Java进制转换

递归实现的进制转换

	//二转十
	public static int twoToTen(String a,int inx){
		if(a.length()==0){
			return 0;
		}
		int temp = Integer.parseInt(""+a.charAt(a.length()-1))*2;
		int res = 1;
		if(temp==0){
			res = 0;
		}else{
			for(int i=0;i<inx;i++){
				res =res * temp;
			}
		}
		return res+twoToTen(a.substring(0,a.length()-1),inx+1);
	}
	//二转八
	public static String twoToEight(String a){
		int len = a.length();
		if(len==0){
			return "";
		}
		String temp = a;
		String nextStr = "";
		if(len>3){
			temp = a.substring(len-3,len); 
			nextStr = a.substring(0,len-3);
		}
		String res = twoToTen(temp,0)+"";
		return twoToEight(nextStr)+res;
	}
	//二转十六
	public static String twoToSixteen(String a){
		int len = a.length();
		if(len==0){
			return "";
		}
		String temp = a;
		String nextStr = "";
		if(len>4){
			temp = a.substring(len-4,len); 
			nextStr = a.substring(0,len-4);
		}
		String res = twoToTen(temp,0)+"";
		int intres = Integer.parseInt(res);
		if(intres>9){
			res = (char)(intres + 55)+"";
		}
		return twoToSixteen(nextStr)+res;
	}
	//十转二
	public static String tenToTwo(int a){
		int y = a%2;
		int s = a/2;
		if(s<2){
			return s+""+y;
		}
		return tenToTwo(s)+y;
	}