jsp真分页

迈不过友情╰ 2024-02-19 12:57 34阅读 0赞

jsp真分页

思路：根据页码确定每一页的记录数范围，然后按需查询数据库，每次只向jsp视图转发 指定页码的指定记录

\-- =========MySQL分页法1=================================  
\-- 从第1条记录开始，返回3条记录（即1~3）  
SELECT \* FROM runoob\_tb LIMIT 0,3;  
\-- 从第4条记录开始，返回3条记录（即4~6）  
SELECT \* FROM runoob\_tb LIMIT 3,3;  
\-- 从第7条记录开始，返回3条记录(剩余的不够3条，就返回剩余记录)  
SELECT \* FROM runoob\_tb LIMIT 6,3;  
\-- ========MySQL分页法2==================================  
\-- 跳过0条记录，返回3条记录（即1~3）  
SELECT \* FROM runoob\_tb LIMIT 3 OFFSET 0;  
\-- 跳过3条记录，返回3条记录（即4~6）  
SELECT \* FROM runoob\_tb LIMIT 3 OFFSET 3;  
\-- 跳过6条记录，返回3条记录(剩余的不够3条，就返回剩余记录)  
SELECT \* FROM runoob\_tb LIMIT 3 OFFSET 6;

====================================================

sql拼接字符串

int pageStartRecord = 0;  
int pageSize =3;  
String sql ="SELECT \* FROM runoob\_tb limit "+pageStartRecord+" ,"+pageSize+" ";  
主要代码如下：

2个po对象

package po;
    
    import java.util.List;
    
    public class Paging {
         int totalRecord;//总记录数
         int totalPageNum;//页面总数
         int pagesize;//1页的记录数
         int pageNow;//当前页页码
         int indexpage=1;//首页页码
         int endpage;//尾页页码
    
    	public int getTotalRecord() {
    		return totalRecord;
    	}
    	public void setTotalRecord(int totalRecord) {
    		this.totalRecord = totalRecord;
    	}
    	public int getTotalPageNum() {
    		return totalPageNum;
    	}
    	public void setTotalPageNum() {
    		//三目运算符，(判断总记录数是否能整除，不能整除则取整后加1)
    		this.totalPageNum=(totalRecord%pagesize==0)?(totalRecord/pagesize):(totalRecord/pagesize+1);
    	}
    	public int getPagesize() {
    		return pagesize;
    	}
    	public void setPagesize(int pagesize) {
    		this.pagesize = pagesize;
    	}
    	public int getPageNow() {
    		return pageNow;
    	}
    	public void setPageNow(int pageNow) {
    		this.pageNow = pageNow;
    	}
    	public int getIndexpage() {
    		return indexpage;
    	}
    	public void setIndexpage(int indexpage) {
    		this.indexpage = indexpage;
    	}
    	public int getEndpage() {
    		return endpage;
    	}
    	public void setEndpage() {
    		//最末页的页码为总页数
    		this.endpage = totalPageNum;
    	}
    	
        
    }

package po;
    
    import java.sql.Date;
    
    public class Runoob {
    	int runoob_id;
    	String runoob_title;
    	String runoob_author;
    	Date submission_date;
    	public int getRunoob_id() {
    		return runoob_id;
    	}
    	public void setRunoob_id(int runoob_id) {
    		this.runoob_id = runoob_id;
    	}
    	public String getRunoob_title() {
    		return runoob_title;
    	}
    	public void setRunoob_title(String runoob_title) {
    		this.runoob_title = runoob_title;
    	}
    	public String getRunoob_author() {
    		return runoob_author;
    	}
    	public void setRunoob_author(String runoob_author) {
    		this.runoob_author = runoob_author;
    	}
    	public Date getSubmission_date() {
    		return submission_date;
    	}
    	public void setSubmission_date(Date submission_date) {
    		this.submission_date = submission_date;
    	}
    	
    }

1 个servlet控制器

package servlet;
 
 import java.io.IOException;
 import java.util.ArrayList;
 import java.util.List;
 
 import javax.servlet.ServletException;
 import javax.servlet.annotation.WebServlet;
 import javax.servlet.http.HttpServlet;
 import javax.servlet.http.HttpServletRequest;
 import javax.servlet.http.HttpServletResponse;
 
 import po.Paging;
 import po.Runoob;
 import service.TestService;
 import service.TestServiceImpl;
 
 /**
 * Servlet implementation class TestServlet
 */
 @WebServlet("/TestServlet")
 public class TestServlet extends HttpServlet {
 	private static final long serialVersionUID = 1L;
 	
 	
 	TestService service =new TestServiceImpl();
 
 /**
 * @see HttpServlet#HttpServlet()
 */
 public TestServlet() {
 super();
 // TODO Auto-generated constructor stub
 }
 
 	/**
 	 * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
 	 */
 	protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
 		
 		
 		//查到总记录数
 		int TotalRecord=service.getTotalRecord();
 		//定义 一个页面的数据多少条
 		int pageSize=3;
 		//定义页面当前页码
 		int page =0;
 		//实例化分页对象
 		Paging paging =new Paging();
 		paging.setTotalRecord(TotalRecord);//数据总数
 		paging.setPagesize(pageSize);//设置一个页面的数据多少条
 		paging.setTotalPageNum();//总的页面数
 		paging.setEndpage();//最后一页
 		paging.setIndexpage(1);//第一页
 		
 		//得到浏览器传过来的当前页
 		String str_page=request.getParameter("page");
 		//判断下一页页码
 		if(str_page !=null) {
 			//将页转换整型判断其大小
 			int pag=Integer.parseInt(str_page);
 			//当大于零，将传过来的pag值赋给当前页page
 			if(pag>0) {
 				page=pag;
 				//如果大于最大值时则，将其传过来的值减1在赋值给当前页，让其一直在最后一页
 				if(pag>(paging.getTotalPageNum()-1)) {
 					page=pag-1;
 				}
 			}
 			//因为page默认值为0，所以如果pag<0,则取page的默认值,外部已经定义，这里不用再写
 		}
 		System.out.println("page="+page);
 		
 		//将下一页页码设置为当前页码
 		paging.setPageNow(page);
 		//定义当前页码对应的起始记录
 		int pageStartRecord = page*3;
 		
 		//list_page存储每次该向jsp发送的数据记录(页码在变，记录也在变)
 		//SELECT * FROM runoob_tb LIMIT page*3,3;
 		List list_page =service.fenyeSelect(pageStartRecord, pageSize);
 					
 		//将分页对象和数据 转发到jsp		
 		request.setAttribute("paging", paging);
 
 		request.setAttribute("list", list_page);
 		
 		request.getRequestDispatcher("fy.jsp").forward(request, response);
 			
 	}
 
 	/**
 	 * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
 	 */
 	protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
 		// TODO Auto-generated method stub
 		doGet(request, response);
 	}
 
 }

1个jsp视图

<%@ page language="java" contentType="text/html; charset=UTF-8"
 pageEncoding="UTF-8"%>
 <%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core"%>
 <!DOCTYPE html>
 <html>
 <head>
 <meta charset="UTF-8">
 <title>分页</title>
 </head>
 <body>
 分页信息 
 	<c:forEach items="${list}" var="list">
 		${list.runoob_id}    
 		${list.runoob_title}    
 		${list.runoob_author}    
 		${list.submission_date} 
 	</c:forEach>
 	
 	 
 <a href="TestServlet?page=${paging.indexpage-1}"><< 首页 </a>   
 <a href="TestServlet?page=${paging.pageNow-1}"> < 上一页 </a>   
 第${paging.pageNow+1}页/共${paging.totalPageNum}页   
 <a href="TestServlet?page=${paging.pageNow+1}">下一页 ></a>   
 <a href="TestServlet?page=${paging.totalPageNum-1}">末页 >></a> 
 
 </body>
 </html>

运行效果

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L1RoaW5rUGV0_size_16_color_FFFFFF_t_70][]

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L1RoaW5rUGV0_size_16_color_FFFFFF_t_70 1][]

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L1RoaW5rUGV0_size_16_color_FFFFFF_t_70 2][]

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L1RoaW5rUGV0_size_16_color_FFFFFF_t_70 3][]

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L1RoaW5rUGV0_size_16_color_FFFFFF_t_70 4][]

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L1RoaW5rUGV0_size_16_color_FFFFFF_t_70 5][]

=========================================================================================

项目下载地址：

链接：https://pan.baidu.com/s/1PgK92TSesWxPuU6VeCyfAQ  
提取码：lq83  
复制这段内容后打开百度网盘手机App，操作更方便哦

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