Java – Convert File to Hex
This article shows how to convert a file into a hexadecimal (hex) representative format. The idea is to read the file into an InputStream and uses String.format(%X) to convert each…
Java – How to save byte[] to a file
This article shows a few ways to save a byte into a file. For JDK 1.7 and above, the NIO Files.write is the simplest solution to save byte to a…
Java – How to convert File to byte[]
In Java, we can use Files.readAllBytes(path) to convert a File object into a byte. Before Java 7, we can initiate a new byte with a predefined size (same with the…
Java – List of available MessageDigest Algorithms
In Java, you can use the Security.getAlgorithms("MessageDigest") to list all the available MessageDigest algorithms.
Java – Create file checksum with SHA and MD5
In this article, we will show you how to use a SHA-256 and MD5 algorithm to generate a checksum for a file. We have 2 ways: (1) using MessageDigest.getInstance(“algorithm”), (2)…
How to assign file content into a variable in Java
Most people will read the file content and assign to StringBuffer or String line by line. Here’s another trick that may interest you – how to assign whole file content…
How to check if a file is hidden in Java
A Java program to demonstrate the use of java.io.File isHidden() to check if a file is hidden. The isHidden() method is system dependent, on UNIX platform, a file is considered…
How to check if a file exists in Java
In Java, we can use Files.exists(path) to test whether a file exists. The path can be a file or a directory. It is better to combine with !Files.isDirectory(path) to ensure…
Java – Count number of lines in a file
This article shows few Java examples to get the total number of lines in a file. The steps are similar: (1) Open the file, (2) Read line by line, and…