chengfan | c58d4be | 2016-09-20 10:33:12 +0800 | [diff] [blame^] | 1 | /* |
| 2 | * Copyright 2016-present Open Networking Laboratory |
| 3 | * |
| 4 | * Licensed under the Apache License, Version 2.0 (the "License"); |
| 5 | * you may not use this file except in compliance with the License. |
| 6 | * You may obtain a copy of the License at |
| 7 | * |
| 8 | * http://www.apache.org/licenses/LICENSE-2.0 |
| 9 | * |
| 10 | * Unless required by applicable law or agreed to in writing, software |
| 11 | * distributed under the License is distributed on an "AS IS" BASIS, |
| 12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 13 | * See the License for the specific language governing permissions and |
| 14 | * limitations under the License. |
| 15 | */ |
| 16 | |
| 17 | package org.onosproject.protocol.restconf.server.utils.parser.json; |
| 18 | |
| 19 | import com.fasterxml.jackson.databind.JsonNode; |
| 20 | import com.fasterxml.jackson.databind.node.ArrayNode; |
| 21 | import com.fasterxml.jackson.databind.node.ObjectNode; |
| 22 | import org.onosproject.protocol.restconf.server.utils.parser.api.JsonWalker; |
| 23 | import org.onosproject.protocol.restconf.server.utils.parser.api.JsonListener; |
| 24 | |
| 25 | import java.util.Iterator; |
| 26 | import java.util.Map; |
| 27 | |
| 28 | /** |
| 29 | * Represents implementation of JSON walk, which walks the JSON object node. |
| 30 | */ |
| 31 | public class DefaultJsonWalker implements JsonWalker { |
| 32 | @Override |
| 33 | public void walk(JsonListener jsonListener, String fieldName, |
| 34 | ObjectNode objectNode) { |
| 35 | |
| 36 | //enter the object node, the original ObjectNode should have a module |
| 37 | //name as fieldName. |
| 38 | jsonListener.enterJsonNode(fieldName, objectNode); |
| 39 | //the node has no children, then exist and return. |
| 40 | if (!objectNode.isContainerNode()) { |
| 41 | jsonListener.exitJsonNode(objectNode); |
| 42 | return; |
| 43 | } |
| 44 | |
| 45 | Iterator<Map.Entry<String, JsonNode>> fields = objectNode.fields(); |
| 46 | while (fields.hasNext()) { |
| 47 | //get the children entry of the node |
| 48 | Map.Entry<String, JsonNode> currentChild = fields.next(); |
| 49 | String key = currentChild.getKey(); |
| 50 | JsonNode value = currentChild.getValue(); |
| 51 | //if the entry's value has its own children, do a recursion. |
| 52 | //if the entry has no children, store the key and value. |
| 53 | //for we don't know the specific type of the entry's value, we |
| 54 | // should give it to a method which can handle JsonNode |
| 55 | if (value.isContainerNode()) { |
| 56 | walkJsonNode(jsonListener, key, value); |
| 57 | } else { |
| 58 | jsonListener.enterJsonNode(key, value); |
| 59 | jsonListener.exitJsonNode(value); |
| 60 | } |
| 61 | } |
| 62 | jsonListener.exitJsonNode(objectNode); |
| 63 | } |
| 64 | |
| 65 | /** |
| 66 | * Walks the JSON data tree. This method is called when we don't know |
| 67 | * the exact type of a json node. |
| 68 | * |
| 69 | * @param jsonListener Json listener implemented by the user |
| 70 | * @param fieldName the original object node field |
| 71 | * @param rootNode the json node which needs to be walk |
| 72 | */ |
| 73 | private void walkJsonNode(JsonListener jsonListener, String fieldName, |
| 74 | JsonNode rootNode) { |
| 75 | if (rootNode.isObject()) { |
| 76 | walk(jsonListener, fieldName, (ObjectNode) rootNode); |
| 77 | return; |
| 78 | } |
| 79 | |
| 80 | if (rootNode.isArray()) { |
| 81 | walkArrayNode(jsonListener, fieldName, (ArrayNode) rootNode); |
| 82 | } |
| 83 | } |
| 84 | |
| 85 | /** |
| 86 | * Walks the JSON data tree. This method is called when the user knows the |
| 87 | * json node type is ArrayNode. |
| 88 | * |
| 89 | * @param jsonListener Json listener implemented by the user |
| 90 | * @param fieldName the original object node field |
| 91 | * @param rootNode the json node which needs to be walk |
| 92 | */ |
| 93 | private void walkArrayNode(JsonListener jsonListener, String fieldName, |
| 94 | ArrayNode rootNode) { |
| 95 | if (rootNode == null) { |
| 96 | return; |
| 97 | } |
| 98 | //enter the array node. |
| 99 | jsonListener.enterJsonNode(fieldName, rootNode); |
| 100 | Iterator<JsonNode> children = rootNode.elements(); |
| 101 | while (children.hasNext()) { |
| 102 | JsonNode currentChild = children.next(); |
| 103 | if (currentChild.isContainerNode()) { |
| 104 | walkJsonNode(jsonListener, null, currentChild); |
| 105 | } |
| 106 | } |
| 107 | jsonListener.exitJsonNode(rootNode); |
| 108 | } |
| 109 | } |