org.apache.avro
Class Schema

java.lang.Object
  org.apache.avro.Schema

public abstract class Schema
extends Object

An abstract data type.

A schema may be one of:

• A record, mapping field names to field value data;
• An enum, containing one of a small set of symbols;
• An array of values, all of the same schema;
• A map, containing string/value pairs, of a declared schema;
• A union of other schemas;
• A fixed sized binary object;
• A unicode string;
• A sequence of bytes;
• A 32-bit signed int;
• A 64-bit signed long;
• A 32-bit IEEE single-float; or
• A 64-bit IEEE double-float; or
• A boolean; or
• null.

Nested Class Summary

static class	Schema.Field A field within a record.
static class	Schema.Type The type of a schema.

Method Summary

static Schema	create(Schema.Type type) Create a schema for a primitive type.
static Schema	createArray(Schema elementType) Create an array schema.
static Schema	createEnum(String name, String namespace, List<String> values) Create an enum schema.
static Schema	createFixed(String name, String space, int size) Create a union schema.
static Schema	createMap(Schema valueType) Create a map schema.
static Schema	createRecord(LinkedHashMap<String,Schema.Field> fields) Create an anonymous record schema.
static Schema	createRecord(String name, String namespace, boolean isError) Create a named record schema.
static Schema	createUnion(List<Schema> types) Create a union schema.
boolean	equals(Object o)
Schema	getElementType() If this is an array, returns its element type.
int	getEnumOrdinal(String symbol) If this is an enum, return a symbol's ordinal value.
List<String>	getEnumSymbols() If this is an enum, return its symbols.
Map<String,Schema.Field>	getFields() If this is a record, returns its fields.
Iterable<Map.Entry<String,Schema>>	getFieldSchemas() If this is a record, enumerate its field names and their schemas.
int	getFixedSize() If this is fixed, returns its size.
String	getName() If this is a record, enum or fixed, returns its name, otherwise the name of the primitive type.
String	getNamespace() If this is a record, enum or fixed, returns its namespace, if any.
Schema.Type	getType() Return the type of this schema.
List<Schema>	getTypes() If this is a union, returns its types.
Schema	getValueType() If this is a map, returns its value type.
int	hashCode()
boolean	isError() Returns true if this record is an error type.
static Schema	parse(File file)
static Schema	parse(String jsonSchema) Construct a schema from JSON text.
void	setFields(LinkedHashMap<String,Schema.Field> fields) If this is a record, set its fields.
String	toString() Render this as JSON.

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Method Detail

create

public static Schema create(Schema.Type type)

Create a schema for a primitive type.

createRecord

public static Schema createRecord(LinkedHashMap<String,Schema.Field> fields)

Create an anonymous record schema.

createRecord

public static Schema createRecord(String name,
                                  String namespace,
                                  boolean isError)

Create a named record schema.

createEnum

public static Schema createEnum(String name,
                                String namespace,
                                List<String> values)

Create an enum schema.

createArray

public static Schema createArray(Schema elementType)

Create an array schema.

createMap

public static Schema createMap(Schema valueType)

Create a map schema.

createUnion

public static Schema createUnion(List<Schema> types)

Create a union schema.

createFixed

public static Schema createFixed(String name,
                                 String space,
                                 int size)

Create a union schema.

getType

public Schema.Type getType()

Return the type of this schema.

getFields

public Map<String,Schema.Field> getFields()

If this is a record, returns its fields.

getFieldSchemas

public Iterable<Map.Entry<String,Schema>> getFieldSchemas()

If this is a record, enumerate its field names and their schemas.

setFields

public void setFields(LinkedHashMap<String,Schema.Field> fields)

If this is a record, set its fields.

getEnumSymbols

public List<String> getEnumSymbols()

If this is an enum, return its symbols.

getEnumOrdinal

public int getEnumOrdinal(String symbol)

If this is an enum, return a symbol's ordinal value.

getName

public String getName()

If this is a record, enum or fixed, returns its name, otherwise the name of the primitive type.

getNamespace

public String getNamespace()

If this is a record, enum or fixed, returns its namespace, if any.

isError

public boolean isError()

Returns true if this record is an error type.

getElementType

public Schema getElementType()

If this is an array, returns its element type.

getValueType

public Schema getValueType()

If this is a map, returns its value type.

getTypes

public List<Schema> getTypes()

If this is a union, returns its types.

getFixedSize

public int getFixedSize()

If this is fixed, returns its size.

toString

public String toString()

Render this as JSON.

Overrides:

toString in class Object

equals

public boolean equals(Object o)

Overrides:

equals in class Object

hashCode

public int hashCode()

Overrides:

hashCode in class Object

parse

public static Schema parse(File file)
                    throws IOException

Throws:

IOException

parse

public static Schema parse(String jsonSchema)

Construct a schema from JSON text.