userdao.java

一个用自己写的新闻系统(Struts) ,比较简单

package com.weipure.struts.dao;

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

import com.weipure.struts.form.LogonForm;
import com.weipure.struts.tool.DBConnection;

public class UserDAO {
	
	private DBConnection dbc = new DBConnection();
	
	public boolean isUserExisted(String username, String password) {
		String sql = "select * from users where usname='" + username
				+ "' and psword='" + password + "'";
		ResultSet rs = (ResultSet) dbc.executeQuery(sql);
		try {
			if (rs.next()) {
				return true;
			} 
		} catch (SQLException e) {
			e.printStackTrace();
		}
		dbc.close();
		return false;
	}
	
//	public String verify(String username, String password) {
//		String result = null;
//		Connection conn = null;
//		Statement st = null;
//		ResultSet rs = null;
//		conn = dbc.getConnection();
//		try {
//			st = conn.createStatement();
//			rs = st.executeQuery("select psword from users where usname='"
//					+ username + "'");
//			if (rs.next()) {
//				if (password.equals(rs.getString("psword"))) {
//					result = "OK";
//				} else {
//					result = "PWD";
//				}
//			} else {
//				result = "NOUSER";
//			}
//		} catch (SQLException e) {
//			e.printStackTrace();
//		}finally{
//			try {
//				if(rs!=null)rs.close();
//				if(st!=null)st.close();
//			
//			} catch (SQLException e) {
//				e.printStackTrace();
//			}
//		}
//
//		return result;
//	}

	
	public String verify(String username, String password) {
		String result = null;
		String sql = "select psword from users where usname='"
			+ username + "'";
		ResultSet rs = (ResultSet) dbc.executeQuery(sql);
		try {
			if (rs.next()) {
				if (password.equals(rs.getString("psword"))) {
					result = "OK";
				} else {
					result = "PWD";
				}
			} else {
				result = "NOUSER";
			}
		} catch (SQLException e) {
			e.printStackTrace();
		}
		dbc.close();
		return result;
	}
	
	public int register(LogonForm lf) {
		int num = 0;
		String sql = "insert into users(usname,psword) values('"
			+ lf.getUsername()+ "','" + lf.getPassword() +"')";
		num = dbc.executeUpdate(sql);
		dbc.close();
		return num;
	}
}