getpassword.java

使用java编写的一个学生选课系统

package Srs;
import java.sql.*;

import Srs.LinkDatabase;
public class GetPassword {
	private LinkDatabase linkDatabase = new LinkDatabase();
	private Connection connection;
	private Statement statement;
	private String sql;
	private ResultSet resultSet;
	public String getPassword(String newId){
		try{
			sql = "select password"+" "+
					"from students"+" "+
					"where id ='"+newId+"';";
			connection = linkDatabase.getlink();
			statement = connection.createStatement();
			resultSet = statement.executeQuery(sql);
			if(!resultSet.next()){
				return null;
			}
			else{
			return resultSet.getString("password");
			}
		}catch(SQLException e){
			e.printStackTrace();
			return null;
		}
	}
}