Java Serialization and Deserialization Examples
In Java, Serialization means converting Java objects into a byte stream; Deserialization means converting the serialized object’s byte stream back to the original Java object. In Java, we have to…
How to read an object from file in Java (ObjectInputStream)
This example shows how to use ObjectInputStream to read a serialized object from a file in Java, aka Deserialization. The below example converts a Person object to bytes stream and…
How to write an object to file in Java (ObjectOutputStream)
This example shows how to use ObjectOutputStream to write objects to a file in Java, aka Serialization. We can serialize or marshal an object which implements a Serializable interface. We…
How to get free disk space in Java
In Java old days, it lacks of method to determine the free disk space on a partition. But this is changed since JDK 1.6 released, a few new methods –…
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…