PageFinder.java

package com.github.ouyangbob.model;

import java.util.List;

public class PageFinder<T> extends AbstractModel {

	/**
	 * 
	 */
	private static final long serialVersionUID = 1L;

	
	private static int DEFAULT_PAGE_SIZE = 20;

	/**
	 * 每页的记录数
	 */
	private int pageSize = DEFAULT_PAGE_SIZE;

	/**
	 * 当前页中存放的数据
	 */
	private List<T> data;

	/**
	 * 总记录数
	 */
	private int rowCount;

	/**
	 * 页数
	 */
	private int pageCount;

	/**
	 * 跳转页数
	 */
	private int pageNo;

	/**
	 * 是否有上一页
	 */
	private boolean hasPrevious = false;

	/**
	 * 是否有下一页
	 */
	private boolean hasNext = false;
	
	
	public PageFinder(int pageNo, int rowCount) {
		this.pageNo = pageNo;
		this.rowCount = rowCount;
		this.pageCount = getTotalPageCount();
		refresh();
	}

	/**
	 * 构造方法
	 */
	public PageFinder(int pageNo, int pageSize, int rowCount) {
		this.pageNo = pageNo;
		this.pageSize = pageSize;
		this.rowCount = rowCount;
		this.pageCount = getTotalPageCount();
		refresh();
	}

	/**
	 *
	 */
	public PageFinder(int pageNo, int pageSize, int rowCount, List<T> data) {
		this.pageNo = pageNo;
		this.pageSize = pageSize;
		this.rowCount = rowCount;
		this.pageCount = getTotalPageCount();
		this.data = data;
		refresh();
	}

	/**
	 * 取总页数
	 */
	private final int getTotalPageCount() {
		if (rowCount % pageSize == 0)
			return rowCount / pageSize;
		else
			return rowCount / pageSize + 1;
	}

	/**
	 * 刷新当前分页对象数据
	 */
	private void refresh() {
		if (pageCount <= 1) {
			hasPrevious = false;
			hasNext = false;
		} else if (pageNo == 1) {
			hasPrevious = false;
			hasNext = true;
		} else if (pageNo == pageCount) {
			hasPrevious = true;
			hasNext = false;
		} else {
			hasPrevious = true;
			hasNext = true;
		}
	}

	/**
	 * 取每页数据数
	 */
	public int getPageSize() {
		return pageSize;
	}

	/**
	 * 取当前页中的记录.
	 */
	public Object getResult() {
		return data;
	}

	public List<T> getData() {
		return data;
	}

	public void setData(List<T> data) {
		this.data = data;
	}

	public int getRowCount() {
		return rowCount;
	}

	public void setRowCount(int rowCount) {
		this.rowCount = rowCount;
	}

	public int getPageCount() {
		return pageCount;
	}

	public void setPageCount(int pageCount) {
		this.pageCount = pageCount;
	}

	public int getPageNo() {
		return pageNo;
	}

	public void setPageNo(int pageNo) {
		this.pageNo = pageNo;
	}

	public boolean isHasPrevious() {
		return hasPrevious;
	}

	public void setHasPrevious(boolean hasPrevious) {
		this.hasPrevious = hasPrevious;
	}

	public boolean isHasNext() {
		return hasNext;
	}

	public void setHasNext(boolean hasNext) {
		this.hasNext = hasNext;
	}

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

	/**
	 * 获取跳转页第**数据在数据集的位**
	 */
	public int getStartOfPage() {
		return (pageNo - 1) * pageSize;
	}
	
}