Integral

说明：  java 写的一个ftp客户端！可以运行ssh！！！(write a java ftp client! Can run ssh! ! !)

大学Java课程实验三，要求学会使用继承接口与多态。(Java course experiment three universities require learn to use interface inheritance and polymorphism.)

二分法，数值分析实现方程求根的算法，这是java程序(Dichotomy, numerical analysis algorithms to achieve Roots of the equation, which is the java program)

编写一个控制台程序，模拟在ATM机的存款和取款过程，当输入给定的卡号和密码（初始卡号和密码到数据文件里查看）时，系统能登录ATM系统，根据用户的身份不同显示不同的程序界面；取款 　　每次取款金额只能为100的倍数，总额不超过2000元，不允许透支。且取款之后，要记录取款的金额和时间。 存款 　　每次存款金额只能为100的倍数，总额不超过2000元。 修改密码 　　新密码长度不小于6位，不允许出现6位完全相同的情况，只有旧密码正确，新密码符合要求，且两次输入相同的情况下才可以成功修改密码。(Write a console program to simulate the ATM deposits and withdrawals process, when you enter a given number and password (the initial number and password to the data file view), the system can log in ATM systems, according to the user' s identity different display different The program interface withdrawal amount each withdrawal can only be a multiple of 100, the total does not exceed 2,000 yuan, does not allow overdrafts. And withdrawals after the withdrawal of the amount to be recorded and time. Deposit Amount per Deposit only a multiple of 100, totaling no more than 2,000 yuan. Change Password New Password length not less than six, allowed six identical situation, only the old password is correct, the new password meets the requirements, and enter the same case twice before they can successfully change the password.)

用JAVA写的带通滤波代码，实现思路很简单，没有采用各种数字滤波的方法。而是通过傅里叶变换到频域，将要求外的频率均置0，再逆傅里叶变换得到的。效果还不错。(Written using JAVA bandpass filtering code to achieve the idea is very simple, without using a variety of digital filtering approach. But through the Fourier transform to the frequency domain, the frequency requirements are set to 0, then the inverse Fourier transform. Results were pretty good.)

Java教程，21天精通JAVA电子书，清晰版。(Java Tutorial, 21 days proficient JAVA books, clear version.)

this is answer for ssd7 exercise 4

说明：  *　程序文件名称：ReadComm.java * 功能：从串行口COM1中接收数据(* Name of program file: ReadComm.java* feature: From the COM1 serial port to receive data)

测试函数行数,计算每个合格的java文本的函数行数(sum code)

说明：  一只青蛙一次可以跳上1级台阶，也可以跳上2级。求该青蛙跳上一个n级的台阶总共有多少种跳法。要求：分别用普通方法和递归方法实现(A frog can jump up a step or two at a time. Find out how many jumping methods the frog can use to jump up an n-step. Requirements: Implemented by common method and recursive method respectively)