NIFI-8613: Improve FlattenJson Processor #5083
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Thanks for the contribution @naddym! The addition of the unflatten option looks useful. The changes look good in general, I noted a few a couple questions about the character set expectations and included a recommendation to adjust error logging.
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| flowFile = session.write(flowFile, os -> os.write(flattened.getBytes())); | ||
| final StringBuilder contents = new StringBuilder(); | ||
| session.read(flowFile, in -> contents.append(IOUtils.toString(in, Charset.defaultCharset()))); |
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Although the previous approach relied on the system default character set when converting from byte array to string, what do you think about either making UTF-8 the standard character set, or adding a new processor property to configure the character set?
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Yeah, let me add new character set property to stay consistent with other processors. Thanks.
| .unflatten(); | ||
| } | ||
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| flowFile = session.write(flowFile, out -> out.write(resultedJson.getBytes())); |
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Related to the comment on handling input, specifying a character set on String.getBytes() would clarify the expected output as opposed to relying on the system defaults.
| if (returnType.equals(RETURN_TYPE_FLATTEN)) { | ||
| resultedJson = new JsonFlattener(contents.toString()) | ||
| .withFlattenMode(flattenMode) | ||
| .withSeparator(separator.charAt(0)) |
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The separator character could be declared once outside of the conditional and reused as opposed to calling separator.charAt(0) in both conditional blocks.
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| session.transfer(flowFile, REL_SUCCESS); | ||
| } catch (Exception ex) { | ||
| } catch (Exception e) { | ||
| getLogger().error("Failed to {} json due to {}", new Object[]{returnType, e}); |
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Recent updates to the logger interface now allow passing placeholder values as variable arguments. If the goal is to include the stack trace of the exception, which would be helpful, then the second placeholder should be removed from the log message string.
| getLogger().error("Failed to {} json due to {}", new Object[]{returnType, e}); | |
| getLogger().error("Failed to {} JSON", returnType, e); |
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Thank you @exceptionfactory for the detailed review. All suggestions pointed out looks good, will work on changing them.. |
| @@ -157,25 +203,36 @@ public void onTrigger(final ProcessContext context, final ProcessSession session | |||
| final String mode = context.getProperty(FLATTEN_MODE).getValue(); | |||
| final FlattenMode flattenMode = getFlattenMode(mode); | |||
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| String separator = context.getProperty(SEPARATOR).evaluateAttributeExpressions(flowFile).getValue(); | |||
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| final Character separator = context.getProperty(SEPARATOR).evaluateAttributeExpressions(flowFile).getValue().charAt(0; | |||
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Thanks for making the updates @naddym, looks like the automated builds failed due to missing a trailing ) on this line.
| final Character separator = context.getProperty(SEPARATOR).evaluateAttributeExpressions(flowFile).getValue().charAt(0; | |
| final Character separator = context.getProperty(SEPARATOR).evaluateAttributeExpressions(flowFile).getValue().charAt(0); |
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Oh, Somehow missed it while copying after test. Thanks again for commenting.
- Unflattening a flattened json - Preserving primitive arrays such as strings, numbers, booleans and null in a nested json - Logging errors when failure - Pretty printing resulted json
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Tested flatten and unflatten operations, changes look good, thanks @naddym! +1 Merging.
- Unflattening a flattened json - Preserving primitive arrays such as strings, numbers, booleans and null in a nested json - Logging errors when failure - Pretty printing resulted json This closes apache#5083 Signed-off-by: David Handermann <exceptionfactory@apache.org>
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Improvement to FlattenJson Processor has following changes:
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