Github user AakashPradeep commented on a diff in the pull request: https://github.com/apache/phoenix/pull/93#discussion_r33425152 --- Diff: phoenix-core/src/main/java/org/apache/phoenix/schema/json/PhoenixJson.java --- @@ -0,0 +1,355 @@ +/* + * Licensed to the Apache Software Foundation (ASF) under one + * or more contributor license agreements. See the NOTICE file + * distributed with this work for additional information + * regarding copyright ownership. The ASF 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.apache.phoenix.schema.json; + +import java.io.IOException; +import java.sql.SQLException; +import java.util.Arrays; +import java.util.ArrayList; +import java.util.Iterator; +import java.util.List; +import java.util.Map; + +import org.apache.hadoop.hbase.util.Bytes; +import org.apache.phoenix.exception.SQLExceptionCode; +import org.apache.phoenix.exception.SQLExceptionInfo; +import org.apache.phoenix.schema.EqualityNotSupportedException; +import org.apache.phoenix.schema.types.*; +import org.codehaus.jackson.JsonFactory; +import org.codehaus.jackson.JsonNode; +import org.codehaus.jackson.JsonParser; +import org.codehaus.jackson.JsonParser.Feature; +import org.codehaus.jackson.JsonProcessingException; +import org.codehaus.jackson.map.ObjectMapper; +import org.codehaus.jackson.node.ValueNode; + +import com.google.common.base.Preconditions; + +/** + * The {@link PhoenixJson} wraps json and uses Jackson library to parse and traverse the json. It + * should be used to represent the JSON data type and also should be used to parse Json data and + * read the value from it. It always conside the last value if same key exist more than once. + */ +public class PhoenixJson implements Comparable<PhoenixJson> { + private final JsonNode rootNode; + /* + * input data has been stored as it is, since some data is lost when json parser runs, for + * example if a JSON object within the value contains the same key more than once then only last + * one is stored rest all of them are ignored, which will defy the contract of PJsonDataType of + * keeping user data as it is. + */ + private final String jsonAsString; + + /** + * Static Factory method to get an {@link PhoenixJson} object. It also validates the json and + * throws {@link SQLException} if it is invalid with line number and character. + * @param jsonData Json data as {@link String}. + * @return {@link PhoenixJson}. + * @throws SQLException + */ + public static PhoenixJson getInstance(String jsonData) throws SQLException { + if (jsonData == null) { + return null; + } + try { + JsonFactory jsonFactory = new JsonFactory(); + JsonParser jsonParser = jsonFactory.createJsonParser(jsonData); + JsonNode jsonNode = getRootJsonNode(jsonParser); + return new PhoenixJson(jsonNode, jsonData); + } catch (IOException x) { + throw new SQLExceptionInfo.Builder(SQLExceptionCode.INVALID_JSON_DATA).setRootCause(x) + .setMessage(x.getMessage()).build().buildException(); + } + + } + + /** + * Returns the root of the resulting {@link JsonNode} tree. + */ + private static JsonNode getRootJsonNode(JsonParser jsonParser) throws IOException, + JsonProcessingException { + jsonParser.configure(Feature.ALLOW_COMMENTS, true); + ObjectMapper objectMapper = new ObjectMapper(); + try { + return objectMapper.readTree(jsonParser); + } finally { + jsonParser.close(); + } + } + + /* Default for unit testing */PhoenixJson(final JsonNode node, final String jsonData) { + Preconditions.checkNotNull(node, "root node cannot be null for json"); + this.rootNode = node; + this.jsonAsString = jsonData; + } + + /** + * Get {@link PhoenixJson} for a given json paths. For example : + * <p> + * <code> + * {"f2":{"f3":1},"f4":{"f5":99,"f6":{"f7":"2"}}}' + * </code> + * <p> + * for this source json, if we want to know the json at path {'f4','f6'} it will return + * {@link PhoenixJson} object for json {"f7":"2"}. It always returns the last key if same key + * exist more than once. + * <p> + * If the given path is unreachable then it throws {@link SQLException}. + * @param paths {@link String []} of path in the same order as they appear in json. + * @return {@link PhoenixJson} for the json against @paths. + * @throws SQLException + */ + public PhoenixJson getPhoenixJson(String[] paths) throws SQLException { + try { + PhoenixJson phoenixJson = getPhoenixJsonInternal(paths); + if (phoenixJson == null) { + throw new SQLException("path: " + Arrays.asList(paths) + " not found."); + } + return phoenixJson; + } catch (NumberFormatException nfe) { + throw new SQLException("path: " + Arrays.asList(paths) + " not found.", nfe); + } + } + + /** + * Get {@link PhoenixJson} for a given json paths. For example : + * <p> + * <code> + * {"f2":{"f3":1},"f4":{"f5":99,"f6":{"f7":"2"}}}' + * </code> + * <p> + * for this source json, if we want to know the json at path {'f4','f6'} it will return + * {@link PhoenixJson} object for json {"f7":"2"}. It always returns the last key if same key + * exist more than once. + * <p> + * If the given path is unreachable then it return null. + * @param paths {@link String []} of path in the same order as they appear in json. + * @return {@link PhoenixJson} for the json against @paths. + */ + public PhoenixJson getPhoenixJsonOrNull(String[] paths) { + try { + return getPhoenixJsonInternal(paths); + } catch (NumberFormatException nfe) { + // ignore + } + return null; + } + + /** + * Serialize the current {@link PhoenixJson} to String. Its required for + * json_extract_path_text(). If we just return node.toString() it will wrap String value in + * double quote which is not the expectation, hence avoiding calling toString() on + * {@link JsonNode} until PhoenixJson represent a Json Array or container for Json object. If + * PhoenixJson just represent a {@link ValueNode} then it should return value returned from + * objects toString(). + */ + public String serializeToString() { + if (this.rootNode == null || this.rootNode.isNull()) { + return null; + } else if (this.rootNode.isValueNode()) { + + if (this.rootNode.isNumber()) { + return this.rootNode.getNumberValue().toString(); + } else if (this.rootNode.isBoolean()) { + return String.valueOf(this.rootNode.getBooleanValue()); + } else if (this.rootNode.isTextual()) { + return this.rootNode.getTextValue(); + } else { + return this.jsonAsString; + } + } else if (this.rootNode.isArray()) { + return this.jsonAsString; + } else if (this.rootNode.isContainerNode()) { + return this.jsonAsString; + } + + return null; + + } + + @Override + public String toString() { + return this.jsonAsString; + } + + @Override + public int hashCode() { + final int prime = 31; + int result = 1; + result = prime * result + this.jsonAsString.hashCode(); + return result; + } + + @Override + public boolean equals(Object obj) { + throw new EqualityNotSupportedException(PJson.INSTANCE); + } + + /** + * @return length of the string represented by the current {@link PhoenixJson}. + */ + public int estimateByteSize() { + String jsonStr = toString(); + return jsonStr == null ? 1 : jsonStr.length(); + } + + public byte[] toBytes() { + return Bytes.toBytes(this.jsonAsString); + } + + @Override + public int compareTo(PhoenixJson o) { + throw new EqualityNotSupportedException(PJson.INSTANCE); + } + + private PhoenixJson getPhoenixJsonInternal(String[] paths) { + JsonNode node = this.rootNode; + for (String path : paths) { + JsonNode nodeTemp = null; + if (node.isArray()) { + int index = Integer.parseInt(path); + nodeTemp = node.path(index); + } else { + nodeTemp = node.path(path); + } + if (nodeTemp == null || nodeTemp.isMissingNode()) { + return null; + } + node = nodeTemp; + } + return new PhoenixJson(node, node.toString()); + } + + public int getJsonArrayLength() { + int count = 0; + Iterator<JsonNode> elements = this.rootNode.getElements(); + while(elements.hasNext()){ + elements.next(); + count++; + } + return count; + } + + public Object[] getJsonArrayElements() { + List<String> elementlist = new ArrayList(); + Iterator<JsonNode> elements = this.rootNode.getElements(); + while(elements.hasNext()){ + JsonNode e = elements.next(); + elementlist.add(e.toString()); + } + return elementlist.toArray(); + } + + public Object[] getJsonObjectKeys() { + List<String> elementlist = new ArrayList(); + Iterator<String> fieldnames = this.rootNode.getFieldNames(); + while(fieldnames.hasNext()){ + elementlist.add(fieldnames.next()); + } + return elementlist.toArray(); + } + + public Object[] getJsonFields() { + List<String> elementlist = new ArrayList(); + Iterator<Map.Entry<String, JsonNode>> fields = this.rootNode.getFields(); + + while(fields.hasNext()){ + String fieldsstr = ""; --- End diff -- Define variable only the places where it requires it makes easier to read the code.
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