001/*
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements.  See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License.  You may obtain a copy of the License at
008 *
009 *     http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017
018package org.apache.commons.configuration2;
019
020import com.fasterxml.jackson.databind.ObjectMapper;
021import com.fasterxml.jackson.databind.type.MapType;
022import org.apache.commons.configuration2.ex.ConfigurationException;
023import org.apache.commons.configuration2.io.InputStreamSupport;
024import org.apache.commons.configuration2.tree.ImmutableNode;
025
026import java.io.IOException;
027import java.io.InputStream;
028import java.io.Reader;
029import java.io.Writer;
030import java.util.Map;
031
032/**
033 * <p>
034 * A specialized hierarchical configuration class that is able to parse JSON
035 * documents.
036 * </p>
037 *
038 * @since 2.2
039 */
040public class JSONConfiguration extends AbstractYAMLBasedConfiguration
041        implements FileBasedConfiguration, InputStreamSupport
042{
043
044    /**
045     * The object mapper used by the {@code JSONConfiguration}.
046     */
047    private final ObjectMapper mapper = new ObjectMapper();
048
049    /**
050     * The {@code MapType} used to convert types.
051     */
052    private final MapType type = mapper.getTypeFactory()
053            .constructMapType(Map.class, String.class, Object.class);
054
055    /**
056     * Creates a new instance of {@code JSONConfiguration}.
057     */
058    public JSONConfiguration()
059    {
060        super();
061    }
062
063    /**
064     * Creates a new instance of {@code JSONConfiguration} as a copy of the
065     * specified configuration.
066     *
067     * @param c the configuration to be copied
068     */
069    public JSONConfiguration(final HierarchicalConfiguration<ImmutableNode> c)
070    {
071        super(c);
072    }
073
074    @Override
075    public void read(final Reader in) throws ConfigurationException
076    {
077        try
078        {
079            final Map<String, Object> map = mapper.readValue(in, this.type);
080            load(map);
081        }
082        catch (final Exception e)
083        {
084            rethrowException(e);
085        }
086    }
087
088    @Override
089    public void write(final Writer out) throws ConfigurationException, IOException
090    {
091        this.mapper.writer().writeValue(out, constructMap(
092                this.getNodeModel().getNodeHandler().getRootNode()));
093    }
094
095    /**
096     * Loads the configuration from the given input stream.
097     *
098     * @param in the input stream
099     * @throws ConfigurationException if an error occurs
100     */
101    @Override
102    public void read(final InputStream in) throws ConfigurationException
103    {
104        try
105        {
106            final Map<String, Object> map = mapper.readValue(in, this.type);
107            load(map);
108        }
109        catch (final Exception e)
110        {
111            rethrowException(e);
112        }
113    }
114
115}