java中利用List的subList方法实现对List分页（简单易学）

/** *//**  
* List分页  
* 实现：利用List的获取子List方法，实现对List的分页  
* @author 显武  
* @date 2010-1-8 16:27:31  
*  
*/  
 
import java.util.ArrayList;  
import java.util.List;  
 
public class PageModel {  
  private int page = 1; // 当前页  
 
  public int totalPages = 0; // 总页数  
 
  private int pageRecorders;// 每页5条数据  
 
  private int totalRows = 0; // 总数据数  
 
  private int pageStartRow = 0;// 每页的起始数  
 
  private int pageEndRow = 0; // 每页显示数据的终止数  
 
  private boolean hasNextPage = false; // 是否有下一页  
 
  private boolean hasPreviousPage = false; // 是否有前一页  
 
  private List list;  
 
  // private Iterator it;  
 
  public PageModel(List list, int pageRecorders) {  
    init(list, pageRecorders);// 通过对象集，记录总数划分  
  }  
   
  /** *//**  
   * 初始化list，并告之该list每页的记录数  
   * @param list  
   * @param pageRecorders  
   */  
  public void init(List list, int pageRecorders) {  
    this.pageRecorders = pageRecorders;  
    this.list = list;  
    totalRows = list.size();  
    // it = list.iterator();  
    hasPreviousPage = false;  
    if ((totalRows % pageRecorders) == 0) {  
      totalPages = totalRows / pageRecorders;  
    } else {  
      totalPages = totalRows / pageRecorders + 1;  
    }  
 
    if (page >= totalPages) {  
      hasNextPage = false;  
    } else {  
      hasNextPage = true;  
    }  
 
    if (totalRows < pageRecorders) {  
      this.pageStartRow = 0;  
      this.pageEndRow = totalRows;  
    } else {  
      this.pageStartRow = 0;  
      this.pageEndRow = pageRecorders;  
    }  
  }  
 
 
  // 判断要不要分页  
  public boolean isNext() {  
    return list.size() > 5;  
  }  
 
  public void setHasPreviousPage(boolean hasPreviousPage) {  
    this.hasPreviousPage = hasPreviousPage;  
  }  
 
  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.getPage() +  
 
    " 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);  
  }  
 
  public List getNextPage() {  
    page = page + 1;  
 
    disposePage();  
 
    System.out.println("用户凋用的是第" + page + "页");  
    this.description();  
    return getObjects(page);  
  }  
 
  /** *//**  
   * 处理分页  
   */  
  private void disposePage() {  
 
    if (page == 0) {  
      page = 1;  
    }  
 
    if ((page - 1) > 0) {  
      hasPreviousPage = true;  
    } else {  
      hasPreviousPage = false;  
    }  
 
    if (page >= totalPages) {  
      hasNextPage = false;  
    } else {  
      hasNextPage = true;  
    }  
  }  
 
  public List getPreviousPage() {  
 
    page = page - 1;  
 
    if ((page - 1) > 0) {  
      hasPreviousPage = true;  
    } else {  
      hasPreviousPage = false;  
    }  
    if (page >= totalPages) {  
      hasNextPage = false;  
    } else {  
      hasNextPage = true;  
    }  
    this.description();  
    return getObjects(page);  
  }  
 
  /** *//**  
   * 获取第几页的内容  
   *  
   * @param page  
   * @return  
   */  
  public List getObjects(int page) {  
    if (page == 0)  
      this.setPage(1);  
    else  
      this.setPage(page);  
    this.disposePage();  
    if (page * pageRecorders < totalRows) {// 判断是否为最后一页  
      pageEndRow = page * pageRecorders;  
      pageStartRow = pageEndRow - pageRecorders;  
    } else {  
      pageEndRow = totalRows;  
      pageStartRow = pageRecorders * (totalPages - 1);  
    }  
 
    List objects = null;  
    if (!list.isEmpty()) {  
      objects = list.subList(pageStartRow, pageEndRow);  
    }  
    //this.description();  
    return objects;  
  }  
 
  public List getFistPage() {  
    if (this.isNext()) {  
      return list.subList(0, pageRecorders);  
    } else {  
      return list;  
    }  
  }  
 
  public boolean isHasNextPage() {  
    return hasNextPage;  
  }  
 
 
  public void setHasNextPage(boolean hasNextPage) {  
    this.hasNextPage = hasNextPage;  
  }  
 
 
  public List getList() {  
    return list;  
  }  
 
 
  public void setList(List list) {  
    this.list = list;  
  }  
 
 
  public int getPage() {  
    return page;  
  }  
 
 
  public void setPage(int page) {  
    this.page = page;  
  }  
 
 
  public int getPageEndRow() {  
    return pageEndRow;  
  }  
 
 
  public void setPageEndRow(int pageEndRow) {  
    this.pageEndRow = pageEndRow;  
  }  
 
 
  public int getPageRecorders() {  
    return pageRecorders;  
  }  
 
 
  public void setPageRecorders(int pageRecorders) {  
    this.pageRecorders = pageRecorders;  
  }  
 
 
  public int getPageStartRow() {  
    return pageStartRow;  
  }  
 
 
  public void setPageStartRow(int pageStartRow) {  
    this.pageStartRow = pageStartRow;  
  }  
 
 
  public int getTotalPages() {  
    return totalPages;  
  }  
 
 
  public void setTotalPages(int totalPages) {  
    this.totalPages = totalPages;  
  }  
 
 
  public int getTotalRows() {  
    return totalRows;  
  }  
 
 
  public void setTotalRows(int totalRows) {  
    this.totalRows = totalRows;  
  }  
 
 
  public boolean isHasPreviousPage() {  
    return hasPreviousPage;  
  }  
 
}  
 
//测试类：  
package com.Gavin.tools.util;  
 
import java.util.ArrayList;  
import java.util.List;  
 
public class TestPagerModel {  
  public static void main(String args[]) {  
    List<String> list = new ArrayList<String>();  
    list.add("a");  
    list.add("b");  
    list.add("c");  
    list.add("d");  
    list.add("e");  
    list.add("f");  
    list.add("g");  
    list.add("h");  
    list.add("h");  
    list.add("i");  
    list.add("j");  
    list.add("k");  
    list.add("l");  
    list.add("m");  
    PageModel pm = new PageModel(list, 5);  
     
    List sublist = pm.getObjects(3);  
    for(int i = 0; i < sublist.size(); i++) {  
      System.out.println(sublist.get(i));  
    }  
    System.out.println(sublist.get(0));  
  }  
 
}