一、POM.xml文件配置
<dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-data-jpa</artifactId> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-thymeleaf</artifactId> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-web</artifactId> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-devtools</artifactId> <scope>runtime</scope> </dependency> <dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> <scope>runtime</scope> </dependency>
二、相关代码
实体:
@Entity @Table(name = "userinfo") public class UserInfo implements Serializable { @Id @GeneratedValue private long userid; private String username; private String password; private int age; 省略getter&setter }
DAO: 仅需要继承JpaRepository, 也可以继承PagingAndSortingRepository 实现更多功能, 这里只做最简单的演示
public interface UserInfoDao extends JpaRepository<UserInfo, Long>, Serializable { }
Service:
public interface UserInfoService { //分页查询 Page<UserInfo> findByPage(Pageable pageable); }
ServiceImpl:
@Service @Transactional public class UserInfoServiceImpl implements UserInfoService { @Override public Page<UserInfo> findByPage(Pageable pageable) { return userInfoDao.findAll(pageable); } }
Controller:
Pageable定义了很多方法,但其核心的信息只有两个:一是分页的信息(page、size(limit)),二是排序的信息。Spring Data Jpa提供了PageRequest的具体实现,Spring MVC提供了对Spring Data JPA非常好的支持,我们只提供分页以及排序信息即可:
//分页 @RequestMapping("/list") public String pageUser(@RequestParam(value = "start", defaultValue = "0") Integer start, @RequestParam(value = "limit", defaultValue = "10") Integer limit, Model model){ start = start <0 ? 0:start; Sort sort = new Sort(Sort.DEFAULT_DIRECTION, "userid"); Pageable pageable = new PageRequest(start, limit, sort); Page<UserInfo> page = userInfoService.findByPage(pageable); model.addAttribute("page", page); return "user/userlist"; } //分页json @RequestMapping("/pagejson") @ResponseBody public Page<UserInfo> pageUser(@PageableDefault(value = 15, sort = "userid", direction = Sort.Direction.ASC)Pageable pageable){ return userInfoService.findByPage(pageable); }
三、返回Json及对象
返回一个Json格式的Pageable方便查看对象:
{ "content": [ { "userid": 1, "username": "sasa", "password": "e", "age": 123 }, { "userid": 11, "username": "问问", "password": "w", "age": 121 } ], "pageable": { "sort": { "sorted": true, "unsorted": false, "empty": false }, "offset": 0, "pageSize": 15, "pageNumber": 0, "paged": true, "unpaged": false }, "totalElements": 16, "totalPages": 2, "last": false, "number": 0, "size": 15, "sort": { "sorted": true, "unsorted": false, "empty": false }, "numberOfElements": 15, "first": true, "empty": false }
Json显示了Pageable的相关属性;, 也可直接使用,
这里我使用的是thymeleaf模板, 于是我使用第一个controller来渲染模板, 核心的显示数据如下, 省略了前后的引入.
<table class="table table-hover"> <thead> <tr> <th>id</th> <th>name</th> <th>password</th> <th>age</th> <th>details</th> <th>操作</th> </tr> </thead> <tbody> <tr th:each="user: ${page.content}"> <th scope="row" th:text="${user.getUserid()}">2</th> <th th:text="${user.getUsername()}">leo</th> <th th:text="${user.getPassword()}">pwd</th> <th th:text="${user.getAge()}">13</th> <th><a th:href="@{/user/findById(id=${user.getUserid()})}" >查看</a></th> <!--代码中未给出实现,可删除或自己实现--> <th><a th:href="@{/user/deleteById(id=${user.getUserid()})}" >删除</a></th> <!--代码中未给出实现,可删除或自己实现--> </tr> </tbody> </table> <ul class="list-group"> <li class="list-group-item"> <a class="btn-default" th:href="@{/user/list(start=0)}">[首页]</a> <a class="btn-default" th:if="${not page.isFirst()}" th:href="@{/user/list(start=${page.number-1})}">[上页]</a> <a class="btn-default" th:if="${not page.isLast()}" th:href="@{/user/list(start=${page.number+1})}">[下页]</a> <a class="btn-default" th:href="@{/user/list(start=${page.totalPages-1})}">[末页]</a> </li> </ul>
四、参考其他
另可参考这篇文章: https://www.tianmaying.com/tutorial/spring-jpa-page-sort(整合Spring Data JPA与Spring MVC: 分页和排序)
详细介绍了PagingAndSortingRepository, Pageable对象等, 但是只返回了Json数据, 而我使用了Thymeleaf返回对象并解析, 更快实现前端.
原文地址:https://www.cnblogs.com/kingstar718/p/10972700.html
时间: 2024-10-08 23:33:24