pagecounter.java

这是我自己做的一个选课系统

package org.chooseClass.pageCounter;

import java.sql.ResultSet;
import java.util.ArrayList;
import java.util.List;

import javax.servlet.http.HttpServletRequest;

import org.chooseClass.database.DBConnect;
import org.chooseClass.setterAndgetter.Student;
import org.chooseClass.setterAndgetter.Teacher;



public class PageCounter {

	private int totalRows;//��ݿ����������
	private int currentPage = 1;//��ʼ����ݿ���ʵ���ʼҳ��
	private int maxSize = 5;//һ����ݿ���ʷ��ص�����¼����
	private int firstRow = 0;//��ݿ���ʵ���ʼ��
	private int totalPage;
	
	

	public PageCounter(){
		
	}

	public int getCurrentPage() {
		return currentPage;
	}

	public void setCurrentPage(int currentPage) {
		this.currentPage = currentPage;
	}

	public int getFirstRow() {
		return firstRow;
	}

	public void setFirstRow(int firstRow) {
		this.firstRow = firstRow;
	}

	public int getMaxSize() {
		return maxSize;
	}

	public void setMaxSize(int maxSize) {
		this.maxSize = maxSize;
	}

	public int getTotalRows() {
		return totalRows;
	}

	public void setTotalRows(int totalRows) {
		this.totalRows = totalRows;
	}
	public int getTotalPage() {
		return totalPage;
	}

	public void setTotalPage(int totalPage) {
		this.totalPage = totalPage;
	}
	public void counter(String type){
		type = type.toLowerCase();
		if(type.equalsIgnoreCase("first")){
			first();
		}else if (type.equalsIgnoreCase("last")){
			last();
		}else if(type.equalsIgnoreCase("next")){
			next();
		}else if(type.equalsIgnoreCase("previous")){
			previous();
		}
	}

	private void previous() {
		// TODO Auto-generated method stub
		if(currentPage == 1){
			currentPage = 1;
		}else{
			currentPage--;
		}
		
		firstRow = (currentPage-1)*maxSize;
		
	}

	private void next() {
		// TODO Auto-generated method stub
		if(currentPage<totalPage){
			currentPage++;
		}else if(currentPage==totalPage){
			currentPage = totalPage;
		}
		
		firstRow = (currentPage-1)*maxSize;
	}

	private void last() {
		// TODO Auto-generated method stub
		currentPage = totalPage;
		firstRow = (currentPage - 1)*maxSize;
	}

	private void first() {
		// TODO Auto-generated method stub
		currentPage = 1;
		firstRow = 0;
	}
	
	public List GetStudentPageData(String sql,HttpServletRequest request) throws Exception{
		ArrayList<Student> tempList =new ArrayList<Student>();
		ResultSet rs=null;
	    
	    DBConnect dbc=new DBConnect(sql);
		rs=dbc.executeQuery();
		Student temp = null;
		while(rs.next()){
			temp = new Student();
			temp.setStu_id(rs.getString("stu_id"));
			temp.setStu_name(rs.getString("stu_name"));
			temp.setSex(rs.getString("stu_sex"));
			temp.setMajor_id(rs.getString("major_name"));
			temp.setDepartment_id(rs.getString("department_name"));
			tempList.add(temp);
		}
		PageCounter pc = new PageCounter();
		pc = (PageCounter)request.getSession().getAttribute("page");
		//int totalPage = 0;
		if(tempList.size()%pc.getMaxSize()==0)
			totalPage = tempList.size()/pc.getMaxSize();
		else totalPage = tempList.size()/pc.getMaxSize()+1;
		
		//pc.setTotalPage(totalPage);
		//query.setFirstResult(pc.getFirstRow());
		//query.setMaxResults(pc.getMaxSize());
		
		List<Student> list=new ArrayList<Student>();
		int i = pc.getFirstRow();
		int maxSize = 0;
		if(tempList.size()-pc.getFirstRow()<pc.getMaxSize()){
		
			maxSize = tempList.size();
		}else{
			
		 maxSize = pc.getFirstRow()+pc.getMaxSize();
		}
		
		for(;i<maxSize;i++){
			
			list.add((Student)(tempList.get(i)));
			
			}
		return list;
		
	}
public List GetNoticePageData(List templist,HttpServletRequest request){
		
		
		PageCounter pc = new PageCounter();
		pc = (PageCounter)request.getSession().getAttribute("page");
		//int totalPage = 0;
		if(templist.size()%pc.getMaxSize()==0)
			totalPage = templist.size()/pc.getMaxSize();
		else totalPage = templist.size()/pc.getMaxSize()+1;
		
		//pc.setTotalPage(totalPage);
		//query.setFirstResult(pc.getFirstRow());
		//query.setMaxResults(pc.getMaxSize());
		
		List<Teacher> list=new ArrayList<Teacher>();
		int i = pc.getFirstRow();
		int maxSize = 0;
		if(templist.size()-pc.getFirstRow()<pc.getMaxSize()){
		
			maxSize = templist.size();
		}else{
			
		 maxSize = pc.getFirstRow()+pc.getMaxSize();
		}
		
		for(;i<maxSize;i++){
			
			list.add((Teacher)(templist.get(i)));
			
			}
		return list;
		
	}
}