usersessionimpl.java

MVC留言

package org.bob.session;

import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;

import org.bob.entity.DynamicEntity;
import org.bob.model.DataAccessAdapter;

public class UserSessionImpl extends DataAccessAdapter{

	private Connection con=null;
	
	@Override
	public String isExist(DynamicEntity entity) throws SQLException {
		//这里没有返回boolean是因为在前台需要用到userid，所以在这里将userid查出来，注意下面的sql
		String userid=null;
		String sql="SELECT USERID FROM USERS WHERE USERNAME=? AND PASSWORD=?";
		this.con=this.getConnection();
		PreparedStatement pstm=con.prepareStatement(sql);
		pstm.setString(1,(String)entity.getElement("USERNAME"));
		pstm.setString(2,(String)entity.getElement("PASSWORD"));
		ResultSet rs=pstm.executeQuery();
		if(rs.next()){
			userid=rs.getString("USERID");
		}
		con.close();
		return userid;
	}
	
}