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