Creating wildcard filters

The WildcardFilter class specifies a wildcard as an inclusion or exclusion filter.

A WildcardFilter is a filter that applies a wildcard to a particular property. The wildcard matcher uses the question-mark (?) character to represent a single wildcard character and the asterisk (*) to represent multiple wildcard characters. Matching is case insensitive: this is not configurable (If case sensitivity is required, consider using a regular expression). In the example below, the filter applies to the Endeca.FileSystem.Name property.

To create a wildcard filter:

Make sure that you have created a SourceConfig and a CrawlConfig.

Instantiate a new, empty WildcardFilter object:

WildcardFilter filter = new WildcardFilter();

Call the setPropertyName() method (inherited from the Filter class) to set the name of the property against which the filter is applied:
```
// filter on the file name
filter.setPropertyName("Endeca.FileSystem.Name");
```

Use the setWildcard() method to set the wildcard:

// exclude Word files
filter.setWildcard("*.doc");

Use the setScope() method (inherited from the Filter class) to set the filter scope. You can set the scope to files (as in the following example), or to folders (FilterScope.DIRECTORY).
```
// set the scope of the filter for only files
filter.setScope(FilterScope.FILE);
```
Create a list of Filter objects and use the add() method (inherited from the List interface) to add the wildcard filter.
```
List<Filter> filterList = new ArrayList<Filter>();  
filterList.add(filter);
```
Use the SourceConfig.setExcludeFilters() method to set the populated list in the SourceConfig configuration object. If this were an inclusion filter, you would use the SourceConfig.setIncludeFilters() method instead.
```
// Set the filter in the source configuration.
sourceConfig.setExcludeFilters(filterList);
```
Use the CrawlConfig.setSourceConfig() method to set the populated SourceConfig in the main CrawlConfig configuration object.
```
// Set the source config in the crawl configuration.
crawlConfig.setSourceConfig(sourceConfig);
```

Note that the WildcardFilter class has a getWildcard() method to retrieve a wildcard value. In addition, the SourceConfig class has the getExcludeFilters() and getIncludeFilters() methods to retrieve the filters from the source configuration.