1.分页功能的作用
分页功能作为各类网站和系统不可或缺的部分(例如百度搜索结果的分页等),当一个页面数据量大的时候分页作用就体现出来的,其作用有以下5个。
(1)减少系统资源的消耗
(2)提高数据库的查询性能
(3)提升页面的访问速度
(4)符合用户的浏览习惯
(5)适配页面的排版
2.建立测试数据库
由于需要实现分页功能,所需的数据较多
- DROP TABLE IF EXISTS tb_user;
-
- CREATE TABLE tb_user (
- id int(11) NOT NULL AUTO_INCREMENT COMMENT '主键id',
- name varchar(100) NOT NULL DEFAULT '' COMMENT '登录名',
- password varchar(100) NOT NULL DEFAULT '' COMMENT '密码',
- PRIMARY KEY (id) USING BTREE
- ) ENGINE = InnoDB CHARACTER SET = utf8;
-
- insert into tb_user (id,name,password)
- value (1,'C','123456'),
- (2,'C++','123456'),
- (3,'Java','123456'),
- (4,'Python','123456'),
- (5,'R','123456'),
- (6,'C#','123456');
-
- insert into tb_user (id,name,password) value (7,'test1','123456');
- insert into tb_user (id,name,password) value (8,'test2','123456');
- insert into tb_user (id,name,password) value (9,'test3','123456');
- insert into tb_user (id,name,password) value (10,'test4','123456');
- insert into tb_user (id,name,password) value (11,'test5','123456');
- insert into tb_user (id,name,password) value (12,'test6','123456');
- insert into tb_user (id,name,password) value (13,'test7','123456');
- insert into tb_user (id,name,password) value (14,'test8','123456');
- insert into tb_user (id,name,password) value (15,'test9','123456');
- insert into tb_user (id,name,password) value (16,'test10','123456');
- insert into tb_user (id,name,password) value (17,'test11','123456');
- insert into tb_user (id,name,password) value (18,'test12','123456');
- insert into tb_user (id,name,password) value (19,'test13','123456');
- insert into tb_user (id,name,password) value (20,'test14','123456');
- insert into tb_user (id,name,password) value (21,'test15','123456');
- insert into tb_user (id,name,password) value (22,'test16','123456');
- insert into tb_user (id,name,password) value (23,'test17','123456');
- insert into tb_user (id,name,password) value (24,'test18','123456');
- insert into tb_user (id,name,password) value (25,'test19','123456');
- insert into tb_user (id,name,password) value (26,'test20','123456');
- insert into tb_user (id,name,password) value (27,'test21','123456');
- insert into tb_user (id,name,password) value (28,'test22','123456');
- insert into tb_user (id,name,password) value (29,'test23','123456');
- insert into tb_user (id,name,password) value (30,'test24','123456');
- insert into tb_user (id,name,password) value (31,'test25','123456');
- insert into tb_user (id,name,password) value (32,'test26','123456');
- insert into tb_user (id,name,password) value (33,'test27','123456');
- insert into tb_user (id,name,password) value (34,'test28','123456');
- insert into tb_user (id,name,password) value (35,'test29','123456');
- insert into tb_user (id,name,password) value (36,'test30','123456');
- insert into tb_user (id,name,password) value (37,'test31','123456');
- insert into tb_user (id,name,password) value (38,'test32','123456');
- insert into tb_user (id,name,password) value (39,'test33','123456');
- insert into tb_user (id,name,password) value (40,'test34','123456');
- insert into tb_user (id,name,password) value (41,'test35','123456');
- insert into tb_user (id,name,password) value (42,'test36','123456');
- insert into tb_user (id,name,password) value (43,'test37','123456');
- insert into tb_user (id,name,password) value (44,'test38','123456');
- insert into tb_user (id,name,password) value (45,'test39','123456');
- insert into tb_user (id,name,password) value (46,'test40','123456');
- insert into tb_user (id,name,password) value (47,'test41','123456');
- insert into tb_user (id,name,password) value (48,'test42','123456');
- insert into tb_user (id,name,password) value (49,'test43','123456');
- insert into tb_user (id,name,password) value (50,'test44','123456');
- insert into tb_user (id,name,password) value (51,'test45','123456');
3.分页功能返回的结果封装
新建一个util包并在包中新建Result通用结果类,代码如下:
- package ltd.newbee.mall.entity;
-
- public class User {
- private Integer id;
- private String name;
- private String password;
-
- public Integer getId() {
- return id;
- }
-
- public void setId(Integer id) {
- this.id = id;
- }
-
- public String getName() {
- return name;
- }
-
- public void setName(String name) {
- this.name = name;
- }
-
- public String getPassword() {
- return password;
- }
-
- public void setPassword(String password) {
- this.password = password;
- }
- }
后端接口返回的数据会根据以上格式进行数据封装,包括业务码、返回信息、实际的数据结果。这个格式是开发人员自行设置的,如果有其他更好的方案也可以进行适当的调整。
在util包中新建PageResult通用结果类,代码如下:
- package ltd.newbee.mall.util;
-
- import java.util.List;
-
- /**
- * 分页工具类
- */
- public class PageResult {
- //总记录数
- private int totalCount;
- //每页记录数
- private int pageSize;
- //总页数
- private int totalPage;
- //当前页数
- private int currPage;
- //列表数据
- private List<?> list;
-
- /**
- *
- * @param totalCount 总记录数
- * @param pageSize 每页记录数
- * @param currPage 当前页数
- * @param list 列表数据
- */
- public PageResult(int totalCount, int pageSize, int currPage, List<?> list) {
- this.totalCount = totalCount;
- this.pageSize = pageSize;
- this.currPage = currPage;
- this.list = list;
- this.totalPage = (int) Math.ceil((double) totalCount / pageSize);
- }
-
- public int getTotalCount() {
- return totalCount;
- }
-
- public void setTotalCount(int totalCount) {
- this.totalCount = totalCount;
- }
-
- public int getPageSize() {
- return pageSize;
- }
-
- public void setPageSize(int pageSize) {
- this.pageSize = pageSize;
- }
-
- public int getTotalPage() {
- return totalPage;
- }
-
- public void setTotalPage(int totalPage) {
- this.totalPage = totalPage;
- }
-
- public int getCurrPage() {
- return currPage;
- }
-
- public void setCurrPage(int currPage) {
- this.currPage = currPage;
- }
-
- public List<?> getList() {
- return list;
- }
-
- public void setList(List<?> list) {
- this.list = list;
- }
- }
4.分页功能代码具体实现
4.1数据层
在UserDao接口中新增两个方法findUsers()和getTotalUser(),代码如下所示:
- /**
- * 返回分页数据列表
- *
- * @param pageUtil
- * @return
- */
- List<User> findUsers(PageQueryUtil pageUtil);
-
- /**
- * 返回数据总数
- *
- * @param pageUtil
- * @return
- */
- int getTotalUser(PageQueryUtil pageUtil);
在UserMapper.xml文件中新增这两个方法的映射语句,代码如下所示:
- <!--分页-->
- <!--查询用户列表-->
- <select id="findUsers" parameterType="Map" resultMap="UserResult">
- select id,name,password from tb_user
- order by id desc
- <if test="start!=null and limit!=null">
- limit #{start}.#{limit}
- </if>
- </select>
- <!--查询用户总数-->
- <select id="getTotalUser" parameterType="Map" resultType="int">
- select count(*) from tb_user
- </select>
4.2业务层
新建service包,并新增业务类UserService,代码如下所示:
- import ltd.newbee.mall.dao.UserDao;
- import ltd.newbee.mall.entity.User;
- import ltd.newbee.mall.util.PageResult;
- import ltd.newbee.mall.util.PageQueryUtil;
- import org.springframework.beans.factory.annotation.Autowired;
- import org.springframework.stereotype.Service;
-
- import java.util.List;
-
- @Service
- public class UserService {
-
- @Autowired
- private UserDao userDao;
-
- public PageResult getUserPage(PageQueryUtil pageUtil){
- //当前页面中的数据列表
- List<User> users = userDao.findUsers(pageUtil);
- //数据总条数,用于计算分页数据
- int total = userDao.getTotalUser(pageUtil);
- //分页信息封装
- PageResult pageResult = new PageResult(users,total,pageUtil.getLimit(),pageUtil.getPage());
- return pageResult;
- }
- }
首先根据当前页面和每页条数查询当前页的数据集合,然后调用select count(*)语句查询数据的总条数用于计算分页数据,最后将获取的数据封装到PageResult对象中并返回给控制层。
4.3控制层
在controller包中新建PageTestController类,用于实现分页请求的处理并返回查询结果,代码如下所示:
- @RestController
- @RequestMapping("users")
- public class PageTestController {
-
- @Autowired
- private UserService userService;
-
- //分页功能测试
- @RequestMapping(value = "/list",method = RequestMethod.GET)
- public Result list(@RequestParam Map<String,Object> params){
- Result result = new Result();
- if (StringUtils.isEmpty(params.get("page"))||StringUtils.isEmpty(params.get("limit"))){
- //返回错误码
- result.setResultCode(500);
- //错误信息
- result.setMessage("参数异常!");
- return result;
- }
- //封装查询参数
- PageQueryUtil queryParamList = new PageQueryUtil(params);
- //查询并封装分页结果集
- PageResult userPage = userService.getUserPage(queryParamList);
- //返回成功码
- result.setResultCode(200);
- result.setMessage("查询成功");
- //返回分页数据
- result.setData(userPage);
- return result;
- }
- }
分页功能的交互流程:前端将所需页码和条数参数传输给后端,后端在接收分页请求后对分页参数进行计算,并利用MySQL的limit关键字查询对应的记录,在查询结果被封装后返回给前端。在TestUserControler类上使用的是@RestController注解,该注解相当于@ResponseBody+@Controller的组合注解。
5.jqGrid分页插件
jqGrid是一个用来显示网格数据的jQuery插件。开发人员通过使用jqGrid可以轻松实现前端页面与后台数据的Ajax异步通信并实现分页功能。同时,jqGrid是一款代码开源的分页插件,源码也一直处于迭代更新的状态中。
下载地址:jqGrid
下载jqGrid后解压文件,将解压的文件直接拖进项目的static目录下

以下是jqGrid实现分页的步骤:
首先,在前端页面代码中引入jqGrid分页插件所需的源文件,代码如下所示:
- <link href="plugins/jqgrid-5.8.2/ui.jqgrid-bootstrap4.css" rel="external nofollow" rel="stylesheet"/>
- <!--jqGrid依赖jQuery,因此需要先引入jquery.min.js文件,下方地址为字节跳动提供的cdn地址-->
- <script src="http://s3.pstatp.com/cdn/expire-1-M/jquery/3.3.1/jquery.min.js"></script>
- <!--grid.locale-cn.js为国际化所需的文件,-cn表示中文-->
- <script src="plugins/jqgrid-5.8.2/grid.locale-cn.js"></script>
- <script src="plugins/jqgrid-5.8.2/jquery.jqGrid.min.js"></script>
其次,在页面中需要展示分页数据的区域添加用于jqGrid初始化的代码:
- <!--jqGrid必要DOM,用于创建表格展示列表数据-->
- <table id="jqGrid" class="table table-bordered"></table>
-
- <!--jqGrid必要DOM,分页信息区域-->
- <div id="jqGridPager"></div>
最后,调用jqGrid分页插件的jqGrid()方法渲染分页展示区域,代码如下所示:


jqGrid()方法中的参数及含义如图所示。

jqGrid前端页面测试:
在resources/static目中新建jqgrid-page-test.html文件,代码如下所示:
- <!DOCTYPE html>
- <html lang="en">
- <head>
- <meta charset="UTF-8">
- <title>jqGrid分页测试</title>
- <!--引入bootstrap样式文件-->
- <link rel="stylesheet" href="/static/bootstrap-5.3.0-alpha3-dist/css/bootstrap.css" rel="external nofollow" />
- <link href="jqGrid-5.8.2/css/ui.jqgrid-bootstrap4.css" rel="external nofollow" rel="stylesheet"/>
- </head>
- <body>
- <div style="margin: 24px;">
- <!--数据展示列表,id为jqGrid-->
- <table id="jqGrid" class="table table-bordered"></table>
- <!--分页按钮展示区-->
- <div id="jqGridPager"></div>
- </div>
- </body>
- <!--jqGrid依赖jQuery,因此需要先引入jquery.min.js文件,下方地址为字节跳动提供的cdn地址-->
- <script src="http://s3.pstatp.com/cdn/expire-1-M/jquery/3.3.1/jquery.min.js"></script>
- <!--grid.locale-cn.js为国际化所需的文件,-cn表示中文-->
- <script src="plugins/jqgrid-5.8.2/grid.locale-cn.js"></script>
- <script src="plugins/jqgrid-5.8.2/jquery.jqGrid.min.js"></script>
- <script src="jqgrid-page-test.js"></script>
- </html>
jqGrid初始化
在resources/static目录下新建jqgrid-page-test.js文件,代码如下所示:
- $(function () {
- $("#jqGrid").jqGrid({
- url: 'users/list',
- datatype: "json",
- colModel: [
- {label: 'id',name: 'id', index: 'id', width: 50, hidden: true,key:true},
- {label: '登录名',name: 'name',index: 'name', sortable: false, width: 80},
- {label: '密码字段',name: 'password',index: 'password', sortable: false, width: 80}
- ],
- height: 485,
- rowNum: 10,
- rowList: [10,30,50],
- styleUI: 'Bootstrap',
- loadtext: '信息读取中...',
- rownumbers: true,
- rownumWidth: 35,
- autowidth: true,
- multiselect: true,
- pager: "#jqGridPager",
- jsonReader:{
- root: "data.list",
- page: "data.currPage",
- total: "data.totalCount"
- },
- prmNames:{
- page: "page",
- rows: "limit",
- order: "order"
- },
- gridComplete: function () {
- //隐藏grid底部滚动条
- $("#jqGrid").closest(".ui-jqgrid-bdiv").css({"overflow-x": "hidden"});
- }
- });
- $(window).resize(function () {
- $("jqGrid").setGridWidth($(".card-body").width());
- });
- });
总结
到此这篇关于springboot实现分页功能的文章就介绍到这了,更多相关springboot分页功能内容请搜索w3xue以前的文章或继续浏览下面的相关文章希望大家以后多多支持w3xue!