    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 java.io.IOException;
    021import java.io.InputStream;
    022import java.io.Reader;
    023import java.io.Writer;
    024import java.util.Map;
    025
    026import org.apache.commons.configuration2.ex.ConfigurationException;
    027import org.apache.commons.configuration2.io.InputStreamSupport;
    028import org.apache.commons.configuration2.tree.ImmutableNode;
    029import org.yaml.snakeyaml.DumperOptions;
    030import org.yaml.snakeyaml.LoaderOptions;
    031import org.yaml.snakeyaml.Yaml;
    032import org.yaml.snakeyaml.constructor.SafeConstructor;
    033import org.yaml.snakeyaml.representer.Representer;
    034
    035/**
    036 * <p>
    037 * A specialized hierarchical configuration class that is able to parse YAML documents.
    038 * </p>
    039 *
    040 * @since 2.2
    041 */
    042public class YAMLConfiguration extends AbstractYAMLBasedConfiguration implements FileBasedConfiguration, InputStreamSupport {
    043    /**
    044     * Creates a new instance of {@code YAMLConfiguration}.
    045     */
    046    public YAMLConfiguration() {
    047    }
    048
    049    /**
    050     * Creates a new instance of {@code YAMLConfiguration} as a copy of the specified configuration.
    051     *
    052     * @param c the configuration to be copied
    053     */
    054    public YAMLConfiguration(final HierarchicalConfiguration<ImmutableNode> c) {
    055        super(c);
    056    }
    057
    058    @Override
    059    public void read(final Reader in) throws ConfigurationException {
    060        try {
    061            final Yaml yaml = createYamlForReading(new LoaderOptions());
    062            final Map<String, Object> map = yaml.load(in);
    063            load(map);
    064        } catch (final Exception e) {
    065            rethrowException(e);
    066        }
    067    }
    068
    069    public void read(final Reader in, final LoaderOptions options) throws ConfigurationException {
    070        try {
    071            final Yaml yaml = createYamlForReading(options);
    072            final Map<String, Object> map = yaml.load(in);
    073            load(map);
    074        } catch (final Exception e) {
    075            rethrowException(e);
    076        }
    077    }
    078
    079    @Override
    080    public void write(final Writer out) throws ConfigurationException, IOException {
    081        final DumperOptions options = new DumperOptions();
    082        options.setDefaultFlowStyle(DumperOptions.FlowStyle.BLOCK);
    083        dump(out, options);
    084    }
    085
    086    public void dump(final Writer out, final DumperOptions options)
    087            throws ConfigurationException, IOException {
    088        final Yaml yaml = new Yaml(options);
    089        yaml.dump(constructMap(getNodeModel().getNodeHandler().getRootNode()), out);
    090    }
    091
    092    /**
    093     * Loads the configuration from the given input stream.
    094     *
    095     * @param in the input stream
    096     * @throws ConfigurationException if an error occurs
    097     */
    098    @Override
    099    public void read(final InputStream in) throws ConfigurationException {
    100        try {
    101            final Yaml yaml = createYamlForReading(new LoaderOptions());
    102            final Map<String, Object> map = yaml.load(in);
    103            load(map);
    104        } catch (final Exception e) {
    105            rethrowException(e);
    106        }
    107    }
    108
    109    public void read(final InputStream in, final LoaderOptions options) throws ConfigurationException {
    110        try {
    111            final Yaml yaml = createYamlForReading(options);
    112            final Map<String, Object> map = yaml.load(in);
    113            load(map);
    114        } catch (final Exception e) {
    115            rethrowException(e);
    116        }
    117    }
    118
    119    /**
    120     * Creates a {@code Yaml} object for reading a Yaml file. The object is configured with some default settings.
    121     *
    122     * @param options options for loading the file
    123     * @return the {@code Yaml} instance for loading a file
    124     */
    125    private static Yaml createYamlForReading(final LoaderOptions options) {
    126        return new Yaml(new SafeConstructor(options), new Representer(new DumperOptions()), new DumperOptions(), options);
    127    }
    128
    129}