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https://issues.apache.org/jira/browse/HAWQ-178?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15132125#comment-15132125
]
ASF GitHub Bot commented on HAWQ-178:
-------------------------------------
Github user tzolov commented on a diff in the pull request:
https://github.com/apache/incubator-hawq/pull/302#discussion_r51856329
--- Diff:
pxf/pxf-json/src/main/java/org/apache/hawq/pxf/plugins/json/JsonResolver.java
---
@@ -0,0 +1,255 @@
+package org.apache.hawq.pxf.plugins.json;
+
+/*
+ * 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.
+ */
+
+import java.io.IOException;
+import java.util.ArrayList;
+import java.util.Iterator;
+import java.util.List;
+
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
+import org.apache.hawq.pxf.api.OneField;
+import org.apache.hawq.pxf.api.OneRow;
+import org.apache.hawq.pxf.api.ReadResolver;
+import org.apache.hawq.pxf.api.io.DataType;
+import org.apache.hawq.pxf.api.utilities.ColumnDescriptor;
+import org.apache.hawq.pxf.api.utilities.InputData;
+import org.apache.hawq.pxf.api.utilities.Plugin;
+import org.codehaus.jackson.JsonFactory;
+import org.codehaus.jackson.JsonNode;
+import org.codehaus.jackson.map.ObjectMapper;
+
+/**
+ * This JSON resolver for PXF will decode a given object from the {@link
JsonAccessor} into a row for HAWQ. It will
+ * decode this data into a JsonNode and walk the tree for each column. It
supports normal value mapping via projections
+ * and JSON array indexing.
+ */
+public class JsonResolver extends Plugin implements ReadResolver {
+
+ private static final Log LOG = LogFactory.getLog(JsonResolver.class);
+
+ private ArrayList<OneField> oneFieldList;
+ private ColumnDescriptorCache[] columnDescriptorCache;
+ private ObjectMapper mapper;
+
+ public JsonResolver(InputData inputData) throws Exception {
+ super(inputData);
+ oneFieldList = new ArrayList<OneField>();
+ mapper = new ObjectMapper(new JsonFactory());
+
+ // Pre-generate all column structure attributes concerning the
JSON to column value resolution.
+ columnDescriptorCache = new
ColumnDescriptorCache[inputData.getColumns()];
+ for (int i = 0; i < inputData.getColumns(); ++i) {
+ ColumnDescriptor cd = inputData.getColumn(i);
+ columnDescriptorCache[i] = new
ColumnDescriptorCache(cd);
+ }
+ }
+
+ @Override
+ public List<OneField> getFields(OneRow row) throws Exception {
+ oneFieldList.clear();
+
+ String jsonRecordAsText = row.getData().toString();
+
+ JsonNode root = decodeLineToJsonNode(jsonRecordAsText);
+
+ if (root == null) {
+ LOG.warn("Return null-fields row due to invalid JSON:"
+ jsonRecordAsText);
--- End diff --
+1
> Add JSON plugin support in code base
> ------------------------------------
>
> Key: HAWQ-178
> URL: https://issues.apache.org/jira/browse/HAWQ-178
> Project: Apache HAWQ
> Issue Type: New Feature
> Components: PXF
> Reporter: Goden Yao
> Assignee: Christian Tzolov
> Fix For: backlog
>
> Attachments: PXFJSONPluginforHAWQ2.0andPXF3.0.0.pdf,
> PXFJSONPluginforHAWQ2.0andPXF3.0.0v.2.pdf,
> PXFJSONPluginforHAWQ2.0andPXF3.0.0v.3.pdf
>
>
> JSON has been a popular format used in HDFS as well as in the community,
> there has been a few JSON PXF plugins developed by the community and we'd
> like to see it being incorporated into the code base as an optional package.
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