solved problem on number conversion

Difficult03/NumberConverter.java

@@ -0,0 +1,100 @@
+
+import java.util.Scanner;
+
+
+public class NumberConverter {
+
+	private String binaryString;
+	private Scanner kbd;
+public NumberConverter() {
+	kbd = new Scanner(System.in);
+
+//obtain binary string
+System.out.println("Enter a binary number (only 1's and 0's)");
+binaryString = kbd.next().trim();
+boolean booleanIsValid = booleanValidate(binaryString);
+
+if(booleanIsValid) {
+//if the number input is a valid boolean stream, get decimal and hexadecimal correspondents and display
+System.out.println(String.format("Decimal Value: %d", convertToDecimal(binaryString)));
+System.out.println(String.format("Hexadecimal Value: %s", convertToHex(binaryString)));
+}
+else {
+System.out.println("You input an invalid binary stream.\n(binary numbers do not contain digits greater than 1\nand contain no minus signs or other mathematical symbols");
+}
+
+}
+
+private boolean booleanValidate(String binaryString) {
+for(int i= binaryString.length(); i>0; i--) {
+
+	String character = binaryString.substring(i-1, i);
+	if(!character.matches("\\d")) {
+		return false;
+	}
+	if(Integer.parseInt(character) > 1 ) {
+		return false;
+	}
+}
+return true;
+}
+
+private int convertToDecimal(String binary) {
+int tmpvalue;
+int result =0;
+int numberOfDigits = binary.length();
+for(int i= numberOfDigits; i>0; i--) {
+tmpvalue = Integer.parseInt(binary.substring(i-1,i));
+result += tmpvalue*(int)Math.pow(2, numberOfDigits-i);
+}
+return result;
+}
+
+private String convertToHex(String binary) {
+String result ="";
+String tmpvalue="";
+int tempCount=0;
+int tempresult;
+
+int numberOfDigits = binary.length();
+for(int i= numberOfDigits; i>0; i--) {
+tmpvalue = binary.substring(i-1, i).concat(tmpvalue);
+tempCount++;
+if (tempCount == 4 || i==1 ) {
+tempresult = convertToDecimal(tmpvalue);
+switch(tempresult) {
+case 10:
+result = "A".concat(result);
+break;
+case 11:
+result = "B".concat(result);
+break;
+case 12:
+result = "C".concat(result);
+break;
+case 13:
+result = "D".concat(result);
+break;
+case 14:
+result = "E".concat(result);
+break;
+case 15:
+result = "F".concat(result);
+break;
+default:
+result = Integer.toString(tempresult).concat(result);
+}
+tmpvalue = "";
+tempCount = 0;
+}
+}
+return result;
+}
+
+
+public static void main(String[] args) {
+
+	NumberConverter nc = new NumberConverter();
+
+}
+}