[
https://issues.apache.org/jira/browse/PHOENIX-628?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14512152#comment-14512152
]
ASF GitHub Bot commented on PHOENIX-628:
----------------------------------------
Github user AakashPradeep commented on a diff in the pull request:
https://github.com/apache/phoenix/pull/76#discussion_r29096442
--- Diff:
phoenix-core/src/main/java/org/apache/phoenix/schema/json/PhoenixJson.java ---
@@ -0,0 +1,280 @@
+/*
+ * 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 org.apache.hadoop.hbase.util.Bytes;
+import org.apache.phoenix.exception.SQLExceptionCode;
+import org.apache.phoenix.exception.SQLExceptionInfo;
+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 node;
+ private 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 data Buffer that contains data to parse
+ * @param offset Offset of the first data byte within buffer
+ * @param length Length of contents to parse within buffer
+ * @return {@link PhoenixJson}.
+ * @throws SQLException
+ */
+ public static PhoenixJson getPhoenixJson(byte[] jsonData, int offset,
int length)
+ throws SQLException {
+
+ String jsonDataStr = Bytes.toString(jsonData, offset, length);
+ return getPhoenixJson(jsonDataStr);
+
+ }
+
+ /**
+ * 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 getPhoenixJson(String jsonData) throws
SQLException {
+ try {
+ JsonFactory jsonFactory = new JsonFactory();
+ JsonParser jsonParser = jsonFactory.createJsonParser(jsonData);
+ PhoenixJson phoenixJson = getPhoneixJson(jsonParser);
+ /*
+ * 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.
+ */
+ phoenixJson.setJsonAsString(jsonData);
+ return phoenixJson;
+ } catch (IOException x) {
+ throw new
SQLExceptionInfo.Builder(SQLExceptionCode.INVALID_JSON_DATA).setRootCause(x)
+ .setMessage(x.getMessage()).build().buildException();
+ }
+
+ }
+
+ private static PhoenixJson getPhoneixJson(JsonParser jsonParser)
throws IOException,
+ JsonProcessingException {
+ jsonParser.configure(Feature.ALLOW_COMMENTS, true);
+ ObjectMapper objectMapper = new ObjectMapper();
+ try {
+ JsonNode rootNode = objectMapper.readTree(jsonParser);
+ PhoenixJson phoenixJson = new PhoenixJson(rootNode);
+ return phoenixJson;
+ } finally {
+ jsonParser.close();
+ }
+ }
+
+ /* Default for unit testing */PhoenixJson(final JsonNode node) {
+ Preconditions.checkNotNull(node, "root node cannot be null for
json");
+ this.node = node;
+ }
+
+ /**
+ * 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
PhoenixJsonException} with the message
+ * having information about not found path. It is caller
responsibility to wrap it in
+ * {@link SQLException} or catch it and return null to client.
+ * @param paths {@link String []} of path in the same order as they
appear in json.
+ * @return {@link PhoenixJson} for the json against @paths.
+ * @throws PhoenixJsonException
+ */
+ public PhoenixJson getPhoenixJson(String[] paths) throws
PhoenixJsonException {
+ JsonNode node = this.node;
+ for (String path : paths) {
+ JsonNode nodeTemp = null;
+ if (node.isArray()) {
+ try {
+ int index = Integer.parseInt(path);
+ nodeTemp = node.path(index);
+ } catch (NumberFormatException nfe) {
+ throw new PhoenixJsonException("path: " + path + " not
found", nfe);
+ }
+ } else {
+ nodeTemp = node.path(path);
+ }
+ if (nodeTemp == null || nodeTemp.isMissingNode()) {
+ throw new PhoenixJsonException("path: " + path + " not
found");
+ }
+ node = nodeTemp;
+ }
+ return new PhoenixJson(node);
+ }
+
+ /**
+ * 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 getNullablePhoenixJson(String[] paths) {
--- End diff --
getPhoenixJson() throws Exception if path is not found. It can be used on
those case where we want to throw exception to user if path is not correct but
in case we just want to return null if path is not valid then I dont want my
logic to be catching the exception and then ignore it since Exception are
always costly so I provided getNullablePhoenixJson() which return null if path
is not valid.
I will try to put them in a helper and have a boolean argument to specify
whether to throw exception or not.
> Support native JSON data type
> -----------------------------
>
> Key: PHOENIX-628
> URL: https://issues.apache.org/jira/browse/PHOENIX-628
> Project: Phoenix
> Issue Type: Task
> Affects Versions: 4.4.0
> Reporter: James Taylor
> Assignee: Aakash Pradeep
> Labels: JSON, Java, SQL
> Fix For: 4.4.0
>
>
> MongoDB and PostGres do some interesting things with JSON. We should look at
> adding similar support. For a detailed description, see JSONB support in
> Postgres:
> http://www.craigkerstiens.com/2014/03/24/Postgres-9.4-Looking-up
> http://www.depesz.com/2014/03/25/waiting-for-9-4-introduce-jsonb-a-structured-format-for-storing-json/
> http://michael.otacoo.com/postgresql-2/manipulating-jsonb-data-with-key-unique/
--
This message was sent by Atlassian JIRA
(v6.3.4#6332)
