Java tutorial
/* * Copyright (c) 2014 Hewlett-Packard Development Company, L.P. * * Licensed 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.hpcloud.util.config; import java.util.HashMap; import java.util.Iterator; import java.util.Map; import com.fasterxml.jackson.databind.JsonNode; import com.fasterxml.jackson.databind.ObjectMapper; import com.fasterxml.jackson.databind.node.ArrayNode; import com.fasterxml.jackson.databind.node.ValueNode; import com.google.common.base.Joiner; public final class Configurations { private static final Joiner DOT_JOINER = Joiner.on("."); private Configurations() { } public static Map<String, String> configFor(String keyPrefix, Object source) { Map<String, String> config = new HashMap<String, String>(); buildConfigFor(keyPrefix, config, new ObjectMapper().valueToTree(source)); return config; } private static void buildConfigFor(String path, Map<String, String> config, JsonNode node) { for (Iterator<Map.Entry<String, JsonNode>> i = node.fields(); i.hasNext();) { Map.Entry<String, JsonNode> field = i.next(); if (field.getValue() instanceof ValueNode) { ValueNode valueNode = (ValueNode) field.getValue(); config.put(DOT_JOINER.join(path, field.getKey()), valueNode.asText()); } else if (field.getValue() instanceof ArrayNode) { StringBuilder combinedValue = new StringBuilder(); ArrayNode arrayNode = (ArrayNode) field.getValue(); for (Iterator<JsonNode> it = arrayNode.elements(); it.hasNext();) { String value = it.next().asText().replaceAll("^\"|\"$", ""); if (combinedValue.length() > 0) combinedValue.append(','); combinedValue.append(value); } config.put(DOT_JOINER.join(path, field.getKey()), combinedValue.toString()); } buildConfigFor(DOT_JOINER.join(path, field.getKey()), config, field.getValue()); } } }