将Map＜String, String[]＞转换成String[]

public static String[] mapToStrings(Map<String, String[]> mapList) {
	String[] res = new String[0];
	for (String[] s : mapList.values()) {
		int a = res.length;
	    int b = s.length;
		res= Arrays.copyOf(res,a + b);//扩容
		System.arraycopy(s, 0, res, a,b);//将第二个数组与第一个数组合并
	}
	return res;
}