org.springframework.kafka.support.serializer

Class JsonDeserializer<T>

java.lang.Object

org.springframework.kafka.support.serializer.JsonDeserializer<T>

Type Parameters:

T - class of the entity, representing messages

All Implemented Interfaces:

java.io.Closeable, java.lang.AutoCloseable, org.apache.kafka.common.serialization.Deserializer<T>

public class JsonDeserializer<T>
extends java.lang.Object
implements org.apache.kafka.common.serialization.Deserializer<T>

Generic Deserializer for receiving JSON from Kafka and return Java objects.

Author:

Igor Stepanov, Artem Bilan, Gary Russell, Yanming Zhou, Elliot Kennedy, Torsten Schleede, Ivan Ponomarev

Field Summary

Fields

Modifier and Type	Field and Description
static java.lang.String	DEFAULT_KEY_TYPE Deprecated. in favor of KEY_DEFAULT_TYPE
static java.lang.String	DEFAULT_VALUE_TYPE Deprecated. in favor of VALUE_DEFAULT_TYPE
static java.lang.String	KEY_DEFAULT_TYPE Kafka config property for the default key type if no header.
protected com.fasterxml.jackson.databind.ObjectMapper	objectMapper
static java.lang.String	REMOVE_TYPE_INFO_HEADERS Kafka config property for removing type headers (default true).
protected com.fasterxml.jackson.databind.JavaType	targetType
static java.lang.String	TRUSTED_PACKAGES Kafka config property for trusted deserialization packages.
static java.lang.String	TYPE_MAPPINGS Kafka config property to add type mappings to the type mapper: 'foo=com.Foo,bar=com.Bar'.
protected Jackson2JavaTypeMapper	typeMapper
static java.lang.String	USE_TYPE_INFO_HEADERS Kafka config property for using type headers (default true).
static java.lang.String	VALUE_DEFAULT_TYPE Kafka config property for the default value type if no header.

Constructor Summary

Constructors

Constructor and Description
JsonDeserializer() Construct an instance with a default ObjectMapper.
JsonDeserializer(java.lang.Class<? super T> targetType) Construct an instance with the provided target type, and a default ObjectMapper.
JsonDeserializer(java.lang.Class<? super T> targetType, boolean useHeadersIfPresent) Construct an instance with the provided target type, and useHeadersIfPresent with a default ObjectMapper.
JsonDeserializer(java.lang.Class<? super T> targetType, com.fasterxml.jackson.databind.ObjectMapper objectMapper) Construct an instance with the provided target type, and ObjectMapper.
JsonDeserializer(java.lang.Class<? super T> targetType, com.fasterxml.jackson.databind.ObjectMapper objectMapper, boolean useHeadersIfPresent) Construct an instance with the provided target type, ObjectMapper and useHeadersIfPresent.
JsonDeserializer(com.fasterxml.jackson.databind.JavaType targetType, com.fasterxml.jackson.databind.ObjectMapper objectMapper, boolean useHeadersIfPresent) Construct an instance with the provided target type, ObjectMapper and useHeadersIfPresent.
JsonDeserializer(com.fasterxml.jackson.databind.ObjectMapper objectMapper) Construct an instance with the provided ObjectMapper.
JsonDeserializer(com.fasterxml.jackson.core.type.TypeReference<? super T> targetType) Construct an instance with the provided target type, and a default ObjectMapper.
JsonDeserializer(com.fasterxml.jackson.core.type.TypeReference<? super T> targetType, boolean useHeadersIfPresent) Construct an instance with the provided target type, and useHeadersIfPresent with a default ObjectMapper.
JsonDeserializer(com.fasterxml.jackson.core.type.TypeReference<? super T> targetType, com.fasterxml.jackson.databind.ObjectMapper objectMapper) Construct an instance with the provided target type, and ObjectMapper.
JsonDeserializer(com.fasterxml.jackson.core.type.TypeReference<? super T> targetType, com.fasterxml.jackson.databind.ObjectMapper objectMapper, boolean useHeadersIfPresent) Construct an instance with the provided target type, ObjectMapper and useHeadersIfPresent.

Method Summary

Modifier and Type	Method and Description
void	addTrustedPackages(java.lang.String... packages) Add trusted packages for deserialization.
void	close()
void	configure(java.util.Map<java.lang.String,?> configs, boolean isKey)
T	deserialize(java.lang.String topic, byte[] data)
T	deserialize(java.lang.String topic, org.apache.kafka.common.header.Headers headers, byte[] data)
JsonDeserializer<T>	dontRemoveTypeHeaders() Don't remove type information headers.
JsonDeserializer<T>	forKeys() Designate this deserializer for deserializing keys (default is values); only applies if the default type mapper is used.
Jackson2JavaTypeMapper	getTypeMapper()
JsonDeserializer<T>	ignoreTypeHeaders() Ignore type information headers and use the configured target class.
void	setRemoveTypeHeaders(boolean removeTypeHeaders) Set to false to retain type information headers after deserialization.
void	setTypeMapper(Jackson2JavaTypeMapper typeMapper) Set a customized type mapper.
void	setUseTypeHeaders(boolean useTypeHeaders) Set to false to ignore type information in headers and use the configured target type instead.
void	setUseTypeMapperForKey(boolean isKey) Configure the default Jackson2JavaTypeMapper to use key type headers.
JsonDeserializer<T>	typeMapper(Jackson2JavaTypeMapper mapper) Use the supplied Jackson2JavaTypeMapper.

Methods inherited from class java.lang.Object

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

Field Detail

DEFAULT_KEY_TYPE

@Deprecated
public static final java.lang.String DEFAULT_KEY_TYPE

Deprecated. in favor of KEY_DEFAULT_TYPE

Kafka config property for the default key type if no header.

See Also:

Constant Field Values

DEFAULT_VALUE_TYPE

@Deprecated
public static final java.lang.String DEFAULT_VALUE_TYPE

Deprecated. in favor of VALUE_DEFAULT_TYPE

Kafka config property for the default value type if no header.

See Also:

Constant Field Values

KEY_DEFAULT_TYPE

public static final java.lang.String KEY_DEFAULT_TYPE

Kafka config property for the default key type if no header.

See Also:

Constant Field Values

VALUE_DEFAULT_TYPE

public static final java.lang.String VALUE_DEFAULT_TYPE

Kafka config property for the default value type if no header.

See Also:

Constant Field Values

TRUSTED_PACKAGES

public static final java.lang.String TRUSTED_PACKAGES

Kafka config property for trusted deserialization packages.

See Also:

Constant Field Values

TYPE_MAPPINGS

public static final java.lang.String TYPE_MAPPINGS

Kafka config property to add type mappings to the type mapper: 'foo=com.Foo,bar=com.Bar'.

See Also:

Constant Field Values

REMOVE_TYPE_INFO_HEADERS

public static final java.lang.String REMOVE_TYPE_INFO_HEADERS

Kafka config property for removing type headers (default true).

See Also:

Constant Field Values

USE_TYPE_INFO_HEADERS

public static final java.lang.String USE_TYPE_INFO_HEADERS

Kafka config property for using type headers (default true).

Since:

2.2.3

See Also:

Constant Field Values

objectMapper

protected final com.fasterxml.jackson.databind.ObjectMapper objectMapper

targetType

protected com.fasterxml.jackson.databind.JavaType targetType

typeMapper

protected Jackson2JavaTypeMapper typeMapper

Constructor Detail

JsonDeserializer

public JsonDeserializer()

Construct an instance with a default ObjectMapper.

JsonDeserializer

public JsonDeserializer(com.fasterxml.jackson.databind.ObjectMapper objectMapper)

Construct an instance with the provided ObjectMapper.

Parameters:

objectMapper - a custom object mapper.

JsonDeserializer

public JsonDeserializer(java.lang.Class<? super T> targetType)

Construct an instance with the provided target type, and a default ObjectMapper.

Parameters:

targetType - the target type to use if no type info headers are present.

JsonDeserializer

public JsonDeserializer(com.fasterxml.jackson.core.type.TypeReference<? super T> targetType)

Construct an instance with the provided target type, and a default ObjectMapper.

Parameters:

targetType - the target type reference to use if no type info headers are present.

Since:

2.3

JsonDeserializer

public JsonDeserializer(@Nullable
                        java.lang.Class<? super T> targetType,
                        boolean useHeadersIfPresent)

Construct an instance with the provided target type, and useHeadersIfPresent with a default ObjectMapper.

Parameters:

targetType - the target type.

useHeadersIfPresent - true to use headers if present and fall back to target type if not.

Since:

2.2

JsonDeserializer

public JsonDeserializer(com.fasterxml.jackson.core.type.TypeReference<? super T> targetType,
                        boolean useHeadersIfPresent)

Construct an instance with the provided target type, and useHeadersIfPresent with a default ObjectMapper.

Parameters:

targetType - the target type reference.

useHeadersIfPresent - true to use headers if present and fall back to target type if not.

Since:

2.3

JsonDeserializer

public JsonDeserializer(java.lang.Class<? super T> targetType,
                        com.fasterxml.jackson.databind.ObjectMapper objectMapper)

Construct an instance with the provided target type, and ObjectMapper.

Parameters:

targetType - the target type to use if no type info headers are present.

objectMapper - the mapper. type if not.

JsonDeserializer

public JsonDeserializer(com.fasterxml.jackson.core.type.TypeReference<? super T> targetType,
                        com.fasterxml.jackson.databind.ObjectMapper objectMapper)

Construct an instance with the provided target type, and ObjectMapper.

Parameters:

targetType - the target type reference to use if no type info headers are present.

objectMapper - the mapper. type if not.

JsonDeserializer

public JsonDeserializer(@Nullable
                        java.lang.Class<? super T> targetType,
                        com.fasterxml.jackson.databind.ObjectMapper objectMapper,
                        boolean useHeadersIfPresent)

Construct an instance with the provided target type, ObjectMapper and useHeadersIfPresent.

Parameters:

targetType - the target type.

objectMapper - the mapper.

useHeadersIfPresent - true to use headers if present and fall back to target type if not.

Since:

2.2

JsonDeserializer

public JsonDeserializer(com.fasterxml.jackson.core.type.TypeReference<? super T> targetType,
                        com.fasterxml.jackson.databind.ObjectMapper objectMapper,
                        boolean useHeadersIfPresent)

Construct an instance with the provided target type, ObjectMapper and useHeadersIfPresent.

Parameters:

targetType - the target type reference.

objectMapper - the mapper.

useHeadersIfPresent - true to use headers if present and fall back to target type if not.

Since:

2.3

JsonDeserializer

public JsonDeserializer(@Nullable
                        com.fasterxml.jackson.databind.JavaType targetType,
                        com.fasterxml.jackson.databind.ObjectMapper objectMapper,
                        boolean useHeadersIfPresent)

Construct an instance with the provided target type, ObjectMapper and useHeadersIfPresent.

Parameters:

targetType - the target type reference.

objectMapper - the mapper.

useHeadersIfPresent - true to use headers if present and fall back to target type if not.

Since:

2.3

Method Detail

getTypeMapper

public Jackson2JavaTypeMapper getTypeMapper()

setTypeMapper

public void setTypeMapper(Jackson2JavaTypeMapper typeMapper)

Set a customized type mapper.

Parameters:

typeMapper - the type mapper.

Since:

2.1

setUseTypeMapperForKey

public void setUseTypeMapperForKey(boolean isKey)

Configure the default Jackson2JavaTypeMapper to use key type headers.

Parameters:

isKey - Use key type headers if true

Since:

2.1.3

setRemoveTypeHeaders

public void setRemoveTypeHeaders(boolean removeTypeHeaders)

Set to false to retain type information headers after deserialization. Default true.

Parameters:

removeTypeHeaders - true to remove headers.

Since:

2.2

setUseTypeHeaders

public void setUseTypeHeaders(boolean useTypeHeaders)

Set to false to ignore type information in headers and use the configured target type instead. Only applies if the preconfigured type mapper is used. Default true.

Parameters:

useTypeHeaders - false to ignore type headers.

Since:

2.2.8

configure

public void configure(java.util.Map<java.lang.String,?> configs,
                      boolean isKey)

Specified by:

configure in interface org.apache.kafka.common.serialization.Deserializer<T>

addTrustedPackages

public void addTrustedPackages(java.lang.String... packages)

Add trusted packages for deserialization.

Parameters:

packages - the packages.

Since:

2.1

deserialize

public T deserialize(java.lang.String topic,
                     org.apache.kafka.common.header.Headers headers,
                     byte[] data)

Specified by:

deserialize in interface org.apache.kafka.common.serialization.Deserializer<T>

deserialize

public T deserialize(java.lang.String topic,
                     @Nullable
                     byte[] data)

Specified by:

deserialize in interface org.apache.kafka.common.serialization.Deserializer<T>

close

public void close()

Specified by:

close in interface java.io.Closeable

Specified by:

close in interface java.lang.AutoCloseable

Specified by:

close in interface org.apache.kafka.common.serialization.Deserializer<T>

forKeys

public JsonDeserializer<T> forKeys()

Designate this deserializer for deserializing keys (default is values); only applies if the default type mapper is used.

Returns:

the deserializer.

Since:

2.3

dontRemoveTypeHeaders

public JsonDeserializer<T> dontRemoveTypeHeaders()

Don't remove type information headers.

Returns:

the deserializer.

Since:

2.3

See Also:

setRemoveTypeHeaders(boolean)

ignoreTypeHeaders

public JsonDeserializer<T> ignoreTypeHeaders()

Ignore type information headers and use the configured target class.

Returns:

the deserializer.

Since:

2.3

See Also:

setUseTypeHeaders(boolean)

typeMapper

public JsonDeserializer<T> typeMapper(Jackson2JavaTypeMapper mapper)

Use the supplied Jackson2JavaTypeMapper.

Parameters:

mapper - the mapper.

Returns:

the deserializer.

Since:

2.3

See Also:

setTypeMapper(Jackson2JavaTypeMapper)