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：

Spring Boot集成mybatis

Spring Boot集成pagehelper分页插件，定义分页的相关类

实现工具类：model转dto，实现数据层和传输层的解耦

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 huangrongyou@yixin.im 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
@Primary
public 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")
@EnableSwagger2
public 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.md pagehelper:
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")
@EnableSwagger2
public 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