Start line:  
End line:  

Snippet Preview

Snippet HTML Code

Stack Overflow Questions
  package com.fasterxml.jackson.databind;
  
  
Abstract class that defines API used by ObjectMapper (and other chained JsonSerializers too) to serialize Objects of arbitrary types into JSON, using provided com.fasterxml.jackson.core.JsonGenerator.

NOTE: it is recommended that custom serializers extend com.fasterxml.jackson.databind.ser.std.StdSerializer instead of this class, since it will implement many of optional methods of this class.

If serializer is an aggregate one -- meaning it delegates handling of some of its contents by using other serializer(s) -- it typically also needs to implement com.fasterxml.jackson.databind.ser.ResolvableSerializer, which can locate secondary serializers needed. This is important to allow dynamic overrides of serializers; separate call interface is needed to separate resolution of secondary serializers (which may have cyclic link back to serializer itself, directly or indirectly).

In addition, to support per-property annotations (to configure aspects of serialization on per-property basis), serializers may want to implement com.fasterxml.jackson.databind.ser.ContextualSerializer, which allows specialization of serializers: call to com.fasterxml.jackson.databind.ser.ContextualSerializer.createContextual(com.fasterxml.jackson.databind.SerializerProvider,com.fasterxml.jackson.databind.BeanProperty) is passed information on property, and can create a newly configured serializer for handling that particular property.

If both com.fasterxml.jackson.databind.ser.ResolvableSerializer and com.fasterxml.jackson.databind.ser.ContextualSerializer are implemented, resolution of serializers occurs before contextualization.

 
 public abstract class JsonSerializer<T>
     implements JsonFormatVisitable // since 2.1
 {
     /*
     /**********************************************************
     /* 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

Parameters:
unwrapper Name transformation to use to convert between names of unwrapper properties
 
     public JsonSerializer<T> unwrappingSerializer(NameTransformer unwrapper) {
         return this;
     }

    
Method that can be called to try to replace serializer this serializer delegates calls to. If not supported (either this serializer does not delegate anything; or it does not want any changes), should either throw java.lang.UnsupportedOperationException (if operation does not make sense or is not allowed); or return this serializer as is.

Since:
2.1
 
     public JsonSerializer<T> replaceDelegatee(JsonSerializer<?> delegatee) {
         throw new UnsupportedOperationException();
     }
     
     /*
     /**********************************************************
     /* Serialization methods
     /**********************************************************
      */

    
Method that can be called to ask implementation to serialize values of type this serializer handles.

Parameters:
value Value to serialize; can not be null.
jgen Generator used to output resulting Json content
provider Provider that can be used to get serializers for serializing Objects value contains, if any.
 
     public abstract void serialize(T valueJsonGenerator jgenSerializerProvider provider)
        throws IOExceptionJsonProcessingException;

    
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 throw java.lang.UnsupportedOperationException to indicate that proper type handling needs to be implemented.

For simple datatypes written as a single scalar value (JSON String, Number, Boolean), implementation would look 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);
and implementations for type serialized as JSON Arrays or Objects would differ slightly, as START-ARRAY>/END-ARRAY and START-OBJECT>/END-OBJECT pairs need to be properly handled with respect to serializing of contents.

Parameters:
value Value to serialize; can not be null.
jgen Generator used to output resulting Json content
provider Provider that can be used to get serializers for serializing Objects value contains, if any.
typeSer Type serializer to use for including type information
    public void serializeWithType(T valueJsonGenerator jgenSerializerProvider provider,
            TypeSerializer typeSer)
        throws IOExceptionJsonProcessingException
    {
        Class<?> clz = handledType();
        if (clz == null) {
            clz = value.getClass();
        }
        throw new UnsupportedOperationException("Type id handling not implemented for type "+clz.getName());
    }
    
    /*
    /**********************************************************
    /* Other accessors
    /**********************************************************
     */
    
    
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<T> handledType() { return null; }

    
Method called to check whether given serializable value is considered "empty" value (for purposes of suppressing serialization of empty values).

Default implementation will consider only null values to be empty.

Since:
2.0
    public boolean isEmpty(T value) {
        return (value == null);
    }

    
Method that can be called to see whether this serializer instance will use Object Id to handle cyclic references.
    public boolean usesObjectId() {
        return false;
    }

    
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.
    public boolean isUnwrappingSerializer() {
        return false;
    }
    
    
Accessor that can be used to determine if this serializer uses another serializer for actual serialization, by delegating calls. If so, will return immediate delegate (which itself may delegate to further serializers); otherwise will return null.

Returns:
Serializer this serializer delegates calls to, if null; null otherwise.
Since:
2.1
    public JsonSerializer<?> getDelegatee() {
        return null;
    }
    /*
    /**********************************************************
    /* Default JsonFormatVisitable implementation
    /**********************************************************
     */

    
    public void acceptJsonFormatVisitor(JsonFormatVisitorWrapper visitorJavaType type)
        throws JsonMappingException
    {
        visitor.expectAnyFormat(type);
    }
    
    /*
    /**********************************************************
    /* 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 com.fasterxml.jackson.databind.annotation.JsonSerialize.

    public abstract static class None
        extends JsonSerializer<Object> { }
New to GrepCode? Check out our FAQ X