Date Operations

How to add weeks to a date in Java?

How to add months to a date in Java?

How to add years to a date in Java?

How to check if a given date is after today in Java?

How to check if a given date is before today in Java?

How to format date object in to specific date format?

How to find day of the week for a given date?

How to find the number of days between 2 dates?

How to find earliest date between 2 dates or a given set of dates?

How to find latest date between 2 dates or a given set of dates?

How to check if a given year is a leap year?

How to find end date of month in any given year?

How to find if the month and year of 2 dates are equal?

How to find a particular occurence of a week day in a month?

How to convert String date to a Calendar?

How to convert a String date to a util date object?

How to format time as AM/PM?

Collection Handling

How to copy or extend an array into another array?

How to find the number of a particular value object in a collection?

How to convert string to array?

How to convert string to array list?

String Manipulations

How to validate email address?

How to validate a phone number?

How to validate a SSN?

How to check if a string contains only alphabets?

How to convert a comma separated string to string array?

File Operations

How to write data to a file?

How to create a date based directory?

How to search for a file in Java?

How to convert input stream to text?

Mathematical Functions

How to find the highest number in a set of numbers?

How to find the least number in a given set of numbers?

How to validate a number?

How to generate a range of tokenized numbers?

Database Operations

How to get Oracle database connection using Java?

Miscellaneous

How to execute a external command from Java?

How to to replace special characters with URL encoders?