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Java Basics
Java Tutorial
Java Installation
Java HelloWorld Program
Java Program Structure
Java Data Types
- byte
- short
- int
- long
- float
- double
- boolean
- char
Java Variables
- Java Variable Types
Java Access Modifiers
Java Operators
- Arithmetic Operators
- Assignment Operators
- Relational Operators
- Logical Operators
- Bitwise Operators
Java Decision Making
- If statement
- If-Else statement
- If-Else-If statement
- Switch statement
Java Loops
- Java While Loop
- Java Do-while Loop
- Java For Loop
- Java ForEach
- Java Break
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- Nested While Loop
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- Infinite While Loop
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Java Array
- Java Array
- Print array
- Initialize array
- Array of integers
- Array of strings
- Array of objects
- Array of arrays
- Iterate over array
- Array For loop
- Array while loop
- Append element to array
- Check if array is empty
- Array average
- Check if array contains
- Array ForEach
- Array - Find Index of Item
- Array sum
- Concatenate arrays
- Find smallest number in array
- Find largest number in array
- Array reverse
Java OOPs
- Classes and Objects
- Inheritance
- Polymorphism
- Method Overloading
- Method Overriding/
- Abstraction
- Abstract methods and classes
- Interfaces
- Encapsulation
- Polymorphism
Java String
- Basics
- Print string
- Read string from console
- Create string from Char array
- Create string from Byte array
- Concatenate two strings
- Get index of the first Occurrence of substring
- Get index of nth occurrence of substring
- Checks
- Check if two strings are equal
- Check if string ends with specific suffix
- Check if string starts with specific prefix
- Check if string is blank
- Check if string is empty
- Check if string contains search substring
- Validate if string is a Phone Number
- Character Level
- Get character at specific index in string
- Get first character in string
- Get last character from string
- Transformations
- Replace first occurrence of string
- Replace all occurrences of a string
- Join strings
- Join strings in string array
- Join strings in ArrayList
- Reverse a string
- Trim string
- Split string
- Remove whitespaces in string
- Replace multiple spaces with single space
- Comparisons
- Compare strings lexicographically
- Compare String and CharSequence
- Compare String and StringBuffer
Java Exception Handling
Java Type Conversions
- Convert string to int
- Convert string to float
- Convert string to double
- Convert string to long
- Convert string to boolean
- Convert int to string
- Convert int to float
- Convert int to double
- Convert int to long
- Convert int to char
- Convert float to string
- Convert float to int
- Convert long to string
- Convert double to string
- Convert boolean to string
Java File Operations
- Create a file
- Read file as string
- Write string to file
- Copy File
- Delete File
- Rename File
- Download File from URL
- Replace a String in File
- Filter list of files or directories
- Check if file is readable
- Check if file is writable
- Check if file is executable
- Read contents of a file line by line using BufferedReader
- Read contents of a File line by line using Stream
Java Programs
- Check if n is positive or negative
- Read integer from console
- Add two integers
- Count digits in number
- Largest of three numbers
- Smallest of three numbers
- Even numbers
- Odd numbers
- Reverse a number
- Prime Number
- Factorial
- Print All Prime Numbers
- Factors of a Number
- Check Palindrome number
- Check Palindrome string
- Swap two numbers
- Even or Odd number
Java Classes
Java ArrayList
- ArrayList add()
- ArrayList addAll()
- ArrayList clear()
- ArrayList clone()
- ArrayList contains()
- ArrayList ensureCapacity()
- ArrayList forEach()
- ArrayList get()
- ArrayList indexOf()
- ArrayList isEmpty()
- ArrayList iterator()
- ArrayList lastIndexOf()
- ArrayList listIterator()
- ArrayList remove()
- ArrayList removeAll()
- ArrayList removeIf()
- ArrayList removeRange()
- ArrayList retainAll()
- ArrayList set()
- ArrayList size()
- ArrayList spliterator()
- ArrayList subList()
- ArrayList toArray()
- ArrayList trimToSize()
Java HashMap
- HashMap clear()
- HashMap clone()
- HashMap compute()
- HashMap computeIfAbsent()
- HashMap computeIfPresent()
- HashMap containsKey()
- HashMap containsValue()
- HashMap entrySet()
- HashMap get()
- HashMap isEmpty()
- HashMap keySet()
- HashMap merge()
- HashMap put()
- HashMap putAll()
- HashMap remove()
- HashMap size()
- HashMap values()
Java HashSet
- HashSet add()
- HashSet clear()
- HashSet clone()
- HashSet contains()
- HashSet isEmpty()
- HashSet iterator()
- HashSet remove()
- HashSet size()
- HashSet spliterator()
Java Integer
- Integer bitCount()
- Integer byteValue()
- Integer compare()
- Integer compareTo()
- Integer doubleValue()
- Integer equals()
- Integer floatValue()
- Integer getInteger()
- Integer intValue()
- Integer longValue()
- Integer max()
- Integer min()
- Integer reverse()
- Integer reverseBytes()
- Integer rotateLeft()
- Integer rotateRight()
- Integer shortValue()
- Integer signum()
- Integer sum()
- Integer toBinaryString()
- Integer toHexString()
- Integer toOctalString()
- Integer toString()
Java StringBuilder
- StringBuilder append()
- StringBuilder appendCodePoint()
- StringBuilder capacity()
- StringBuilder charAt()
- StringBuilder chars()
- StringBuilder codePointAt()
- StringBuilder codePointBefore()
- StringBuilder codePointCount()
- StringBuilder codePoints()
- StringBuilder delete()
- StringBuilder deleteCharAt()
- StringBuilder ensureCapacity()
- StringBuilder getChars()
- StringBuilder indexOf()
- StringBuilder insert()
- StringBuilder lastIndexOf()
- StringBuilder length()
- StringBuilder offsetByCodePoints()
- StringBuilder replace()
- StringBuilder reverse()
- StringBuilder setCharAt()
- StringBuilder setLength()
- StringBuilder subSequence()
- StringBuilder substring()
- StringBuilder toString()
- StringBuilder trimToSize()
Java java.util.Arrays
- Arrays.asList()
- Arrays.copyOf()
- Arrays.sort()
Java Random
- Random doubles()
- Random ints()
- Random longs()
- Random next()
- Random nextBoolean()
- Random nextBytes()
- Random nextDouble()
- Random nextFloat()
- Random nextGaussian()
- Random nextInt()
- Random nextLong()
- Random setSeed()
Java Math
- Math abs
- Math acos
- Math asin
- Math atan
- Math cbrt
- Math ceil
- Math cos
- Math cosh
- Math exp
- Math floor
- Math hypot
- Math log
- Math max
- Math min
- Math pow
- Math random
- Math round
- Math rint
- Math signum
- Math sin
- Math sinh
- Math sqrt
- Math tan
- Math tanh
- Math toDegrees
- Math toRadians
Advanced
Java Date & Time
Java MySQL

Java – Read file as byte array

In this tutorial, you will learn how to read a file as byte array in Java, using readAllBytes() method of java.nio.file.Files class.

Java – Read file as byte array

To read a file as byte array in Java, given a file path, call readAllBytes() method of the java.nio.file.Files class and pass the file path as argument to the method. The readAllBytes() method returns a byte array with the bytes of the file.

If filePath is the given file path, then use the following expression to get the bytes in file.

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Copy

Files.readAllBytes(filePath)

1. Read the file “data.txt” as byte array in Java

In the following program, we take a file path "/Users/tutorialkart/data.txt", read the content of this file as byte array, and print them to standard output.