io.katharsis.jackson.serializer.ContainerSerializer Maven / Gradle / Ivy
package io.katharsis.jackson.serializer;
import com.fasterxml.jackson.core.JsonGenerator;
import com.fasterxml.jackson.core.type.TypeReference;
import com.fasterxml.jackson.databind.JsonSerializer;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.databind.SerializerProvider;
import com.fasterxml.jackson.databind.introspect.Annotated;
import com.fasterxml.jackson.databind.introspect.AnnotatedClass;
import com.fasterxml.jackson.databind.introspect.JacksonAnnotationIntrospector;
import com.fasterxml.jackson.databind.ser.FilterProvider;
import com.fasterxml.jackson.databind.ser.PropertyWriter;
import com.fasterxml.jackson.databind.ser.impl.SimpleFilterProvider;
import io.katharsis.jackson.exception.JsonSerializationException;
import io.katharsis.queryParams.params.IncludedFieldsParams;
import io.katharsis.queryParams.params.IncludedRelationsParams;
import io.katharsis.queryParams.params.TypedParams;
import io.katharsis.request.dto.Attributes;
import io.katharsis.resource.field.ResourceField;
import io.katharsis.resource.information.ResourceInformation;
import io.katharsis.resource.registry.RegistryEntry;
import io.katharsis.resource.registry.ResourceRegistry;
import io.katharsis.response.Container;
import io.katharsis.response.ContainerType;
import io.katharsis.response.DataLinksContainer;
import io.katharsis.utils.BeanUtils;
import io.katharsis.utils.Predicate2;
import io.katharsis.utils.PropertyUtils;
import io.katharsis.utils.java.Optional;
import java.io.IOException;
import java.lang.reflect.InvocationTargetException;
import java.util.HashSet;
import java.util.Map;
import java.util.Set;
/**
* This class serializes an single resource which can be included in data field of JSON API response.
*
* @see Container
*/
public class ContainerSerializer extends JsonSerializer {
private static final String TYPE_FIELD_NAME = "type";
private static final String ID_FIELD_NAME = "id";
private static final String ATTRIBUTES_FIELD_NAME = "attributes";
private static final String RELATIONSHIPS_FIELD_NAME = "relationships";
private static final String LINKS_FIELD_NAME = "links";
private static final String META_FIELD_NAME = "meta";
private static final String SELF_FIELD_NAME = "self";
private static final String JACKSON_ATTRIBUTE_FILTER_NAME = "katharsisFilter";
private final ResourceRegistry resourceRegistry;
public ContainerSerializer(ResourceRegistry resourceRegistry) {
this.resourceRegistry = resourceRegistry;
}
@Override
public void serialize(Container container, JsonGenerator gen, SerializerProvider serializers) throws IOException {
if (container != null && container.getData() != null) {
gen.writeStartObject();
TypedParams includedFields = null;
IncludedRelationsParams includedRelationsParams = null;
if (container.getResponse().getQueryParams() != null) {
includedFields = container.getResponse()
.getQueryParams()
.getIncludedFields();
TypedParams includedRelations = container.getResponse()
.getQueryParams()
.getIncludedRelations();
Class dataClass = container.getData().getClass();
String resourceType = resourceRegistry.getResourceType(dataClass);
if (includedRelations != null &&
includedRelations.getParams().containsKey(resourceType)) {
includedRelationsParams = includedRelations.getParams().get(resourceType);
} else if (includedRelations != null &&
container.getContainerType() != null &&
container.getContainerType().equals(ContainerType.INCLUDED)) {
for (IncludedRelationsParams includedRelationsParamsInner : includedRelations.getParams().values()) {
if (includedRelationsParamsInner.getParams().iterator().next().getPathList().get(0).equals(container.getIncludedFieldName())) {
includedRelationsParams = includedRelationsParamsInner;
}
}
}
}
writeData(container, gen, container.getData(), includedFields, includedRelationsParams);
gen.writeEndObject();
} else {
gen.writeObject(null);
}
}
/**
* Writes a value. Each serialized container must contain type field whose value is string
* .
*/
private void writeData(Container container, JsonGenerator gen, Object data, TypedParams includedFields,
IncludedRelationsParams includedRelations) throws IOException {
Class dataClass = data.getClass();
String resourceType = resourceRegistry.getResourceType(dataClass);
gen.writeStringField(TYPE_FIELD_NAME, resourceType);
RegistryEntry entry = resourceRegistry.getEntry(dataClass);
ResourceInformation resourceInformation = entry.getResourceInformation();
try {
writeId(gen, data, resourceInformation.getIdField());
} catch (IllegalAccessException | InvocationTargetException | NoSuchMethodException e) {
throw new JsonSerializationException(
"Error writing id field: " + resourceInformation.getIdField().getUnderlyingName());
}
Set notAttributesFields = entry.getResourceInformation().getNotAttributeFields();
writeAttributes(gen, data, includedFields, notAttributesFields);
Set relationshipFields = getRelationshipFields(resourceType, resourceInformation, includedFields);
if (!relationshipFields.isEmpty()) {
writeRelationshipFields(container, gen, data, relationshipFields, includedRelations);
}
writeMetaField(gen, data, entry);
writeLinksField(gen, data, entry);
}
private Set getRelationshipFields(String resourceType, ResourceInformation resourceInformation,
TypedParams includedFields) {
Set relationshipFields = new HashSet<>();
Optional> fields = includedFields(resourceType, includedFields);
if (fields.isPresent()) {
for (ResourceField resourceField : resourceInformation.getRelationshipFields()) {
if (fields.get().contains(resourceField.getJsonName())) {
relationshipFields.add(resourceField);
}
}
} else {
relationshipFields.addAll(resourceInformation.getRelationshipFields());
}
return relationshipFields;
}
/**
* The id MUST be written as a string
* Resource IDs.
*/
private static void writeId(JsonGenerator gen, Object data, ResourceField idField)
throws IllegalAccessException, InvocationTargetException, NoSuchMethodException, IOException {
String sourceId = BeanUtils.getProperty(data, idField.getUnderlyingName());
gen.writeObjectField(ID_FIELD_NAME, sourceId);
}
/**
* Writes resource attributes object taking into account fields query params. It doesn't allow writing
* null resource attributes.
*
* @param gen Jackson generator
* @param data resource object
* @param includedFields field query param values
* @param notAttributesFields names of relationships and id field
* @throws IOException if couldn't write attributes
*/
private void writeAttributes(JsonGenerator gen, final Object data, TypedParams includedFields,
final Set notAttributesFields)
throws IOException {
String resourceType = resourceRegistry.getResourceType(data.getClass());
final Optional> fields = includedFields(resourceType, includedFields);
Map dataMap;
if (fields.isPresent()) {
Predicate2 includeChecker = new Predicate2() {
@Override
public boolean test(Object bean, PropertyWriter writer) {
return bean != data || (fields.get().contains(writer.getName()) &&
!notAttributesFields.contains(writer.getName()));
}
};
ObjectMapper om = getObjectMapper(gen, data, includeChecker);
dataMap = om.convertValue(data, new TypeReference>() {
});
} else {
Predicate2 includeChecker = new Predicate2() {
@Override
public boolean test(Object bean, PropertyWriter writer) {
return bean != data || !notAttributesFields.contains(writer.getName());
}
};
ObjectMapper om = getObjectMapper(gen, data, includeChecker);
dataMap = om.convertValue(data, new TypeReference>() {
});
}
Attributes attributesObject = new Attributes();
for (Map.Entry entry : dataMap.entrySet()) {
attributesObject.addAttribute(entry.getKey(), entry.getValue());
}
gen.writeObjectField(ATTRIBUTES_FIELD_NAME, attributesObject);
}
/**
* When fields filter is passed in the query params, attributes and relationships should be
* filtered accordingly to the requested fields. If there are included fields defined for other resources but not
* for the current one, empty set is returned
*
* @param resourceType JSON API name of a resource
* @param includedFields field query param values
* @return true if it should be included in the response, false otherwise
*/
private static Optional> includedFields(String resourceType, TypedParams includedFields) {
IncludedFieldsParams typeIncludedFields = findIncludedFields(includedFields, resourceType);
if (noResourceIncludedFieldsSpecified(typeIncludedFields)) {
return Optional.empty();
} else {
return Optional.of(typeIncludedFields.getParams());
}
}
/**
* Checks if a value has included fields for a resource
*
* @param typeIncludedFields found fields set to be checked
* @return true if there are no resource fields for inclusion, false otherwise
*/
private static boolean noResourceIncludedFieldsSpecified(IncludedFieldsParams typeIncludedFields) {
return typeIncludedFields == null || typeIncludedFields.getParams().isEmpty();
}
/**
* Returns included elements for a resource
*
* @param includedFields included fields from request
* @param elementName resource name
* @return included field params
*/
private static IncludedFieldsParams findIncludedFields(TypedParams includedFields, String
elementName) {
IncludedFieldsParams includedFieldsParams = null;
if (includedFields != null) {
for (Map.Entry entry : includedFields.getParams()
.entrySet()) {
if (elementName.equals(entry.getKey())) {
includedFieldsParams = entry.getValue();
}
}
}
return includedFieldsParams;
}
private static void writeRelationshipFields(Container container, JsonGenerator gen, Object data, Set relationshipFields,
IncludedRelationsParams includedRelations)
throws IOException {
DataLinksContainer dataLinksContainer = new DataLinksContainer(data, relationshipFields, includedRelations, container.getContainerType(), container.getIncludedFieldName());
gen.writeObjectField(RELATIONSHIPS_FIELD_NAME, dataLinksContainer);
}
private void writeLinksField(JsonGenerator gen, Object data, RegistryEntry entry) throws IOException {
gen.writeFieldName(LINKS_FIELD_NAME);
if (entry.getResourceInformation().getLinksFieldName() != null) {
gen.writeObject(PropertyUtils.getProperty(data, entry.getResourceInformation().getLinksFieldName()));
} else {
gen.writeStartObject();
writeSelfLink(gen, data);
gen.writeEndObject();
}
}
private void writeSelfLink(JsonGenerator gen, Object data) throws IOException {
Class sourceClass = data.getClass();
String resourceUrl = resourceRegistry.getResourceUrl(sourceClass);
RegistryEntry entry = resourceRegistry.getEntry(sourceClass);
ResourceField idField = entry.getResourceInformation().getIdField();
Object sourceId = PropertyUtils.getProperty(data, idField.getUnderlyingName());
gen.writeStringField(SELF_FIELD_NAME, resourceUrl + "/" + sourceId);
}
private void writeMetaField(JsonGenerator gen, Object data, RegistryEntry entry) throws IOException {
if (entry.getResourceInformation().getMetaFieldName() != null) {
gen.writeFieldName(META_FIELD_NAME);
gen.writeObject(PropertyUtils.getProperty(data, entry.getResourceInformation().getMetaFieldName()));
}
}
public Class handledType() {
return Container.class;
}
/**
* Generate a new object mapper and configure the filter to exclude some properties.
*/
private static ObjectMapper getObjectMapper(JsonGenerator gen, final Object data,
Predicate2 includedFields) {
ObjectMapper attributesObjectMapper = ((ObjectMapper) gen.getCodec())
.copy();
FilterProvider fp = new SimpleFilterProvider()
.addFilter(JACKSON_ATTRIBUTE_FILTER_NAME, new KatharsisFieldPropertyFilter(includedFields));
attributesObjectMapper.setFilters(fp);
attributesObjectMapper.setAnnotationIntrospector(new JacksonAnnotationIntrospector() {
@Override
public Object findFilterId(Annotated a) {
Object filterId = null;
if (a instanceof AnnotatedClass) {
AnnotatedClass ac = (AnnotatedClass) a;
if (ac.getRawType().equals(data.getClass())) {
filterId = JACKSON_ATTRIBUTE_FILTER_NAME;
}
}
return filterId;
}
});
return attributesObjectMapper;
}
}
© 2015 - 2024 Weber Informatics LLC | Privacy Policy