org.jberet.support.io

Class JsonItemReader

java.lang.Object

org.jberet.support.io.ItemReaderWriterBase

org.jberet.support.io.JsonItemReaderWriterBase

org.jberet.support.io.JsonItemReader

All Implemented Interfaces:

javax.batch.api.chunk.ItemReader

Direct Known Subclasses:

ArrayItemReader

@Named
 @Dependent
public class JsonItemReader
extends JsonItemReaderWriterBase
implements javax.batch.api.chunk.ItemReader

An implementation of javax.batch.api.chunk.ItemReader that reads from Json resource that consists of a collection of same-typed data items. Its readItem() method reads one item at a time, and binds it to a user-provided bean type that represents individual data item in the source Json resource. The data item may also be bound to java.util.Map or com.fasterxml.jackson.databind.JsonNode for applications that do not need application bean type.

Since:

1.0.2

See Also:

JsonItemWriter, JsonItemReaderWriterBase

Field Summary

Fields

Modifier and Type	Field and Description
protected Class	beanType The bean type that represents individual data item in the source Json ItemReaderWriterBase.resource.
protected String	deserializationProblemHandlers A comma-separated list of fully-qualified names of classes that implement com.fasterxml.jackson.databind.deser.DeserializationProblemHandler, which can be registered to get called when a potentially recoverable problem is encountered during deserialization process.
protected int	end Specify the end position in the data set (inclusive).
protected Class	inputDecorator Fully-qualified name of a class that extends com.fasterxml.jackson.core.io.InputDecorator, which can be used to decorate input sources.
protected com.fasterxml.jackson.core.JsonParser	jsonParser
protected Map<String,String>	jsonParserFeatures A comma-separated list of key-value pairs that specify com.fasterxml.jackson.core.JsonParser features.
protected int	rowNumber
protected int	start Specifies the start position (a positive integer starting from 1) to read the data.

Fields inherited from class org.jberet.support.io.JsonItemReaderWriterBase

customDataTypeModules, customDeserializers, customSerializers, deserializationFeatures, jsonFactory, jsonFactoryFeatures, jsonFactoryLookup, mapperFeatures, objectMapper, serializationFeatures

Fields inherited from class org.jberet.support.io.ItemReaderWriterBase

NEW_LINE, resource, skipBeanValidation

Constructor Summary

Constructors

Constructor and Description
JsonItemReader()

Method Summary

Modifier and Type	Method and Description
Serializable	checkpointInfo()
void	close()
protected static com.fasterxml.jackson.core.JsonParser	configureJsonParser(JsonItemReaderWriterBase batchReaderArtifact, Class<?> inputDecorator, String deserializationProblemHandlers, Map<String,String> jsonParserFeatures)
void	open(Serializable checkpoint)
Object	readItem()

Methods inherited from class org.jberet.support.io.JsonItemReaderWriterBase

initJsonFactory, initJsonFactoryAndObjectMapper, registerModule

Methods inherited from class org.jberet.support.io.ItemReaderWriterBase

getInputStream, getOutputStream, getValidator, validate

Methods inherited from class java.lang.Object

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

Field Detail

beanType

@Inject
protected Class beanType

The bean type that represents individual data item in the source Json ItemReaderWriterBase.resource. Required property, and valid values are:

• any custom bean type, for example org.jberet.support.io.StockTrade
• java.util.Map
• com.fasterxml.jackson.databind.JsonNode

start

@Inject
protected int start

Specifies the start position (a positive integer starting from 1) to read the data. If reading from the beginning of the input Json resource, there is no need to specify this property.

end

@Inject
protected int end

Specify the end position in the data set (inclusive). Optional property, and defaults to Integer.MAX_VALUE. If reading till the end of the input Json resource, there is no need to specify this property.

jsonParserFeatures

@Inject
protected Map<String,String> jsonParserFeatures

A comma-separated list of key-value pairs that specify com.fasterxml.jackson.core.JsonParser features. Optional property and defaults to null. For example,

 ALLOW_COMMENTS=true, ALLOW_YAML_COMMENTS=true, ALLOW_NUMERIC_LEADING_ZEROS=true, STRICT_DUPLICATE_DETECTION=true
 

See Also:

"com.fasterxml.jackson.core.JsonParser.Feature"

deserializationProblemHandlers

@Inject
protected String deserializationProblemHandlers

A comma-separated list of fully-qualified names of classes that implement com.fasterxml.jackson.databind.deser.DeserializationProblemHandler, which can be registered to get called when a potentially recoverable problem is encountered during deserialization process. Handlers can try to resolve the problem, throw an exception or do nothing. Optional property and defaults to null. For example,

 org.jberet.support.io.JsonItemReaderTest$UnknownHandler, org.jberet.support.io.JsonItemReaderTest$UnknownHandler2
 

See Also:

"com.fasterxml.jackson.databind.deser.DeserializationProblemHandler", "com.fasterxml.jackson.databind.ObjectMapper#addHandler(com.fasterxml.jackson.databind.deser.DeserializationProblemHandler)", MappingJsonFactoryObjectFactory.configureDeserializationProblemHandlers(com.fasterxml.jackson.databind.ObjectMapper, java.lang.String, java.lang.ClassLoader)

inputDecorator

@Inject
protected Class inputDecorator

Fully-qualified name of a class that extends com.fasterxml.jackson.core.io.InputDecorator, which can be used to decorate input sources. Typical use is to use a filter abstraction (filtered stream, reader) around original input source, and apply additional processing during read operations. Optional property and defaults to null. For example,

 org.jberet.support.io.JsonItemReaderTest$NoopInputDecorator
 

See Also:

"com.fasterxml.jackson.core.JsonFactory#setInputDecorator(com.fasterxml.jackson.core.io.InputDecorator)", "com.fasterxml.jackson.core.io.InputDecorator"

jsonParser

protected com.fasterxml.jackson.core.JsonParser jsonParser

rowNumber

protected int rowNumber

Constructor Detail

JsonItemReader

public JsonItemReader()

Method Detail

open

public void open(Serializable checkpoint)
          throws Exception

Specified by:

open in interface javax.batch.api.chunk.ItemReader

Throws:

Exception

readItem

public Object readItem()
                throws Exception

Specified by:

readItem in interface javax.batch.api.chunk.ItemReader

Throws:

Exception

checkpointInfo

public Serializable checkpointInfo()
                            throws Exception

Specified by:

checkpointInfo in interface javax.batch.api.chunk.ItemReader

Throws:

Exception

close

public void close()
           throws Exception

Specified by:

close in interface javax.batch.api.chunk.ItemReader

Throws:

Exception

configureJsonParser

protected static com.fasterxml.jackson.core.JsonParser configureJsonParser(JsonItemReaderWriterBase batchReaderArtifact,
                                                                           Class<?> inputDecorator,
                                                                           String deserializationProblemHandlers,
                                                                           Map<String,String> jsonParserFeatures)
                                                                    throws Exception

Throws:

Exception