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DATAMONGO-1005 - Improve cycle-detection for DbRef's.

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Introduced ObjectPath that collects the target objects while converting a DBObject to a domain object. If we detect that a potentially nested DBRef points to an object that is already under construction we simply return a reference to that object in order to avoid StackOverFlowErrors.

Original pull request: #209.
This commit is contained in:
Thomas Darimont
2014-07-24 16:33:51 +02:00
committed by Oliver Gierke
parent f9ccf4f532
commit c5ff7cdb2b
2 changed files with 273 additions and 29 deletions
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241
spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/convert/MappingMongoConverter.java
View File

@@ -20,6 +20,7 @@ import java.util.Arrays;
import java.util.Collection;
import java.util.Collections;
import java.util.HashSet;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Map.Entry;
@@ -185,11 +186,11 @@ public class MappingMongoConverter extends AbstractMongoConverter implements App
}
protected <S extends Object> S read(TypeInformation<S> type, DBObject dbo) {
return read(type, dbo, null);
return read(type, dbo, ObjectPath.toObjectPath(null));
}
@SuppressWarnings("unchecked")
protected <S extends Object> S read(TypeInformation<S> type, DBObject dbo, Object parent) {
private <S extends Object> S read(TypeInformation<S> type, DBObject dbo, ObjectPath objectPath) {
if (null == dbo) {
return null;
@@ -207,11 +208,11 @@ public class MappingMongoConverter extends AbstractMongoConverter implements App
}
if (typeToUse.isCollectionLike() && dbo instanceof BasicDBList) {
return (S) readCollectionOrArray(typeToUse, (BasicDBList) dbo, parent);
return (S) readCollectionOrArray(typeToUse, (BasicDBList) dbo, objectPath);
}
if (typeToUse.isMap()) {
return (S) readMap(typeToUse, dbo, parent);
return (S) readMap(typeToUse, dbo, objectPath);
}
// Retrieve persistent entity info
@@ -221,40 +222,55 @@ public class MappingMongoConverter extends AbstractMongoConverter implements App
throw new MappingException("No mapping metadata found for " + rawType.getName());
}
return read(persistentEntity, dbo, parent);
return read(persistentEntity, dbo, objectPath);
}
private ParameterValueProvider<MongoPersistentProperty> getParameterProvider(MongoPersistentEntity<?> entity,
DBObject source, DefaultSpELExpressionEvaluator evaluator, Object parent) {
DBObject source, DefaultSpELExpressionEvaluator evaluator, ObjectPath objectPath) {
MongoDbPropertyValueProvider provider = new MongoDbPropertyValueProvider(source, evaluator, parent);
MongoDbPropertyValueProvider provider = new MongoDbPropertyValueProvider(source, evaluator, objectPath);
PersistentEntityParameterValueProvider<MongoPersistentProperty> parameterProvider = new PersistentEntityParameterValueProvider<MongoPersistentProperty>(
entity, provider, parent);
entity, provider, objectPath.getCurrentObject());
return new ConverterAwareSpELExpressionParameterValueProvider(evaluator, conversionService, parameterProvider,
parent);
objectPath.getCurrentObject());
}
private <S extends Object> S read(final MongoPersistentEntity<S> entity, final DBObject dbo, final Object parent) {
private <S extends Object> S read(final MongoPersistentEntity<S> entity, final DBObject dbo,
final ObjectPath parentPath) {
final DefaultSpELExpressionEvaluator evaluator = new DefaultSpELExpressionEvaluator(dbo, spELContext);
ParameterValueProvider<MongoPersistentProperty> provider = getParameterProvider(entity, dbo, evaluator, parent);
ParameterValueProvider<MongoPersistentProperty> provider = getParameterProvider(entity, dbo, evaluator, parentPath);
EntityInstantiator instantiator = instantiators.getInstantiatorFor(entity);
S instance = instantiator.createInstance(entity, provider);
final BeanWrapper<S> wrapper = BeanWrapper.create(instance, conversionService);
final S result = wrapper.getBean();
// make sure id property is set before all other properties
Object idValue = null;
if (entity.getIdProperty() != null) {
idValue = getValueInternal(entity.getIdProperty(), dbo, evaluator, parentPath);
wrapper.setProperty(entity.getIdProperty(), idValue);
}
final ObjectPath currentPath = parentPath.push(result, entity, idValue);
// Set properties not already set in the constructor
entity.doWithProperties(new PropertyHandler<MongoPersistentProperty>() {
public void doWithPersistentProperty(MongoPersistentProperty prop) {
// we skip the id property since it was already set
if (entity.getIdProperty() != null && entity.getIdProperty().equals(prop)) {
return;
}
if (!dbo.containsField(prop.getFieldName()) || entity.isConstructorArgument(prop)) {
return;
}
wrapper.setProperty(prop, getValueInternal(prop, dbo, evaluator, result));
wrapper.setProperty(prop, getValueInternal(prop, dbo, evaluator, currentPath));
}
});
@@ -274,7 +290,7 @@ public class MappingMongoConverter extends AbstractMongoConverter implements App
@Override
public Object resolve(MongoPersistentProperty property) {
return getValueInternal(property, dbo, evaluator, parent);
return getValueInternal(property, dbo, evaluator, currentPath);
}
}));
}
@@ -799,9 +815,9 @@ public class MappingMongoConverter extends AbstractMongoConverter implements App
}
protected Object getValueInternal(MongoPersistentProperty prop, DBObject dbo, SpELExpressionEvaluator evaluator,
Object parent) {
ObjectPath objectPath) {
return new MongoDbPropertyValueProvider(dbo, evaluator, parent).getPropertyValue(prop);
return new MongoDbPropertyValueProvider(dbo, evaluator, objectPath).getPropertyValue(prop);
}
/**
@@ -809,11 +825,13 @@ public class MappingMongoConverter extends AbstractMongoConverter implements App
*
* @param targetType must not be {@literal null}.
* @param sourceValue must not be {@literal null}.
* @param objectPath must not be {@literal null}.
* @return the converted {@link Collection} or array, will never be {@literal null}.
*/
private Object readCollectionOrArray(TypeInformation<?> targetType, BasicDBList sourceValue, Object parent) {
private Object readCollectionOrArray(TypeInformation<?> targetType, BasicDBList sourceValue, ObjectPath objectPath) {
Assert.notNull(targetType);
Assert.notNull(objectPath);
Class<?> collectionType = targetType.getType();
@@ -834,9 +852,9 @@ public class MappingMongoConverter extends AbstractMongoConverter implements App
if (dbObjItem instanceof DBRef) {
items.add(DBRef.class.equals(rawComponentType) ? dbObjItem : read(componentType, readRef((DBRef) dbObjItem),
parent));
objectPath));
} else if (dbObjItem instanceof DBObject) {
items.add(read(componentType, (DBObject) dbObjItem, parent));
items.add(read(componentType, (DBObject) dbObjItem, objectPath));
} else {
items.add(getPotentiallyConvertedSimpleRead(dbObjItem, rawComponentType));
}
@@ -849,13 +867,15 @@ public class MappingMongoConverter extends AbstractMongoConverter implements App
* Reads the given {@link DBObject} into a {@link Map}. will recursively resolve nested {@link Map}s as well.
*
* @param type the {@link Map} {@link TypeInformation} to be used to unmarshall this {@link DBObject}.
* @param dbObject
* @param dbObject must not be {@literal null}
* @param objectPath must not be {@literal null}
* @return
*/
@SuppressWarnings("unchecked")
protected Map<Object, Object> readMap(TypeInformation<?> type, DBObject dbObject, Object parent) {
protected Map<Object, Object> readMap(TypeInformation<?> type, DBObject dbObject, ObjectPath objectPath) {
Assert.notNull(dbObject);
Assert.notNull(objectPath);
Class<?> mapType = typeMapper.readType(dbObject, type).getType();
@@ -882,7 +902,7 @@ public class MappingMongoConverter extends AbstractMongoConverter implements App
Object value = entry.getValue();
if (value instanceof DBObject) {
map.put(key, read(valueType, (DBObject) value, parent));
map.put(key, read(valueType, (DBObject) value, objectPath));
} else if (value instanceof DBRef) {
map.put(key, DBRef.class.equals(rawValueType) ? value : read(valueType, readRef((DBRef) value)));
} else {
@@ -1028,7 +1048,7 @@ public class MappingMongoConverter extends AbstractMongoConverter implements App
private final DBObjectAccessor source;
private final SpELExpressionEvaluator evaluator;
private final Object parent;
private final ObjectPath objectPath;
/**
* Creates a new {@link MongoDbPropertyValueProvider} for the given source, {@link SpELExpressionEvaluator} and
@@ -1038,14 +1058,14 @@ public class MappingMongoConverter extends AbstractMongoConverter implements App
* @param evaluator must not be {@literal null}.
* @param parent can be {@literal null}.
*/
public MongoDbPropertyValueProvider(DBObject source, SpELExpressionEvaluator evaluator, Object parent) {
public MongoDbPropertyValueProvider(DBObject source, SpELExpressionEvaluator evaluator, ObjectPath objectPath) {
Assert.notNull(source);
Assert.notNull(evaluator);
this.source = new DBObjectAccessor(source);
this.evaluator = evaluator;
this.parent = parent;
this.objectPath = objectPath;
}
/*
@@ -1061,7 +1081,7 @@ public class MappingMongoConverter extends AbstractMongoConverter implements App
return null;
}
return readValue(value, property.getTypeInformation(), parent);
return readValue(value, property.getTypeInformation(), objectPath);
}
}
@@ -1103,21 +1123,73 @@ public class MappingMongoConverter extends AbstractMongoConverter implements App
@SuppressWarnings("unchecked")
private <T> T readValue(Object value, TypeInformation<?> type, Object parent) {
ObjectPath objectPath = ObjectPath.toObjectPath(parent);
Class<?> rawType = type.getType();
if (conversions.hasCustomReadTarget(value.getClass(), rawType)) {
return (T) conversionService.convert(value, rawType);
} else if (value instanceof DBRef) {
return (T) (rawType.equals(DBRef.class) ? value : read(type, readRef((DBRef) value), parent));
return potentiallyReadOrResolveDbRef((DBRef) value, type, objectPath, rawType);
} else if (value instanceof BasicDBList) {
return (T) readCollectionOrArray(type, (BasicDBList) value, parent);
return (T) readCollectionOrArray(type, (BasicDBList) value, objectPath);
} else if (value instanceof DBObject) {
return (T) read(type, (DBObject) value, parent);
return (T) read(type, (DBObject) value, objectPath);
} else {
return (T) getPotentiallyConvertedSimpleRead(value, rawType);
}
}
@SuppressWarnings("unchecked")
private <T> T potentiallyReadOrResolveDbRef(DBRef dbref, TypeInformation<?> type, ObjectPath objectPath,
Class<?> rawType) {
if (rawType.equals(DBRef.class)) {
return (T) dbref;
}
Object object = getObjectFromPathForRefOrNull(objectPath, dbref);
if (object != null) {
return (T) object;
}
return (T) (object != null ? object : read(type, readRef(dbref), objectPath));
}
/**
* Returns the object from the given {@link ObjectPath} iff the given {@link DBRef} points to it or {@literal null}.
*
* @param path
* @param dbref
* @return
*/
private Object getObjectFromPathForRefOrNull(ObjectPath path, DBRef dbref) {
if (path == null || dbref == null) {
return null;
}
for (ObjectPathItem item : path) {
Object object = item.getObject();
if (object == null) {
continue;
}
if (item.getIdValue() == null) {
continue;
}
if (dbref.getRef().equals(item.getCollection()) && dbref.getId().equals(item.getIdValue())) {
return object;
}
}
return null;
}
/**
* Performs the fetch operation for the given {@link DBRef}.
*
@@ -1127,4 +1199,117 @@ public class MappingMongoConverter extends AbstractMongoConverter implements App
DBObject readRef(DBRef ref) {
return ref.fetch();
}
/**
* An immutable ordered set of target objects for {@link DBObject} to {@link Object} conversions. Object paths can be
* constructed by the {@link #toObjectPath(Object)} method and extended via {@link #push(Object)}.
*
* @author Thomas Darimont
* @since 1.6
*/
static class ObjectPath implements Iterable<ObjectPathItem> {
private final List<ObjectPathItem> items;
/**
* Creates a new {@link ObjectPath} from the given parent {@link ObjectPath} by adding the provided
* {@link ObjectPathItem} to it.
*
* @param parent
* @param item
*/
private ObjectPath(ObjectPath parent, ObjectPathItem item) {
if (parent == null) {
this.items = Collections.singletonList(item);
return;
}
List<ObjectPathItem> list = new ArrayList<ObjectPathItem>(parent.items);
list.add(item);
this.items = list;
}
/**
* Returns a copy of the {@link ObjectPath} with the given {@link Object} as current object.
*
* @param object
* @param entity
* @param idValue
* @return
*/
public ObjectPath push(Object object, MongoPersistentEntity<?> entity, Object idValue) {
return new ObjectPath(this, new ObjectPathItem(object, idValue, entity != null ? entity.getCollection() : null));
}
public Object getRootObject() {
return getRoot().getObject();
}
private ObjectPathItem getRoot() {
return items.get(0);
}
public Object getCurrentObject() {
return getCurrent().getObject();
}
private ObjectPathItem getCurrent() {
return items.get(items.size() - 1);
}
@Override
public Iterator<ObjectPathItem> iterator() {
return items.iterator();
}
/**
* Returns the {@link ObjectPath} represented by the given {@link Object} or creates a new {@link ObjectPath}
* wrapping the given {@link Object}.
*
* @param object
* @return
*/
public static ObjectPath toObjectPath(Object object) {
return object instanceof ObjectPath ? ((ObjectPath) object) : new ObjectPath(null, new ObjectPathItem(object,
null, null));
}
}
/**
* @author Thomas Darimont
*/
static class ObjectPathItem {
private final Object object;
private final Object idValue;
private final String collection;
/**
* Creates a new {@link ObjectPathItem}.
*
* @param object
* @param idValue
* @param collection
*/
ObjectPathItem(Object object, Object idValue, String collection) {
this.object = object;
this.idValue = idValue;
this.collection = collection;
}
public Object getObject() {
return object;
}
public Object getIdValue() {
return idValue;
}
public String getCollection() {
return collection;
}
}
}

61
spring-data-mongodb/src/test/java/org/springframework/data/mongodb/core/convert/DbRefMappingMongoConverterUnitTests.java
View File

@@ -15,7 +15,7 @@
*/
package org.springframework.data.mongodb.core.convert;
import static org.hamcrest.Matchers.*;
import static org.hamcrest.CoreMatchers.*;
import static org.junit.Assert.*;
import static org.mockito.Matchers.*;
import static org.mockito.Mockito.*;
@@ -450,6 +450,47 @@ public class DbRefMappingMongoConverterUnitTests {
assertThat(result.dbRefToConcreteTypeWithPersistenceConstructorWithoutDefaultConstructor, is(nullValue()));
}
/**
* @see DATAMONGO-1005
*/
@Test
public void shouldBeAbleToStoreDirectReferencesToSelf() {
DBObject dbo = new BasicDBObject();
ClassWithDbRefField o = new ClassWithDbRefField();
o.id = "123";
o.reference = o;
converter.write(o, dbo);
ClassWithDbRefField found = converter.read(ClassWithDbRefField.class, dbo);
assertThat(found, is(notNullValue()));
assertThat(found.reference, is(found));
}
/**
* @see DATAMONGO-1005
*/
@Test
public void shouldBeAbleToStoreNestedReferencesToSelf() {
DBObject dbo = new BasicDBObject();
ClassWithNestedDbRefField o = new ClassWithNestedDbRefField();
o.id = "123";
o.nested = new NestedReferenceHolder();
o.nested.reference = o;
converter.write(o, dbo);
ClassWithNestedDbRefField found = converter.read(ClassWithNestedDbRefField.class, dbo);
assertThat(found, is(notNullValue()));
assertThat(found.nested, is(notNullValue()));
assertThat(found.nested.reference, is(found));
}
private Object transport(Object result) {
return SerializationUtils.deserialize(SerializationUtils.serialize(result));
}
@@ -626,4 +667,22 @@ public class DbRefMappingMongoConverterUnitTests {
@org.springframework.data.mongodb.core.mapping.DBRef(lazy = true) EqualsAndHashCodeObjectMethodOverrideLazyDbRefTarget dbRefEqualsAndHashcodeObjectMethodOverride2;
@org.springframework.data.mongodb.core.mapping.DBRef(lazy = true) EqualsAndHashCodeObjectMethodOverrideLazyDbRefTarget dbRefEqualsAndHashcodeObjectMethodOverride1;
}
class ClassWithDbRefField {
String id;
@org.springframework.data.mongodb.core.mapping.DBRef ClassWithDbRefField reference;
}
static class NestedReferenceHolder {
String id;
@org.springframework.data.mongodb.core.mapping.DBRef ClassWithNestedDbRefField reference;
}
static class ClassWithNestedDbRefField {
String id;
NestedReferenceHolder nested;
}
}