org.codehaus.jackson.map.JsonSerializer Maven / Gradle / Ivy
package org.codehaus.jackson.map;
import java.io.IOException;
import org.codehaus.jackson.*;
/**
* Abstract class that defines API used by {@link ObjectMapper} (and
* other chained {@link JsonSerializer}s too) to serialize Objects of
* arbitrary types into JSON, using provided {@link JsonGenerator}.
*
* NOTE: it is recommended that custom serializers extend
* {@link org.codehaus.jackson.map.ser.std.SerializerBase} instead
* of this class, since it will implement many of optional
* methods of this class.
*/
public abstract class JsonSerializer
{
/*
/**********************************************************
/* Fluent factory methods for constructing decorated versions
/**********************************************************
*/
/**
* Method that will return serializer instance that produces
* "unwrapped" serialization, if applicable for type being
* serialized (which is the case for some serializers
* that produce JSON Objects as output).
* If no unwrapped serializer can be constructed, will simply
* return serializer as-is.
*
* Default implementation just returns serializer as-is,
* indicating that no unwrapped variant exists
*
* @since 1.9
*/
public JsonSerializer unwrappingSerializer() {
return this;
}
/**
* Accessor for checking whether this serializer is an
* "unwrapping" serializer; this is necessary to know since
* it may also require caller to suppress writing of the
* leading property name.
*
* @since 1.9
*/
public boolean isUnwrappingSerializer() {
return false;
}
/*
/**********************************************************
/* Serialization methods
/**********************************************************
*/
/**
* Method that can be called to ask implementation to serialize
* values of type this serializer handles.
*
* @param value Value to serialize; can not be null.
* @param jgen Generator used to output resulting Json content
* @param provider Provider that can be used to get serializers for
* serializing Objects value contains, if any.
*/
public abstract void serialize(T value, JsonGenerator jgen, SerializerProvider provider)
throws IOException, JsonProcessingException;
/**
* Method that can be called to ask implementation to serialize
* values of type this serializer handles, using specified type serializer
* for embedding necessary type information.
*
* Default implementation will ignore serialization of type information,
* and just calls {@link #serialize}: serializers that can embed
* type information should override this to implement actual handling.
* Most common such handling is done by something like:
*
* // note: method to call depends on whether this type is serialized as JSON scalar, object or Array!
* typeSer.writeTypePrefixForScalar(value, jgen);
* serialize(value, jgen, provider);
* typeSer.writeTypeSuffixForScalar(value, jgen);
*
*
* @param value Value to serialize; can not be null.
* @param jgen Generator used to output resulting Json content
* @param provider Provider that can be used to get serializers for
* serializing Objects value contains, if any.
* @param typeSer Type serializer to use for including type information
*
* @since 1.5
*/
public void serializeWithType(T value, JsonGenerator jgen, SerializerProvider provider,
TypeSerializer typeSer)
throws IOException, JsonProcessingException
{
serialize(value, jgen, provider);
}
/*
/**********************************************************
/* Introspection methods needed for type handling
/**********************************************************
*/
/**
* Method for accessing type of Objects this serializer can handle.
* Note that this information is not guaranteed to be exact -- it
* may be a more generic (super-type) -- but it should not be
* incorrect (return a non-related type).
*
* Default implementation will return null, which essentially means
* same as returning Object.class would; that is, that
* nothing is known about handled type.
*
*/
public Class handledType() { return null; }
/*
/**********************************************************
/* Helper class(es)
/**********************************************************
*/
/**
* This marker class is only to be used with annotations, to
* indicate that no serializer is configured.
*
* Specifically, this class is to be used as the marker for
* annotation {@link org.codehaus.jackson.map.annotate.JsonSerialize}.
*/
public abstract static class None
extends JsonSerializer