下划线分隔的字符串，转换为驼峰式字符串

方法一：

public static void main(String[] args) {
		 String aa="part_vote_num";
		
		 Pattern p = Pattern.compile("_[a-z]");
		 Matcher m = p.matcher(aa);
		 StringBuffer sb = new StringBuffer();
		 while (m.find()) {
			 String firstChar =  m.group().substring(1,2);
		     m.appendReplacement(sb, firstChar.toUpperCase());
		 }
		 m.appendTail(sb);
		 System.out.println(sb.toString());
	}

方法二：

public static void main(String[] args) {
		String aa="part_vote_num";
		StringBuilder sb = new StringBuilder();
		
		boolean low = true;
		for(int i=0; i

方法三：

public static void main(String[] args) {
		String aa="part_vote_num";
		
		StringBuilder sb = new StringBuilder();
		String[] arr = aa.split("_");
		sb.append(arr[0]);
		for(int i=1; i