public static void main(String[] args) {
	String aa = "qwzhongqianQwhahaQWhahaqwhahQW";
	String bb = "a   aa    aaaa      bbbb       ccccc                  ddd        ";
	System.out.println(aa.replaceAll("( i)qw", "&"));
	String[] strArray = bb.split("\\s++");
	for (String s: strArray) {
		System.out.println(s);
	}

运行结果：