org.zalando.logbook.QueryParameters.java Source code

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Here is the source code for org.zalando.logbook.QueryParameters.java

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package org.zalando.logbook;

/*
 * #%L
 * Logbook: Core
 * %%
 * Copyright (C) 2015 Zalando SE
 * %%
 * 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.
 * #L%
 */

import com.google.common.annotations.VisibleForTesting;
import com.google.common.base.Joiner;
import com.google.common.base.Splitter;
import com.google.common.collect.ForwardingMultimap;
import com.google.common.collect.ImmutableMultimap;
import com.google.common.collect.Maps;
import com.google.common.collect.Multimap;
import com.google.common.collect.Multimaps;
import com.google.gag.annotation.remark.Hack;
import com.google.gag.annotation.remark.OhNoYouDidnt;

import javax.annotation.Nullable;
import java.net.URLEncoder;
import java.util.Iterator;
import java.util.List;
import java.util.Map;

import static com.google.common.base.CharMatcher.anyOf;
import static com.google.common.collect.Iterables.transform;
import static java.util.stream.Collectors.toList;

final class QueryParameters extends ForwardingMultimap<String, String> {

    private static final QueryParameters EMPTY = new QueryParameters();

    private final Multimap<String, String> parameters;

    public QueryParameters() {
        this(ImmutableMultimap.of());
    }

    QueryParameters(final Multimap<String, String> parameters) {
        this.parameters = parameters;
    }

    @Override
    protected Multimap<String, String> delegate() {
        return parameters;
    }

    public QueryParameters obfuscate(final Obfuscator obfuscator) {
        return new QueryParameters(Multimaps.transformEntries(parameters, obfuscator::obfuscate));
    }

    @Override
    public String toString() {
        return Joiner.on("&").withKeyValueSeparator("=").useForNull("")
                .join(parameters.entries().stream().map(QueryParameters::encodeEntry).collect(toList()));
    }

    private static Map.Entry<String, String> encodeEntry(final Map.Entry<String, String> entry) {
        return Maps.immutableEntry(urlEncodeUTF8(entry.getKey()), urlEncodeUTF8(entry.getValue()));
    }

    @VisibleForTesting
    @SuppressWarnings("ConstantConditions")
    static String urlEncodeUTF8(@Nullable final String s) {
        try {
            return URLEncoder.encode(s, "UTF-8");
        } catch (@Hack("Just so we can trick the code coverage") @OhNoYouDidnt final Exception e) {
            throw new AssertionError(e);
        }
    }

    public static QueryParameters parse(@Nullable final String queryString) {
        if (queryString == null || queryString.isEmpty()) {
            return EMPTY;
        }

        final ImmutableMultimap.Builder<String, String> entries = ImmutableMultimap.builder();

        for (final Map.Entry<String, String> entry : splitEntries(queryString)) {
            entries.put(entry.getKey(), entry.getValue());
        }

        return new QueryParameters(entries.build());
    }

    private static Iterable<Map.Entry<String, String>> splitEntries(final String queryString) {
        final List<String> entryStrings = Splitter.on(anyOf("&;")).splitToList(queryString);

        return transform(entryStrings, input -> {
            final Iterator<String> split = Splitter.on('=').split(input).iterator();
            return Maps.immutableEntry(split.next(), split.next());
        });
    }

}