org.apache.beam.sdk.schemas

Class FieldAccessDescriptor

java.lang.Object

org.apache.beam.sdk.schemas.FieldAccessDescriptor

All Implemented Interfaces:

java.io.Serializable

@Experimental(value=SCHEMAS)
public abstract class FieldAccessDescriptor
extends java.lang.Object
implements java.io.Serializable

Used inside of a DoFn to describe which fields in a schema type need to be accessed for processing.

This class always puts the selected fields in a deterministic order.

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor and Description
FieldAccessDescriptor()

Method Summary

Modifier and Type	Method and Description
boolean	allFields()
static FieldAccessDescriptor	create() Return an empty FieldAccessDescriptor.
java.util.Set<java.lang.Integer>	fieldIdsAccessed()
java.util.Map<java.lang.Integer,FieldAccessDescriptor>	nestedFields()
FieldAccessDescriptor	resolve(Schema schema)
static FieldAccessDescriptor	withAllFields()
static FieldAccessDescriptor	withFieldIds(java.lang.Integer... ids) Return a descriptor that access the specified fields.
static FieldAccessDescriptor	withFieldIds(java.lang.Iterable<java.lang.Integer> ids) Return a descriptor that access the specified fields.
static FieldAccessDescriptor	withFieldNames(java.lang.Iterable<java.lang.String> fieldNames) Return a descriptor that access the specified fields.
static FieldAccessDescriptor	withFieldNames(java.lang.String... names) Return a descriptor that access the specified fields.
FieldAccessDescriptor	withNestedField(int nestedFieldId, FieldAccessDescriptor fieldAccess) Return a descriptor that access the specified nested field.
FieldAccessDescriptor	withNestedField(java.lang.String nestedFieldName, FieldAccessDescriptor fieldAccess) Return a descriptor that access the specified nested field.
FieldAccessDescriptor	withOrderByFieldInsertionOrder() By default, fields are sorted by name.

Methods inherited from class java.lang.Object

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

Constructor Detail

FieldAccessDescriptor

public FieldAccessDescriptor()

Method Detail

withAllFields

public static FieldAccessDescriptor withAllFields()

withFieldNames

public static FieldAccessDescriptor withFieldNames(java.lang.String... names)

Return a descriptor that access the specified fields.

By default, if the field is a nested row (or a container containing a row), all fields of said rows are accessed. For finer-grained acccess to nested rows, call withNestedField and pass in a recursive FieldAccessDescriptor.

withFieldNames

public static FieldAccessDescriptor withFieldNames(java.lang.Iterable<java.lang.String> fieldNames)

Return a descriptor that access the specified fields.

By default, if the field is a nested row (or a container containing a row), all fields of said rows are accessed. For finer-grained acccess to nested rows, call withNestedField and pass in a recursive FieldAccessDescriptor.

withFieldIds

public static FieldAccessDescriptor withFieldIds(java.lang.Integer... ids)

Return a descriptor that access the specified fields.

By default, if the field is a nested row (or a container containing a row), all fields of said rows are accessed. For finer-grained acccess to nested rows, call withNestedField and pass in a recursive FieldAccessDescriptor.

withFieldIds

public static FieldAccessDescriptor withFieldIds(java.lang.Iterable<java.lang.Integer> ids)

Return a descriptor that access the specified fields.

By default, if the field is a nested row (or a container containing a row), all fields of said rows are accessed. For finer-grained acccess to nested rows, call withNestedField and pass in a recursive FieldAccessDescriptor.

create

public static FieldAccessDescriptor create()

Return an empty FieldAccessDescriptor.

withNestedField

public FieldAccessDescriptor withNestedField(int nestedFieldId,
                                             FieldAccessDescriptor fieldAccess)

Return a descriptor that access the specified nested field. The nested field must be of type Schema.TypeName.ROW, and the fieldAccess argument specifies what fields of the nested type will be accessed.

withNestedField

public FieldAccessDescriptor withNestedField(java.lang.String nestedFieldName,
                                             FieldAccessDescriptor fieldAccess)

Return a descriptor that access the specified nested field. The nested field must be of type Schema.TypeName.ROW, and the fieldAccess argument specifies what fields of the nested type will be accessed.

withOrderByFieldInsertionOrder

public FieldAccessDescriptor withOrderByFieldInsertionOrder()

By default, fields are sorted by name. If this is set, they will instead be sorted by insertion order. All sorting happens in the resolve(Schema) method.

allFields

public boolean allFields()

fieldIdsAccessed

public java.util.Set<java.lang.Integer> fieldIdsAccessed()

nestedFields

public java.util.Map<java.lang.Integer,FieldAccessDescriptor> nestedFields()

resolve

public FieldAccessDescriptor resolve(Schema schema)