参考文章链接：https://www.zhihu.com/question/29779842/answer/71475305
国外程序员 martyr2s提出的可以用于巩固计算机知识的练手小项目。分为数值，文本，面向对象，多线程，网络，Web,文件，数据库，图像与多媒体等多个类别。
我的目标是使用java来实现全部的项目。
Numbers
Find PI to the Nth Digit – Enter a number and have the program generate PI up to that many decimal places. Keep a limit to how far the program will go.
Fibonacci Sequence – Enter a number and have the program generate the Fibonacci sequence to that number or to the Nth number.
Prime Factorization – Have the user enter a number and find all Prime Factors (if there are any) and display them.
Next Prime Number – Have the program find prime numbers until the user chooses to stop asking for the next one.
Find Cost of Tile to Cover W x H Floor – Calculate the total cost of tile it would take to cover a floor plan of width and height, using a cost entered by the user.
Mortgage Calculator – Calculate the monthly payments of a fixed term mortgage over given Nth terms at a given interest rate. Also figure out how long it will take the user to pay back the loan.
Change Return Program – The user enters a cost and then the amount of money given. The program will figure out the change and the number of quarters, dimes, nickels, pennies needed for the change.
Binary to Decimal and Back Converter – Develop a converter to convert a decimal number to binary or a binary number to its decimal equivalent.
Calculator – A simple calculator to do basic operators. Make it a scientific calculator for added complexity.
Unit Converter (temp, currency, volume, mass and more) – Converts various units between one another. The user enters the type of unit being entered, the type of unit they want to convert to and then the value. The program will then make the conversion.
Alarm Clock – A simple clock where it plays a sound after X number of minutes/seconds or at a particular time.
Distance Between Two Cities – Calculates the distance between two cities and allows the user to specify a unit of distance. This program may require finding coordinates for the cities like latitude and longitude.
Credit Card Validator – Takes in a credit card number from a common credit card vendor (Visa, MasterCard, American Express, Discoverer) and validates it to make sure that it is a valid number (look into how credit cards use a checksum).
Tax Calculator – Asks the user to enter a cost and either a country or state tax. It then returns the tax plus the total cost with tax.
Dijkstra’s Algorithm – Create a program that finds the shortest path through a graph using its edges.
Text
Reverse a String – Enter a string and the program will reverse it and print it out.
Pig Latin – Pig Latin is a game of alterations played on the English language game. To create the Pig Latin form of an English word the initial consonant sound is transposed to the end of the word and an ay is affixed (Ex.: "banana" would yield anana-bay). Read Wikipedia for more information on rules.
Count Vowels – Enter a string and the program counts the number of vowels in the text. For added complexity have it report a sum of each vowel found.
Check if Palindrome – Checks if the string entered by the user is a palindrome. That is that it reads the same forwards as backwards like “racecar”
Count Words in a String – Counts the number of individual words in a string. For added complexity read these strings in from a text file and generate a summary.
Text Editor – Notepad style application that can open, edit, and save text documents. Add syntax highlighting and other features.
RSS Feed Creator – A program which can read in text from other sources and put it in RSS or Atom news format for syndication.
Post it Notes Program – A program where you can add text reminders and post them. You can have the program also add popup reminders.
Quote Tracker (market symbols etc) – A program which can go out and check the current value of stocks for a list of symbols entered by the user. The user can set how often the stocks are checked and the program can show green up and red down arrows to show which direction the stock value has moved.
Guestbook / Journal – A simple application that allows people to add comments or write journal entries. It can allow comments or not and timestamps for all entries. Could also be made into a shout box.
News Ticker and Game Scores – A program which sits on your desktop and aggregates news and game scores from various sources on the net. It then scrolls them across the screen on regular intervals.
Fortune Teller (Horoscope) – A program that checks your horoscope on various astrology sites and puts them together for you each day.
Vigenere / Vernam / Ceasar Ciphers – Functions for encrypting and decrypting data messages. Then send them to a friend.