RouteResult.java

/*
 * Copyright 2015 The Netty Project
 *
 * The Netty Project licenses this file to you under the Apache License,
 * version 2.0 (the "License"); you may not use this file except in compliance
 * with the License. You may obtain a copy of the License at:
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
 * License for the specific language governing permissions and limitations
 * under the License.
 */
package io.netty.handler.codec.http.router;

import io.netty.handler.codec.http.HttpMethod;
import io.netty.util.internal.ObjectUtil;

import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collection;
import java.util.Collections;
import java.util.List;
import java.util.Map;

/** Result of calling {@link Router#route(HttpMethod, String)}. */
public class RouteResult<T> {
    private final T                         target;
    private final Map<String, String>       pathParams;
    private final Map<String, List<String>> queryParams;

    /** The maps will be wrapped in Collections.unmodifiableMap. */
    public RouteResult(T target, Map<String, String> pathParams, Map<String, List<String>> queryParams) {
        this.target      = ObjectUtil.checkNotNull(target,      "target");
        this.pathParams  = Collections.unmodifiableMap(ObjectUtil.checkNotNull(pathParams,  "pathParams"));
        this.queryParams = Collections.unmodifiableMap(ObjectUtil.checkNotNull(queryParams, "queryParams"));
    }

    public T target() {
        return target;
    }

    /** Returns all params embedded in the request path. */
    public Map<String, String> pathParams() {
        return pathParams;
    }

    /** Returns all params in the query part of the request URI. */
    public Map<String, List<String>> queryParams() {
        return queryParams;
    }

    //----------------------------------------------------------------------------
    // Utilities to get params.

    /**
     * Extracts the first matching param in {@code queryParams}.
     *
     * @return {@code null} if there's no match
     */
    public String queryParam(String name) {
        List<String> values = queryParams.get(name);
        return (values == null)? null : values.get(0);
    }

    /**
     * Extracts the param in {@code pathParams} first, then falls back to the first matching
     * param in {@code queryParams}.
     *
     * @return {@code null} if there's no match
     */
    public String param(String name) {
        String pathValue = pathParams.get(name);
        return (pathValue == null)? queryParam(name) : pathValue;
    }

    /**
     * Extracts all params in {@code pathParams} and {@code queryParams} matching the name.
     *
     * @return Unmodifiable list; the list is empty if there's no match
     */
    public List<String> params(String name) {
        List<String> values = queryParams.get(name);
        String       value  = pathParams.get(name);

        if (values == null) {
            return (value == null)? Collections.<String>emptyList() : Arrays.asList(value);
        }

        if (value == null) {
            return Collections.unmodifiableList(values);
        } else {
            List<String> aggregated = new ArrayList(values.size() + 1);
            aggregated.addAll(values);
            aggregated.add(value);
            return Collections.unmodifiableList(aggregated);
        }
    }
}