字符连续出现次数

package com.a.b;

public class StringAnalysis {
	public static void main(String[] args) {
		//功能、边界、特殊值测试
		String string = "  aaacc   c  ";// "   ";//null;//"aabbcccd";
		System.out.println(transfer(string));
	}

	private static String transfer(String source) {
		if (null == source || source.equals("")) {
			System.out.println("transfer source is null");
			return null;
		}
		StringBuilder sb = new StringBuilder();
		int length = source.length();
		int count = 1;
		int i = 0;
		for (; i < length - 1; i++) {
			if (source.charAt(i) == source.charAt(i + 1)) {
				count++;
			} else {
				sb.append(source.charAt(i)).append(count);
				count = 1;
			}
		}
		if (source.charAt(i) != source.charAt(i - 1)) {
			count = 1;
		}
		sb.append(source.charAt(i)).append(count);
		return sb.toString();
	}
}