代码:
JDBC工具类链接:☞点此查看
public class Login {
public static void main(String[] args) {
Scanner in = new Scanner(System.in);
System.out.println("请输入用户名:");
String username = in.nextLine();
System.out.println("请输入密码:");
String password = in.nextLine();
boolean flag = new Login().login(username, password);
if (flag) {
//登陆成功
System.out.println("登陆成功!");
} else {
//登陆失败
System.out.println("请检查用户名或密码!");
}
}
/**
* 登陆的方法
* 将用户名和密码作为参数传入本方法,再利用jdbc连接数据库查询是否有对应的数据
*
* @param username 用户名
* @param password 密码
* @return true或false
*/
public boolean login(String username, String password) {
//判断参数是否为null
if (username == null || password == null) {
//为空返回false
return false;
}
String sql = "select * from user where username='" + username + "' and password='" + password + "'";
Connection conn = null;
Statement stmt = null;
ResultSet rs = null;
try {
//创建连接
conn = JDBCUtils.getConnection();
//获取执行sql的对象
stmt = conn.createStatement();
//执行sql语句
rs = stmt.executeQuery(sql);
//判断结果,如果有下一行就返回true,没有返回false
return rs.next();
} catch (SQLException e) {
e.printStackTrace();
} finally {
//释放资源
JDBCUtils.close(rs, stmt, conn);
}
return false;
}
}