java 判断字符串A包含多少个指定字符串

 我有一个我正在使用的程序，它使用String.format(...)和格式字符串： 
 
// in the constants section
private static final String DISPLAY_FORMAT_STR = "%02d:%02d:%02d:%01d";   


private void showTimeLeft() {
  int oldMin = min;
  hours = (int) (deltaTime / (MS_PER_SEC * SEC_PER_MIN * MIN_PER_HR));
  min = (int) (deltaTime / (MS_PER_SEC * SEC_PER_MIN) % MIN_PER_HR);
  sec = (int) (deltaTime / (MS_PER_SEC) % SEC_PER_MIN);
  msec = (int) (deltaTime % MS_PER_SEC);

  String displayString = String.format(DISPLAY_FORMAT_STR, hours, min, sec,
        msec / 100);
  displayField.setText(displayString);

  // ... etc...
 
 否则，如果您正在处理Date对象（我不是），您可以使用SimpleDateFormat对象来更好地格式化输出。 

I've got a program that I'm working on now that uses String.format(...) and a format String for this:
 
// in the constants section
private static final String DISPLAY_FORMAT_STR = "%02d:%02d:%02d:%01d";   


private void showTimeLeft() {
  int oldMin = min;
  hours = (int) (deltaTime / (MS_PER_SEC * SEC_PER_MIN * MIN_PER_HR));
  min = (int) (deltaTime / (MS_PER_SEC * SEC_PER_MIN) % MIN_PER_HR);
  sec = (int) (deltaTime / (MS_PER_SEC) % SEC_PER_MIN);
  msec = (int) (deltaTime % MS_PER_SEC);

  String displayString = String.format(DISPLAY_FORMAT_STR, hours, min, sec,
        msec / 100);
  displayField.setText(displayString);

  // ... etc...
 
Otherwise if you're dealing with a Date object (I'm not), you could use a SimpleDateFormat object to better format your output.