Лучшее решение - использовать действительно сложные алгоритмы поиска и индексации строк. Если вы не заботитесь о производительности, то что-то вроде этого довольно легко реализовать:
import java.util.*;
public class SearchAndContext {
public static void main(String[] args) {
String text = "The path of the righteous man is beset on all sides by "
+ "the iniquities of the selfish and the tyranny of evil men. Blessed "
+ "is he, who in the name of charity and good will, shepherds the "
+ "weak through the valley of darkness, for he is truly his brother's "
+ "keeper and the finder of lost children. And I will strike down "
+ "upon thee with great vengeance and furious anger those who would "
+ "attempt to poison and destroy my brothers. And you will know my "
+ "name is the Lord when I lay my vengeance upon thee.";
List<String> words = Arrays.asList(text.split(" "));
final int W = 3;
final int N = words.size();
String[] queries = { "vengeance", "and", "monkeys" };
for (String query : queries) {
List<String> search = words;
System.out.println("Searching for " + query);
for (int idx = -1, pos; (pos = search.indexOf(query)) != -1; ) {
idx += (pos+1);
int left = Math.max(0, idx - W);
int right = Math.min(N, idx + W + 1);
System.out.println(words.subList(left, right));
search = search.subList(pos+1, search.size());
}
}
}
}
Это печатает:
Searching for vengeance
[thee, with, great, vengeance, and, furious, anger]
[I, lay, my, vengeance, upon, thee.]
Searching for and
[of, the, selfish, and, the, tyranny, of]
[name, of, charity, and, good, will,, shepherds]
[his, brother's, keeper, and, the, finder, of]
[with, great, vengeance, and, furious, anger, those]
[attempt, to, poison, and, destroy, my, brothers.]
Searching for monkeys
Как вы можете видеть, это находит вхождения поискового запроса, а также обеспечивает контекст до W=3 слов вокруг "удара".
API ссылки