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https://issues.apache.org/jira/browse/NIFI-360?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14341879#comment-14341879
]
ASF GitHub Bot commented on NIFI-360:
-------------------------------------
Github user apiri commented on a diff in the pull request:
https://github.com/apache/incubator-nifi/pull/28#discussion_r25563122
--- 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 --
Yeah, looking at what that method is actually doing is just catching an
exception when parsing it instead of just inspecting. Good catch. Have to see
what the API provides, but seems like it is not buying much.
> 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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