pageutil.java

一个基本的数据库分页类

/*
 * WRM
 * Created on 2005-4-17  15:12:39
 * @author: zhuqf
 */
package com.neu.wrm.util;

import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;

/**
 * @author zhuqf
 *
 */
public class pageutil {
    private List list;//数据列表
    private int totalPage;//总页数
    private int totalRows=0;//总数据数
    private int currentPage=1;//当前页
    private int pageRecorders=10;//每页数据数
    private int pageStartRow=0;//每页的起事数
    private int pageEndRow=0;//每页显示书句的终止数
    private boolean hasNextPage=false;//是否有下一页
    private boolean hasPreviousPage=false;//是否有前一页
    private String baseUrl;
    private String[] index;
    private Iterator it;
    /**
     * @return Returns the baseUrl.
     */
    public String getBaseUrl() {
        return baseUrl;
    }
    /**
     * @param baseUrl The baseUrl to set.
     */
    public void setBaseUrl(String baseUrl) {
        this.baseUrl = baseUrl;
    }
    /**
     * @return Returns the index.
     */
    public String[] getIndex() {
        return index;
    }
    /**
     * @param index The index to set.
     */
    public void setIndex(String[] index) {
        this.index = index;
    }
    /**
     * @return Returns the totalPage.
     */
    public int getTotalPage() {
        return totalPage;
    }
    /**
     * @param totalPage The totalPage to set.
     */
    public void setTotalPage(int totalPage) {
        this.totalPage = totalPage;
    }
    /**
     * @return Returns the totalRows.
     */
    public int getTotalRows() {
        return totalRows;
    }
    /**
     * @param totalRows The totalRows to set.
     */
    public void setTotalRows(int totalRows) {
        this.totalRows = totalRows;
    }
    /**
     * @return Returns the currentPage.
     */
    public int getCurrentPage() {
        return currentPage;
    }
    /**
     * @param currentPage The currentPage to set.
     */
    public void setCurrentPage(int currentPage) {
        this.currentPage = currentPage;
    }
    /**
     * @return Returns the hasNextPage.
     */
    public boolean isHasNextPage() {
        return hasNextPage;
    }
    /**
     * @param hasNextPage The hasNextPage to set.
     */
    public void setHasNextPage(boolean hasNextPage) {
        this.hasNextPage = hasNextPage;
    }
    /**
     * @return Returns the hasPreviousPage.
     */
    public boolean isHasPreviousPage() {
        return hasPreviousPage;
    }
    /**
     * @param hasPreviousPage The hasPreviousPage to set.
     */
    public void setHasPreviousPage(boolean hasPreviousPage) {
        this.hasPreviousPage = hasPreviousPage;
    }
    /**
     * @return Returns the list.
     */
    public List getList() {
        return list;
    }
    /**
     * @param list The list to set.
     */
    public void setList(List list) {
        this.list = list;
    }
    /**
     * @return Returns the pageEndRow.
     */
    public int getPageEndRow() {
        return pageEndRow;
    }
    /**
     * @param pageEndRow The pageEndRow to set.
     */
    public void setPageEndRow(int pageEndRow) {
        this.pageEndRow = pageEndRow;
    }
    /**
     * @return Returns the pageRecorders.
     */
    public int getPageRecorders() {
        return pageRecorders;
    }
    /**
     * @param pageRecorders The pageRecorders to set.
     */
    public void setPageRecorders(int pageRecorders) {
        this.pageRecorders = pageRecorders;
    }
    /**
     * @return Returns the pageStartRow.
     */
    public int getPageStartRow() {
        return pageStartRow;
    }
    /**
     * @param pageStartRow The pageStartRow to set.
     */
    public void setPageStartRow(int pageStartRow) {
        this.pageStartRow = pageStartRow;
    }
    /**
     * construter
     * @param list
     */
    public pageutil(List list){
        this.list=list;
        if(list==null);
        else{
        totalRows=list.size();
        it=list.iterator();
        hasPreviousPage=false;
        currentPage=1;
        if((totalRows%pageRecorders)==0){
           totalPage=totalRows/pageRecorders; 
        }
        else{
            totalPage=totalRows/pageRecorders+1;
            }
        if(currentPage>=totalPage){
            hasNextPage=false;
            }
        else
        {
            hasNextPage=true;
            }
        if(totalRows<pageRecorders)
        {
            this.pageStartRow=0;
            this.pageEndRow=totalRows;
            }
        else{
            this.pageStartRow=0;
            this.pageEndRow=pageRecorders;
            }
        
        this.index=new String[this.totalPage];
        }
        }
    /**
     * 得到指定页的数据
     * @param 指定的页码
     * @return 指定页的数据
     */
    public List getSpecifiedPage(int i){
        currentPage=i;
        if((currentPage-1)>0){//显示页不为第1页
            hasPreviousPage=true;
            }
        else{
            hasPreviousPage=false;
            }
        if(currentPage>=totalPage)
        {
            hasNextPage=false;
        }
        else{
            hasNextPage=true;
            }
        return getPages();
        }
    /**
     * 得到当前页的数据
     * @return 当前页的数据
     */
    public List getPages(){
        if(currentPage*pageRecorders<totalRows){//判断是否为最后一页
            pageEndRow=currentPage*pageRecorders;
            pageStartRow=pageEndRow-pageRecorders;
            if(pageStartRow<0)pageStartRow=0;
        }
        else{
            pageEndRow=totalRows;
            pageStartRow=pageRecorders*(totalPage-1);
            if(pageStartRow<0)pageStartRow=0;
        }
        List l=new ArrayList();
        for(int i=pageStartRow;i<pageEndRow;i++){
            l.add(list.get(i));
            }
        return l;
        }
    public void InitIndex(String url){
        for(int i=0;i<totalPage;i++){
            index[i]=url+"?page="+Integer.toString(i+1);
            }
        }
}