Lesson 11 - Binary Files in Java
In the previous exercise, Solved tasks for Java Files Lessons 6-10, we've practiced our knowledge from previous lessons.
In the last lesson, Solved tasks for Java Files Lessons 6-10, we focused on serialization and deserialization. Throughout this course, we've already mentioned several ways to store data (or instances if possible) into files. Whether it was the CSV or XML format, we have always technically worked with text files. In today's Java tutorial, we're going to introduce you to a different way of storing data and talk about its advantages and disadvantages.
Binary Files
So far, we always converted data types to strings and saved them to a text
file. When we read the data back again, we had to parse it from the
String
back to the original data type. However, we aren't limited
to storing data as text into files. Today, we'll go over storing data into
binary files.
As you already know, variables are stored in the computer's RAM memory.
Physically, we can imagine the memory as a really long line of "boxes" with
either a zero or a one in each box. The individual elements in the boxes are
bits. We usually don't work with bits individually but by 8 at a time. Sets of
eight bits are known as bytes (1 byte = 8 bits). Each Java data type occupies a
certain number of bytes in memory. For example, int
occupies 4 (a
total of 32 zeros and ones). It doesn't matter whether there is a value of
0
or 1,000,000
stored inside, it always has 4 bytes
reserved in memory. If we need to store a variable of the int
type
in a file, we simply
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This Java tutorial introduces you to binary files and the DataOutputStream and DataInputStream classes. We'll learn to read and write instances in binary.
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