I have a large binary string "101101110...", and I am trying to store it into a byte array. what is the best way of doing it?
Lets say I have largeString = "0100111010111011011000000001000110101"
Result that I'm looking for:
[78, 187, 96, 17, 21]
01001110 10111011 01100000 00010001 10101
What i've tried:
byte[] b= new BigInteger(largeString,2).toByteArray();
however it did not give me the result I'm looking for...
You can easily build an ArrayList on which you can call toArray if you want an actual array;
List<Integer> list = new ArrayList<>();
for(String str : largeString.split("(?<=\\G.{8})"))
list.add(Integer.parseInt(str, 2));
System.out.println(list); // Outputs [78, 187, 96, 17, 21]
Assuming that your binary string module 8 equals 0 binString.lenght()%8==0
/**
* Get an byte array by binary string
* @param binaryString the string representing a byte
* @return an byte array
*/
public static byte[] getByteByString(String binaryString) {
int splitSize = 8;
if(binaryString.length() % splitSize == 0){
int index = 0;
int position = 0;
byte[] resultByteArray = new byte[binaryString.length()/splitSize];
StringBuilder text = new StringBuilder(binaryString);
while (index < text.length()) {
String binaryStringChunk = text.substring(index, Math.min(index + splitSize, text.length()));
Integer byteAsInt = Integer.parseInt(binaryStringChunk, 2);
resultByteArray[position] = byteAsInt.byteValue();
index += splitSize;
position ++;
}
return resultByteArray;
}
else{
System.out.println("Cannot convert binary string to byte[], because of the input length. '" +binaryString+"' % 8 != 0");
return null;
}
}
Do it in a loop. Split the string at 8-character chunks and convert them separately. In "pseudocode" it's something like:
byte[] result = new byte[subs.size()];
int i = 0;
int j = 0;
while(i+8 <= s.length){
result[j] = new Byte.valueOf(largeString.substring(i, i+8), 2);
i+=8;
j++;
}
result[j] = new Byte.valueOf(largeString.substring(i, largeString.length));
