org.elasticsearch.common.xcontent.XContentHelper Maven / Gradle / Ivy

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/*
 * Licensed to Elastic Search and Shay Banon under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership. Elastic Search 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 org.elasticsearch.common.xcontent;

import java.io.IOException;
import java.util.Map;

/**
 * @author kimchy (shay.banon)
 */
public class XContentHelper {

    /**
     * Merges the defaults provided as the second parameter into the content of the first. Only does recursive merge
     * for inner maps.
     */
    @SuppressWarnings({"unchecked"}) public static void mergeDefaults(Map content, Map defaults) {
        for (Map.Entry defaultEntry : defaults.entrySet()) {
            if (!content.containsKey(defaultEntry.getKey())) {
                // copy it over, it does not exists in the content
                content.put(defaultEntry.getKey(), defaultEntry.getValue());
            } else {
                // in the content and in the default, only merge compound ones (maps)
                if (content.get(defaultEntry.getKey()) instanceof Map && defaultEntry.getValue() instanceof Map) {
                    mergeDefaults((Map) content.get(defaultEntry.getKey()), (Map) defaultEntry.getValue());
                }
            }
        }
    }

    public static void copyCurrentStructure(XContentGenerator generator, XContentParser parser) throws IOException {
        XContentParser.Token t = parser.currentToken();

        // Let's handle field-name separately first
        if (t == XContentParser.Token.FIELD_NAME) {
            generator.writeFieldName(parser.currentName());
            t = parser.nextToken();
            // fall-through to copy the associated value
        }

        switch (t) {
            case START_ARRAY:
                generator.writeStartArray();
                while (parser.nextToken() != XContentParser.Token.END_ARRAY) {
                    copyCurrentStructure(generator, parser);
                }
                generator.writeEndArray();
                break;
            case START_OBJECT:
                generator.writeStartObject();
                while (parser.nextToken() != XContentParser.Token.END_OBJECT) {
                    copyCurrentStructure(generator, parser);
                }
                generator.writeEndObject();
                break;
            default: // others are simple:
                copyCurrentEvent(generator, parser);
        }
    }

    public static void copyCurrentEvent(XContentGenerator generator, XContentParser parser) throws IOException {
        switch (parser.currentToken()) {
            case START_OBJECT:
                generator.writeStartObject();
                break;
            case END_OBJECT:
                generator.writeEndObject();
                break;
            case START_ARRAY:
                generator.writeStartArray();
                break;
            case END_ARRAY:
                generator.writeEndArray();
                break;
            case FIELD_NAME:
                generator.writeFieldName(parser.currentName());
                break;
            case VALUE_STRING:
                if (parser.hasTextCharacters()) {
                    generator.writeString(parser.textCharacters(), parser.textOffset(), parser.textLength());
                } else {
                    generator.writeString(parser.text());
                }
                break;
            case VALUE_NUMBER:
                switch (parser.numberType()) {
                    case INT:
                        generator.writeNumber(parser.intValue());
                        break;
                    case LONG:
                        generator.writeNumber(parser.longValue());
                        break;
                    case FLOAT:
                        generator.writeNumber(parser.floatValue());
                        break;
                    case DOUBLE:
                        generator.writeNumber(parser.doubleValue());
                        break;
                }
                break;
            case VALUE_BOOLEAN:
                generator.writeBoolean(parser.booleanValue());
                break;
            case VALUE_NULL:
                generator.writeNull();
                break;
        }
    }

}