????8.????????????????????
?????????:???Apache Commons Lang???StringUtils??????
????String str = "abcd";
????String repeated = StringUtils.repeat(str??3);//abcdabcdabcd
???????????????StringBuilder????????
String src = "name";
int len = src.length();
int repeat = 5;
StringBuilder builder = new StringBuilder(len * repeat);
for(int i=0; i<repeat; i++){
builder.append(src);
}
String dst = builder.toString();
????9.??ν?String??????????
????SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd");
????String str = "2013-11-07";
????Date date = format.parse(str);
????System.out.println(format.format(date));//2013-11-07
????10.??????????????????????
??????????Apache Commons Lang ??StringUtils??
????int n = StringUtils.countMatches("11112222"?? "1");
????System.out.println(n);