Java BigInteger from Stream readLuposBigInteger(final int numberOfBits, final InputStream is)

Description

readLuposBigInteger.

License

Open Source License

Parameter

Parameter	Description
numberOfBits	a int.
is	a java.io.InputStream object.

Exception

Parameter	Description

Return

a object.

Declaration

public final static BigInteger readLuposBigInteger(final int numberOfBits, final InputStream is)
        throws IOException 

Method Source Code

//package com.java2s;

import java.io.IOException;
import java.io.InputStream;

import java.math.BigInteger;

public class Main {
    /**//from  w  w  w  .j a  va2 s .c om
     * <p>readLuposBigInteger.</p>
     *
     * @param numberOfBits a int.
     * @param is a {@link java.io.InputStream} object.
     * @return a {@link java.math.BigInteger} object.
     * @throws java.io.IOException if any.
     */
    public final static BigInteger readLuposBigInteger(final int numberOfBits, final InputStream is)
            throws IOException {
        BigInteger result = BigInteger.ZERO;
        BigInteger factor = BigInteger.ONE;
        final BigInteger BYTE = BigInteger.valueOf(256);
        int remainingBits = numberOfBits;
        while (remainingBits > 0) {
            final int currentValueByte = is.read();
            if (currentValueByte < 0) {
                // EOF reached!
                return null;
            }
            final BigInteger currentValue = BigInteger.valueOf(currentValueByte);
            result = result.add(currentValue.multiply(factor));
            factor = factor.multiply(BYTE);
            remainingBits -= 8;
        }
        return result;
    }
}

Related

1. readBigInteger(ByteArrayInputStream bais)
2. readBigInteger(DataInputStream dis)
3. readBigInteger(InputStream input)
4. readBigInteger(int n, DataInput dis)
5. readLineAsBigInteger(BufferedReader br)