XiaoLi’s Blog

【來源】 http://blog.csdn.net/yq76034150
最近看到很好的一種分頁方法，就貼出來大家共同分享！（原作在javaworld),有不完善的地方，希望大家改正！！！

使用一個頁面控制類，它記錄頁面信息，如上頁，下頁，當前頁等。在查詢的Action中，將這個控制類和查詢條件一起傳遞給數據庫訪問bean，然后將這兩個參數保存在用戶session中。在分頁控制Action中，利用接收到的分頁參數調用數據庫訪問的bean.
(1)分頁控制類

package com.tower.util;
public class PageController {
    int totalRowsAmount; file://總行數
    boolean rowsAmountSet; file://是否設置過totalRowsAmount
    int pageSize=2;   file://每頁行數
    int currentPage=1; file://當前頁碼
    int nextPage;
    int previousPage;
    int totalPages;  file://總頁數
    boolean hasNext;  file://是否有下一頁
    boolean hasPrevious; file://是否有前一頁
    String description;
    int pageStartRow;
    int pageEndRow;
    
    public PageController(int totalRows){
  setTotalRowsAmount(totalRows);
    }
    public PageController(){}
public void setTotalRowsAmount(int i) {
  if(!this.rowsAmountSet){
   totalRowsAmount = i;
   totalPages=totalRowsAmount/pageSize+1;
      setCurrentPage(1);
   this.rowsAmountSet=true;
  }
  
}
public void setCurrentPage(int i) {
  currentPage = i;
  nextPage=currentPage+1;
  previousPage=currentPage-1;
  file://計算當前頁開始行和結束行
  if(currentPage*pageSize
      pageEndRow=currentPage*pageSize;
      pageStartRow=pageEndRow-pageSize+1;
      
  }else{
      pageEndRow=totalRowsAmount;
      pageStartRow=pageSize*(totalPages-1)+1;
  }
  if (nextPage>totalPages){
      hasNext=false;
  }else{
   hasNext=true;
  }
  if(previousPage==0){
     hasPrevious=false;
  }else{
   hasPrevious=true;
  };
  System.out.println(this.description());
}
public int getCurrentPage() {
  return currentPage;
}
public boolean isHasNext() {
  return hasNext;
}
public boolean isHasPrevious() {
  return hasPrevious;
}
public int getNextPage() {
  return nextPage;
}
public int getPageSize() {
  return pageSize;
}
public int getPreviousPage() {
  return previousPage;
}
public int getTotalPages() {
  return totalPages;
}
public int getTotalRowsAmount() {
  return totalRowsAmount;
}
public void setHasNext(boolean b) {
  hasNext = b;
}
public void setHasPrevious(boolean b) {
  hasPrevious = b;
}
public void setNextPage(int i) {
  nextPage = i;
}
public void setPageSize(int i) {
  pageSize = i;
}
public void setPreviousPage(int i) {
  previousPage = i;
}
public void setTotalPages(int i) {
  totalPages = i;
}
public int getPageEndRow() {
  return pageEndRow;
}
public int getPageStartRow() {
  return pageStartRow;
}

public String getDescription(){
    String description=\"Total:\"+this.getTotalRowsAmount()+
    \" items \"+this.getTotalPages() +\" pages\";
//    this.currentPage+\" Previous \"+this.hasPrevious +
//    \" Next:\"+this.hasNext+
//    \" start row:\"+this.pageStartRow+
//    \" end row:\"+this.pageEndRow;
    return description;
}

public String description(){
    String description=\"Total:\"+this.getTotalRowsAmount()+
    \" items \"+this.getTotalPages() +\" pages,Current page:\"+
    this.currentPage+\" Previous \"+this.hasPrevious +
    \" Next:\"+this.hasNext+
    \" start row:\"+this.pageStartRow+
    \" end row:\"+this.pageEndRow;
    return description;
}


public static void main(String args[]){
  PageController pc=new PageController(3);
        System.out.println(pc.getDescription());
//        pc.setCurrentPage(2);
//  System.out.println(pc.description());
//  pc.setCurrentPage(3);
//  System.out.println(pc.description());
}