获取汉字串拼音首字母，英文字符不变

package com.sprucetec.tms.utils;

import net.sourceforge.pinyin4j.PinyinHelper;
import net.sourceforge.pinyin4j.format.HanyuPinyinCaseType;
import net.sourceforge.pinyin4j.format.HanyuPinyinOutputFormat;
import net.sourceforge.pinyin4j.format.HanyuPinyinToneType;
import net.sourceforge.pinyin4j.format.exception.BadHanyuPinyinOutputFormatCombination;
import org.apache.commons.lang.StringUtils;

/**
 * 描述: 拼音工具类
 *
 * @author yangweiqiang
 * @date 2016/8/9
 */
public class PinYinUtils {

    /**
     * 获取汉字串拼音首字母，英文字符不变
     *
     * @param chinese  汉字串
     * @param caseType 大写 or 小写
     * @return 汉语拼音首字母
     */
    public static String getFirstSpell(String chinese, HanyuPinyinCaseType caseType) {
        if (StringUtils.isBlank(chinese)) {
            return null;
        }

        StringBuffer sb = new StringBuffer();
        char[] arr = chinese.toCharArray();

        HanyuPinyinOutputFormat defaultFormat = new HanyuPinyinOutputFormat();
        defaultFormat.setCaseType(caseType);
        defaultFormat.setToneType(HanyuPinyinToneType.WITHOUT_TONE);

        for (int i = 0; i < arr.length; i++) {
            if (arr[i] > 128) {
                try {
                    String[] temp = PinyinHelper.toHanyuPinyinStringArray(arr[i], defaultFormat);
                    if (temp != null) {
                        sb.append(temp[0].charAt(0));
                    }
                } catch (BadHanyuPinyinOutputFormatCombination e) {
                    e.printStackTrace();
                }
            } else {
                sb.append(arr[i]);
            }
        }
        return sb.toString().replaceAll("\W", "").trim();
    }

}