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 – 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 read file in Java – FileInputStream
In Java, we use FileInputStream to read bytes from a file, such as an image file or binary file. The FileInputStream.read() reads a byte at a time, and it will…
How to read file in Java – BufferedInputStream
Here is another example to show how to read a file in Java with BufferedInputStream and DataInputStream classes. The readLine() from the type DataInputStream is deprecated. Sun officially announced this…
How to set the file permission in Java
In Java, file permissions are very OS specific: *nix , NTFS (windows) and FAT/FAT32, all have different kind of file permissions. Java comes with some generic file permission to deal…
How to create a file in Java
In Java, there are many ways to create and write to a file: using Files.newBufferedWriter (Java 8), using Files.write (Java 7), using PrintWriter, using File.createNewFile