com.cloudera.parcel.components.JsonAlternativesParser.java Source code

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Here is the source code for com.cloudera.parcel.components.JsonAlternativesParser.java

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// Licensed to Cloudera, Inc. under one
// or more contributor license agreements.  See the NOTICE file
// distributed with this work for additional information
// regarding copyright ownership.  Cloudera, Inc. licenses this file
// to you 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.cloudera.parcel.components;

import com.cloudera.common.Parser;
import com.cloudera.parcel.descriptors.AlternativeDescriptor;
import com.cloudera.parcel.descriptors.AlternativesDescriptor;
import com.fasterxml.jackson.annotation.JsonAnySetter;
import com.fasterxml.jackson.core.type.TypeReference;
import com.google.common.collect.ImmutableMap;

import java.util.Map;

/**
 * This class is used to read an alternatives.json file
 */
public class JsonAlternativesParser extends JsonGenericParser<AlternativesDescriptor>
        implements Parser<AlternativesDescriptor> {

    /**
     * This adaptor class is required to transform the generic Map, otherwise returned
     * from deserializing an alternatives.json file, into a POJO with the Map stored
     * as a field. This is necessary for JSR303 validation to work. Attempts to
     * validate the Map directly do not validate the values inside it.
     */
    private static class AlternativesDescriptorImpl implements AlternativesDescriptor {
        private final ImmutableMap.Builder<String, AlternativeDescriptor> alternatives = ImmutableMap.builder();

        @Override
        public Map<String, AlternativeDescriptor> getAlternatives() {
            return alternatives.build();
        }

        @JsonAnySetter
        private void add(String name, AlternativeDescriptor alternative) {
            alternatives.put(name, alternative);
        }

    }

    public JsonAlternativesParser() {
        super(new TypeReference<AlternativesDescriptorImpl>() {
        });
    }
}