Republished articles with source attribution. This collection is separate from Diary Coding’s original guides and does not display ads.
The following code snippet will teach you how to align string in left, right or center alignment when you want to print out string to a console. We will print the string using the printf(String format, Object… args) method. The format specifier / parameter defines how the string will be formatted for output and the […]
To sort file names by their extension, we can use the ExtensionFileComparator class from the Apache Commons IO library. This class provides a couple instances of comparator such as: Comparator Description EXTENSION_COMPARATOR Case sensitive extension comparator EXTENSION_REVERSE Reverse case sensitive extension comparator EXTENSION_INSENSITIVE_COMPARATOR Case insensitive extension comparator EXTENSION_INSENSITIVE_REVERSE Reverse case insensitive extension comparator EXTENSION...
In this example, you will learn how to sort files and directories based on their size. Using the Apache Commons IO, we can utilize the SizeFileComparator class. This class provides some instances to sort file size such as: Comparator Description SIZE_COMPARATOR Size comparator instance – directories are treated as zero size SIZE_REVERSE Reverse size comparator […]
The following example show how to use the Apache Commons IO library to read a text file line by line to a List of String. In the code snippet below we will read the contents of a file called sample.txt using FileUtils class. We use FileUtils.readLines() method to read the contents line by line and […]
package org.kodejava.security; import java.security.SecureRandom; import java.util.Random; public class RandomString { public static final String SOURCES = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz1234567890"; public static void main(String[] args) { RandomString rs = new RandomString(); System.out.println(rs.generateString(new Random(), SOURCES, 10)); System.out.println(rs.generateString(new Random(), SOURCES, 10)); System.out.println(rs.generateString(new Secure...
Usually, if not always, we use the if statement combined with == or != operators to check if an object reference is null or not. We do this to validate arguments passed to constructors or methods doesn’t contain a null value. These null check can be seen as clutter in our code. The solution is […]
Stay curious. There is always something new to learn.
Writer and founder of Diary Coding — sharing notes, tutorials, and experiences about programming for anyone who wants to keep learning.