在JSP中用bean封装数据库常用的功能

在jsp中用bean封装数据库常用的功能

1、建立一个bean

package guestbook;
import java.sql.*;


public class sql_data
{
    string sdbdriver="sun.jdbc.odbc.jdbcodbcdriver";
    string sconnstr="jdbc:odbc:guestbook";
    connection conn=null;
    resultset rs=null;
    public sql_data()
    {
        try{
            class.forname(sdbdriver);
        }
        catch(java.lang.classnotfoundexception e)
        {
            system.err.println("sql_data():"+e.getmessage());
        }
    }

    public void executeinsert(string sql)
    {
        try
        {
            conn=drivermanager.getconnection(sconnstr);
            statement stmt=conn.createstatement();
            stmt.executeupdate(sql);
        }
        catch(sqlexception ex)
        {
            system.err.println("sql_data.executeupdate:"+ex.getmessage());
        }
    }

    public resultset executequery(string sql)
    {
        rs=null;
        try
        {
            conn=drivermanager.getconnection(sconnstr);
            statement stmt=conn.createstatement();
            rs=stmt.executequery(sql);
        }
        catch(sqlexception ex)
        {
            system.err.println("sql_data.executequery:"+ex.getmessage());
        }
    }

    public void executedelete(string sql)
    {
        try
        {
            conn=drivermanager.getconnection(sconnstr);
            statement stmt=conn.createstatement();
            stmt.executeupdate(sql);
        }
        catch(sqlexception ex)
        {
            system.err.println("sql_data.executedelete:"+ex.getmessage());
        }
    }
}

2、在jsp中声明bean：

……

<jsp:usebean id="sqlbean" scope="session" class="guestbook.sql_data"/>

<%!string sql,name;%>

<%

sql="select * from table";

resultset rs=sqlbean.executequery(sql);

while(rs.nex()){

    name=rs.getstring("name")

}

%>

……

name:<%=name%>

……

<%

rs.close();

%>

……