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https://issues.apache.org/jira/browse/PHOENIX-1661?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14604812#comment-14604812
]
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_r33425159
--- 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 = "";
+ Map.Entry<String, JsonNode> entry = fields.next();
+ fieldsstr += entry.getKey() +","+entry.getValue().toString();
--- End diff --
If you define String variable here, you do not need to use "+" operator,
which is a costly affair avoid using it as much as possible.
> 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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