Fix expression defining entire query in annotated repository methods.

This fix enables defining an entire JSON-based query in Query and Aggregate annotations using a single parameter or SpEL Expression.

Resolves: #3871
Original Pull Request: #3907

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/util/json/ParameterBindingDocumentCodec.java

@@ -20,7 +20,6 @@ import static org.bson.assertions.Assertions.*;
 import static org.bson.codecs.configuration.CodecRegistries.*;
 
 import java.util.ArrayList;
-import java.util.Collection;
 import java.util.Date;
 import java.util.List;
 import java.util.Map;
@@ -31,6 +30,7 @@ import org.bson.AbstractBsonReader.State;
 import org.bson.BsonBinarySubType;
 import org.bson.BsonDocument;
 import org.bson.BsonDocumentWriter;
+import org.bson.BsonInvalidOperationException;
 import org.bson.BsonReader;
 import org.bson.BsonType;
 import org.bson.BsonValue;
@@ -61,6 +61,7 @@ import org.springframework.util.StringUtils;
  * @author Ross Lawley
  * @author Ralph Schaer
  * @author Christoph Strobl
+ * @author Rocco Lagrotteria
  * @since 2.2
  */
 public class ParameterBindingDocumentCodec implements CollectibleCodec<Document> {
@@ -172,7 +173,7 @@ public class ParameterBindingDocumentCodec implements CollectibleCodec<Document>
 
 	public Document decode(@Nullable String json, ParameterBindingContext bindingContext) {
 
-		if (StringUtils.isEmpty(json)) {
+		if (!StringUtils.hasText(json)) {
 			return new Document();
 		}
 
@@ -193,7 +194,7 @@ public class ParameterBindingDocumentCodec implements CollectibleCodec<Document>
 	public ExpressionDependencies captureExpressionDependencies(@Nullable String json, ValueProvider valueProvider,
 			ExpressionParser expressionParser) {
 
-		if (StringUtils.isEmpty(json)) {
+		if (!StringUtils.hasText(json)) {
 			return ExpressionDependencies.none();
 		}
 
@@ -217,19 +218,24 @@ public class ParameterBindingDocumentCodec implements CollectibleCodec<Document>
 			if (bindingReader.currentValue instanceof org.bson.Document) {
 				return (Document) bindingReader.currentValue;
 			}
+
 		}
 
 		Document document = new Document();
-		reader.readStartDocument();
 
 		try {
 
+			reader.readStartDocument();
+
 			while (reader.readBsonType() != BsonType.END_OF_DOCUMENT) {
 				String fieldName = reader.readName();
 				Object value = readValue(reader, decoderContext);
 				document.put(fieldName, value);
 			}
-		} catch (JsonParseException e) {
+
+			reader.readEndDocument();
+
+		} catch (JsonParseException | BsonInvalidOperationException e) {
 			try {
 
 				Object value = readValue(reader, decoderContext);
@@ -244,8 +250,6 @@ public class ParameterBindingDocumentCodec implements CollectibleCodec<Document>
 			}
 		}
 
-		reader.readEndDocument();
-
 		return document;
 	}
 

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/util/json/ParameterBindingJsonReader.java

@@ -57,11 +57,12 @@ import org.springframework.util.ObjectUtils;
  * @author Florian Buecklers
  * @author Brendon Puntin
  * @author Christoph Strobl
+ * @author Rocco Lagrotteria
  * @since 2.2
  */
 public class ParameterBindingJsonReader extends AbstractBsonReader {
 
-	private static final Pattern PARAMETER_ONLY_BINDING_PATTERN = Pattern.compile("^\\?(\\d+)$");
+	private static final Pattern ENTIRE_QUERY_BINDING_PATTERN = Pattern.compile("^\\?(\\d+)$|^[\\?:]#\\{.*\\}$");
 	private static final Pattern PARAMETER_BINDING_PATTERN = Pattern.compile("\\?(\\d+)");
 	private static final Pattern EXPRESSION_BINDING_PATTERN = Pattern.compile("[\\?:]#\\{.*\\}");
 
@@ -70,7 +71,6 @@ public class ParameterBindingJsonReader extends AbstractBsonReader {
 	private final JsonScanner scanner;
 	private JsonToken pushedToken;
 	Object currentValue;
-	private Mark mark;
 
 	/**
 	 * Constructs a new instance with the given JSON string.
@@ -106,15 +106,8 @@ public class ParameterBindingJsonReader extends AbstractBsonReader {
 	public ParameterBindingJsonReader(String json, ValueProvider accessor, SpelExpressionParser spelExpressionParser,
 			Supplier<EvaluationContext> evaluationContext) {
 
-		this.scanner = new JsonScanner(json);
-		setContext(new Context(null, BsonContextType.TOP_LEVEL));
+		this(json, new ParameterBindingContext(accessor, spelExpressionParser, evaluationContext));
 
-		this.bindingContext = new ParameterBindingContext(accessor, spelExpressionParser, evaluationContext);
-
-		Matcher matcher = PARAMETER_ONLY_BINDING_PATTERN.matcher(json);
-		if (matcher.find()) {
-			currentValue = bindableValueFor(new JsonToken(JsonTokenType.UNQUOTED_STRING, json)).getValue();
-		}
 	}
 
 	public ParameterBindingJsonReader(String json, ParameterBindingContext bindingContext) {
@@ -124,10 +117,23 @@ public class ParameterBindingJsonReader extends AbstractBsonReader {
 
 		this.bindingContext = bindingContext;
 
-		Matcher matcher = PARAMETER_ONLY_BINDING_PATTERN.matcher(json);
+		Matcher matcher = ENTIRE_QUERY_BINDING_PATTERN.matcher(json);
 		if (matcher.find()) {
-			currentValue = bindableValueFor(new JsonToken(JsonTokenType.UNQUOTED_STRING, json)).getValue();
+			BindableValue bindingResult = bindableValueFor(new JsonToken(JsonTokenType.UNQUOTED_STRING, json));
+			try {
+
+				if (bindingResult.getValue() instanceof String) {
+					currentValue = Document.parse((String)bindingResult.getValue());
+				} else {
+					currentValue = bindingResult.getValue();
+				}
+
+			} catch (JsonParseException jsonParseException) {
+				throw new IllegalArgumentException(
+						String.format("Resulting value of expression '%s' is not a valid json query", json), jsonParseException);
+			}
 		}
+
 	}
 
 	// Spring Data Customization END

spring-data-mongodb/src/test/java/org/springframework/data/mongodb/util/json/ParameterBindingJsonReaderUnitTests.java

@@ -41,6 +41,7 @@ import org.springframework.expression.spel.support.StandardEvaluationContext;
  *
  * @author Christoph Strobl
  * @author Mark Paluch
+ * @author Rocco Lagrotteria
  */
 class ParameterBindingJsonReaderUnitTests {
 
@@ -192,7 +193,6 @@ class ParameterBindingJsonReaderUnitTests {
 	@Test // DATAMONGO-2315
 	void bindStringAsDate() {
 
-		Date date = new Date();
 		Document target = parse("{ 'end_date' : { $gte : { $date : ?0 } } }", "2019-07-04T12:19:23.000Z");
 
 		assertThat(target).isEqualTo(Document.parse("{ 'end_date' : { $gte : { $date : '2019-07-04T12:19:23.000Z' } } } "));
@@ -347,7 +347,7 @@ class ParameterBindingJsonReaderUnitTests {
 		evaluationContext.setRootObject(new DummySecurityObject(new DummyWithId("wonderwoman")));
 
 		String json = "?#{  T(" + this.getClass().getName()
-				+ ").isBatman() ? {'_class': { '$eq' : 'region' }} : { '$and' : { {'_class': { '$eq' : 'region' } }, {'user.supervisor':  principal.id } } } }";
+				+ ").isBatman() ? \"{'_class': { '$eq' : 'region' }}\" : \"{ '$and' : [ {'_class': { '$eq' : 'region' } }, {'user.supervisor': '\"+ principal.id +\"' } ] }\" }";
 
 		ParameterBindingJsonReader reader = new ParameterBindingJsonReader(json,
 				new ParameterBindingContext((index) -> args[index], new SpelExpressionParser(), evaluationContext));
@@ -357,6 +357,43 @@ class ParameterBindingJsonReaderUnitTests {
 				.isEqualTo(new Document("$and", Arrays.asList(new Document("_class", new Document("$eq", "region")),
 						new Document("user.supervisor", "wonderwoman"))));
 	}
+	
+	@Test
+	void bindEntireQueryUsingSpelExpression() {
+
+		Object[] args = new Object[] {"region"};
+		StandardEvaluationContext evaluationContext = (StandardEvaluationContext) EvaluationContextProvider.DEFAULT
+				.getEvaluationContext(args);
+		evaluationContext.setRootObject(new DummySecurityObject(new DummyWithId("wonderwoman")));
+
+		String json = "?#{  T(" + this.getClass().getName() + ").applyFilterByUser('?0' ,principal.id) }";
+
+		ParameterBindingJsonReader reader = new ParameterBindingJsonReader(json,
+				new ParameterBindingContext((index) -> args[index], new SpelExpressionParser(), evaluationContext));
+		Document target = new ParameterBindingDocumentCodec().decode(reader, DecoderContext.builder().build());
+
+		assertThat(target)
+				.isEqualTo(new Document("$and", Arrays.asList(new Document("_class", new Document("$eq", "region")),
+						new Document("user.supervisor", "wonderwoman"))));
+	}
+
+	@Test
+	void bindEntireQueryUsingParameter() {
+
+		Object[] args = new Object[] {"{ 'itWorks' : true }"};
+		StandardEvaluationContext evaluationContext = (StandardEvaluationContext) EvaluationContextProvider.DEFAULT
+				.getEvaluationContext(args);
+
+		String json = "?0";
+
+		ParameterBindingJsonReader reader = new ParameterBindingJsonReader(json,
+				new ParameterBindingContext((index) -> args[index], new SpelExpressionParser(), evaluationContext));
+		Document target = new ParameterBindingDocumentCodec().decode(reader, DecoderContext.builder().build());
+
+		assertThat(target)
+				.isEqualTo(new Document("itWorks", true));
+		
+	}
 
 	@Test // DATAMONGO-2571
 	void shouldParseRegexCorrectly() {
@@ -400,6 +437,19 @@ class ParameterBindingJsonReaderUnitTests {
 	public static boolean isBatman() {
 		return false;
 	}
+	
+	public static String applyFilterByUser(String _class, String username) {
+		switch (username) {
+			case "batman":
+				return "{'_class': { '$eq' : '"
+						+ _class
+						+ "' }}";
+			default:
+				return "{ '$and' : [ {'_class': { '$eq' : '"
+						+ _class
+						+ "' } }, {'user.supervisor':  '" + username + "' } ] }";
+		}
+	}
 
 	@Data
 	@AllArgsConstructor