com.linecorp.armeria.server.PathMappingResult.java Source code

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Here is the source code for com.linecorp.armeria.server.PathMappingResult.java

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/*
 * Copyright 2017 LINE Corporation
 *
 * LINE Corporation 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 com.linecorp.armeria.server;

import static java.util.Objects.requireNonNull;

import java.util.Map;

import javax.annotation.Nullable;

import com.google.common.base.MoreObjects;
import com.google.common.collect.ImmutableMap;

/**
 * The result returned by {@link PathMapping#apply(String, String)}.
 */
public final class PathMappingResult {

    private static final PathMappingResult EMPTY = new PathMappingResult(null, null, null);

    /**
     * The {@link PathMappingResult} whose {@link #isPresent()} returns {@code false}. It is returned by
     * {@link PathMapping#apply(String, String)} when the specified path did not match.
     */
    public static PathMappingResult empty() {
        return EMPTY;
    }

    /**
     * Creates a new instance with the specified {@code path} and {@code query}, without any path parameters.
     */
    public static PathMappingResult of(String path, @Nullable String query) {
        return of(path, query, ImmutableMap.of());
    }

    /**
     * Creates a new instance with the specified {@code path}, {@code query} and the extracted path parameters.
     */
    public static PathMappingResult of(String path, @Nullable String query, Map<String, String> pathParams) {
        requireNonNull(path, "path");
        requireNonNull(pathParams, "pathParams");
        return new PathMappingResult(path, query, pathParams);
    }

    private final String path;
    private final String query;
    private final Map<String, String> pathParams;

    private PathMappingResult(@Nullable String path, @Nullable String query,
            @Nullable Map<String, String> pathParams) {
        assert path == null && query == null && pathParams == null || path != null && pathParams != null;

        this.path = path;
        this.query = query;
        this.pathParams = pathParams != null ? ImmutableMap.copyOf(pathParams) : null;
    }

    /**
     * Returns {@code true} if this result is not {@link #empty()}.
     */
    public boolean isPresent() {
        return path != null;
    }

    /**
     * Returns the path mapped by the {@link PathMapping}.
     *
     * @throws IllegalStateException if there's no match
     */
    public String path() {
        ensurePresence();
        return path;
    }

    /**
     * Returns the query mapped by the {@link PathMapping}.
     *
     * @return the query string. {@code null} If there is no query part.
     * @throws IllegalStateException if there's no match
     */
    @Nullable
    public String query() {
        ensurePresence();
        return query;
    }

    /**
     * Returns the path parameters extracted by the {@link PathMapping}.
     *
     * @throws IllegalStateException if there's no match
     */
    public Map<String, String> pathParams() {
        ensurePresence();
        return pathParams;
    }

    private void ensurePresence() {
        if (!isPresent()) {
            throw new IllegalStateException("mapping unavailable");
        }
    }

    @Override
    public String toString() {
        if (isPresent()) {
            return MoreObjects.toStringHelper(this).add("path", path).add("query", query)
                    .add("pathParams", pathParams).toString();
        } else {
            return getClass().getSimpleName() + "{<empty>}";
        }
    }
}