信息管理系统——分页标签实现

一 分页实体

package org.fkit.common.util.pager;

public class PageModel {
     /** 分页中默认一个4条数据 */
     public static final int PAGE_DEFAULT_SIZE = 4;
     /** 分页总数据条数 */
     private long recordCount;
     /** 当前页面 */
     private int pageIndex;
     /** 每页分多少条数据 */
     private int pageSize = PAGE_DEFAULT_SIZE;
     /** 总页数 */
     private int totalSize;
     public long getRecordCount() {
           this.recordCount = this.recordCount <= 0 ? 0 :  this.recordCount;
           return recordCount;
     }
     public void setRecordCount(long recordCount) {
           this.recordCount = recordCount;
     }
     public int getPageIndex() {
//         this.pageIndex =  this.pageIndex>=this.getTotalSize()?this.getTotalSize():this.pageIndex;
           this.pageIndex = this.pageIndex <= 0 ? 1 :  this.pageIndex;
//         /** 判断当前页面是否超过了总页数:如果超过了默认给最后一页作为当前页  */
           return pageIndex;
     }
     public void setPageIndex(int pageIndex) {
           this.pageIndex = pageIndex;
     }
     public int getPageSize() {
           this.pageSize = this.pageSize <= PAGE_DEFAULT_SIZE ?  PAGE_DEFAULT_SIZE : this.pageSize;
           return pageSize;
     }
     public void setPageSize(int pageSize) {
           this.pageSize = pageSize;
     }
     public int getTotalSize() {
           if (this.getRecordCount() <= 0) {
                totalSize = 0;
           } else {
                totalSize = (int) ((this.getRecordCount() - 1) /  this.getPageSize() + 1);
           }
           return totalSize;
     }
     public int getFirstLimitParam() {
           return (this.getPageIndex() - 1) *  this.getPageSize();
     }
}

二 定义标签

package org.fkit.common.util.pager;


import java.io.IOException;


import javax.servlet.jsp.JspException;
import javax.servlet.jsp.tagext.SimpleTagSupport;

public class PagerTag extends SimpleTagSupport {


    /** 定义请求URL中的占位符常量 */
    private static final String TAG = "{0}";


    /** 当前页码 */
    private int pageIndex;
    /** 每页显示的数量 */
    private int pageSize;
    /** 总记录条数 */
    private int recordCount;
    /** 请求URL page.action?pageIndex={0} */
    private String submitUrl;


    /** 定义总页数 */
    private int totalPage = 0;


    /** 在页面上引用自定义标签就会触发一个标签处理类 */
    @Override
    public void doTag() throws JspException, IOException {
        /** 定义它拼接是终的结果 */
        StringBuilder res = new StringBuilder();


        res.append("\n" + "\t\t
\n" + "\t\t\t\n"
                + "\t\t\t
\n" + "\t\t\t\t 
");
        /** 定义它拼接中间的页码 */
        StringBuilder str = new StringBuilder();
        /** 判断总记录条数 */
        if (recordCount > 0) { // 1499 / 15 = 100
            /** 需要显示分页标签，计算出总页数 需要分多少页 */
            totalPage = (this.recordCount - 1) / this.pageSize + 1;


            /** 判断上一页或下一页需不需要加a标签 */
            if (this.pageIndex == 1) { // 首页
                str.append("
上一页
");


                /** 计算中间的页码 */
                this.calcPage(str);


                /** 下一页需不需要a标签 */
                if (this.pageIndex == totalPage) {
                    /** 只有一页 */
                    str.append("
下一页
");
                } else {
                    String tempUrl = this.submitUrl.replace(TAG, String.valueOf(pageIndex + 1));
                    str.append("
下一页
");
                }
            } else if (this.pageIndex == totalPage) { // 尾页
                String tempUrl = this.submitUrl.replace(TAG, String.valueOf(pageIndex - 1));
                str.append("
上一页
");


                /** 计算中间的页码 */
                this.calcPage(str);


                str.append("
下一页
");
            } else { // 中间
                String tempUrl = this.submitUrl.replace(TAG, String.valueOf(pageIndex - 1));
                str.append("
上一页
");


                /** 计算中间的页码 */
                this.calcPage(str);


                tempUrl = this.submitUrl.replace(TAG, String.valueOf(pageIndex + 1));
                str.append("
下一页
");
            }


            res.append(str);


            /** 开始条数 */
            int startNum = (this.pageIndex - 1) * this.pageSize + 1;
            /** 结束条数 */
            int endNum = (this.pageIndex == this.totalPage) ? this.recordCount : this.pageIndex * this.pageSize;


            res.append("
共" + this.recordCount
                    + "条记录,当前显示" + startNum + "-" + endNum + "条记录 
");


            res.append("
\n"
                    + "\t\t\t\t\t\t\t\t\t      \n" + "\t\t\t\t\t\t\t\t\t      \n"
                    + "\t\t\t\t\t\t\t\t\t        GO\n"
                    + "\t\t\t\t\t\t\t\t\t      \n" + "\t\t\t\t\t   \t\t\t\t 
");


            res.append("");


        } else {
            res.append(
                    "
总共0条记录,当前显示0-0条记录。 
");
        }


        res.append("
");
        this.getJspContext().getOut().print(res.toString());
    }


    /** 计算中间页码的方法 */
    private void calcPage(StringBuilder str) {
        /** 判断总页数 */
        if (this.totalPage <= 11) {
            /** 一次性显示全部的页码 */
            for (int i = 1; i <= this.totalPage; i++) {
                if (this.pageIndex == i) {
                    /** 当前页码 */
                    str.append("
" + i + "
");
                } else {
                    String tempUrl = this.submitUrl.replace(TAG, String.valueOf(i));
                    str.append("
" + i + "
");
                }
            }
        } else {
            /** 靠首页近些 */
            if (this.pageIndex <= 8) {
                for (int i = 1; i <= 10; i++) {
                    if (this.pageIndex == i) {
                        /** 当前页码 */
                        str.append("
" + i + "
");
                    } else {
                        String tempUrl = this.submitUrl.replace(TAG, String.valueOf(i));
                        str.append("
" + i + "
");
                    }
                }
                str.append("
...
");
                String tempUrl = this.submitUrl.replace(TAG, String.valueOf(this.totalPage));
                str.append("
" + this.totalPage + "
");


            }
            /** 靠尾页近些 */
            else if (this.pageIndex + 8 >= this.totalPage) {
                String tempUrl = this.submitUrl.replace(TAG, String.valueOf(1));
                str.append("
1
");
                str.append("
...
");


                for (int i = this.totalPage - 10; i <= this.totalPage; i++) {
                    if (this.pageIndex == i) {
                        /** 当前页码 */
                        str.append("
" + i + "
");
                    } else {
                        tempUrl = this.submitUrl.replace(TAG, String.valueOf(i));
                        str.append("
" + i + "
");
                    }
                }
            }
            /** 在中间 */
            else {
                String tempUrl = this.submitUrl.replace(TAG, String.valueOf(1));
                str.append("
1
");
                str.append("
...
");


                for (int i = this.pageIndex - 4; i <= this.pageIndex + 4; i++) {
                    if (this.pageIndex == i) {
                        /** 当前页码 */
                        str.append("
" + i + "
");
                    } else {
                        tempUrl = this.submitUrl.replace(TAG, String.valueOf(i));
                        str.append("
" + i + "
");
                    }
                }


                str.append("
...
");
                tempUrl = this.submitUrl.replace(TAG, String.valueOf(this.totalPage));
                str.append("
" + this.totalPage + "
");
            }
        }
    }


    /** setter method */
    public void setPageIndex(int pageIndex) {
        this.pageIndex = pageIndex;
    }


    public void setPageSize(int pageSize) {
        this.pageSize = pageSize;
    }


    public void setRecordCount(int recordCount) {
        this.recordCount = recordCount;
    }


    public void setSubmitUrl(String submitUrl) {
        this.submitUrl = submitUrl;
    }
}

三 tld标签文件

     
     Pager 1.0 core library
     
     Pager core
     
     1.0
     
     fkjava
     
     /pager-tags
     
     
           
           pager
           
           org.fkit.common.util.pager.PagerTag
           
           empty
           
           
                
                pageIndex
                
                true
                
                true
           
           
           
                
                pageSize
                
                true
                
                true
           
           
           
                
                recordCount
                
                true
                
                true
           
           
           
                
                submitUrl
                
                true
                
                true
           
           
           
                
                style
                
                false
                
                true
           
     

四 标签的使用

1 包含标签taglib.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="fmt" uri="http://java.sun.com/jsp/jstl/fmt"  %>

<%@ taglib prefix="fkjava" uri="/pager-tags" %>

2 标签使用片段

                

                     
                             
<%--                                   --%>
                                     
<%--                                  --%>
<%--                                  --%>
<%--                                  --%>
                                     

                           

                                

                                     

                                     
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${module.code}
                                     
${module.name.replaceAll("-","")}
${module.remark}
${module.url}
                                     
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${module.creater.name  }
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五 显示效果