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https://issues.apache.org/jira/browse/NIFI-360?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14340835#comment-14340835
]
ASF GitHub Bot commented on NIFI-360:
-------------------------------------
Github user markap14 commented on a diff in the pull request:
https://github.com/apache/incubator-nifi/pull/28#discussion_r25540061
--- Diff:
nifi/nifi-nar-bundles/nifi-standard-bundle/nifi-standard-processors/src/main/java/org/apache/nifi/processors/standard/util/JsonUtils.java
---
@@ -0,0 +1,127 @@
+/*
+ * 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.nifi.processors.standard.util;
+
+import com.jayway.jsonpath.Configuration;
+import com.jayway.jsonpath.DocumentContext;
+import com.jayway.jsonpath.InvalidPathException;
+import com.jayway.jsonpath.JsonPath;
+import com.jayway.jsonpath.spi.json.JsonProvider;
+import net.minidev.json.JSONValue;
+import org.apache.nifi.components.ValidationContext;
+import org.apache.nifi.components.ValidationResult;
+import org.apache.nifi.components.Validator;
+import org.apache.nifi.flowfile.FlowFile;
+import org.apache.nifi.processor.ProcessSession;
+import org.apache.nifi.processor.io.InputStreamCallback;
+import org.apache.nifi.stream.io.BufferedInputStream;
+import org.apache.nifi.util.BooleanHolder;
+import org.apache.nifi.util.ObjectHolder;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.InputStreamReader;
+import java.util.List;
+import java.util.Map;
+
+/**
+ * Provides utilities for interacting with JSON elements and JsonPath
expressions and results
+ *
+ * @see <a href="http://json.org";>http://json.org</a>
+ * @see <a
href="https://github.com/jayway/JsonPath";>https://github.com/jayway/JsonPath</a>
+ */
+public class JsonUtils {
+
+ static final JsonProvider JSON_PROVIDER =
Configuration.defaultConfiguration().jsonProvider();
+
+ public static final Validator JSON_PATH_VALIDATOR = new Validator() {
+ @Override
+ public ValidationResult validate(final String subject, final
String input, final ValidationContext context) {
+ String error = null;
+ try {
+ JsonPath compile = JsonPath.compile(input);
+ } catch (InvalidPathException ipe) {
+ error = ipe.toString();
+ }
+ return new ValidationResult.Builder().valid(error ==
null).explanation(error).build();
+ }
+ };
+
+ public static DocumentContext
validateAndEstablishJsonContext(ProcessSession processSession, FlowFile
flowFile) {
+
+ final BooleanHolder validJsonHolder = new BooleanHolder(false);
+ processSession.read(flowFile, new InputStreamCallback() {
+ @Override
+ public void process(InputStream in) throws IOException {
+ validJsonHolder.set(JsonUtils.isValidJson(in));
+ }
+ });
+
+ // Parse the document once into an associated context to support
multiple path evaluations if specified
+ final ObjectHolder<DocumentContext> contextHolder = new
ObjectHolder<>(null);
+
+ if (validJsonHolder.get()) {
+ processSession.read(flowFile, new InputStreamCallback() {
--- End diff --
Do we need to read the content to validate it above and then read it again
here? Can we just assume that it's valid unless an Exception is thrown?
> Create Processors to work against JSON data
> -------------------------------------------
>
> Key: NIFI-360
> URL: https://issues.apache.org/jira/browse/NIFI-360
> Project: Apache NiFi
> Issue Type: New Feature
> Components: Extensions
> Reporter: Aldrin Piri
> Assignee: Aldrin Piri
> Priority: Minor
> Labels: processor
>
> I have created two Processors, EvaluateJsonPath and SplitJson which are
> analogs of the functionality provided through EvaluateXPath and SpiltXML.
> Both are powered primarily around the usage of [JsonPath by
> Jayway|https://github.com/jayway/JsonPath].
> Their capability descriptions are provided below:
> {panel:title= EvaluateJsonPath}
> Evaluates one or more JsonPath expressions against the content of a FlowFile.
> The results of those expressions are assigned to FlowFile Attributes or are
> written to the content of the FlowFile itself, depending on configuration of
> the Processor. JsonPaths are entered by adding user-defined properties; the
> name of the property maps to the Attribute Name into which the result will be
> placed (if the Destination is flowfile-attribute; otherwise, the property
> name is ignored).
> The value of the property must be a valid JsonPath expression. If the
> JsonPath evaluates to a JSON array or JSON object and the Return Type is set
> to 'scalar' the FlowFile will be unmodified and will be routed to failure. A
> Return Type of JSON can return scalar values if the provided JsonPath
> evaluates to the specified value and will be routed as a match. If
> Destination is 'flowfile-content' and the JsonPath does not evaluate to a
> defined path, the FlowFile will be routed to 'unmatched' without having its
> contents modified. If Destination is flowfile-attribute and the expression
> matches nothing, attributes will be created with empty strings as the value,
> and the FlowFile will always be routed to 'matched.'
> {panel}
> {panel:title=SplitJson}
> Splits a JSON File into multiple, separate FlowFiles for an array element
> specified by a JsonPath expression. Each generated FlowFile is comprised of
> an element of the specified array and transferred to relationship 'split,
> with the original file transferred to the 'original' relationship. If the
> specified JsonPath is not found or does not evaluate to an array element,
> the original file is routed to 'failure' and no files are generated.
> {panel}
> One item of note is the transitive dependency of ASM through Json-Smart
> through JsonPath.
> I have included, what I believe is needed to appropriately make use of this
> item in the LICENSE. Review of its correctness would is requested.
> Any feedback is appreciated. Thanks!
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