com.google.mr4c.content.ContentTypes.java Source code

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Here is the source code for com.google.mr4c.content.ContentTypes.java

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/**
  * Copyright 2014 Google Inc. All rights reserved.
  * 
  * 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.mr4c.content;

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

import org.apache.commons.collections.CollectionUtils;
import org.apache.commons.collections.Predicate;
import org.apache.commons.io.FilenameUtils;

public abstract class ContentTypes {

    public static final String DEFAULT_TYPE = "application/octet-stream";
    public static final String DEFAULT_SUFFIX = "bin";

    private static Map<String, String> s_typeToCanonicalSuffix = new HashMap<String, String>();
    private static Map<String, List<String>> s_typeToSuffixes = new HashMap<String, List<String>>();
    private static Map<String, String> s_suffixToType = new HashMap<String, String>();

    private static void add(String type, String suffix, boolean canonical) {
        s_suffixToType.put(suffix, type);
        if (canonical) {
            s_typeToCanonicalSuffix.put(type, suffix);
        }
        List<String> suffixes = s_typeToSuffixes.get(type);
        if (suffixes == null) {
            suffixes = new ArrayList<String>();
            s_typeToSuffixes.put(type, suffixes);
        }
        suffixes.add(suffix);
    }

    static {
        add("image/jp2", "jp2", true);
        add("image/jp2", "jpc", false);
        add("image/jp2", "j2k", false);
        add("image/jpg", "jpg", true);
        add("image/jpg", "jpeg", false);
        add("image/tiff", "tif", true);
        add("image/png", "png", true);
        add("application/json", "json", true);
        add(DEFAULT_TYPE, DEFAULT_SUFFIX, true);
    }

    public static String getContentTypeForName(String name) {
        return getContentTypeForSuffix(extractSuffix(name));
    }

    public static String getContentTypeForSuffix(String suffix) {
        String type = s_suffixToType.get(suffix);
        if (type == null) {
            type = DEFAULT_TYPE;
        }
        return type;
    }

    public static String getSuffix(String contentType) {
        String suffix = s_typeToCanonicalSuffix.get(contentType);
        if (suffix == null) {
            suffix = DEFAULT_SUFFIX;
        }
        return suffix;
    }

    public static Collection<String> getSuffixes(String contentType) {
        Collection<String> suffixes = s_typeToSuffixes.get(contentType);
        if (suffixes == null) {
            throw new IllegalArgumentException(String.format("No suffix for content type=[%s]", contentType));
        }
        return suffixes;
    }

    public static String appendSuffix(String name, String contentType) {
        return name + "." + getSuffix(contentType);
    }

    public static Collection<String> appendSuffixes(String name, String contentType) {
        Collection<String> result = new ArrayList<String>();
        for (String suffix : getSuffixes(contentType)) {
            result.add(name + "." + suffix);
        }
        return result;
    }

    private static String extractSuffix(String name) {
        return FilenameUtils.getExtension(name);
    }

    public static Collection<String> filterByContentType(Collection<String> fileNames, final String contentType,
            final boolean canonicalOnly) {
        return CollectionUtils.predicatedCollection(fileNames, new Predicate() {
            public boolean evaluate(Object obj) {
                String name = (String) obj;
                if (canonicalOnly) {
                    String suffix = ContentTypes.getSuffix(contentType);
                    return FilenameUtils.isExtension(name, suffix);
                } else {
                    Collection<String> suffixes = ContentTypes.getSuffixes(contentType);
                    return FilenameUtils.isExtension(name, suffixes);
                }
            }
        });
    }

}