How to match a string (phrase) to a HashMap values quickly?

Question

I have a HashMap whose key is id and whose value is text:

HashMap<String,String> textMap = new HashMap<String,String>();
textMap.put("id_1","She");
textMap.put("id_2","has");
textMap.put("id_3","a"); 
textMap.put("id_4","neck");
textMap.put("id_5","pain");
//.. more elements in textMap

I would like to find the related ids given a phrase, like 'neck pain', so in this case the result should be id_4 and id_5.

Can anybody suggest an efficient algorithm to match the phrase with ids?

I'm sorry I forgot to include an important condition. I have both the phrase and the offset of word, like "start_5_end_14", which means that 5 should be the start of "neck" given that the start of "She" is 0. However, what complicates the case is that the offset might not be correct.

Answer 1

Maintain a reversed map in which you map the words to the id's. Then, traverse over your phrase and call reversedTextMap.get(word) for each word in the phrase.