org.coursera.pegasus

Class TypedDefinitionCodec

java.lang.Object

org.coursera.pegasus.TypedDefinitionCodec

All Implemented Interfaces:

com.linkedin.data.codec.DataCodec, com.linkedin.data.codec.TextDataCodec

public class TypedDefinitionCodec
extends java.lang.Object
implements com.linkedin.data.codec.TextDataCodec

Extends existing Pegasus codecs to support for the "typedDefinition" and "flatTypedDefinition" serializations originally used in our Play! JSON classes. (See JsonFormats.typedDefinitionFormat() and JsonFormats.flatTypedDefinitionFormat() in infra-services for the Play! JSON implementation).
WARNING: This codec filters out unrecognized fields (any fields in the data that are not defined in the schema) when reading and writing data by default. It is only when this codec is used exclusively for reading and writing of data that passthrough is guaranteed to propagate data in unrecognized fields correctly, in which case the 'passthroughEnabled' may be safely set to true.
Usage: In order to indicate a Pegasus union should be serialized using "typedDefinition" or "flatTypedDefinition", a typeref must be defined for the union and annotated with a property defining the mapping between the "memberKeys" of the Pegasus union and the "typeNames" of the typed definition format.
For example, the Peagsus schema:

 
 {
   "name": "ExampleTypedDefinition",
   "type": "typeref",
   "ref": [ "org.example.TextEntry", "org.example.MultipleChoice" ],
   "typedDefinition": {
     "org.example.TextEntry": "textEntry",
     "org.example.MultipleChoice": "multipleChoice"
   }
 }
 
 

defines a "typedDefinition" union where the "memberKeys" of "org.example.TextEntry" and "org.example.MultipleChoice" map to the "typeNames" of "textEntry" and "multipleChoice".
For a "flatTypedDefinition", instead do:

 
 {
   "name": "ExampleTypedDefinition",
   "type": "typeref",
   "ref": [ "org.example.TextEntry", "org.example.MultipleChoice" ],
   "flatTypedDefinition": {
     "org.example.TextEntry": "textEntry",
     "org.example.MultipleChoice": "multipleChoice"
   }
 }
 
 

"memberKeys" referencing types in the same namespace as the typeref may use simple names. Fully qualified names are only required when referencing types in other namespaces.

Constructor Summary

Constructors

Constructor and Description
TypedDefinitionCodec(com.linkedin.data.schema.DataSchema schema, com.linkedin.data.codec.TextDataCodec underlying)
TypedDefinitionCodec(com.linkedin.data.schema.DataSchema schema, com.linkedin.data.codec.TextDataCodec underlying, java.lang.Boolean passthroughEnabled)

Method Summary

Modifier and Type	Method and Description
com.linkedin.data.DataList	bytesToList(byte[] input)
com.linkedin.data.DataMap	bytesToMap(byte[] input)
java.lang.String	getStringEncoding()
byte[]	listToBytes(com.linkedin.data.DataList list)
java.lang.String	listToString(com.linkedin.data.DataList list)
byte[]	mapToBytes(com.linkedin.data.DataMap map)
java.lang.String	mapToString(com.linkedin.data.DataMap map)
com.linkedin.data.DataList	readList(java.io.InputStream in)
com.linkedin.data.DataList	readList(java.io.Reader in)
com.linkedin.data.DataMap	readMap(java.io.InputStream in)
com.linkedin.data.DataMap	readMap(java.io.Reader in)
com.linkedin.data.DataList	stringToList(java.lang.String input)
com.linkedin.data.DataMap	stringToMap(java.lang.String input)
void	writeList(com.linkedin.data.DataList list, java.io.OutputStream out)
void	writeList(com.linkedin.data.DataList list, java.io.Writer out)
void	writeMap(com.linkedin.data.DataMap map, java.io.OutputStream out)
void	writeMap(com.linkedin.data.DataMap map, java.io.Writer out)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

TypedDefinitionCodec

public TypedDefinitionCodec(com.linkedin.data.schema.DataSchema schema,
                            com.linkedin.data.codec.TextDataCodec underlying)

Parameters:

schema - provides the schema of the data to serialize.

underlying - provides the codec to use to serialize/deserialize. Typically this is [[JacksonDataCodec]], [[PrettyPrinterJacksonDataCodec]] or similar.

TypedDefinitionCodec

public TypedDefinitionCodec(com.linkedin.data.schema.DataSchema schema,
                            com.linkedin.data.codec.TextDataCodec underlying,
                            java.lang.Boolean passthroughEnabled)

Parameters:

schema - provides the schema of the data to serialize.

underlying - provides the codec to use to serialize/deserialize. Typically this is [[JacksonDataCodec]], [[PrettyPrinterJacksonDataCodec]] or similar.

passthroughEnabled - configures if passthrough of recognized fields is enabled. Only enable this when reading and writing data exclusively with this codec.

Method Detail

mapToBytes

public byte[] mapToBytes(com.linkedin.data.DataMap map)
                  throws java.io.IOException

Specified by:

mapToBytes in interface com.linkedin.data.codec.DataCodec

Throws:

java.io.IOException

writeMap

public void writeMap(com.linkedin.data.DataMap map,
                     java.io.OutputStream out)
              throws java.io.IOException

Specified by:

writeMap in interface com.linkedin.data.codec.DataCodec

Throws:

java.io.IOException

bytesToMap

public com.linkedin.data.DataMap bytesToMap(byte[] input)
                                     throws java.io.IOException

Specified by:

bytesToMap in interface com.linkedin.data.codec.DataCodec

Throws:

java.io.IOException

readMap

public com.linkedin.data.DataMap readMap(java.io.InputStream in)
                                  throws java.io.IOException

Specified by:

readMap in interface com.linkedin.data.codec.DataCodec

Throws:

java.io.IOException

listToBytes

public byte[] listToBytes(com.linkedin.data.DataList list)
                   throws java.io.IOException

Specified by:

listToBytes in interface com.linkedin.data.codec.DataCodec

Throws:

java.io.IOException

writeList

public void writeList(com.linkedin.data.DataList list,
                      java.io.OutputStream out)
               throws java.io.IOException

Specified by:

writeList in interface com.linkedin.data.codec.DataCodec

Throws:

java.io.IOException

bytesToList

public com.linkedin.data.DataList bytesToList(byte[] input)
                                       throws java.io.IOException

Specified by:

bytesToList in interface com.linkedin.data.codec.DataCodec

Throws:

java.io.IOException

readList

public com.linkedin.data.DataList readList(java.io.InputStream in)
                                    throws java.io.IOException

Specified by:

readList in interface com.linkedin.data.codec.DataCodec

Throws:

java.io.IOException

getStringEncoding

public java.lang.String getStringEncoding()

Specified by:

getStringEncoding in interface com.linkedin.data.codec.TextDataCodec

mapToString

public java.lang.String mapToString(com.linkedin.data.DataMap map)
                             throws java.io.IOException

Specified by:

mapToString in interface com.linkedin.data.codec.TextDataCodec

Throws:

java.io.IOException

writeMap

public void writeMap(com.linkedin.data.DataMap map,
                     java.io.Writer out)
              throws java.io.IOException

Specified by:

writeMap in interface com.linkedin.data.codec.TextDataCodec

Throws:

java.io.IOException

stringToList

public com.linkedin.data.DataList stringToList(java.lang.String input)
                                        throws java.io.IOException

Specified by:

stringToList in interface com.linkedin.data.codec.TextDataCodec

Throws:

java.io.IOException

readMap

public com.linkedin.data.DataMap readMap(java.io.Reader in)
                                  throws java.io.IOException

Specified by:

readMap in interface com.linkedin.data.codec.TextDataCodec

Throws:

java.io.IOException

writeList

public void writeList(com.linkedin.data.DataList list,
                      java.io.Writer out)
               throws java.io.IOException

Specified by:

writeList in interface com.linkedin.data.codec.TextDataCodec

Throws:

java.io.IOException

stringToMap

public com.linkedin.data.DataMap stringToMap(java.lang.String input)
                                      throws java.io.IOException

Specified by:

stringToMap in interface com.linkedin.data.codec.TextDataCodec

Throws:

java.io.IOException

listToString

public java.lang.String listToString(com.linkedin.data.DataList list)
                              throws java.io.IOException

Specified by:

listToString in interface com.linkedin.data.codec.TextDataCodec

Throws:

java.io.IOException

readList

public com.linkedin.data.DataList readList(java.io.Reader in)
                                    throws java.io.IOException

Specified by:

readList in interface com.linkedin.data.codec.TextDataCodec

Throws:

java.io.IOException