Java Code Examples for org.apache.nifi.components.PropertyValue#isExpressionLanguagePresent()

@OnEnabled
public void storeSchemaWriteStrategy(final ConfigurationContext context) {
    this.configurationContext = context;

    // If Schema Protocol Version is specified without EL then we can create it up front, otherwise when
    // EL is present we will re-create it later so we can re-evaluate the EL against the incoming variables

    final String strategy = context.getProperty(getSchemaWriteStrategyDescriptor()).getValue();
    if (strategy != null) {
        final RecordSchemaCacheService recordSchemaCacheService = context.getProperty(SCHEMA_CACHE).asControllerService(RecordSchemaCacheService.class);

        final PropertyValue protocolVersionValue = getConfigurationContext().getProperty(SCHEMA_PROTOCOL_VERSION);
        if (!protocolVersionValue.isExpressionLanguagePresent()) {
            final int protocolVersion = context.getProperty(SCHEMA_PROTOCOL_VERSION).asInteger();
            this.schemaAccessWriter = createSchemaWriteStrategy(strategy, protocolVersion, recordSchemaCacheService);
        }
    }
}
 

protected SchemaAccessWriter getSchemaAccessWriter(final RecordSchema schema, final Map<String,String> variables) throws SchemaNotFoundException {
    // If Schema Protocol Version is using expression language, then we reevaluate against the passed in variables
    final PropertyValue protocolVersionValue = getConfigurationContext().getProperty(SCHEMA_PROTOCOL_VERSION);
    if (protocolVersionValue.isExpressionLanguagePresent()) {
        final int protocolVersion;
        final String protocolVersionString = protocolVersionValue.evaluateAttributeExpressions(variables).getValue();
        try {
            protocolVersion = Integer.parseInt(protocolVersionString);
        } catch (NumberFormatException nfe) {
            throw new SchemaNotFoundException("Unable to create Schema Write Strategy because " + SCHEMA_PROTOCOL_VERSION.getDisplayName()
                    + " must be a positive integer, but was '" + protocolVersionString + "'", nfe);
        }

        // Now recreate the SchemaAccessWriter since we may have a new value for Schema Protocol Version
        final String strategy = getConfigurationContext().getProperty(getSchemaWriteStrategyDescriptor()).getValue();
        if (strategy != null) {
            final RecordSchemaCacheService recordSchemaCacheService = getConfigurationContext().getProperty(SCHEMA_CACHE).asControllerService(RecordSchemaCacheService.class);
            schemaAccessWriter = createSchemaWriteStrategy(strategy, protocolVersion, recordSchemaCacheService);
        }
    }

    schemaAccessWriter.validateSchema(schema);
    return schemaAccessWriter;
}
 

@Override
protected Collection<ValidationResult> customValidate(ValidationContext validationContext) {
    List<ValidationResult> results = new ArrayList<>(super.customValidate(validationContext));
    final PropertyValue columnForPartitioning = validationContext.getProperty(COLUMN_FOR_VALUE_PARTITIONING);
    // If no EL is present, ensure it's a single column (i.e. no commas in the property value)
    if (columnForPartitioning.isSet() && !columnForPartitioning.isExpressionLanguagePresent() && columnForPartitioning.getValue().contains(",")) {
        results.add(new ValidationResult.Builder().valid(false).explanation(
                COLUMN_FOR_VALUE_PARTITIONING.getDisplayName() + " requires a single column name, but a comma was detected").build());
    }

    return results;
}
 

@Override
protected Collection<ValidationResult> customValidate(ValidationContext validationContext) {
    List<ValidationResult> results = new ArrayList<>(super.customValidate(validationContext));

    PropertyValue cacheEntryIdentifier = validationContext.getProperty(PROP_CACHE_ENTRY_IDENTIFIER);
    boolean elPresent = false;
    try {
        elPresent = cacheEntryIdentifier.isExpressionLanguagePresent();
    } catch (NullPointerException npe) {
        // Unfortunate workaround to a mock framework bug (NIFI-4590)
    }

    if (elPresent) {
        // This doesn't do a full job of validating against the requirement that Put Cache Value In Attribute must be set if multiple
        // Cache Entry Identifiers are supplied (if Expression Language is used). The user could conceivably have a comma-separated list of EL statements,
        // or a single EL statement with commas inside it but that evaluates to a single item.
        results.add(new ValidationResult.Builder().valid(true).explanation("Contains Expression Language").build());
    } else {
        if (!validationContext.getProperty(FetchDistributedMapCache.PROP_PUT_CACHE_VALUE_IN_ATTRIBUTE).isSet()) {
            String identifierString = cacheEntryIdentifier.getValue();
            if (identifierString.contains(",")) {
                results.add(new ValidationResult.Builder().valid(false)
                        .explanation("Multiple Cache Entry Identifiers specified without Put Cache Value In Attribute set").build());
            }
        }
    }
    return results;
}
 

@Test
public void testisExpressionLanguagePresentShouldHandleNPE() {
    // Arrange
    final PropertyValue value = new StandardPropertyValue(null, lookup, ParameterLookup.EMPTY, null, null);

    // Act
    boolean elPresent = value.isExpressionLanguagePresent();

    // Assert
    assertFalse(elPresent);
}