org.apache.beam.sdk.io.xml

Class XmlIO.Read<T>

java.lang.Object

org.apache.beam.sdk.transforms.PTransform<PBegin,PCollection<T>>

org.apache.beam.sdk.io.xml.XmlIO.Read<T>

All Implemented Interfaces:

java.io.Serializable, HasDisplayData

Enclosing class:

XmlIO

public abstract static class XmlIO.Read<T>
extends PTransform<PBegin,PCollection<T>>

Implementation of XmlIO.read().

See Also:

Serialized Form

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	XmlIO.Read.CompressionType Strategy for determining the compression type of XML files being read.

Field Summary

Fields inherited from class org.apache.beam.sdk.transforms.PTransform

name

Constructor Summary

Constructors

Constructor and Description
Read()

Method Summary

Modifier and Type	Method and Description
PCollection<T>	expand(PBegin input) Override this method to specify how this PTransform should be expanded on the given InputT.
XmlIO.Read<T>	from(java.lang.String fileOrPatternSpec) Reads a single XML file or a set of XML files defined by a Java "glob" file pattern.
void	populateDisplayData(DisplayData.Builder builder) Register display data for the given transform or component.
void	validate(PipelineOptions options) Called before running the Pipeline to verify this transform is fully and correctly specified.
XmlIO.Read<T>	withCharset(java.nio.charset.Charset charset) Sets the XML file charset.
XmlIO.Read<T>	withCompressionType(XmlIO.Read.CompressionType compressionType) Decompresses all input files using the specified compression type.
XmlIO.Read<T>	withMinBundleSize(long minBundleSize) Sets a parameter minBundleSize for the minimum bundle size of the source.
XmlIO.Read<T>	withRecordClass(java.lang.Class<T> recordClass) Sets a JAXB annotated class that can be populated using a record of the provided XML file.
XmlIO.Read<T>	withRecordElement(java.lang.String recordElement) Sets name of the record element of the XML document.
XmlIO.Read<T>	withRootElement(java.lang.String rootElement) Sets name of the root element of the XML document.
XmlIO.Read<T>	withValidationEventHandler(javax.xml.bind.ValidationEventHandler validationEventHandler) Sets the ValidationEventHandler to use with JAXB.

Methods inherited from class org.apache.beam.sdk.transforms.PTransform

getAdditionalInputs, getDefaultOutputCoder, getDefaultOutputCoder, getDefaultOutputCoder, getKindString, getName, toString

Methods inherited from class java.lang.Object

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

Constructor Detail

Read

public Read()

Method Detail

from

public XmlIO.Read<T> from(java.lang.String fileOrPatternSpec)

Reads a single XML file or a set of XML files defined by a Java "glob" file pattern. Each XML file should be of the form defined in XmlIO.read().

withRootElement

public XmlIO.Read<T> withRootElement(java.lang.String rootElement)

Sets name of the root element of the XML document. This will be used to create a valid starting root element when initiating a bundle of records created from an XML document. This is a required parameter.

withRecordElement

public XmlIO.Read<T> withRecordElement(java.lang.String recordElement)

Sets name of the record element of the XML document. This will be used to determine offset of the first record of a bundle created from the XML document. This is a required parameter.

withRecordClass

public XmlIO.Read<T> withRecordClass(java.lang.Class<T> recordClass)

Sets a JAXB annotated class that can be populated using a record of the provided XML file. This will be used when unmarshalling record objects from the XML file. This is a required parameter.

withMinBundleSize

public XmlIO.Read<T> withMinBundleSize(long minBundleSize)

Sets a parameter minBundleSize for the minimum bundle size of the source. Please refer to OffsetBasedSource for the definition of minBundleSize. This is an optional parameter.

withCompressionType

public XmlIO.Read<T> withCompressionType(XmlIO.Read.CompressionType compressionType)

Decompresses all input files using the specified compression type.

If no compression type is specified, the default is XmlIO.Read.CompressionType.AUTO. In this mode, the compression type of the file is determined by its extension. Supports .gz, .bz2, .zip and .deflate compression.

withCharset

public XmlIO.Read<T> withCharset(java.nio.charset.Charset charset)

Sets the XML file charset.

withValidationEventHandler

public XmlIO.Read<T> withValidationEventHandler(javax.xml.bind.ValidationEventHandler validationEventHandler)

Sets the ValidationEventHandler to use with JAXB. Calling this with a null parameter will cause the JAXB unmarshaller event handler to be unspecified.

validate

public void validate(PipelineOptions options)

Description copied from class: PTransform

Called before running the Pipeline to verify this transform is fully and correctly specified.

By default, does nothing.

Overrides:

validate in class PTransform<PBegin,PCollection<T>>

populateDisplayData

public void populateDisplayData(DisplayData.Builder builder)

Description copied from class: PTransform

Register display data for the given transform or component.

populateDisplayData(DisplayData.Builder) is invoked by Pipeline runners to collect display data via DisplayData.from(HasDisplayData). Implementations may call super.populateDisplayData(builder) in order to register display data in the current namespace, but should otherwise use subcomponent.populateDisplayData(builder) to use the namespace of the subcomponent.

By default, does not register any display data. Implementors may override this method to provide their own display data.

Specified by:

populateDisplayData in interface HasDisplayData

Overrides:

populateDisplayData in class PTransform<PBegin,PCollection<T>>

Parameters:

builder - The builder to populate with display data.

See Also:

HasDisplayData

expand

public PCollection<T> expand(PBegin input)

Description copied from class: PTransform

Override this method to specify how this PTransform should be expanded on the given InputT.

NOTE: This method should not be called directly. Instead apply the PTransform should be applied to the InputT using the apply method.

Composite transforms, which are defined in terms of other transforms, should return the output of one of the composed transforms. Non-composite transforms, which do not apply any transforms internally, should return a new unbound output and register evaluators (via backend-specific registration methods).

Specified by:

expand in class PTransform<PBegin,PCollection<T>>