jj.resource.FileTypeSettingsDefaultProvider.java Source code

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Here is the source code for jj.resource.FileTypeSettingsDefaultProvider.java

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/*
 *    Copyright 2012 Jason Miller
 *
 * 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 jj.resource;

import java.io.InputStream;
import java.nio.charset.Charset;
import java.util.Collections;
import java.util.HashMap;
import java.util.Map;

import javax.inject.Provider;
import javax.inject.Singleton;

import com.fasterxml.jackson.core.type.TypeReference;
import com.fasterxml.jackson.databind.ObjectMapper;

/**
 * provides the default set of type configurations for
 * {@link ResourceConfiguration#fileTypeSettings()}
 * 
 * @author jason
 *
 */
@Singleton
public class FileTypeSettingsDefaultProvider implements Provider<Map<String, ResourceSettings>> {

    // this class has to be public or the config system can't find it
    // and the error is WEIRD, seriously not even comprehensible, since it's just
    // an immutable set of data, it's fine

    private static final Map<String, ResourceSettings> settings;

    static {
        try (InputStream is = FileTypeSettingsDefaultProvider.class
                .getResourceAsStream("api/resource-configurations.json")) {

            ObjectMapper objectMapper = new ObjectMapper();
            Map<String, Map<String, Object>> configuration = objectMapper.readValue(is,
                    new TypeReference<Map<String, Map<String, Object>>>() {
                    });

            HashMap<String, ResourceSettings> result = new HashMap<>(configuration.size() * 2);

            for (String ext : configuration.keySet()) {
                result.put(ext, makeSettings(configuration.get(ext)));
            }
            settings = Collections.unmodifiableMap(result);

        } catch (Exception e) {
            throw new AssertionError("trouble reading default resource configurations", e);
        }
    }

    private static ResourceSettings makeSettings(Map<String, Object> input) {
        String mimeType = (String) input.get("mimeType");
        Charset charset = input.containsKey("charset") ? Charset.forName((String) input.get("charset")) : null;
        boolean compressible = input.containsKey("compressible") && Boolean.TRUE.equals(input.get("compressible"));

        return new ResourceSettings(mimeType, charset, compressible);
    }

    @Override
    public Map<String, ResourceSettings> get() {
        return settings;
    }

}