Converts a number encoded as a String in any radix to an int in decimal representation using Java 8 based on http://stackoverflow.com/a/18552071/4240010

StringToIntConversion.java

import java.util.*;
import java.util.stream.*;
import java.util.concurrent.atomic.*;

class StringToIntConversion {
  public static void main(String[] args) {
    
    String binary = "01110";
    System.out.println(Integer.valueOf(binary, 2));
    System.out.println(toRadix(binary, 2));
     System.out.println(toRadix2(binary, 2));
    
  }
  
  public static int toRadix(String s, int radix) {
    char[] c = s.toCharArray();
    return (int) IntStream.range(0, c.length)
        .mapToDouble(i -> Character.getNumericValue(c[i])*Math.pow(radix, c.length-i-1))
        .sum();
  }
   
  public static int toRadix2(String s, int radix) {   
     AtomicInteger i = new AtomicInteger(s.length());
     return (int) s.chars()
        .mapToDouble(c -> Character.getNumericValue((char)c)*Math.pow(radix, i.decrementAndGet()))
        .sum();        
  }  
}