managerdb.java

基于JSP＋MYSQL的教学资源库系统

package database;
import java.sql.*;
public class managerDB
{
	
	private String database="multiMedia";
	private String userName="root";
	private String password="";
	private Connection cnn=null;
	private Statement stm=null;
	private ResultSet rs=null;
	
	public boolean connectDB()
	{
		try
		{
			Class.forName("com.mysql.jdbc.Driver");
			cnn=DriverManager.getConnection("jdbc:mysql://localhost/"+this.database+"?useUnicode=true&characterEncoding=gb2312",this.userName,this.password);
			stm=cnn.createStatement();
			return(true);
		}
		catch(Exception e)
		{
			return(false);
		}
	}
	public void closeDB()
	{
		try
		{
			stm.close();
		    cnn.close();
		}
		catch(Exception e)
		{
			System.out.println(e.getMessage());
		}
	}
	public void executeSQL(String sql)
	{
		try
		{
		    stm.executeUpdate(sql);
		}
		catch(Exception e)
		{
			System.out.println(e.getMessage());
		}
	}
	public ResultSet queryDB(String sql)
	{
		try
		{
		    rs=stm.executeQuery(sql);
		    return(rs);	    
		}
		catch(Exception e)
		{
			return(null);
		}
	}
	public String displayMultiType(String sql)
	{
		String subjectType="";
		try
		{
		    rs=stm.executeQuery(sql);
		    while(rs.next())
		    {
			    subjectType+="<a href=displayMultiInfo.jsp?mmt="+rs.getString("MultiMediaType")+"&st="+rs.getString("SubjectType")+">"+rs.getString("SubjectType")+"</a>&nbsp;&nbsp;&nbsp;";
		    }    
		    return(subjectType);
		}
		catch(Exception e)
		{
			return("数据查询有误!");
		}
	}
}