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https://issues.apache.org/jira/browse/PHOENIX-1661?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14604794#comment-14604794
]
ASF GitHub Bot commented on PHOENIX-1661:
-----------------------------------------
Github user AakashPradeep commented on a diff in the pull request:
https://github.com/apache/phoenix/pull/93#discussion_r33424861
--- 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;
--- End diff --
Please add comment here, its hard to follow why we require this method and
where we gonna use this.
Probably it seems it will be used for json_array_length() function
implementation. In that case first requirement will be to make sure that input
is a valid Json array and if it is so then just check whether the rootnode
(member variable of this class) isArray() or not, if it is an array then simply
use size() method of ArrayNode class.
> Implement built-in functions for JSON
> -------------------------------------
>
> Key: PHOENIX-1661
> URL: https://issues.apache.org/jira/browse/PHOENIX-1661
> Project: Phoenix
> Issue Type: Bug
> Reporter: James Taylor
> Labels: JSON, Java, SQL, gsoc2015, mentor
> Attachments: PhoenixJSONSpecification-First-Draft.pdf
>
>
> Take a look at the JSON built-in functions that are implemented in Postgres
> (http://www.postgresql.org/docs/9.3/static/functions-json.html) and implement
> the same for Phoenix in Java following this guide:
> http://phoenix-hbase.blogspot.com/2013/04/how-to-add-your-own-built-in-function.html
> Examples of functions include ARRAY_TO_JSON, ROW_TO_JSON, TO_JSON, etc. The
> implementation of these built-in functions will be impacted by how JSON is
> stored in Phoenix. See PHOENIX-628. An initial implementation could work off
> of a simple text-based JSON representation and then when a native JSON type
> is implemented, they could be reworked to be more efficient.
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