Customized Wicket ResourceStreamLocator

TraversalResourceStreamLocator.java

import java.util.Arrays;
import java.util.List;
import java.util.ListIterator;

import org.apache.wicket.util.resource.IResourceStream;
import org.apache.wicket.util.resource.locator.ResourceStreamLocator;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

public class TraversalResourceStreamLocator extends ResourceStreamLocator {

    private static final Logger logger = LoggerFactory.getLogger(TraversalResourceStreamLocator.class);

    private final int maxDepth;

    private TraversalResourceStreamLocator(int maxDepth) {
        this.maxDepth = maxDepth;
    }
    
    public static TraversalResourceStreamLocator newInstance() {
        return new TraversalResourceStreamLocator(0);
    }
    
    public static TraversalResourceStreamLocator newInstance(int maxDepth) {
        return new TraversalResourceStreamLocator(maxDepth);
    }

    /*
     * (non-Javadoc)
     * @see org.apache.wicket.util.resource.locator.ResourceStreamLocator#locate(java.lang.Class, java.lang.String)
     */
    @Override
    public IResourceStream locate(Class<?> clazz, String path) {
        String resolvedPath = resolvePath(clazz, path);
        logger.debug("searching {}.", resolvedPath);
        IResourceStream located = super.locate(clazz, resolvedPath);
        if (located != null) {
            return located;
        }
        return super.locate(clazz, path);
    }

    String resolvePath(final Class<?> clazz, final String path) {
        List<String> clippedPackageNameList = 
            Arrays.asList(clazz.getPackage().getName().split("\\."));
        int depth = clippedPackageNameList.size() >= maxDepth ? clippedPackageNameList.size() - maxDepth: 0;
        StringBuilder sb = new StringBuilder();
        for (ListIterator<String> itor = clippedPackageNameList.listIterator(depth); itor.hasNext();) {
            sb.append(String.valueOf(itor.next()));
            sb.append('/');
        }
        int start = path.indexOf(sb.toString());
        if (start == -1) {
            return path;
        }
        return path.substring(start);
    }
}