在java中使用索引匹配字符串

I have two list of string. the first is a list of names (6MB) and the second is a list of sentences (around three millions sentences). I want to look for each name through the sentences. It takes days. I am using pattern matching and also check for regular expression, since the sentences and names are generated by users and uncertain. how can I do it faster?I have two list of string. the first is a list