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SpringBoot整合MyBatis分页插件PageHelper

步骤

第一步：首先整合MyBatis

参照之前SpringBoot整合系列-整合MyBatis

第二步：添加必要的依赖

<dependency>
<groupId>com.github.pagehelper</groupId>
<artifactId>pagehelper</artifactId>
<version>4.1.6</version>
</dependency>

第三步：添加必要的配置

无

第四步：添加必要的配置类

@Configuration
public class PageHelperConfig {
@Bean
public PageHelper pageHelper(){
PageHelper pageHelper = new PageHelper();
Properties properties = new Properties();
properties.setProperty("offsetAsPageNum","true");
properties.setProperty("rowBoundsWithCount","true");
properties.setProperty("reasonable","true");
properties.setProperty("dialect","mysql");    //配置mysql数据库的方言
pageHelper.setProperties(properties);
return pageHelper;
}
}

第五步：使用插件

6-1 定义mapper，延用之前的mapper

BookRepository.xml

<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.example.springbootdemo.mapper.BookRepository">

<!--省略多余内容-->

<select id="getBooks" resultMap="bookResultMap">
select * from BOOK WHERE 1=1
<if test="bookId != null">
and BOOK_ID = #{bookId}
</if>
<if test="pageNum != null">
and PAGE_NUM = #{pageNum}
</if>
<if test="bookType != null">
and BOOK_TYPE = #{bookType}
</if>
<if test="bookDesc != null">
and BOOK_DESC = #{bookDesc}
</if>
<if test="bookPrice != null">
and BOOK_PRICE = #{bookPrice}
</if>
<if test="bookName != null">
and BOOK_NAME = #{bookName}
</if>
</select>
<select id="count" resultType="int">
select count(1) from BOOK WHERE 1=1
<if test="bookId != null">
and BOOK_ID = #{bookId}
</if>
<if test="pageNum != null">
and PAGE_NUM = #{pageNum}
</if>
<if test="bookType != null">
and BOOK_TYPE = #{bookType}
</if>
<if test="bookDesc != null">
and BOOK_DESC = #{bookDesc}
</if>
<if test="bookPrice != null">
and BOOK_PRICE = #{bookPrice}
</if>
<if test="bookName != null">
and BOOK_NAME = #{bookName}
</if>
</select>
<resultMap id="bookResultMap" type="Book">
<id column="BOOK_ID" property="bookId"/>
<result column="PAGE_NUM" property="pageNum"/>
<result column="BOOK_NAME" property="bookName"/>
<result column="BOOK_TYPE" property="bookType"/>
<result column="BOOK_DESC" property="bookDesc"/>
<result column="BOOK_PRICE" property="bookPrice"/>
<result column="CREATE_TIME" property="createTime"/>
<result column="MODIFY_TIME" property="modifyTime"/>
</resultMap>
</mapper>

BookRepository.java

public interface BookRepository {

//省略多余内容

List<Book> getBooks(Book book);
int count(Book book);
}

6-2 定义service

@Service
@Log4j2
public class BookService {

@Autowired
private BookRepository bookRepository;

// 省略多余内容

public ResponseEntity<PageInfo<Book>> getBooksByPageHelper(int pageId, int pageSize) {
PageHelper.startPage(pageId, pageSize);
List<Book> books = bookRepository.getBooks(Book.builder().build());
int totalNum  = bookRepository.count(Book.builder().build());
PageInfo<Book> page = new PageInfo<>();
page.setPageNum(pageId);
page.setPageSize(pageSize);
page.setSize(totalNum);
page.setList(books);
return ResponseEntity.ok(page);
}
}

6-3 定义controller

@RestController
@RequestMapping("/book")
@Api(description = "书籍接口")
@Log4j2
public class BookApi {

@Autowired
private BookService bookService;

// 省略多余内容

@RequestMapping(value = "/getBooksByPageHelper", method = RequestMethod.GET)
@ApiOperation(value = "分页获取书籍", notes = "通过PageHelper分页获取书籍", httpMethod = "GET")
public ResponseEntity<PageInfo<Book>> getBooksByPageHelper(final int pageId, final int pageNum){
return bookService.getBooksByPageHelper(pageId, pageNum);
}

}