### Question:
PPUserFansUpdateRun implements Runnable { public static String strArrToStr(String[] arr) { StringBuffer result = new StringBuffer(); for (String str : arr) { result.append(str).append(","); } return result.substring(0, result.length() - 1); } PPUserFansUpdateRun(WeiboJDBC weiboJDBC, String uid, SinaUserInfoDao sinaUserInfoDao); @Override void run(); static String strArrToStr(String[] arr); static SinaUserInfo userTrans(User user); static final String PP_SINA_FANS_DAILY; }### Answer:
@Test public void testStrArrToStr() { String[] arr = { "aaa", "bbb", "ccc" }; System.out.println(PPUserFansUpdateRun.strArrToStr(arr)); }