jsp页面显示分页

　pagebean.java

public class PageBean {    private int page = 1;// 页码    private int rows = 10;// 页大小    private int total = 0;// 总记录数    private boolean pagination = true;// 是否分页    private Map
     
       paMap=new HashMap<>();    private String url;    public void setRequest(HttpServletRequest req) {        //保存上一次请求所携带得参数        this.setPaMap(req.getParameterMap());        this.setUrl(req.getRequestURI().toString());        //在jsp页面来控制是否分页        this.setPagination(req.getParameter("pagination"));        //在jsp页面控制一页展示多少条数据        this.setRows(req.getParameter("rows"));        this.setPage(req.getParameter("page"));    }    public void setPage(String page) {        this.page=StringUtils.isNotBlank(page)?Integer.valueOf(page):this.page;    }        public void setPagination(String pagination) {        this.pagination=StringUtils.isNotBlank(pagination)?!"false".equals(pagination):this.pagination;    }    public void setRows(String rows) {        this.rows=StringUtils.isNotBlank(rows)?Integer.valueOf(rows):this.rows;            }    public Map
      
        getPaMap() {        return paMap;    }    public void setPaMap(Map
       
         paMap) {        this.paMap = paMap;    }    public String getUrl() {        return url;    }    public void setUrl(String url) {        this.url = url;    }    public PageBean() {        super();    }    public int getPage() {        return page;    }    public void setPage(int page) {        this.page = page;    }    public int getRows() {        return rows;    }    public void setRows(int rows) {        this.rows = rows;    }    public int getTotal() {        return total;    }    public void setTotal(int total) {        this.total = total;    }    public void setTotal(String total) {        this.total = Integer.parseInt(total);    }    public boolean isPagination() {        return pagination;    }    public void setPagination(boolean pagination) {        this.pagination = pagination;    }    /**     * 获得起始记录的下标     *      * @return     */    public int getStartIndex() {        return (this.page - 1) * this.rows;    }    @Override    public String toString() {        return "PageBean [page=" + page + ", rows=" + rows + ", total=" + total + ", pagination=" + pagination + "]";    }    /**     * 获取最大的页码数     * @return     */    public int getMaxPage() {        return this.total%this.rows==0 ? this.total/this.rows : this.total/this.rows+1;    }    /**     * 获取下一页     * @return     */    public int getNextPage() {        return this.page < this.getMaxPage() ? this.page+1:this.page;    }    /**     * 获取上一页     * @return     */    public int getpreviousPage() {        return this.page>1 ? this.page-1:this.page;    }}
       
      
     

 

　bookServlet.java

package com.web;import java.io.IOException;import java.sql.SQLException;import java.util.List;import java.util.Map;import javax.jws.WebService;import javax.servlet.ServletException;import javax.servlet.annotation.WebFilter;import javax.servlet.annotation.WebServlet;import javax.servlet.http.HttpServlet;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;import com.entity.Book;import com.jt.dao.BookDao;import com.util.PageBean;@WebServlet("/bookServlet ")public class BookServlet extends HttpServlet {        private static final long serialVersionUID = 6304839939800249916L;    private BookDao bookDao=new BookDao();        @Override    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {        // TODO Auto-generated method stub        doPost(req, resp);    }    @Override    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {        // TODO Auto-generated method stub        String bname=req.getParameter("bname");        Book book=new Book();        book.setBname(bname);        //        Map
     
       parameterMap=req.getParameterMap();//        StringBuffer url= req.getRequestURL();                        PageBean pageBean=new PageBean();        try {            pageBean.setRequest(req);            List
      
        list= this.bookDao.list(book, pageBean);            req.setAttribute("bookList", list);            req.setAttribute("pageBean",pageBean);            req.getRequestDispatcher("/BookList.jsp").forward(req, resp);        } catch (InstantiationException | IllegalAccessException | SQLException e) {            // TODO Auto-generated catch block            e.printStackTrace();        }    }    }
      
     

 

　过滤器：EncodingFiter.java

package com.util;import java.io.IOException;import java.util.Iterator;import java.util.Map;import java.util.Set;import javax.servlet.Filter;import javax.servlet.FilterChain;import javax.servlet.FilterConfig;import javax.servlet.ServletException;import javax.servlet.ServletRequest;import javax.servlet.ServletResponse;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;/** * 中文乱码处理 *  */public class EncodingFiter implements Filter {	private String encoding = "UTF-8";// 默认字符集	public EncodingFiter() {		super();	}	public void destroy() {	}	public void doFilter(ServletRequest request, ServletResponse response,			FilterChain chain) throws IOException, ServletException {		HttpServletRequest req = (HttpServletRequest) request;		HttpServletResponse res = (HttpServletResponse) response;		// 中文处理必须放到 chain.doFilter(request, response)方法前面		res.setContentType("text/html;charset=" + this.encoding);		if (req.getMethod().equalsIgnoreCase("post")) {			req.setCharacterEncoding(this.encoding);		} else {			Map map = req.getParameterMap();// 保存所有参数名=参数值(数组)的Map集合			Set set = map.keySet();// 取出所有参数名			Iterator it = set.iterator();			while (it.hasNext()) {				String name = (String) it.next();				String[] values = (String[]) map.get(name);// 取出参数值[注：参数值为一个数组]				for (int i = 0; i < values.length; i++) {					values[i] = new String(values[i].getBytes("ISO-8859-1"),							this.encoding);				}			}		}		chain.doFilter(request, response);	}	public void init(FilterConfig filterConfig) throws ServletException {		String s = filterConfig.getInitParameter("encoding");// 读取web.xml文件中配置的字符集		if (null != s && !s.trim().equals("")) {			this.encoding = s.trim();		}	}}

　　自定义标签类：PageTag.java

package com.tag;import java.io.IOException;import java.util.Map;import java.util.Map.Entry;import java.util.Set;import javax.servlet.jsp.JspException;import javax.servlet.jsp.JspWriter;import javax.servlet.jsp.tagext.BodyTagSupport;import com.util.PageBean;public class PageTag extends BodyTagSupport {    private static final long serialVersionUID = -553969530960334073L;    private PageBean pageBean;    public PageBean getPageBean() {        return pageBean;    }    public void setPageBean(PageBean pageBean) {        this.pageBean = pageBean;    }    @Override    public int doStartTag() throws JspException {        JspWriter out = pageContext.getOut();        try {            out.print(toHTML());        } catch (IOException e) {            // TODO Auto-generated catch block            e.printStackTrace();        }        return super.doStartTag();    }    private String toHTML() {        // TODO Auto-generated method stub        StringBuilder sb=new StringBuilder();        //拼接下一次发送请求所要提交得隐藏得form表单        sb.append("
     
      ");        sb.append(" 
      ");        Map
      
        paMap = pageBean.getPaMap();        if(paMap!=null&&paMap.size()>0) {            Set
       
        
         > entrySet = paMap.entrySet();            for (Entry
         
           entry : entrySet) {                //上一次请求可能携带页码naempage得参数，但是改参数在前面以及单独赋值                //为什么要单独赋值？因为上一次请求时第一页得数据，下一次可能时第二页，以后这前后请求page对应得值不一样，需要单独赋值                if(!"page".equals(entry.getKey())) {//                    
          //                    
                              //[1,2]                    for(String val:entry.getValue()) {                        sb.append("
          ");                    }                }            }        }         sb.append("");        //拼接分页条        sb.append("
          
           "); sb.append("每页"+pageBean.getRows()+"条，共"+pageBean.getTotal()+"条，第"+pageBean.getPage()+"页，共"+pageBean.getMaxPage()+"页  
           首页  
           
            上一页  
            
             下一页  
             
              尾页  
                
              
               Go"); sb.append("
              
             
            
           
          
");        //拼接分页所需要得js代码        sb.append("
          ");                    return sb.toString();    }}
         
        
       
      
     

 

　jsp页面：bookList.jsp

<%@ page language="java" contentType="text/html; charset=UTF-8"    pageEncoding="UTF-8"%>    <%@taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>    <%@taglib prefix="z" uri="/jt" %>
     
小说目录
    
    
     
              书名：
       
          
     
    
                 
     
     
              
       
                    
编号
                    
名称
                    
价格
               
               
                        
${b.bid }
                        
${b.bname }
                        
${b.price }
                   
                  
     
     

接下来就是运行结果：

 （在这里我们可以跳转，首页尾页下一页上一页）

 

 

再接下来就是通用分页带给我们的好处演示啦

新建一个servlet跟jsp页面

servlet

package com.web;import java.io.IOException;import java.sql.SQLException;import java.util.List;import javax.servlet.ServletException;import javax.servlet.annotation.WebFilter;import javax.servlet.annotation.WebServlet;import javax.servlet.http.HttpServlet;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;import com.entity.Blog;import com.jt.dao.BlogDao;import com.util.PageBean;@WebServlet("/blogServlet")public class BlogServlet extends HttpServlet {    private BlogDao blogDao=new BlogDao();    @Override    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {        // TODO Auto-generated method stub        doPost(req, resp);    }    @Override    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {        // TODO Auto-generated method stub        Blog blog=new Blog();        blog.setBookname(req.getParameter("bookname"));        PageBean pageBean=new PageBean();        try {            List
     
       list = this.blogDao.list(blog, pageBean);            req.setAttribute("blogList",list);            req.setAttribute("pageBean",pageBean);            req.getRequestDispatcher("/BlogList.jsp").forward(req, resp);        } catch (InstantiationException | IllegalAccessException | SQLException e) {            // TODO Auto-generated catch block            e.printStackTrace();        }    }}
     

　　jsp页面

<%@ page language="java" contentType="text/html; charset=UTF-8"    pageEncoding="UTF-8"%>    <%@taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>  <%@taglib prefix="z" uri="/jt" %>
     
小说目录
    
    
     
              书名：
       
          
     
    
                 
     
     
              
       
                    
编号
                    
名称
               
           
                        
${b.id }
                        
${b.bookname }
                   
                  
     
     

　　

 演示到这里就结束啦！！！