如何使用Groovy检索某些文件元素并将元素存储为arraylist

Question

I'm new to groovy programming and I am trying to use groovy to retrieve phone numbers that are randomly present in a text file and then store these values in an arraylist in my groovy program. An example of what the text file looks like is this:

Line of code Hello how are you 111-111-1111 Cat dog dog cat 999-999-9999 Another line of code 777-777-7777

The output I'm trying to display: 111-111-1111 999-999-9999 777-777-7777

I know how to reference the file and retrieve all lines of code and specific numbers/words/etc., but I am unsure of the groovy way to retrieve just the phone numbers present in the text file

Answer 1

The easiest way to add an element to a list is += operator.

Below you have an example program, which extracts phone numbers from each source row of a multiline string, collects them in a list, and prints the list.

def src = '''\
Line of code Hello how are you 111-111-1111 Cat dog dog cat 999-999-9999.
I'm fine and how are you 111-111-2222 Cat dog dog cat 999-999-8888.
No phone number here.
Another line of code  777-777-8888\
'''
def pat = ~/\b\d{3}-\d{3}-\d{4}\b/
def phones = []
def cnt = 0
src.eachLine{
  def matcher = (it =~ pat)
  def mCnt = matcher.getCount()
  printf("Row %d: %s / %d phones.\n", ++cnt, it, mCnt)
  for (i = 0; i < mCnt; ++i) {
    phones += matcher[i]
  }
}
printf("%d phones: %s.\n", phones.size(), phones.join(', '))