Convert Hex to Decimal by IEEE Standards

Utils.java

import android.util.Log;

import com.android.sustlabs.pojo.BinaryObj;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Set;

/**
 * Created by maheshgiri on 02/09/17.
 */

public class Utils {

    private static HashMap<String, BinaryObj> stringBinaryObjHashMap = new LinkedHashMap<>();
    private static List<Integer> resultBinaryList = new ArrayList<>();


    public static void initBinaryMapping() {
        stringBinaryObjHashMap.put("0", new BinaryObj(0, 0, 0, 0));
        stringBinaryObjHashMap.put("1", new BinaryObj(0, 0, 0, 1));
        stringBinaryObjHashMap.put("2", new BinaryObj(0, 0, 1, 0));
        stringBinaryObjHashMap.put("3", new BinaryObj(0, 0, 1, 1));
        stringBinaryObjHashMap.put("4", new BinaryObj(0, 1, 0, 0));
        stringBinaryObjHashMap.put("5", new BinaryObj(0, 1, 0, 1));
        stringBinaryObjHashMap.put("6", new BinaryObj(0, 1, 1, 0));
        stringBinaryObjHashMap.put("7", new BinaryObj(0, 1, 1, 1));
        stringBinaryObjHashMap.put("8", new BinaryObj(1, 0, 0, 0));
        stringBinaryObjHashMap.put("9", new BinaryObj(1, 0, 0, 1));
        stringBinaryObjHashMap.put("A", new BinaryObj(1, 0, 1, 0));
        stringBinaryObjHashMap.put("B", new BinaryObj(1, 0, 1, 1));
        stringBinaryObjHashMap.put("C", new BinaryObj(1, 1, 0, 0));
        stringBinaryObjHashMap.put("D", new BinaryObj(1, 1, 0, 1));
        stringBinaryObjHashMap.put("E", new BinaryObj(1, 1, 1, 0));
        stringBinaryObjHashMap.put("F", new BinaryObj(1, 1, 1, 1));
    }


    public static double convert(String hexvalue) throws Exception{
        resultBinaryList=new ArrayList<>();
        for (int i = 0; i < hexvalue.length(); i++) {
            Character hexval=hexvalue.charAt(i);

            if(hexval.compareTo('4')>0){
                //Log.d("UTILS", "convert: ");
            }

            for (String keyvalue : stringBinaryObjHashMap.keySet()) {
                if (hexval.compareTo(keyvalue.charAt(0))==0) {
                    Log.d("UTILS", "convert: ");

                    resultBinaryList.add(stringBinaryObjHashMap.get(keyvalue).getB1());
                    resultBinaryList.add(stringBinaryObjHashMap.get(keyvalue).getB2());
                    resultBinaryList.add(stringBinaryObjHashMap.get(keyvalue).getB3());
                    resultBinaryList.add(stringBinaryObjHashMap.get(keyvalue).getB4());
                }


            }

        }
        double exponent =0;
        double dec_bin=0;

        for (int i = 1; i < 9; i++) {

            dec_bin= (resultBinaryList.get(i)*(Math.pow(2,8-i)));
            //console.log(i, dec_bin);
            exponent=exponent+dec_bin;

        }

        exponent=exponent-127;

        double mantissa=0;

        for (int i = 9; i < 32; i++) {

            dec_bin= (resultBinaryList.get(i)*(Math.pow(2,8-i)));
            //console.log(i, dec_bin);
            mantissa=mantissa+dec_bin;

        }

        double finalvalue= ((1+mantissa)*Math.pow(2,exponent));

        if (resultBinaryList.get(0)==1){
            finalvalue=-1*finalvalue;
        }

        return  finalvalue;

    }
}