Update BinaryToHexadecimal.java

yanglbme · web-flow · commit d082862fb461 · 2019-01-30T17:05:40.000+08:00
diff --git a/src/main/java/com/conversions/BinaryToHexadecimal.java b/src/main/java/com/conversions/BinaryToHexadecimal.java
@@ -2,43 +2,51 @@
 
 import java.math.BigInteger;
 import java.util.HashMap;
+import java.util.Map;
+
 
 public class BinaryToHexadecimal {
 
+    /**
+     * hm to store hexadecimal codes for binary numbers
+     * within the range: 0000 to 1111 i.e. for decimal numbers 0 to 15
+     */
+   private static Map<Integer, String> hmHexadecimal = new HashMap<>(16);
+
+    static {
+        int i;
+        for (i = 0; i < 10; i++)
+            hmHexadecimal.put(i, String.valueOf(i));
+
+        for (i = 10; i < 16; i++)
+            hmHexadecimal.put(i, String.valueOf((char) ('A' + i - 10)));
+    }
+
     /**
      * This method converts a binary number to
      * a hexadecimal number.
      *
-     * @param binary The binary number
+     * @param binStr The binary number
      * @return The hexadecimal number
      */
 
-    public String binToHex(BigInteger binary) {
-        //hm to store hexadecimal codes for binary numbers within the range: 0000 to 1111 i.e. for decimal numbers 0 to 15
-        HashMap<Integer,String> hmHexadecimal = new HashMap<>();
+    public String binToHex(String binStr) {
+        BigInteger binary = new BigInteger(binStr);
+        // String to store hexadecimal code
+        String hex = "";
 
-        //String to store hexadecimal code
-        String hex="";
-        int i;
-        for(i=0 ; i<10 ; i++)
-            hmHexadecimal.put(i, String.valueOf(i));
-
-        for(i=10 ; i<16 ; i++)
-            hmHexadecimal.put(i,String.valueOf((char)('A'+i-10)));
-
-        int currentbit;
+        int currentBit;
         BigInteger tenValue = new BigInteger("10");
-        while(binary.compareTo(BigInteger.ZERO) != 0) {
-            int code4 = 0;	//to store decimal equivalent of number formed by 4 decimal digits
-            for(i=0 ; i<4 ; i++)
-            {
-                currentbit = binary.mod(tenValue).intValueExact();
+        while (binary.compareTo(BigInteger.ZERO) != 0) {
+            // to store decimal equivalent of number formed by 4 decimal digits
+            int code4 = 0;
+            for (int i = 0; i < 4; i++) {
+                currentBit = binary.mod(tenValue).intValueExact();
                 binary = binary.divide(tenValue);
-                code4 += currentbit*Math.pow(2, i);
+                code4 += currentBit * Math.pow(2, i);
             }
-            hex= hmHexadecimal.get(code4) + hex;
+            hex = hmHexadecimal.get(code4) + hex;
         }
         return hex;
-
     }
-}
+}
