com.github.ferstl.maven.pomenforcers.model.functions.AbstractOneToOneMatcher.java Source code

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Here is the source code for com.github.ferstl.maven.pomenforcers.model.functions.AbstractOneToOneMatcher.java

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/*
 * Copyright (c) 2012 - 2015 by Stefan Ferstl <st.ferstl@gmail.com>
 *
 * 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.github.ferstl.maven.pomenforcers.model.functions;

import java.util.ArrayList;
import java.util.Collection;
import java.util.List;

import org.apache.maven.enforcer.rule.api.EnforcerRuleHelper;

import com.google.common.collect.BiMap;
import com.google.common.collect.ImmutableBiMap;
import com.google.common.collect.ImmutableBiMap.Builder;

public abstract class AbstractOneToOneMatcher<U, V> {

    private final EnforcerRuleHelper helper;

    AbstractOneToOneMatcher(EnforcerRuleHelper helper) {
        this.helper = helper;
    }

    public final BiMap<V, V> match(Collection<U> superset, Collection<V> subset) {
        Builder<V, V> mapBuilder = ImmutableBiMap.builder();

        // Transform the superset here in order not to do it in each nested loop
        Collection<V> transformedSuperset = transformSuperset(superset);

        for (V subsetItem : subset) {
            boolean itemMatched = false;

            for (V supersetItem : transformedSuperset) {
                if (matches(supersetItem, subsetItem)) {
                    itemMatched = true;
                    mapBuilder.put(supersetItem, subsetItem);
                    break;
                }
            }

            if (!itemMatched) {
                handleUnmatchedItem(mapBuilder, subsetItem);
            }
        }

        return mapBuilder.build();
    }

    protected void handleUnmatchedItem(Builder<V, V> mapBuilder, V subsetItem) {
        throw new IllegalArgumentException("Could not match item " + subsetItem + " with superset");
    }

    protected abstract V transform(U supersetItem);

    protected abstract boolean matches(V supersetItem, V subsetItem);

    EnforcerRuleHelper getHelper() {
        return this.helper;
    }

    private Collection<V> transformSuperset(Collection<U> superset) {
        List<V> transformed = new ArrayList<>(superset.size());
        for (U supersetItem : superset) {
            transformed.add(transform(supersetItem));
        }
        return transformed;
    }
}