layouteo.java

这是AJAX例子希望能够给大家带来有用的东西

package book.portal.table;

import java.sql.*;
import java.util.Vector;

import book.portal.*;

public class LayoutEO {	
	protected int id;//代表数据库中layout_id列
	protected int userId;//代表数据库中user_id列
	protected String colNarrowLeft;//代表数据库中col_narrow_left列
	protected String colNarrowRight;//代表数据库中col_narrow_right列
	protected String colWide;//代表数据库中col_wide列
	protected String activeStatus = "Y";//代表数据库中active_status列
	public LayoutEO() {//无参的构造方法 
		this.id = -1;
	}
	public LayoutEO(int id) {//有参的构造方法，参数为portlet_id
		this.id = id;
		if (!FromDb())//如果有找到该id的layout
			this.id = -1;
	}
	public boolean FromDb() {//从数据库中读出，并更新bean
		int row = -1;
        //读记录的sql语句
		String sql = "select * from ajax_layout where layout_id=" + this.id
				+ " and active_status='Y'";
		ResultSet rs = DbManager.getResultSet(sql);//执行sql语句并返回ResultSet
		try {
			rs.last();//移动到最后一行
			row = rs.getRow();//得到总记录数
			if (row == 1) {//如果只查询到一条记录，则代表该记录存在并更新该类的属性
				this.userId = rs.getInt("USER_ID");
				this.colNarrowLeft = rs.getString("COL_NARROW_LEFT");
				this.colNarrowRight = rs.getString("COL_NARROW_RIGHT");
				this.colWide = rs.getString("COL_WIDE");
				this.activeStatus = rs.getString("ACTIVE_STATUS");
				return true;
			} else
				return false;
		} catch (SQLException e) {
			e.printStackTrace();
			return false;
		} finally {
			try {//最后关闭ResutltSet,Statement.并释放连接
				if (rs != null)
					rs.close();
				if (rs.getStatement() != null)
					rs.getStatement().close();
				DbManager.releaseConnection();
			} catch (SQLException e) {
				e.printStackTrace();
			}
		}
	}
	public boolean ToDb() {//更新数据库，并重新设置bean
		if (getId() == -1)//如果此时id为-1
		{
			return false;
		} else {
            //更新该记录的sql语句
			String sql = "update ajax_layout set user_id=" + getUserId()
					+ ",col_narrow_left='" + getColNarrowLeft()
					+ "',col_narrow_right='" + getColNarrowRight()
					+ "',col_wide='" + getColWide() + "',active_status='"
					+ getActiveStatus() + "' where layout_id=" + getId();
			DbManager.excute(sql);//执行sql语句
			return FromDb();//重新读出bean的属性
		}
	}
	public String getActiveStatus() {
		return activeStatus;
	}
	public void setActiveStatus(String activeStatus) {
		this.activeStatus = activeStatus;
	}
	public String getColNarrowLeft() {
		return colNarrowLeft;
	}
	public void setColNarrowLeft(String colNarrowLeft) {
		this.colNarrowLeft = colNarrowLeft;
	}
	public String getColNarrowRight() {
		return colNarrowRight;
	}
	public void setColNarrowright(String colNarrowRight) {
		this.colNarrowRight = colNarrowRight;
	}
	public String getColWide() {
		return colWide;
	}
	public void setColWide(String colWide) {
		this.colWide = colWide;
	}
	public int getId() {
		return id;
	}
	public void setId(int id) {
		this.id = id;
	}
	public int getUserId() {
		return userId;
	}
	public void setUserId(int userId) {
		this.userId = userId;
	}
	public static LayoutEO getInstance ( UserEO user )//获得该用户layout的方法
	{
		LayoutEO layout = new LayoutEO();//定义LayoutEO对象
		//查询该用户所使用layout的sql语句
		String sql = "select layout_id from ajax_layout where user_id="+user.getId();		
		try {
			ResultSet rs = DbManager.getResultSet(sql);//获得记录集
			rs.last();//移动记录集到最后
			if (rs.getRow()==1)//如果只查询到一条记录，则初始化该layout,并返回该layout
			{
			  int layoutId = rs.getInt("LAYOUT_ID");
			  return new LayoutEO(layoutId);
			}
		} catch (SQLException e) {
			e.printStackTrace();
		}
		return layout;
	}
	public Vector getWide()//将逗号分割符分割的数字转化为Vector
	{
		if ( getColWide()==null&&getColWide().equals("") )  
			return new Vector();
		return Util.parseCSV(getColWide());
	}
	public Vector getNarrowRight()//将逗号分割符分割的数字转化为Vector
	{
		if ( getColNarrowRight()==null&&getColNarrowRight().equals("") )  
			return new Vector();
		return Util.parseCSV(getColNarrowRight());
	}
	public Vector getNarrowLeft()//将逗号分割符分割的数字转化为Vector
	{
		if ( getColNarrowLeft()==null&&getColNarrowLeft().equals("") )  
			return new Vector();
		return Util.parseCSV(getColNarrowLeft());
	}
}