How to search string with all possible combination in java?

问题

How to implement string matching with all possible combination of given key in Java just like Android studio. does? Any regex pattern available.

回答1:

You do not need a regex for this, because a greedy algorithm will do.

You can match a string against a pattern in O(n+p), where n is the length of string and p is the length of pattern, by following a very simple strategy: for each character of the pattern, look for a matching character in the string starting at the current index. If you find a match, advance the index past it, and look for the next character from the pattern. If the pattern gets exhausted before end of string, you have a match; otherwise, you do not have a match.

public static boolean match(String s, String p) {
    String us = s.toUpperCase();
    int i = 0;
    for (char c : p.toUpperCase().toCharArray()) {
        int next = us.indexOf(c, i);
        if (next < 0) {
            return false;
        }
        i = next+1;
    }
    return true;
}

Demo.

回答2:

You can use java.util.regex.Matcher.

So for example ...

String key = "asdf"; // the String or regex you are looking to find
String data = "asdfskdljfd"; // the String you are searching through

Pattern pattern = Pattern.compile(key);

Matcher m = pattern.matcher(data);
while (m.find()) {
    String s = m.group(1);
    // s = "asdf"
}

来源：https://stackoverflow.com/questions/34554246/how-to-search-string-with-all-possible-combination-in-java

标签

java

regex

string

string-matching