commonuserdaoimpl.java

电子商务网站前台代码。基于开源软件编写

package dao;

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

import javax.naming.Context;
import javax.naming.InitialContext;
import javax.naming.NamingException;
import javax.sql.DataSource;

public class CommonUserDAOImpl implements CommonUserDAO {

	//网络有问题或者查询到的名字不存在将会返回false,如果名字有重复返回true
	
	public Connection getConnect() {
		// TODO Auto-generated method stub
		Context ctx = null;
		Connection con = null;
		try {
			ctx = new InitialContext();
			DataSource ds = (DataSource) ctx.lookup("java:/MySqlDS");
			con = ds.getConnection();
		} catch (NamingException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} catch (SQLException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
		return con;
	}
	
	public boolean selectUserForCheck(String username){
		Connection conn = this.getConnect();
		try {			
			PreparedStatement preproc = conn.prepareStatement("select userName from usertable where userName=?");
			preproc.setString(1,username);		
			preproc.execute();
			ResultSet rs = preproc.getResultSet();			
			if(rs.next()){				
				return true;
			}else
				return false;			
		}catch (SQLException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
			return false;
		}finally{
			try {
				conn.close();
			} catch (SQLException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}
		}		
	}	
	

	
}