transformer un string en biginteger java

1 
2package org.arpit.java2blog;
3 
4import java.math.BigInteger;
5 
6public class StringToBigIntegerMain {
7 
8	public static void main(String[] args) {
9 
10		String str="45";
11		BigInteger bigIntegerStr=new BigInteger(str);
12		System.out.println("Converted String to BigInteger: "+bigIntegerStr);
13	}
14}
15 
16

1String foo = "some text";
2byte[] fooBytes = foo.getBytes();
3BigInteger bi = new BigInteger(fooBytes);

1package com.mkyong;
2
3import java.math.BigInteger;
4
5public class JavaExample {
6
7    public static void main(String[] args) {
8
9        int n = 100;
10        System.out.println(n);
11
12        // convert int to Integer
13        Integer integer = Integer.valueOf(n);
14        System.out.println(integer);
15
16        // convert int to BigInteger
17        BigInteger bigInteger = BigInteger.valueOf(n);
18        System.out.println(bigInteger);
19
20        // convert Integer to BigInteger
21        //BigInteger bigInteger2 = BigInteger.valueOf(integer); // works
22        BigInteger bigInteger2 = BigInteger.valueOf(integer.intValue());
23        System.out.println(bigInteger2);
24
25    }
26
27}

1foo = new String(bi.toByteArray());

1public BigInteger toBigInteger(String foo)
2{
3    return new BigInteger(foo.getBytes());
4}
5
6public String fromBigInteger(BigInteger bar)
7{
8    return new String(bar.toByteArray());
9}