myexam.java

在线考试系统

/* myexam.java  
   Bean to connect database */

package myexam;
import java.sql.*;

public class myexam
{ 
    String strDBDriver="com.microsoft.jdbc.sqlserver.SQLServerDriver";
    String strDBUrl="jdbc:microsoft:sqlserver://localhost:1433;DatabaseName=myexam";
    private Connection conn=null;
    private Statement stmt=null;
    ResultSet rs=null;
    //<!--注册数据库驱动程序-->
    public myexam() throws SQLException, InstantiationException, IllegalAccessException
    {
    	try
    	{
    		Driver driver = (Driver) Class.forName("com.microsoft.jdbc.sqlserver.SQLServerDriver").newInstance();
    		DriverManager.registerDriver(driver);
    	   // Class.forName(strDBDriver);
    	    System.out.println("++++++++++++++++++");
    	}
    	//异常处理
    	catch(java.lang.ClassNotFoundException e) 
        {
            System.err.println("exam():"+e.getMessage());
        }
    }
    //<!--建立数据库连接及定义数据查询-->
    public ResultSet executeQuery(String sql)
    {
        rs=null;
        try
        {
    	    conn=DriverManager.getConnection(strDBUrl,"sa","sa");//创建数据库连接对象 
            stmt=conn.createStatement(ResultSet.TYPE_SCROLL_SENSITIVE,ResultSet.CONCUR_UPDATABLE);
            rs=stmt.executeQuery(sql);
        }
        catch(SQLException ex) 
        {
    	    System.err.println("aq.executeQuery:"+ex.getMessage());
        }
        return rs;
    }
    //<!--定义数据操作-->
    public void executeUpdate(String sql)
    {
        stmt=null;
        rs=null;
        try
        {
    	    conn=DriverManager.getConnection(strDBUrl,"sa","sa");
    	    stmt=conn.createStatement(ResultSet.TYPE_SCROLL_SENSITIVE,ResultSet.CONCUR_UPDATABLE);
    	    stmt.executeQuery(sql);
    	    stmt.close();
    	    conn.close();
        }
        catch(SQLException ex)
        {
            System.err.println("aq.executeQuery:"+ex.getMessage());
        }
    }
    //<!--关闭数据库连接-->
    public void closeStmt()
    {
        try
        {
        	stmt.close();
        }
        catch(SQLException e)
        {
    	    e.printStackTrace();
        }
    }
    public void closeConn()
    {
	    try
	    {
		    conn.close();
	    }
	    catch(SQLException e)
	    {
		    e.printStackTrace();
	    }
    }
    public static void main(String[] args) throws SQLException, InstantiationException, IllegalAccessException, ClassNotFoundException{
    	myexam exam = new myexam();
  
    	ResultSet rs = exam.executeQuery("select * from answer");
    	try {
			if(rs.next()){
				System.out.println(rs.getString(1));
				System.out.println(rs.getString(2));
				System.out.println(rs.getString(3));
				System.out.println(rs.getString(4));
				System.out.println(rs.getString(5));
				
			}
		} catch (SQLException e) {
			// TODO 自动生成 catch 块
			e.printStackTrace();
		}
    	
    	
    	
    }
}