page.java

一个简单的汽车租赁系统 jsp+struts+oracle

package page;

import java.util.Collections;
import java.util.List;

public class Page {
	/**
	 * 空页面常量
	 */	
	public Page(){
		
	}
	public static final Page EMPTY_PAGE = new Page(){
		public List<Object> object() {
			return Collections.EMPTY_LIST;
		}

		public int getNo() {
			return 0;
		}

		public int getSize() {
			return 0;
		}

		public boolean isNext() {
			return false;
		}

		public boolean isPrevious() {
			return false;
		}

		public int getAmount() {
			return 0;
		}

		public int getRecordSize() {
			return 0;
		}

	};
	/**
	 * 
	 * @return 总页数
	 */
	public int getAmount() {
		return (int) Math.ceil((double) this.recordSize / this.pageSize);
	}
	/**
	 * 
	 * @param results
	 *            结果列表
	 * @param pageNo
	 *            页号
	 * @param pageSize
	 *            页面大小
	 * @param recordSize
	 *            记录总数
	 */
	private List<Object> object;

	private int pageNo;

	private int pageSize;

	private int recordSize;
	
	public Page(List<Object> object, int pageNo, int pageSize, int recordSize) {
		this.object = object;
		this.pageNo = pageNo;
		this.pageSize = pageSize;
		this.recordSize = recordSize;
	}
	/**
	 * 
	 * @return 分页的结果列表
	 */
	public List<Object> getObject() {
		return object;
	}

	/**
	 * 
	 * @return 页号
	 */
	public int getPageNo() {
		return this.pageNo;
	}

	/**
	 * 
	 * @return 页面大小
	 */
	public int getSize() {
		return this.pageSize;
	}

	/**
	 * 
	 * @return 是否有下页
	 */
	public boolean isNext() {
		return this.pageNo < this.getAmount();
	}

	/**
	 * 
	 * @return 是否有上页
	 */
	public boolean isPrevious() {
		return this.pageNo > 1;
	}
	/**
	 * 
	 * @return 结果总数
	 */
	public int getRecordSize() {
		return this.recordSize;
	}

	@Override
	public String toString() {
		StringBuffer buffer = new StringBuffer();
		buffer.append("userinfo: ").append(this.object).append(" pageNo:")
				.append(this.pageNo).append(" previous:").append(
						this.isPrevious()).append(" next:").append(
						this.isNext());
		return buffer.toString();
	}

}