Convert Binary String to Binary

Question

How do I convert a String written as Binary, to binary (in byte array)?

If I have a String:

String binary = "0000"

I want the binary data to be 0000.

below is what happens when I set the binary to a byte array (which in turn returns 48, which is ASCII)

Binary String: 0000 Binary Byte array: 48 Binary Byte array: 48 Binary Byte array: 48 Binary Byte array: 48

I'm not good at explaining so hopefully the above example was enough to tell you what I want.

EDIT: This is to set the data into a binary file.

• PM 77-1: possible duplicate of Convert Java String to byte[] array
• AMDG: At least @Braj knows what Im talking about. PM 77-1 This is in no possible way a duplicate of Coverting a Java String to a byte[] array. Im aware of how to do that, Im NOT aware however, of how to put the actual input string value and set it as binary.
• Braj: OK I got it your point. Let me update it.
• PM 77-1: @LinkTheProgrammer - You seem to be confused about different represenations of a value.
• Braj: You have to mention that you want decimal value from binary.

Answer 1

Use this:

 System.out.println(Integer.toBinaryString(Integer.parseInt("000",2))); // gives 0
 System.out.println(Integer.toBinaryString(Integer.parseInt("010",2))); // gives 10
 System.out.println(Integer.toBinaryString(Integer.parseInt("100",2))); // gives 100

• AMDG: This is exactly what I was looking for! And well, probably the only place too that has this code...
• ajb: So is this any different than just stripping leading 0's off the input string, without doing any binary/decimal conversions? (Assuming the input is valid.)
• AMDG: Well not having to strip anything, this is more efficient. Plus Strings are NOT my forte.

Answer 2

Maybe you want this:

int i = Integer.valueOf(binary, 2); // ie base 2

This call expects the input to be a string of 0 and 1 chars.

Then if you want an array of bytes:

byte[] bytes = new ByteBuffer().putInt(i).compact().array();

• Alexandre Santos: This will give 4 for the input "100".
• Braj: I want the binary data to be 0000. what does it mean. The value is in decimal and OP wants to convert it into binary.
• Bohemian: @AlexandreSantos yes - I think hhat's what OP wants, but the question is a bit unclear - you could well be right that OP wants a different result.
• Bohemian: @Braj that's not how I read the question: there are only 0 chars in his example input, so we can't be sure.
• Braj: yes that's why I don't want to delete my post to make it helpful for others.

Answer 3

Convert into Decimal from Binary

System.out.println(new BigInteger("1010",2).toString()); // 10 decimal

Convert into Binary/Octal/Hex from Decimal

You can use BigInteger#toString(radix) method to get value in any radix.

System.out.println(new BigInteger("10").toString(2)); // 1010 binary
System.out.println(new BigInteger("10").toString(8)); // 12 octal
System.out.println(new BigInteger("10").toString(16)); // a hexadecimal

---

Let me explain you a bit more how it works with different base

(10)₁₀ = (1010)₂

(10)₁₀ = (12)₈

(10)₁₀ = (a)₁₆

• AMDG: ehm I already tried that, I dont want ASCII, I want the String to be the actual binary data in my file, otherwise I end up with 48 48 48 48 WHICH ISNT BINARY.
• AMDG: This is no doubt helpful, System.out.println(newBigInteger(int radix).toString(2)); however this is a String input that I want to write as text and then put into a new binary file. Not something confusing for the consumer of the software I want to make.
• Braj: have a look at updated post with base value. It's simple mathematics.
• AMDG: Yeah, but I mean the highest value you can get with a 4-bit binary value is 256. Im talking ALLLLLL binary here. Nothing really to do with decimals at all. This is binary in String form that I want to write to a binary file. And dang it is hard for me to explain :(

Answer 4

JBBP framework has in utils a special method to convert a string contains a binary defined data into byte array

 byte [] converted = JBBPUtils.str2bin("00000000");