com.google.api.tools.framework.aspects.http.MethodMatcher.java Source code

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Here is the source code for com.google.api.tools.framework.aspects.http.MethodMatcher.java

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/*
 * Copyright (C) 2016 Google, Inc.
 *
 * Licensed 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.google.api.tools.framework.aspects.http;

import com.google.api.tools.framework.aspects.http.RestPatterns.MethodPattern;
import com.google.api.tools.framework.aspects.http.RestPatterns.SegmentPattern;
import com.google.api.tools.framework.aspects.http.model.HttpAttribute;
import com.google.api.tools.framework.aspects.http.model.HttpAttribute.LiteralSegment;
import com.google.api.tools.framework.aspects.http.model.HttpAttribute.PathSegment;
import com.google.api.tools.framework.aspects.http.model.HttpAttribute.WildcardSegment;
import com.google.api.tools.framework.aspects.http.model.RestMethod;
import com.google.api.tools.framework.model.Method;
import com.google.common.collect.Iterables;
import java.util.List;
import java.util.regex.Matcher;

/** Helper class to match a method against a method pattern. */
public class MethodMatcher {
    private final MethodPattern pattern;
    private final Method method;
    private final HttpAttribute httpConfig;
    private Matcher nameMatcher;
    private boolean matches;

    public MethodMatcher(MethodPattern pattern, Method method, HttpAttribute httpConfig) {
        this.pattern = pattern;
        this.method = method;
        this.httpConfig = httpConfig;

        matches = false;

        // Check http method.
        if (httpConfig.getMethodKind() != pattern.httpMethod()) {
            return;
        }

        // Check name regexp.
        nameMatcher = pattern.nameRegexp().matcher(method.getSimpleName());
        if (!nameMatcher.matches()) {
            return;
        }

        // Determine match on last segment.
        List<PathSegment> flatPath = httpConfig.getFlatPath();
        PathSegment lastSegment = Iterables.getLast(flatPath);
        switch (pattern.lastSegmentPattern()) {
        case CUSTOM_VERB_WITH_COLON:
            // Allow only standard conforming custom method which uses <prefix>:<literal>.
            matches = lastSegment instanceof LiteralSegment
                    && ((LiteralSegment) lastSegment).isTrailingCustomVerb();
            break;
        case CUSTOM_VERB:
            // Allow both a custom verb literal and a regular literal, the latter is for supporting
            // legacy custom verbs.
            matches = lastSegment instanceof LiteralSegment;
            break;
        case VARIABLE:
            matches = lastSegment instanceof WildcardSegment;
            break;
        case LITERAL:
            matches = lastSegment instanceof LiteralSegment
                    && !((LiteralSegment) lastSegment).isTrailingCustomVerb();
            break;
        }
    }

    // Creates a RestMethod from this matcher.
    RestMethod createRestMethod() {
        if (pattern.lastSegmentPattern() == SegmentPattern.CUSTOM_VERB
                || pattern.lastSegmentPattern() == SegmentPattern.CUSTOM_VERB_WITH_COLON) {
            return RestAnalyzer.createCustomMethod(method, httpConfig, pattern.customPrefix());
        }
        return RestMethod.create(method, pattern.restKind(),
                RestAnalyzer.buildCollectionName(httpConfig.getFlatPath()), null);
    }

    public boolean matches() {
        return matches;
    }
}