NIFI-5261: Added JSON_VALIDATOR to StandardValidators

This closes #2758

Signed-off-by: Mike Thomsen <mikerthomsen@gmail.com>

nifi-commons/nifi-utils/pom.xml

@@ -40,5 +40,10 @@
             <artifactId>nifi-api</artifactId>
             <version>1.7.0-SNAPSHOT</version>
         </dependency>
+        <dependency>
+            <groupId>com.google.code.gson</groupId>
+            <artifactId>gson</artifactId>
+            <version>2.8.1</version>
+        </dependency>
     </dependencies>
 </project>

nifi-commons/nifi-utils/src/main/java/org/apache/nifi/processor/util/StandardValidators.java

@@ -30,6 +30,9 @@ import java.util.List;
 import java.util.concurrent.TimeUnit;
 import java.util.regex.Pattern;
 
+import com.google.gson.Gson;
+import com.google.gson.JsonElement;
+import com.google.gson.JsonSyntaxException;
 import org.apache.nifi.components.PropertyValue;
 import org.apache.nifi.components.ValidationContext;
 import org.apache.nifi.components.ValidationResult;
@@ -480,6 +483,25 @@ public class StandardValidators {
 
     public static final Validator FILE_EXISTS_VALIDATOR = new FileExistsValidator(true);
 
+    /**
+     * {@link Validator} that ensures the value is a valid JSON
+     */
+    public static final Validator JSON_VALIDATOR = (subject, input, context) -> {
+        if (context.isExpressionLanguageSupported(subject) && context.isExpressionLanguagePresent(input)) {
+            return new ValidationResult.Builder().subject(subject).input(input).explanation("Expression Language Present").valid(true).build();
+        }
+
+        try {
+            new Gson().fromJson(input, JsonElement.class);
+        } catch (JsonSyntaxException e) {
+            return new ValidationResult.Builder().subject(subject).input(input).valid(false)
+                    .explanation(subject + " is not a valid JSON representation due to " + e.getLocalizedMessage())
+                    .build();
+        }
+
+        return new ValidationResult.Builder().subject(subject).input(input).valid(true).build();
+    };
+
     //
     //
     // FACTORY METHODS FOR VALIDATORS

nifi-commons/nifi-utils/src/test/java/org/apache/nifi/util/validator/TestStandardValidators.java

@@ -288,4 +288,42 @@ public class TestStandardValidators {
         vr = val.validate("foo", "2016-01-01T01:01:01.000Z", vc);
         assertTrue(vr.isValid());
     }
+
+    @Test
+    public void testJSONObjectValidator() {
+        final Validator validator = StandardValidators.JSON_VALIDATOR;
+        final ValidationContext context = mock(ValidationContext.class);
+        final String DUMMY_JSON_PROPERTY = "JSONProperty";
+        ValidationResult validationResult;
+
+        // Flat JSON
+        validationResult = validator.validate(DUMMY_JSON_PROPERTY,"{\"Name\" : \"Crockford, Douglas\"}", context);
+        assertTrue(validationResult.isValid());
+
+        // Nested JSON
+        validationResult = validator.validate(DUMMY_JSON_PROPERTY, "{ \"Name\" : \"Crockford, Douglas\", \"ContactInfo\": { \"Mobile\" : 0987654321, \"Email\" : \"mrx@xyz.zyx\" } }", context);
+        assertTrue(validationResult.isValid());
+
+        // JSON object with JSON array
+        validationResult = validator.validate(DUMMY_JSON_PROPERTY, "{ \"name\":\"Smith, John\", \"age\":30, \"cars\":[ \"Ford\", \"BMW\", \"Fiat\" ] } ", context);
+        assertTrue(validationResult.isValid());
+
+        // JSON array
+        validationResult = validator.validate(DUMMY_JSON_PROPERTY, "[\"one\", \"two\", \"three\"]", context);
+        assertTrue(validationResult.isValid());
+
+        // JSON Primitives
+        validationResult = validator.validate(DUMMY_JSON_PROPERTY, "bncjbhjfjhj", context);
+        assertTrue(validationResult.isValid());
+
+        // Empty JSON
+        validationResult = validator.validate(DUMMY_JSON_PROPERTY, "{}", context);
+        assertTrue(validationResult.isValid());
+
+        // Invalid JSON
+        validationResult = validator.validate(DUMMY_JSON_PROPERTY, "\"Name\" : \"Smith, John\"", context);
+        assertFalse(validationResult.isValid());
+        assertTrue(validationResult.getExplanation().contains("not a valid JSON representation"));
+
+    }
 }

nifi-nar-bundles/nifi-elasticsearch-bundle/nifi-elasticsearch-restapi-processors/src/main/java/org/apache/nifi/processors/elasticsearch/ElasticSearchRestProcessor.java

@@ -55,7 +55,7 @@ public interface ElasticSearchRestProcessor {
                     "If this parameter is not set, the query will be read from the flowfile content.")
             .required(false)
             .expressionLanguageSupported(ExpressionLanguageScope.FLOWFILE_ATTRIBUTES)
-            .addValidator(StandardValidators.NON_EMPTY_VALIDATOR)
+            .addValidator(StandardValidators.JSON_VALIDATOR)
             .build();
     PropertyDescriptor QUERY_ATTRIBUTE = new PropertyDescriptor.Builder()
             .name("el-query-attribute")

nifi-nar-bundles/nifi-gcp-bundle/nifi-gcp-processors/src/main/java/org/apache/nifi/processors/gcp/credentials/factory/CredentialPropertyDescriptors.java

@@ -83,7 +83,7 @@ public final class CredentialPropertyDescriptors {
             .displayName("Service Account JSON")
             .expressionLanguageSupported(ExpressionLanguageScope.VARIABLE_REGISTRY)
             .required(false)
-            .addValidator(StandardValidators.NON_EMPTY_VALIDATOR)
+            .addValidator(StandardValidators.JSON_VALIDATOR)
             .description("The raw JSON containing a Service Account keyfile.")
             .sensitive(true)
             .build();

nifi-nar-bundles/nifi-mongodb-bundle/nifi-mongodb-processors/src/main/java/org/apache/nifi/processors/mongodb/GetMongo.java

@@ -29,7 +29,6 @@ import org.apache.nifi.annotation.documentation.CapabilityDescription;
 import org.apache.nifi.annotation.documentation.Tags;
 import org.apache.nifi.components.AllowableValue;
 import org.apache.nifi.components.PropertyDescriptor;
-import org.apache.nifi.components.ValidationResult;
 import org.apache.nifi.components.Validator;
 import org.apache.nifi.expression.ExpressionLanguageScope;
 import org.apache.nifi.flowfile.FlowFile;
@@ -60,23 +59,6 @@ import java.util.Set;
 @InputRequirement(Requirement.INPUT_ALLOWED)
 @CapabilityDescription("Creates FlowFiles from documents in MongoDB")
 public class GetMongo extends AbstractMongoProcessor {
-    public static final Validator DOCUMENT_VALIDATOR = (subject, value, context) -> {
-        final ValidationResult.Builder builder = new ValidationResult.Builder();
-        builder.subject(subject).input(value);
-
-        if (context.isExpressionLanguageSupported(subject) && context.isExpressionLanguagePresent(value)) {
-            return builder.valid(true).explanation("Contains Expression Language").build();
-        }
-
-        String reason = null;
-        try {
-            Document.parse(value);
-        } catch (final RuntimeException e) {
-            reason = e.getLocalizedMessage();
-        }
-
-        return builder.explanation(reason).valid(reason == null).build();
-    };
 
     static final Relationship REL_SUCCESS = new Relationship.Builder().name("success").description("All files are routed to success").build();
     static final Relationship REL_FAILURE = new Relationship.Builder()
@@ -97,7 +79,7 @@ public class GetMongo extends AbstractMongoProcessor {
                 "that will result in a full collection fetch using a \"{}\" query.")
         .required(false)
         .expressionLanguageSupported(ExpressionLanguageScope.FLOWFILE_ATTRIBUTES)
-        .addValidator(DOCUMENT_VALIDATOR)
+        .addValidator(StandardValidators.JSON_VALIDATOR)
         .build();
 
     static final PropertyDescriptor PROJECTION = new PropertyDescriptor.Builder()
@@ -105,14 +87,14 @@ public class GetMongo extends AbstractMongoProcessor {
             .description("The fields to be returned from the documents in the result set; must be a valid BSON document")
             .required(false)
             .expressionLanguageSupported(ExpressionLanguageScope.FLOWFILE_ATTRIBUTES)
-            .addValidator(DOCUMENT_VALIDATOR)
+            .addValidator(StandardValidators.JSON_VALIDATOR)
             .build();
     static final PropertyDescriptor SORT = new PropertyDescriptor.Builder()
             .name("Sort")
             .description("The fields by which to sort; must be a valid BSON document")
             .required(false)
             .expressionLanguageSupported(ExpressionLanguageScope.FLOWFILE_ATTRIBUTES)
-            .addValidator(DOCUMENT_VALIDATOR)
+            .addValidator(StandardValidators.JSON_VALIDATOR)
             .build();
     static final PropertyDescriptor LIMIT = new PropertyDescriptor.Builder()
             .name("Limit")

nifi-nar-bundles/nifi-mongodb-bundle/nifi-mongodb-processors/src/main/java/org/apache/nifi/processors/mongodb/PutMongo.java

@@ -100,7 +100,7 @@ public class PutMongo extends AbstractMongoProcessor {
         .displayName("Update Query")
         .description("Specify a full MongoDB query to be used for the lookup query to do an update/upsert.")
         .required(false)
-        .addValidator(StandardValidators.NON_BLANK_VALIDATOR)
+        .addValidator(StandardValidators.JSON_VALIDATOR)
         .expressionLanguageSupported(ExpressionLanguageScope.FLOWFILE_ATTRIBUTES)
         .build();
 

nifi-nar-bundles/nifi-mongodb-bundle/nifi-mongodb-processors/src/main/java/org/apache/nifi/processors/mongodb/RunMongoAggregation.java

@@ -28,14 +28,13 @@ import org.apache.nifi.annotation.behavior.InputRequirement;
 import org.apache.nifi.annotation.documentation.CapabilityDescription;
 import org.apache.nifi.annotation.documentation.Tags;
 import org.apache.nifi.components.PropertyDescriptor;
-import org.apache.nifi.components.ValidationResult;
-import org.apache.nifi.components.Validator;
 import org.apache.nifi.expression.ExpressionLanguageScope;
 import org.apache.nifi.flowfile.FlowFile;
 import org.apache.nifi.processor.ProcessContext;
 import org.apache.nifi.processor.ProcessSession;
 import org.apache.nifi.processor.Relationship;
 import org.apache.nifi.processor.exception.ProcessException;
+import org.apache.nifi.processor.util.StandardValidators;
 import org.bson.Document;
 import org.bson.conversions.Bson;
 import com.fasterxml.jackson.databind.ObjectMapper;
@@ -83,31 +82,13 @@ public class RunMongoAggregation extends AbstractMongoProcessor {
         return result;
     }
 
-    public static final Validator AGG_VALIDATOR = (subject, value, context) -> {
-        final ValidationResult.Builder builder = new ValidationResult.Builder();
-        builder.subject(subject).input(value);
-
-        if (context.isExpressionLanguageSupported(subject) && context.isExpressionLanguagePresent(value)) {
-            return builder.valid(true).explanation("Contains Expression Language").build();
-        }
-
-        String reason = null;
-        try {
-            buildAggregationQuery(value);
-        } catch (final RuntimeException | IOException e) {
-            reason = e.getLocalizedMessage();
-        }
-
-        return builder.explanation(reason).valid(reason == null).build();
-    };
-
     static final PropertyDescriptor QUERY = new PropertyDescriptor.Builder()
             .name("mongo-agg-query")
             .displayName("Query")
             .expressionLanguageSupported(ExpressionLanguageScope.FLOWFILE_ATTRIBUTES)
             .description("The aggregation query to be executed.")
             .required(true)
-            .addValidator(AGG_VALIDATOR)
+            .addValidator(StandardValidators.JSON_VALIDATOR)
             .build();
 
     static {