FilterPattern.java

package io.graceland.filter;

import java.util.EnumSet;
import javax.servlet.DispatcherType;

import com.google.common.base.Preconditions;
import com.google.common.collect.ImmutableList;

/**
 * Holds the URL patterns that a filter will be associated with.
 *
 * @see io.graceland.filter.FilterSpec
 */
public class FilterPattern {
    public static final EnumSet<DispatcherType> DEFAULT_DISPATCHER_TYPES = EnumSet.allOf(DispatcherType.class);
    public static final boolean DEFAULT_MATCH_AFTER = true;

    private final EnumSet<DispatcherType> dispatcherTypes;
    private final boolean matchAfter;
    private final ImmutableList<String> urlPatterns;

    FilterPattern(EnumSet<DispatcherType> dispatcherTypes, boolean matchAfter, ImmutableList<String> urlPatterns) {
        Preconditions.checkNotNull(dispatcherTypes, "Dispatcher Types cannot be null.");
        Preconditions.checkNotNull(urlPatterns, "URL Patterns cannot be null.");

        Preconditions.checkArgument(!dispatcherTypes.isEmpty(), "Dispatcher Arguments cannot be empty");
        Preconditions.checkArgument(!urlPatterns.isEmpty(), "URL Patterns cannot be empty");

        this.dispatcherTypes = dispatcherTypes;
        this.matchAfter = matchAfter;
        this.urlPatterns = urlPatterns;
    }

    /**
     * Returns a new instance of FilterPattern, using the passed in arguments.
     */
    public static FilterPattern newInstance(
            EnumSet<DispatcherType> dispatcherTypes,
            boolean matchAfter,
            Iterable<String> patterns) {

        return new FilterPattern(dispatcherTypes, matchAfter, ImmutableList.copyOf(patterns));
    }

    /**
     * Returns a new instance of FilterPattern, using the passed in arguments.
     */
    public static FilterPattern newInstance(
            EnumSet<DispatcherType> dispatcherTypes,
            boolean matchAfter,
            String... patterns) {

        return new FilterPattern(dispatcherTypes, matchAfter, ImmutableList.copyOf(patterns));
    }

    /**
     * Returns a new intance of FitlerPattern using default values and the patterns passed in.
     * <p/>
     * The default values are {@link io.graceland.filter.FilterPattern#DEFAULT_DISPATCHER_TYPES} and
     * {@link io.graceland.filter.FilterPattern#DEFAULT_MATCH_AFTER}.
     *
     * @param patterns The URL patterns to use.
     */
    public static FilterPattern forPatterns(String... patterns) {
        return new FilterPattern(DEFAULT_DISPATCHER_TYPES, DEFAULT_MATCH_AFTER, ImmutableList.copyOf(patterns));
    }

    /**
     * Returns a new intance of FitlerPattern using default values and the patterns passed in.
     * <p/>
     * The default values are {@link io.graceland.filter.FilterPattern#DEFAULT_DISPATCHER_TYPES} and
     * {@link io.graceland.filter.FilterPattern#DEFAULT_MATCH_AFTER}.
     *
     * @param patterns The URL patterns to use.
     */
    public static FilterPattern forPatterns(Iterable<String> patterns) {
        return new FilterPattern(DEFAULT_DISPATCHER_TYPES, DEFAULT_MATCH_AFTER, ImmutableList.copyOf(patterns));
    }

    public EnumSet<DispatcherType> getDispatcherTypes() {
        return dispatcherTypes;
    }

    public boolean isMatchAfter() {
        return matchAfter;
    }

    public ImmutableList<String> getUrlPatterns() {
        return urlPatterns;
    }
}