Package org.springframework.batch.item.json

Class JsonItemReader<T>

java.lang.Object

org.springframework.batch.item.ItemStreamSupport

org.springframework.batch.item.support.AbstractItemStreamItemReader<T>

org.springframework.batch.item.support.AbstractItemCountingItemStreamItemReader<T>

org.springframework.batch.item.json.JsonItemReader<T>

Type Parameters:

T - the type of json objects to read

All Implemented Interfaces:

ResourceAwareItemReaderItemStream<T>, ItemReader<T>, ItemStream, ItemStreamReader<T>

public class JsonItemReader<T>
extends AbstractItemCountingItemStreamItemReader<T>
implements ResourceAwareItemReaderItemStream<T>

ItemStreamReader implementation that reads Json objects from a Resource having the following format:

[ { // JSON object }, { // JSON object } ]

The implementation is not thread-safe.

Since:

4.1

Author:

Mahmoud Ben Hassine, Jimmy Praet

Constructor Summary

Constructors

Constructor	Description
JsonItemReader()	Create a new JsonItemReader instance.
JsonItemReader(org.springframework.core.io.Resource resource, JsonObjectReader<T> jsonObjectReader)	Create a new JsonItemReader instance.

Method Summary

Modifier and Type	Method	Description
protected void	doClose()	Close the resources opened in AbstractItemCountingItemStreamItemReader.doOpen().
protected void	doOpen()	Open resources necessary to start reading input.
protected T	doRead()	Read next item from input.
protected void	jumpToItem(int itemIndex)	Move to the given item index.
void	setJsonObjectReader(JsonObjectReader<T> jsonObjectReader)	Set the JsonObjectReader to use to read and map Json fragments to domain objects.
void	setResource(org.springframework.core.io.Resource resource)
void	setStrict(boolean strict)	In strict mode the reader will throw an exception on AbstractItemCountingItemStreamItemReader.open(org.springframework.batch.item.ExecutionContext) if the input resource does not exist.

Methods inherited from class org.springframework.batch.item.support.AbstractItemCountingItemStreamItemReader

close, getCurrentItemCount, isSaveState, open, read, setCurrentItemCount, setMaxItemCount, setSaveState, update

Methods inherited from class org.springframework.batch.item.ItemStreamSupport

getExecutionContextKey, getName, setExecutionContextName, setName

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.springframework.batch.item.ItemReader

read

Methods inherited from interface org.springframework.batch.item.ItemStream

close, open, update

Constructor Details

JsonItemReader

public JsonItemReader(org.springframework.core.io.Resource resource,
 JsonObjectReader<T> jsonObjectReader)

Create a new JsonItemReader instance.

Parameters:

resource - the input json resource

jsonObjectReader - the json object reader to use

JsonItemReader

public JsonItemReader()

Create a new JsonItemReader instance.

Method Details

setJsonObjectReader

public void setJsonObjectReader(JsonObjectReader<T> jsonObjectReader)

Set the JsonObjectReader to use to read and map Json fragments to domain objects.

Parameters:

jsonObjectReader - the json object reader to use

setStrict

public void setStrict(boolean strict)

In strict mode the reader will throw an exception on AbstractItemCountingItemStreamItemReader.open(org.springframework.batch.item.ExecutionContext) if the input resource does not exist.

Parameters:

strict - true by default

setResource

public void setResource(org.springframework.core.io.Resource resource)

Specified by:

setResource in interface ResourceAwareItemReaderItemStream<T>

doRead

@Nullable
protected T doRead()
            throws Exception

Description copied from class: AbstractItemCountingItemStreamItemReader

Read next item from input.

Specified by:

doRead in class AbstractItemCountingItemStreamItemReader<T>

Returns:

an item or null if the data source is exhausted

Throws:

Exception - Allows subclasses to throw checked exceptions for interpretation by the framework

doOpen

protected void doOpen()
               throws Exception

Description copied from class: AbstractItemCountingItemStreamItemReader

Open resources necessary to start reading input.

Specified by:

doOpen in class AbstractItemCountingItemStreamItemReader<T>

Throws:

Exception - Allows subclasses to throw checked exceptions for interpretation by the framework

doClose

protected void doClose()
                throws Exception

Description copied from class: AbstractItemCountingItemStreamItemReader

Close the resources opened in AbstractItemCountingItemStreamItemReader.doOpen().

Specified by:

doClose in class AbstractItemCountingItemStreamItemReader<T>

Throws:

Exception - Allows subclasses to throw checked exceptions for interpretation by the framework

jumpToItem

protected void jumpToItem(int itemIndex)
                   throws Exception

Description copied from class: AbstractItemCountingItemStreamItemReader

Move to the given item index. Subclasses should override this method if there is a more efficient way of moving to given index than re-reading the input using AbstractItemCountingItemStreamItemReader.doRead().

Overrides:

jumpToItem in class AbstractItemCountingItemStreamItemReader<T>

Parameters:

itemIndex - index of item (0 based) to jump to.

Throws:

Exception - Allows subclasses to throw checked exceptions for interpretation by the framework