com.facebook.presto.jdbc.internal.jackson.databind.annotation.JsonDeserialize Maven / Gradle / Ivy
package com.facebook.presto.jdbc.internal.jackson.databind.annotation;
import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;
import com.facebook.presto.jdbc.internal.jackson.databind.JsonDeserializer;
import com.facebook.presto.jdbc.internal.jackson.databind.KeyDeserializer;
import com.facebook.presto.jdbc.internal.jackson.databind.util.Converter;
/**
* Annotation use for configuring deserialization aspects, by attaching
* to "setter" methods or fields, or to value classes.
* When annotating value classes, configuration is used for instances
* of the value class but can be overridden by more specific annotations
* (ones that attach to methods or fields).
*
* An example annotation would be:
*
* @JsonDeserialize(using=MySerializer.class,
* as=MyHashMap.class,
* keyAs=MyHashKey.class,
* contentAs=MyHashValue.class
* )
*
*
* Something to note on usage:
*
* - All other annotations regarding behavior during building should be on Builder
* class and NOT on target POJO class: for example @JsonIgnoreProperties should be on
* Builder to prevent "unknown property" errors.
*
* - Similarly configuration overrides (see {@link com.facebook.presto.jdbc.internal.jackson.databind.ObjectMapper#configOverride})
* should be targeted at Builder class, not target POJO class.
*
*
*
*/
@Target({ElementType.ANNOTATION_TYPE, ElementType.METHOD, ElementType.FIELD, ElementType.TYPE, ElementType.PARAMETER})
@Retention(RetentionPolicy.RUNTIME)
@com.facebook.presto.jdbc.internal.jackson.annotation.JacksonAnnotation
public @interface JsonDeserialize
{
// // // Annotations for explicitly specifying deserialize/builder
/**
* Deserializer class to use for deserializing associated value.
* Depending on what is annotated,
* value is either an instance of annotated class (used globablly
* anywhere where class deserializer is needed); or only used for
* deserializing property access via a setter method.
*/
@SuppressWarnings("rawtypes") // to work around JDK8 bug wrt Class-valued annotation properties
public Class using()
default JsonDeserializer.None.class;
/**
* Deserializer class to use for deserializing contents (elements
* of a Collection/array, values of Maps) of annotated property.
* Can only be used on instances (methods, fields, constructors),
* and not value classes themselves.
*/
@SuppressWarnings("rawtypes") // to work around JDK8 bug wrt Class-valued annotation properties
public Class contentUsing()
default JsonDeserializer.None.class;
/**
* Deserializer class to use for deserializing Map keys
* of annotated property.
* Can only be used on instances (methods, fields, constructors),
* and not value classes themselves.
*/
public Class keyUsing()
default KeyDeserializer.None.class;
/**
* Annotation for specifying if an external Builder class is to
* be used for building up deserialized instances of annotated
* class. If so, an instance of referenced class is first constructed
* (possibly using a Creator method; or if none defined, using default
* constructor), and its "with-methods" are used for populating fields;
* and finally "build-method" is invoked to complete deserialization.
*/
public Class builder() default Void.class;
// // // Annotations for specifying intermediate Converters (2.2+)
/**
* Which helper object (if any) is to be used to convert from Jackson-bound
* intermediate type (source type of converter) into actual property type
* (which must be same as result type of converter). This is often used
* for two-step deserialization; Jackson binds data into suitable intermediate
* type (like Tree representation), and converter then builds actual property
* type.
*
* @since 2.2
*/
@SuppressWarnings("rawtypes") // to work around JDK8 bug wrt Class-valued annotation properties
public Class converter() default Converter.None.class;
/**
* Similar to {@link #converter}, but used for values of structures types
* (List, arrays, Maps).
*
* @since 2.2
*/
@SuppressWarnings("rawtypes") // to work around JDK8 bug wrt Class-valued annotation properties
public Class contentConverter() default Converter.None.class;
// // // Annotations for explicitly specifying deserialization type
// // // (which is used for choosing deserializer, if not explicitly
// // // specified
/**
* Concrete type to deserialize values as, instead of type otherwise
* declared. Must be a subtype of declared type; otherwise an
* exception may be thrown by deserializer.
*
* Bogus type {@link Void} can be used to indicate that declared
* type is used as is (i.e. this annotation property has no setting);
* this since annotation properties are not allowed to have null value.
*
* Note: if {@link #using} is also used it has precedence
* (since it directly specified
* deserializer, whereas this would only be used to locate the
* deserializer)
* and value of this annotation property is ignored.
*/
public Class as() default Void.class;
/**
* Concrete type to deserialize keys of {@link java.util.Map} as,
* instead of type otherwise declared.
* Must be a subtype of declared type; otherwise an exception may be
* thrown by deserializer.
*/
public Class keyAs() default Void.class;
/**
* Concrete type to deserialize content (elements
* of a Collection/array, values of Maps) values as,
* instead of type otherwise declared.
* Must be a subtype of declared type; otherwise an exception may be
* thrown by deserializer.
*/
public Class contentAs() default Void.class;
}