pagebean.java

一个极其简单的struts分页源码

package student_info.commons;

import student_info.model.beans.S_I_Bean;

import java.util.*;
/**
* @作者 李敏强
* Struts分页显示逻辑Bean
*/
public class PageBean {

        int currentPage=1;  //当前页
public        int totalPages=0;  //总页数
        int pageRecorders=5;//每页5条数据
        int totalRows=0;  //总数据数
        int pageStartRow=0;//每页的起始数
        int pageEndRow=0;  //每页显示数据的终止数
        boolean hasNextPage=false; //是否有下一页
        boolean hasPreviousPage=false; //是否有前一页
        ArrayList arrayList;
        Iterator it;
public PageBean(){}
        
public PageBean(ArrayList arrayList){
        this.arrayList=arrayList;        
        totalRows=arrayList.size();//bean的个数                
    it=arrayList.iterator();         
        hasPreviousPage=false;
        currentPage=1;
        if((totalRows%pageRecorders)==0)
        {
        totalPages=totalRows/pageRecorders;         
        }
        else
        {
                totalPages=totalRows/pageRecorders+1;        
        }        
        
        if(currentPage>=totalPages)  
        {
                hasNextPage=false;        
        }
        else                        
        {
                hasNextPage=true;
        }

    
    if(totalRows<pageRecorders) 
    {
    this.pageStartRow=0;           
    this.pageEndRow=totalRows;   
    }
    else                       
    {
    this.pageStartRow=0;         
    this.pageEndRow=pageRecorders;   
    }

}

        /**
         * @return Returns the currentPage.
         */
        public String getCurrentPage() {
                return this.toString(currentPage);
        }
        /**
         * @param currentPage The currentPage to set.
         */
        public void setCurrentPage(int currentPage) {
                this.currentPage = currentPage;
        }
        /**
         * @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 pageEndRow.
         */
        public int getPageEndRow() {
                return pageEndRow;
        }
        /**
         * @return Returns the pageStartRow.
         */
        public int getPageStartRow() {
                return pageStartRow;
        }
        /**
         * @return Returns the totalPages.
         */
        public String getTotalPages() {
        
                return this.toString(totalPages);
        }
        /**
         * @return Returns the totalRows.
         */
        public String getTotalRows() {
                return this.toString(totalRows);
        }
        /**
         * @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;
        }
public S_I_Bean[] getNextPage(){
        
        currentPage=currentPage+1;
        System.out.println("PageBean.getNextPage()正在执行；");
        System.out.println("参数currentPage="+currentPage);

        if((currentPage-1)>0){
                hasPreviousPage=true;        
        }
       else{
            hasPreviousPage=false;        
       }
        
        if(currentPage>=totalPages) {
                hasNextPage=false;        
        }
        else{
                hasNextPage=true;
        }
        System.out.println("参数hasNextPage="+hasNextPage);
        System.out.println("准备执行PageBean.getAddressBooks()");
        S_I_Bean[] sibeans=getS_I_Beans();
        this.description();
        
        return sibeans;
}

public S_I_Bean[] getPreviouspage(){
        
        currentPage=currentPage-1;

    if(currentPage==0){currentPage=1;}
        
        if(currentPage>=totalPages)  
        {
                hasNextPage=false;        
        }
        else                         
        {
                hasNextPage=true;
        }
        if((currentPage-1)>0)
        {
                hasPreviousPage=true;        
        }
    else
    {
            hasPreviousPage=false;        
    }
        S_I_Bean[] sibeans=getS_I_Beans();
        this.description();
        return sibeans;
}

public S_I_Bean[] getS_I_Beans(){
        System.out.println("pageBean.getBooks（）开始执行；");
        
        
        if(currentPage*pageRecorders<totalRows){//判断是否为最后一页
                pageEndRow=currentPage*pageRecorders;
            pageStartRow=pageEndRow-pageRecorders;
        }
        else{
                pageEndRow=totalRows;
                pageStartRow=pageRecorders*(totalPages-1);
        }
        S_I_Bean[] sibeans=new S_I_Bean[pageEndRow-pageStartRow+1];
        
        System.out.println("pageStartRow="+pageStartRow);
        System.out.println("pageEndRow="+pageEndRow);
         int j=0;        
        for(int i=pageStartRow;i<pageEndRow;i++)
        {
        
         S_I_Bean sibean=(S_I_Bean)arrayList.get(i);        
         sibeans[j++]=sibean;
        
        }
        System.out.println("要显示的页面数据已经封装,具体信息如下：");
        this.description();
        return sibeans;
}

public String toString(int temp)
{
String str=Integer.toString(temp);
return str;
}

public void description()
{

   String description="共有数据数:"+this.getTotalRows()+

   "共有页数: "+this.getTotalPages() +

   "当前页数为:"+this.getCurrentPage()+
   
   " 是否有前一页: "+this.isHasPreviousPage() +

   " 是否有下一页:"+this.isHasNextPage()+

   " 开始行数:"+this.getPageStartRow()+

   " 终止行数:"+this.getPageEndRow();

   System.out.println(description);

}
}