subjectdbbean.java

北大青鸟在线考试系统,包括在线考试模块,教师管理模块,系统管理模块

/*
 *定义试题数据操作组件
 */
package TestClass;

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

public class SubjectDBbean
{
	//数据库连接指向空
	private Connection conn=null;
	//根据试题编号列出试题内容
	private PreparedStatement GetOne=null;
	//引入外部查询语句
	private Statement stmt=null;
	private Statement stmt1=null;
	//列出所有试题内容
	private PreparedStatement GetAll=null;
	//添加试题
	private PreparedStatement AddStmt=null;
	//修改试题
	private PreparedStatement UpStmt=null;
	//删除试题
	private PreparedStatement DelStmt=null;	
	
	public SubjectDBbean()
	{
		//声明数据库连接
		String driver,user,pass,dbURL;
		PropertyResourceBundle resourceBundle = (PropertyResourceBundle) PropertyResourceBundle.getBundle("Config");

		driver = resourceBundle.getString("jdbc.driver");
		user = resourceBundle.getString("jdbc.user");
		pass = resourceBundle.getString("jdbc.password");
		dbURL = resourceBundle.getString("jdbc.dbURL");

		try  
		{
			Class.forName(driver);
			conn =DriverManager.getConnection(dbURL,user,pass);
			//根据试题编号列出试题内容
			GetOne=conn.prepareStatement("Select * From Subject Where SubID=?");
			//引入外部查询语句
			stmt=conn.createStatement();
			stmt1=conn.createStatement();
			//列出所有试题内容
			GetAll=conn.prepareStatement("Select * From Subject Order by OutID");
			//添加试题
			AddStmt=conn.prepareStatement("Insert into Subject values(?,?,?,?,?,?,?,?)");
			//修改试题
			UpStmt=conn.prepareStatement("Update Subject set Question=?,A=?,B=?,C=?,D=?,Answer=?,OutID=? Where SubID=?)");
//			UpStmt=conn.prepareStatement("Update Subject set OutID=? Where SubID=?)");
			//删除试题
			DelStmt=conn.prepareStatement("Delete From Subject Where SubID=?)");
		}
		catch(java.lang.ClassNotFoundException e) 
		{
			System.err.println("SubjectDBbean(): 0" + e.getMessage());
		}
		catch(java.sql.SQLException e)
		{
			System.err.println("SubjectDBbean(): 1" + e.getMessage());
		}
		catch(Exception e)
		{
			System.err.println("SubjectDBbean(): 2" + e.getMessage());	
		}
	}
	
	/*
	 * 数据访问
	 */	
	 
	//列出所有试题内容
	public ArrayList GetAllData()
	{
		ArrayList rt=new ArrayList();
		
		try 
		{
			ResultSet Rs=GetAll.executeQuery();
			
			SubjectBean beanObj=null;
			while(Rs.next())
			{
				beanObj=new SubjectBean();
				beanObj.setSubID(Rs.getInt(1));
				beanObj.setQuestion(Rs.getString(2));
				beanObj.setA(Rs.getString(3));
				beanObj.setB(Rs.getString(4));
				beanObj.setC(Rs.getString(5));
				beanObj.setD(Rs.getString(6));
				beanObj.setAnswer(Rs.getString(7));
				beanObj.setOutID(Rs.getInt(8));
				rt.add(beanObj);
			}
			Rs.close();
		}
		catch(SQLException ex) 
		{
			System.err.println("SubjectDBbean.GetAllData: " + ex.getMessage());
		}
		return rt;
	}
	
	//根据试题编号列出试题内容
	public SubjectBean GetOne(int PK_SubID)
	{
		SubjectBean rt=null;
		try 
		{
			GetOne.setInt(1,PK_SubID);
			
			ResultSet Rs=GetOne.executeQuery();
			
			if (Rs.next())
			{
				rt=new SubjectBean();
				rt.setSubID(Rs.getInt(1));
				rt.setQuestion(Rs.getString(2));
				rt.setA(Rs.getString(3));
				rt.setB(Rs.getString(4));
				rt.setC(Rs.getString(5));
				rt.setD(Rs.getString(6));
				rt.setAnswer(Rs.getString(7));
				rt.setOutID(Rs.getInt(8));
			}
			Rs.close();
		}
		catch(SQLException ex) 
		{
			System.err.println("SubjectDBbean.GetOne: " + ex.getMessage());
		}
		return rt;
	}

	//引入外部查询语句
	public ResultSet executeQuery(String sql)
	{
		ResultSet Rs=null;
		try
		{
			if(conn!=null)
			{
				Rs=stmt.executeQuery(sql);
			}
		}
		catch(SQLException ex) 
		{
			System.err.println("AttendmentDBbean.ResultSet executeQuery: " + ex.getMessage());
		}
		return Rs;
	}
	public boolean executeUpdate(String sql)
	{
		boolean rt=false;
		try
		{
			if(conn!=null)
			{
				stmt1.executeUpdate(sql);
			}
		}
		catch(SQLException ex) 
		{
			System.err.println("AttendmentDBbean.ResultSet executeQuery: " + ex.getMessage());
		}
		return rt;
	}

	//添加试题
	public boolean InsertDB(SubjectBean obj)
	{
		boolean rt=false;
		try 
		{
			AddStmt.setInt(1,obj.getSubID());
			AddStmt.setString(2,obj.getQuestion());
			AddStmt.setString(3,obj.getA());
			AddStmt.setString(4,obj.getB());
			AddStmt.setString(5,obj.getC());
			AddStmt.setString(6,obj.getD());
			AddStmt.setString(7,obj.getAnswer());
			AddStmt.setInt(8,obj.getOutID());
			
			rt=(AddStmt.executeUpdate()==1);
		}
		catch(SQLException ex) 
		{
			System.err.println("SubjectDBbean.InsertDB: " + ex.getMessage());
		}
		return rt;
	}
		
	//修改试题
	public boolean UpdateDB(SubjectBean obj)
	{
		boolean rt=false;
		try 
		{
			UpStmt.setInt(8,obj.getSubID());
			UpStmt.setString(1,obj.getQuestion());
			UpStmt.setString(2,obj.getA());
			UpStmt.setString(3,obj.getB());
			UpStmt.setString(4,obj.getC());
			UpStmt.setString(5,obj.getD());
			UpStmt.setString(6,obj.getAnswer());
			UpStmt.setInt(7,obj.getOutID());
			
			rt=(UpStmt.executeUpdate()==1);
		}
		catch(SQLException ex) 
		{
			System.err.println("SubjectDBbean.UpdateDB: " + ex.getMessage());
		}	
		
		return rt;
	}
/*	public boolean UpdateDB(SubjectBean obj)
	{
		boolean rt=false;
		try 
		{
			UpStmt.setInt(2,obj.getSubID());
			UpStmt.setInt(1,obj.getOutID());
			rt=(UpStmt.executeUpdate()==1);
		}
		catch(SQLException ex) 
		{
			System.err.println("SubjectDBbean.UpdateDB: " + ex.getMessage());
		}	
		return rt;
	}*/
	//删除试题	
	public boolean DeleteDB(int PK)
	{
		boolean rt=false;
		try 
		{
			DelStmt.setInt(1,PK);
			rt=(DelStmt.executeUpdate()==1);
		}
		catch(SQLException ex) 
		{
			System.err.println("SubjectDBbean.DeleteDB: " + ex.getMessage());
		}
		
		return rt;		
	}
	
	//关闭数据	
	public void Close()
	{
		try
		{
			if(conn != null)
			{
				GetAll.close();
				AddStmt.close();
				UpStmt.close();
				DelStmt.close();
				GetOne.close();
				conn.close();
				conn=null;
			}
		}
		catch(java.sql.SQLException e)
		{
			System.err.println("DataBaseBean():close " + e.getMessage());
		}
	}
		
}