pagemetadata.java

本文论述了一个前台笔记本销售系统的开发过程

package com.set.utils;

public class PageMetaData {

	private int pageNum; // 当前页数

	private int pageSize; // 每页显示记录的个数

	private int pageCount; // 总的页面数

	private int recordCount; // 符合条件的记录数

	private int first = -1; // 第一页面

	private int previous = -1; // 第一页面

	private int next = -1; // 第一页面

	private int last = -1; // 第一页面

	// attribute set methods
	public void setCurrentPageNum(int value) {
		this.pageNum = value;
	}

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

	public void setRecordCount(int value) {
		this.recordCount = value;
	}

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

	private void setFirst(int value) {
		this.first = value;
	}

	private void setPrevious(int value) {
		this.previous = value;
	}

	private void setNext(int value) {
		this.next = value;
	}

	private void setLast(int value) {
		this.last = value;
	}

	// attribute Get methods
	public int getCurrentPageNum() {
		return this.pageNum;
	}

	public int getPageSize() {
		return this.pageSize;
	}

	public int getPageCount() {
		return this.pageCount;
	}

	public int getRecordCount() {
		return this.recordCount;
	}

	public int getFirst() {
		return this.first;
	} // return -1 表示记录已经在第一页

	public int getPrevious() {
		return this.previous;
	} // return -1 表示记录已经在第一页

	public int getNext() {
		return this.next;
	} // return -1 表示记录已经在最后一页

	public int getLast() {
		return this.last;
	} // return -1 表示记录已经在最后一页

	// compute some attribute;
	public void init() {
		// 设置页面总数
		if (this.recordCount == 0) {
			this.pageNum = 0;
			this.pageCount = 0;
		} else if ((recordCount % pageSize) == 0) {
			this.pageCount = recordCount / pageSize;
		} else {
			this.pageCount = recordCount / pageSize + 1;
		}
		// 设置当前页数
		if (this.pageNum > this.pageCount) {
			this.pageNum = pageCount;
		}
		if (this.pageCount > 0 && this.pageNum <= 0) {
			this.pageNum = 1;
		}
		// 设置第一页,前一页
		if ((pageNum <= pageCount) && pageCount > 1 && pageNum > 1) {
			this.setFirst(1);
			this.setPrevious(this.pageNum - 1);
		} else {
			this.setFirst(-1);
			this.setPrevious(-1);
		}
		// 设置最后一页，下一页
		if (pageNum < pageCount) {
			this.setNext(pageNum + 1);
			this.setLast(pageCount);
		} else {
			this.setNext(-1);
			this.setLast(-1);
		}
	}

	public static void setInitParam(int pageSize, int pageNum,
			int totalRecordCount, PageMetaData pageMetaData) {
		pageMetaData.setCurrentPageNum(pageNum);
		pageMetaData.setRecordCount(totalRecordCount);
		pageMetaData.setPageSize(pageSize);
		pageMetaData.init();
	}

	public static void setPageMetaDataParameter(int pageSize, int pageNum,
			int totalRecordCount, PageMetaData pageMetaData) {
		pageMetaData.setCurrentPageNum(pageNum);
		pageMetaData.setRecordCount(totalRecordCount);
		pageMetaData.setPageSize(pageSize);
		pageMetaData.init();
	}

}