Searching for all files with certain extension in Java API and some issues with search queries

Hello!

I'm building a small function in which i want to get metadata from for example all of PDF's and DOC files. So I am using a SearchV2Builder withFileExtension option. But i don't know hot write a query for any string. I tried with regexes, wildcards characters and nothing works.

```

private final String extensions[] = {"pdf","docx","doc","odt","jpg"};

public void findFile(String query){
try{

SearchV2Builder searchBuilder = client.files().searchV2Builder(query);

 List<String> fileExtensions = Arrays.asList(extensions);
 SearchOptions searchOptions = SearchOptions.newBuilder().withFileExtensions(fileExtensions).build();

 SearchV2Result searchResult = searchBuilder.withOptions(searchOptions).start();
 List<SearchMatchV2> searchMatches = searchResult.getMatches();

 System.out.println(searchMatches.size());
 for (SearchMatchV2 s: searchMatches){
System.out.println(s.getMetadata().getMetadataValue().getPathDisplay());
 }

}
catch(DbxException e){
e.printStackTrace();
 }

}

```

So my question is how to write that query? Maybe there is different solution for that. Thanks in advance!