut id="pt" expression="execution(* com.hry.spring.mybatis.service..*.*(..))" />    <aop:advisor pointcut-ref="pt" advice-ref="txAdvice"/></aop:config> <!-- ### Mybatis和事物配置  end ###-->

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></configuration>

2.4. application.yml

配置数据库的信息如下：

# 数据库配置spring:  datasource:    #### Datasource 配置 ####    type: com.alibaba.druid.pool.DruidDataSource    username: root    password: root    url: jdbc:mysql://127.0.0.1:3306/test?zeroDateTimeBehavior=convertToNull&serverTimezone=GMT%2b8&useSSL=true    # url: jdbc:mysql://127.0.0.1:3306/test    driverClassName: com.mysql.cj.jdbc.Driver    # driverClassName: oracle.jdbc.driver.OracleDriver    # 下面为连接池的补充设置，应用到上面所有数据源中# 初始化大小，最小，最大    initialSize: 5    minIdle: 5    maxActive: 20    # 配置获取连接等待超时的时间    maxWait: 30000    # 配置一个连接在池中最小生存的时间，单位是毫秒    minEvictableIdleTimeMillis: 300000    timeBetweenEvictionRunsMillis: 60000    validationQuery: SELECT 1 FROM DUAL    # 打开PSCache，并且指定每个连接上PSCache的大小    poolPreparedStatements: false    maxPoolPreparedStatementPerConnectionSize: 20    testWhileIdle: true    testOnBorrow: false    testOnReturn: false    # 配置监控统计拦截的filters，去掉后监控界面sql无法统计，'wall'用于防火墙    filters: log4j    connectionProperties: druid.stat.mergeSql=true;druid.stat.slowSqlMillis=5000

2.5. spring boot集成mybatis

通过@ImportResource加载mybatis的配置
用@Bean注解的方法fastJsonHttpMessageConverters表示使用fastjson解析json

@SpringBootApplication// 加载mybatis配置@ImportResource({"classpath:config/spring/spring_*.xml"})public class MybatisSpringBoot {    public static void main(String[] args){        SpringApplication.run(MybatisSpringBoot.class, args);    }    @Bean    public HttpMessageConverters fastJsonHttpMessageConverters() {        // 格式化时间        SerializeConfig mapping = new SerializeConfig();        mapping.put(Date.class, new SimpleDateFormatSerializer(               "yyyy-MM-dd HH:mm:ss"));        FastJsonHttpMessageConverter fastConverter = new FastJsonHttpMessageConverter();        FastJsonConfig fastJsonConfig = new FastJsonConfig();        //  fastJsonConfig.setSerializerFeatures(SerializerFeature.PrettyFormat);        fastJsonConfig.setSerializeConfig(mapping);        fastConverter.setFastJsonConfig(fastJsonConfig);        HttpMessageConverter<?> converter = fastConverter;        return new HttpMessageConverters(converter);    }}

3. Spring Boot集成分布插件Pagehelper

以上的功能实现了简单的mybatis应用。但是涉及到数据库的查询，不可避免需要使用到分页。这里我推荐pagehelper插件实现分页功能

3.1. pom.xml

引入相关的jar

<!-- 分布插件 --><dependency>    <groupId>com.github.pagehelper</groupId>    <artifactId>pagehelper</artifactId>    <version>5.1.1</version></dependency><!-- Spring Boot集成 pagehelper--><dependency>    <groupId>com.github.pagehelper</groupId>    <artifactId>pagehelper-spring-boot-starter</artifactId>    <version>1.2.1</version></dependency>

3.2. 分页相关的辅助类

MyPage
包装返回给前台的信息，包括本次查询的状态码、错误信息、记录总数和数据列表

public class MyPage<T> {    @JSONField(ordinal = 1)    private Integer code = 200;// 状态码，默认状态    @JSONField(ordinal = 2)    private String message = "";// 提示消息或者错误消息    @JSONField(ordinal = 3)    private String apiId = "";// 请求的唯一标识，预留    @JSONField(ordinal = 4)    private Integer totalCount = 0;//记录总数    @JSONField(ordinal = 5)    private List<T> rows = Collections.emptyList();//本次返回的数据列表   // set/get略}

IPageHelperPageCallBack
定义分页的回调方法，如果使分页，则必须在这个方法里使用mapper的方法。
此接口作为下文的PageCallBackUtil的参数

public interface IPageHelperPageCallBack {    <T> List<T> select();}

PageCallBackUtil
pagehelper的使用核心是：调用PageHelper.startPage(pageNum, pageSize,requireTotalCount)方法设置查询记录起始地址后，然后马上调用mapper类的方法，得到返回列表List，使用（ PageInfo pageInfo = new PageInfo(list)）包装list的PageInfo，PageInfo包含本次查询的信息，包括本次查询的总数，然后将Model转化为Dto类

/** * 分页的回调函数 * Created by [e-mail] on 2017/9/6. */public class PageCallBackUtil {    /**     * 封装公共PageHelper的操作     * @param qry     * @param callBack     * @param <T>     * @return     */    public static<T>  MyPage<T> selectRtnPage(AbstractQry qry, IPageHelperPageCallBack callBack){        Assert.notNull(qry, "qry can't be null!");        Assert.notNull(callBack, "callBack cant' be null!");        setPageHelperStartPage(qry);        List<T> list = callBack.select();        // 分页时，实际返回的结果list类型是Page<E>        if(!(list instanceof Page)){            throw new RuntimeException("list must be 'com.github.pagehelper.Page', now is " + list.getClass().getCanonicalName());        }        MyPage<T> myPage = new MyPage<T>();        PageInfo<T> pageInfo = new PageInfo<T>(list);        myPage.setTotalCount((int) pageInfo.getTotal());        myPage.setRows(pageInfo.getList());        return myPage;    }    /**     * 设置PageHelper的startPage     * @param qry     */    private static void setPageHelperStartPage(AbstractQry qry) {        // 设置分页信息        // pageNum        Integer pageNum = qry.getPageNum();        pageNum = pageNum == null? AbstractQry.DEFAULT_PAGENUM : pageNum;        // pageSize        Integer pageSize = qry.getPageSize();        pageSize = pageSize == null ? AbstractQry.DEFAULT_PAGESIZE : pageSize;        // requireTotalCount        Boolean requireTotalCount = qry.getRequireTotalCount();        requireTotalCount = requireTotalCount == null ? AbstractQry.DEFAULT_REQUIRETOTALCOUNT : requireTotalCount;        PageHelper.startPage(pageNum, pageSize,requireTotalCount);    }}

Qry
查询条件的基类

public interface Qry {    String getId();    void setId(String id);}

AbstractQry
定义分页的查询的页码信息

public class AbstractQry implements Qry {    public static final int DEFAULT_PAGENUM = 1;    public static final int DEFAULT_PAGESIZE = 1;    public static final boolean DEFAULT_REQUIRETOTALCOUNT = false;    private String id;    private Integer pageNum = 1;// 第几页，首页为1    private Integer pageSize = 10;// 每页记录条数    private Boolean requireTotalCount = Boolean.FALSE;// 是否需要记录总数    // set/get略}

TestQry
这个类用来定义具体的查询条件

public class TestQry extends AbstractQry{}

3.3. 服务层：ITestService和TestServiceImpl

ITestService

public interface ITestService {    int deleteByPrimaryKey(Integer id);    int insertSelective(TestModel record);    TestModel selectByPrimaryKey(Integer id);    List<TestModel> selectAll(TestQry qry);    MyPage<TestModel> selectAllWithPage(TestQry qry);}

TestServiceImpl
selectAllWithPage定义了方法的使用

@Service@Primarypublic class TestServiceImpl implements ITestService{    @Autowired    private TestMapper testMapper;    @Override    public int deleteByPrimaryKey(Integer id) {        Assert.notNull(id, "id can't be null!");        return testMapper.deleteByPrimaryKey(id);    }    @Override    public MyPage<TestModel> selectAllWithPage(TestQry qry) {        if(qry == null){            qry = new TestQry();        }        MyPage<TestModel> myPage = PageCallBackUtil.selectRtnPage(qry, new IPageHelperPageCallBack() {            @Override            public List<TestModel> select() {                return  testMapper.selectAll();            }        });        return myPage;    }    … 其他方法略}

3.4. Control层

类 TestCtl

@RestController@RequestMapping(value = "/simple")@EnableSwagger2public class TestCtl {    @Autowired    private ITestService testService;    @RequestMapping(value = "delete-by-primary-key/{id}", method = RequestMethod.GET)    public int deleteByPrimaryKey( @PathVariable("id") Integer id){        // 参数验证略        return testService.deleteByPrimaryKey(id);    }    @RequestMapping(value = "insert-selective", method = RequestMethod.POST)    public int insertSelective(@RequestBody TestDto dto){        // 参数验证略        TestModel record = new TestModel();        record.setId(dto.getId());        record.setAge(dto.getAge());        record.setName(dto.getName());        return testService.insertSelective(record);    }    @RequestMapping(value = "select-by-primary-key/{id}", method = RequestMethod.POST)    public TestDto selectByPrimaryKey(@PathVariable("id") String id){        // 参数验证略        return Model2DtoUtil.model2Dto(testService.selectByPrimaryKey(Integer.parseInt(id)), TestDto.class);    }    @RequestMapping(value = "select-all", method = {RequestMethod.POST })    public List<TestDto> selectAll(@RequestBody TestQry qry){        return Model2DtoUtil.model2Dto(testService.selectAll(qry), TestDto.class);    }    @RequestMapping(value = "select-all-with-page", method = {RequestMethod.POST })    public MyPage<TestDto> selectAllWithPage(@RequestBody TestQry qry){        MyPage<TestDto> page = Model2DtoUtil.model2Dto(testService.selectAllWithPage(qry), TestDto.class);        page.setMessage(getLocalInfo());        return page;    }    private String getLocalInfo(){        StringBuilder sb = new StringBuilder();        try {            InetAddress inetAddress = InetAddress.getLocalHost();            sb.append("server info :")                    .append("[ip:").append(inetAddress.getHostAddress()).append(",hostname:").append(inetAddress.getHostName())                    .append("]");        } catch (UnknownHostException e) {            e.printStackTrace();        }        return sb.toString();    }}

3.5. model转化为dto类的工具类

Model2DtoUtil
工具类，封装将model转化为dto类，实现数据层和传输层的解耦

public class Model2DtoUtil {    /**     * 将 MyPage<model> 修改为  MyPage<Dto>     *     * @param sourcePage     * @param cls     * @param <T>     * @param <K>     * @return     */    public static <T, K> MyPage<K> model2Dto(MyPage<T> sourcePage, Class<K> cls) {        if(sourcePage == null){            return null;        }        Assert.notNull(cls, "cls can't be null!");        MyPage<K> dstPage = new MyPage<K>();        dstPage.setTotalCount(sourcePage.getTotalCount());        dstPage.setApiId(sourcePage.getApiId());        dstPage.setMessage(sourcePage.getMessage());        dstPage.setCode(sourcePage.getCode());        // list        List<T> sourceList = sourcePage.getRows();        List<K> dstList = new ArrayList<K>();        dealListModel2Dto(sourceList, cls, dstList);        dstPage.setRows(dstList);        return dstPage;    }    private static <T, K> void dealListModel2Dto(List<T> sourceList, Class<K> cls, List<K> dstList) {        for (T source : sourceList) {            try {                K dst = cls.newInstance();                CommonBeanUtils.copyProperties(source, dst);                dstList.add(dst);            } catch (InstantiationException e) {                e.printStackTrace();                throw new BeanCreationException(e.getMessage());            } catch (IllegalAccessException e) {                e.printStackTrace();                throw new BeanCreationException(e.getMessage());            }        }    }}

CommonBeanUtils
BeanUtils工具类：

public class CommonBeanUtils {    public static void copyProperties(Object source, Object target){        BeanUtils.copyProperties(source, target);    }}

3.6. application.yml

pagehelper相关的配置，其它的配置参数见官网

如果不配置以下参数，则分页机制不会启作用

# 分页配置： https://github.com/pagehelper/Mybatis-PageHelper/blob/master/wikis/zh/HowToUse.mdpagehelper:    helperDialect: oracle    reasonable: true    supportMethodsArguments: true    params: count=countSql

4. Spring Boot集成swagger和测试

为了对测试方便，我们引入swagger

4.1. pom.xml

<!-- swagger2 --><!-- https://mvnrepository.com/artifact/io.springfox/springfox-swagger2 --><dependency>    <groupId>io.springfox</groupId>    <artifactId>springfox-swagger2</artifactId>    <version>2.7.0</version></dependency><!-- https://mvnrepository.com/artifact/io.springfox/springfox-swagger-ui --><dependency>    <groupId>io.springfox</groupId>    <artifactId>springfox-swagger-ui</artifactId>    <version>2.7.0</version></dependency>

4.2. @EnableSwagger2

在TestCtl的类上加上@EnableSwagger2

@RestController@RequestMapping(value = "/simple")@EnableSwagger2public class TestCtl {    …}

4.3. 测试

打开地址：http://127.0.0.1:8080/swagger-ui.html
可以看到当前可用的url接口

测试 /simple/select-all-with-page接口的分页功能，设置查询功能

返回结果如下

5.代码

上文的详细代码见github代码，请尽量使用tag v0.2，不要使用master，因为master一直在变，不能保证文章中代码和github上的代码一直相同