Multi tool use

Search with wildcard in a Collection of String

I have a HashMap<Integer,String>. I tried the following code to query the Map and return all possible values

HashMap<Integer,String>

public Collection<String> query(String queryStr) {
List<String> list = new ArrayList<String>();
for (Map.Entry<String, Integer> entry : myMap.entrySet()) {
if (queryStr.matches(entry.getKey()))
list.add(entry.getKey());
}
if (list.isEmpty())
return null;
else
return list;
}


If map has "test","best","crest","zest","testy","tether","temper","teat","tempest". A query of te*t should return "teat","tempest","test". For 'test*' it should return "test", "testy". How to implement it? Is there any wildcard search for string? And I can't use any external libraries.

"test","best","crest","zest","testy","tether","temper","teat","tempest"

te*t

"teat","tempest","test"

String

matches

Pattern

Matcher

2 Answers
2

String queryStr="te*t";

queryStr = queryStr.replaceAll("*", "\w*");

System.out.println(query(queryStr));


The Complete program

public class sample {

static List<String> values = Arrays.asList("test","best","crest","zest","testy","tether","temper","teat","tempest");

/**
* @param args
*/
public static void main(String args) {

String queryStr = "te*t";
queryStr = queryStr.replaceAll("*", "\w*");
System.out.println(queryStr);
System.out.println(query(queryStr));

}

public static Collection<String> query(String queryStr) {
List<String> list = new ArrayList<String>();
for (String str : values) {
if (str.matches(queryStr))
list.add(str);
}
if (list.isEmpty())
return null;
else
return list;
}
}


The matcher w* searches for the following chars only : [a-zA-Z_0-9]
If you would like to search for all the chars using the * matcher then you should try this:

w*

[a-zA-Z_0-9]

*

queryStr = queryStr.replaceAll("*", ".*");


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