java ssm框架实现分页功能的示例代码(oracle)

Z时代
2024-01-10
分类：IT

java web 实现分页功能，分享给大家，具体如下：

使用框架：ssm

数据库：oracle

话说 oracle 的分页查询比 mysql 复杂多了，在这里简单谈一下：

查询前十条数据：


SELECT * FROM(
 SELECT ROWNUM WN,RN.* FROM (
  SELECT
   id,
   title,
   create_time as createTime,
   musictor,
   musictitle
  FROM
   krry_blog
  ORDER BY create_time desc
  )RN
 )WN
WHERE WN <= 10 AND WN > 0

语法较为复杂，

同样的结果，mysql 的语法是：用一个 LIMIT 就可以解决。

SELECT

id,

title,

create_time as createTime,

musictor,

musictitle

FROM

krry_blog

ORDER BY create_time desc

LIMIT 0,5

SSM 框架的搭建，就不多说了，以前的博客有详细介绍，这里就谈谈实现 java web 分页的功能。

用到插件 js ： krry_page.js，还有jQuery

mapper 持久层：

BlogMapper.java


package com.krry.mapper;
import java.util.HashMap;
import java.util.List;
import com.krry.entity.Params;
/**
 * 
 * Mapper：操作数据库
 * @author krry
 * @version 1.0.0
 *
 */
public interface BlogMapper {
 /**
 * 查询所有博客
 * @param params
 * @return
 */
 public List<HashMap<String, Object>> findBlogs(Params params);
 /**
 * 计算博客数量
 * com.krry.dao.admin 
 * 方法名：countBlogs
 * @author krry 
 * @param params
 * @return int
 * @exception 
 * @since 1.0.0
 */
 public long countBlogs(); 
}

BlogMapper.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.krry.mapper.BlogMapper" > 
 <!-- 分页查询所有的博客信息 -->
 <select id="findBlogs" resultType="java.util.HashMap" parameterType="Params">
 SELECT * FROM(
  SELECT ROWNUM WN,RN.* FROM (
  SELECT
   id,
   title,
   create_time as createTime,
   musictor,
   musictitle
  FROM
   krry_blog
  ORDER BY create_time desc
  )RN
 )WN
 WHERE WN <= #{pageSize} AND WN > #{pageNo}
 </select>
 <!-- 查询博客数量 -->
 <select id="countBlogs" resultType="long">
 SELECT
  count(*)
 FROM
  krry_blog
 </select> 
</mapper>

service业务层：

接口类：IBlogService.java


package com.krry.service;
import java.util.HashMap;
import java.util.List;
import javax.servlet.http.HttpServletRequest;
import org.apache.ibatis.annotations.Param;
import com.krry.entity.Blog;
import com.krry.entity.Params;
/**
 * service层：处理业务逻辑（impl里面实现）
 * @author asusaad
 *
 */
public interface IBlogService { 
 /**
 * 分页查询所有博客
 * @param params
 * @return
 */
 public List<HashMap<String, Object>> findBlogs(Params params);
 /**
 * 计算博客数量
 * @param params
 * @return
 */
 public long countBlogs(); 
}

impl 实现类：BlogService.java


package com.krry.service.impl;
import java.util.HashMap;
import java.util.List;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import org.springframework.web.servlet.ModelAndView;
import com.krry.entity.Params;
import com.krry.mapper.BlogMapper;
import com.krry.service.IBlogService;
/**
 * 实现service层接口
 * @author asusaad
 *
 */
@Service
public class BlogService implements IBlogService{
 @Autowired
 private BlogMapper blogMapper;
 /**
 * 查询博客
 */
 public List<HashMap<String, Object>> findBlogs(Params params) {
 //查询博客信息
 List<HashMap<String, Object>> blog = blogMapper.findBlogs(params);
 return blog;
 }
 /**
 * 计算博客数量
 * @param params
 * @return
 */
 public long countBlogs(){
  long coutBlogs = blogMapper.countBlogs(); 
 return coutBlogs;
 } 
}

controller控制层：

KrryController.java


package com.krry.controller;
import java.util.HashMap;
import java.util.List;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.ResponseBody;
import org.springframework.web.servlet.ModelAndView;
import com.krry.entity.Params;
import com.krry.service.IBlogService;
/**
 * KrryController
 * controller层，作为请求转发
 * @author asusaad
 *
 */
@Controller //表示是多例模式，每个用户返回的web层是不一样的
public class KrryController { 
 @Autowired
 private IBlogService blogService;
 /**
 * 首页，并且分页查询
 * @return
 */
 @RequestMapping("/index")
 public ModelAndView index(Params params){ 
 params.setPageNo(0);
 params.setPageSize(10); //一开始只查询10条 
 //调用业务层
 List<HashMap<String, Object>> blogs = blogService.findBlogs(params);
 //查询博客数量
 long coutBlogs = blogService.countBlogs(); 
 ModelAndView modelAndView = new ModelAndView();
 modelAndView.addObject("blogs", blogs);
 modelAndView.addObject("coutBlogs", coutBlogs);
 modelAndView.setViewName("index"); 
 return modelAndView;
 }
 /**
 * ajax请求 的 分页查询
 * @param params
 * @return
 */
 @ResponseBody
 @RequestMapping("/loadData")
 public HashMap<String, Object> loadData(Params params){
 HashMap<String, Object> map = new HashMap<String, Object>();
 List<HashMap<String, Object>> blogs = blogService.findBlogs(params);
 map.put("blogs", blogs); 
 return map;
 } 
}

这里要有两个实体类，作为数据库查询的注入 Blog，还有分页查询的两个参数 Params：

设置data参数：pageNo（下一页）：就是当前页数 * 下一页要显示的数量

　　　　　　 pageSize（下一页）：已经查询出来的数量（pageNo） + 每页要显示的数量

在数据库中是 WN <= pageSize and WN > pageNo 来查询分页数据

Blog.java


package com.krry.entity;
/**
 * 
 * User
 * @author krry
 * @version 1.0.0
 *
 */
public class Blog {
 // 主键
 private String id;
 //博客标题
 private String title;
 //音乐作者
 private String musictor;
 //音乐标题
 private String musictitle;
 //创建时间
 private String createTime; 
 public Blog(String id, String title, String musictor, String musictitle,
  String createTime) {
 this.id = id;
 this.title = title;
 this.musictor = musictor;
 this.musictitle = musictitle;
 this.createTime = createTime;
 }
 public String getId() {
 return id;
 }
 public void setId(String id) {
 this.id = id;
 }
 public String getTitle() {
 return title;
 }
 public void setTitle(String title) {
 this.title = title;
 }
 public String getMusictor() {
 return musictor;
 }
 public void setMusictor(String musictor) {
 this.musictor = musictor;
 }
 public String getMusictitle() {
 return musictitle;
 }
 public void setMusictitle(String musictitle) {
 this.musictitle = musictitle;
 }
 public String getCreateTime() {
 return createTime;
 }
 public void setCreateTime(String createTime) {
 this.createTime = createTime;
 } 
}

Params.java


package com.krry.entity;
/**
 * 
 * Params
 * @author krry
 * @version 1.0.0
 *
 */
public class Params {
 private Integer pageSize = 0;
 private Integer pageNo = 0;
 public Integer getPageNo() {
  return pageNo;
 }
 public void setPageNo(Integer pageNo) {
  this.pageNo = pageNo;
 }
 public Integer getPageSize() {
  return pageSize;
 }
 public void setPageSize(Integer pageSize) {
  this.pageSize = pageSize;
 }
}

web 页面 index.jsp


<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<%@taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
pageContext.setAttribute("basePath", basePath);
%>
<!DOCTYPE HTML>
<html>
 <head>
 <title>分页</title>
 <style>
  body{background:url("resource/images/78788.jpg");background-size:cover;}
  .titless{font-size: 34px;text-align: center;color: black;margin-bottom: 16px;}
  .ke_tabbox{min-height:556px;width:900px;background:#f9f9f9;margin:20px auto 0;padding:6px;position:relative;}
   .ke_tabbox .sendMy{text-align: center;
     font-family: "微软雅黑";
     font-size: 28px;
     -webkit-text-fill-color: transparent;
     background: -webkit-gradient(linear,left top,left bottom,from(#FD8700),to(#FF00B1));
     -webkit-background-clip: text;
     margin:8px auto 0;line-height: 35px;}
   .ke_tabbox .ke_table{width:100%;margin-top: 26px;}
   .ke_tabbox th{background:#ccc;font-weight:bold;}
   .ke_tabbox .ke_table td,th{overflow: hidden;white-space: nowrap;text-overflow: ellipsis;border:1px solid #fff;padding:4px 12px;color:#666;font-size:12px;}
   /*分页相关*/
   .tzPage{font-size: 12px;position: absolute;top: 480px;right: 0px;}
   #tbody tr:hover{background:#eaeaea;}
   #tbody .t_mode{padding-right:4px;}
   #tbody .t_avbiaoq:hover{color:#FF6857;transition:.4s}
   #tbody .t_dele{padding-left:4px;}
   .tzPage a{text-decoration:none;border:none;color:#7d7d7d;background-color:#f2f2f2;border-radius: 3px;}
   .tzPage a:hover{background:#dd5862;color:#FFF;}
   .tzPage a,.tzPage span{display:block;float:left;padding:0em 0.5em;margin-right:5px;margin-bottom:5px;min-width:1em;text-align:center;line-height: 22px;height: 22px;}
   .tzPage .current{background:#dd5862;color:#FFF;border:none;border-radius: 3px;}
   .tzPage .current.prev,.tzPage .current.next{color:#999;border:1px solid #e5e5e5;background:#fff;}
   .tm_psize_go{margin-right:4px;float:left;height:24px;line-height:33px;position:relative;border:1px solid #e5e5e5;color:#999}
   #tm_pagego{border-radius:3px;height:18px;width:30px;float:left;text-align:center;border:1px solid #e5e5e5;line-height: 22px;color:#999}
   .sortdesc{border-top:5px solid;width:0px;height:0px;display:inline-block;vertical-align:middle;border-right:5px solid transparent;border-left:5px solid transparent;margin-left:5px;}
   .sortasc{border-bottom:5px solid;width:0px;height:0px;display:inline-block;vertical-align:middle;border-right:5px solid transparent;border-left:5px solid transparent;margin-left:5px;}
   .red{color:red} 
   .green{color:green}
   .hideAdd{height: 300px;
     text-align: center;
     line-height: 300px;
     margin-top: 16px;display:none;}
   .hideAdd a{font-size:28px;-webkit-text-fill-color:transparent;background: -webkit-gradient(linear,left top,left bottom,from(#FD0051),to(#A22C93));-webkit-background-clip: text;}
 </style>
 </head>
 <body>
  <div class="ke_tabbox">
   <p class="titless">分页展示</p>
  <table class="ke_table">
   <thead>
    <tr>
     <th style="width:25%">标题</th>
     <th style="width:25%">音乐人</th>
     <th style="width:30%">音乐标题</th>
     <th style="width:20%">发布时间</th>
    </tr>
   </thead>
   <tbody id="tbody" data-itemcount="${coutBlogs}">
    <c:forEach var="blog" items="${blogs}">
     <tr>
      <td><a class="t_avbiaoq" title="${blog.TITLE}">${blog.TITLE}</a></td>
      <td><a class="t_avbiaoq" title="${blog.MUSICTOR}">${blog.MUSICTOR}</a></td>
      <td><a class="t_avbiaoq" title="${blog.MUSICTITLE}">${blog.MUSICTITLE}</a></td>
      <td>${blog.CREATETIME}</td>
     </tr>
    </c:forEach>
   </tbody>
  </table>
  <div id="krryPage"></div>
 </div>
 <script type="text/javascript" src="${basePath}/resource/js/jquery-1.11.3.min.js"></script>
 <script type="text/javascript" src="${basePath}/resource/js/krry_page.js"></script>
 <script type="text/javascript">var basePath = "${basePath}";</script>
 <script type="text/javascript">
  var krryAdminBlog = {
   initPage:function(itemCount){
    $("#krryPage").tzPage(itemCount, {
     num_display_entries : 5, //主体页数
     num_edge_entries : 4,//边缘页数
     current_page : 0,//指明选中页码
     items_per_page : 10, //每页显示多少条
     prev_text : "上一页",
     next_text : "下一页",
     showGo:true,//显示
     showSelect:false,
     callback : function(pageNo, psize) {//会回传两个参数，第一个是当前页数，第二个是每页要显示的数量
      krryAdminBlog.loadData(pageNo,psize);
     }
    });
   },
   //设置data参数：pageNo（下一页）：就是当前页数 * 下一页要显示的数量
   //   pageSize（下一页）：已经查询出来的数量（pageNo） + 每页要显示的数量
   //在数据库中是 WN <= pageSize and WN > pageNo 来查询分页数据
   loadData:function(pageNo,pageSize){
    pageNo = pageNo * pageSize;
    pageSize = pageNo + 10;
    $.ajax({
     type:"post",
     url:basePath+"/loadData",
     data:{pageNo:pageNo,pageSize:pageSize},
     success:function(data){
      if(data){
       var html = "";
       var blogArr = data.blogs;
       for(var i=0,len=blogArr.length;i < len;i++){
        var json = blogArr[i];
        html+= "<tr>"+
        " <td><a class='t_avbiaoq' title='"+json.TITLE+"'>"+json.TITLE+"</a></td>"+
        " <td><a class='t_avbiaoq' title='"+json.NAME+"'>"+json.MUSICTOR+"</a></td>"+
        " <td><a class='t_avbiaoq' title='"+json.MUSICTITLE+"'>"+json.MUSICTITLE+"</a></td>"+
        " <td>"+json.CREATETIME+"</td>"+
        "</tr>";
       }
       $("#tbody").html(html);
      }
     }
    });
   }
  };
  krryAdminBlog.initPage($("#tbody").data("itemcount"));
 </script>
 </body>
</html>