GenericData (Apache Avro Java 1.10.2 API)

java.lang.Object
- org.apache.avro.generic.GenericData

Direct Known Subclasses:

ProtobufData, SpecificData, ThriftData
```
public class GenericData
extends Object
```
Utilities for generic Java data. See GenericRecordBuilder for a convenient way to build GenericRecord instances.

See Also:

GenericRecordBuilder

Nested Class Summary

Nested Classes
Modifier and Type	Class and Description
`static class`	`GenericData.Array<T>` Default implementation of an array.
`static class`	`GenericData.EnumSymbol` Default implementation of `GenericEnumSymbol`.
`static class`	`GenericData.Fixed` Default implementation of `GenericFixed`.
`static interface`	`GenericData.InstanceSupplier`
`static class`	`GenericData.Record` Default implementation of `GenericRecord`.
`static class`	`GenericData.StringType` Used to specify the Java type for a string schema.

Field Summary

Fields
Modifier and Type Field and Description

static String FAST_READER_PROP

static String STRING_PROP

protected static String STRING_TYPE_STRING

Fields
Modifier and Type	Field and Description
`static String`	`FAST_READER_PROP`
`static String`	`STRING_PROP`
`protected static String`	`STRING_TYPE_STRING`

Constructor Summary

Constructors
Constructor and Description

GenericData()
For subclasses.

GenericData(ClassLoader classLoader)
For subclasses.

Constructors
Constructor and Description
`GenericData()` For subclasses.
`GenericData(ClassLoader classLoader)` For subclasses.

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`void`	`addLogicalTypeConversion(Conversion<?> conversion)` Registers the given conversion to be used when reading and writing with this data model.
`int`	`compare(Object o1, Object o2, Schema s)` Compare objects according to their schema.
`protected int`	`compare(Object o1, Object o2, Schema s, boolean equals)` Comparison implementation.
`DatumReader`	`createDatumReader(Schema schema)` Returns a `DatumReader` for this kind of data.
`DatumReader`	`createDatumReader(Schema writer, Schema reader)` Returns a `DatumReader` for this kind of data.
`DatumWriter`	`createDatumWriter(Schema schema)` Returns a `DatumWriter` for this kind of data.
`Object`	`createEnum(String symbol, Schema schema)` Called to create an enum value.
`Object`	`createFixed(Object old, byte[] bytes, Schema schema)` Called to create an fixed value.
`Object`	`createFixed(Object old, Schema schema)` Called to create an fixed value.
`Object`	`createString(Object value)` Called to create an string value.
`<T> T`	`deepCopy(Schema schema, T value)` Makes a deep copy of a value given its schema.
`static GenericData`	`get()` Return the singleton instance.
`protected Collection`	`getArrayAsCollection(Object datum)` Called to access an array as a collection.
`ClassLoader`	`getClassLoader()` Return the class loader that's used (by subclasses).
`<T> Conversion<T>`	`getConversionByClass(Class<T> datumClass)` Returns the first conversion found for the given class.
`<T> Conversion<T>`	`getConversionByClass(Class<T> datumClass, LogicalType logicalType)` Returns the conversion for the given class and logical type.
`Conversion<Object>`	`getConversionFor(LogicalType logicalType)` Returns the Conversion for the given logical type.
`Collection<Conversion<?>>`	`getConversions()`
`Object`	`getDefaultValue(Schema.Field field)` Gets the default value of the given field, if any.
`protected Schema`	`getEnumSchema(Object enu)` Called to obtain the schema of a enum.
`FastReaderBuilder`	`getFastReaderBuilder()`
`Object`	`getField(Object record, String name, int position)` Called by `GenericDatumReader.readRecord(java.lang.Object, org.apache.avro.Schema, org.apache.avro.io.ResolvingDecoder)` to retrieve a record field value from a reused instance.
`protected Object`	`getField(Object record, String name, int pos, Object state)` Version of `getField(java.lang.Object, java.lang.String, int)` that has state.
`protected Schema`	`getFixedSchema(Object fixed)` Called to obtain the schema of a fixed.
`GenericData.InstanceSupplier`	`getNewRecordSupplier(Schema schema)` create a supplier that allows to get new record instances for a given schema in an optimized way
`protected Schema`	`getRecordSchema(Object record)` Called to obtain the schema of a record.
`protected Object`	`getRecordState(Object record, Schema schema)` Produce state for repeated calls to `getField(Object,String,int,Object)` and `setField(Object,String,int,Object,Object)` on the same record.
`protected String`	`getSchemaName(Object datum)` Return the schema full name for a datum.
`int`	`hashCode(Object o, Schema s)` Compute a hash code according to a schema, consistent with `compare(Object,Object,Schema)`.
`protected int`	`hashCodeAdd(int hashCode, Object o, Schema s)` Add the hash code for an object into an accumulated hash code.
`Schema`	`induce(Object datum)` Create a schema given an example datum.
`protected boolean`	`instanceOf(Schema schema, Object datum)` Called by `resolveUnion(Schema,Object)`.
`protected boolean`	`isArray(Object datum)` Called by the default implementation of `instanceOf(org.apache.avro.Schema, java.lang.Object)`.
`protected boolean`	`isBoolean(Object datum)` Called by the default implementation of `instanceOf(org.apache.avro.Schema, java.lang.Object)`.
`protected boolean`	`isBytes(Object datum)` Called by the default implementation of `instanceOf(org.apache.avro.Schema, java.lang.Object)`.
`protected boolean`	`isDouble(Object datum)` Called by the default implementation of `instanceOf(org.apache.avro.Schema, java.lang.Object)`.
`protected boolean`	`isEnum(Object datum)` Called by the default implementation of `instanceOf(org.apache.avro.Schema, java.lang.Object)`.
`boolean`	`isFastReaderEnabled()`
`protected boolean`	`isFixed(Object datum)` Called by the default implementation of `instanceOf(org.apache.avro.Schema, java.lang.Object)`.
`protected boolean`	`isFloat(Object datum)` Called by the default implementation of `instanceOf(org.apache.avro.Schema, java.lang.Object)`.
`protected boolean`	`isInteger(Object datum)` Called by the default implementation of `instanceOf(org.apache.avro.Schema, java.lang.Object)`.
`protected boolean`	`isLong(Object datum)` Called by the default implementation of `instanceOf(org.apache.avro.Schema, java.lang.Object)`.
`protected boolean`	`isMap(Object datum)` Called by the default implementation of `instanceOf(org.apache.avro.Schema, java.lang.Object)`.
`protected boolean`	`isRecord(Object datum)` Called by the default implementation of `instanceOf(org.apache.avro.Schema, java.lang.Object)`.
`protected boolean`	`isString(Object datum)` Called by the default implementation of `instanceOf(org.apache.avro.Schema, java.lang.Object)`.
`Object`	`newArray(Object old, int size, Schema schema)`
`Object`	`newMap(Object old, int size)` Called to create new array instances.
`Object`	`newRecord(Object old, Schema schema)` Called to create new record instances.
`int`	`resolveUnion(Schema union, Object datum)` Return the index for a datum within a union.
`GenericData`	`setFastReaderEnabled(boolean flag)`
`void`	`setField(Object record, String name, int position, Object value)` Called by `GenericDatumReader.readRecord(java.lang.Object, org.apache.avro.Schema, org.apache.avro.io.ResolvingDecoder)` to set a record fields value to a record instance.
`protected void`	`setField(Object record, String name, int position, Object value, Object state)` Version of `setField(java.lang.Object, java.lang.String, int, java.lang.Object)` that has state.
`static void`	`setStringType(Schema s, GenericData.StringType stringType)` Set the Java type to be used when reading this schema.
`String`	`toString(Object datum)` Renders a Java datum as JSON.
`protected void`	`toString(Object datum, StringBuilder buffer, IdentityHashMap<Object,Object> seenObjects)` Renders a Java datum as JSON.
`boolean`	`validate(Schema schema, Object datum)` Returns true if a Java datum matches a schema.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - STRING_PROP
```
public static final String STRING_PROP
```
    See Also:
    
    Constant Field Values
  - STRING_TYPE_STRING
```
protected static final String STRING_TYPE_STRING
```
    See Also:
    
    Constant Field Values
  - FAST_READER_PROP
```
public static final String FAST_READER_PROP
```
    See Also:
    
    Constant Field Values
- Constructor Detail
  - GenericData
```
public GenericData()
```
    For subclasses. Applications normally use get().
  - GenericData
```
public GenericData(ClassLoader classLoader)
```
    For subclasses. GenericData does not use a ClassLoader.
- Method Detail
  - setStringType
```
public static void setStringType(Schema s,
                                 GenericData.StringType stringType)
```
    Set the Java type to be used when reading this schema. Meaningful only only string schemas and map schemas (for the keys).
  - get
```
public static GenericData get()
```
    Return the singleton instance.
  - getClassLoader
```
public ClassLoader getClassLoader()
```
    Return the class loader that's used (by subclasses).
  - getConversions
```
public Collection<Conversion<?>> getConversions()
```
  - addLogicalTypeConversion
```
public void addLogicalTypeConversion(Conversion<?> conversion)
```
    Registers the given conversion to be used when reading and writing with this data model.
    
    Parameters:
    
    conversion - a logical type Conversion.
  - getConversionByClass
```
public <T> Conversion<T> getConversionByClass(Class<T> datumClass)
```
    Returns the first conversion found for the given class.
    
    Parameters:
    
    datumClass - a Class
    
    Returns:
    
    the first registered conversion for the class, or null
  - getConversionByClass
```
public <T> Conversion<T> getConversionByClass(Class<T> datumClass,
                                              LogicalType logicalType)
```
    Returns the conversion for the given class and logical type.
    
    Parameters:
    
    datumClass - a Class
    
    logicalType - a LogicalType
    
    Returns:
    
    the conversion for the class and logical type, or null
  - getConversionFor
```
public Conversion<Object> getConversionFor(LogicalType logicalType)
```
    Returns the Conversion for the given logical type.
    
    Parameters:
    
    logicalType - a logical type
    
    Returns:
    
    the conversion for the logical type, or null
  - setFastReaderEnabled
```
public GenericData setFastReaderEnabled(boolean flag)
```
  - isFastReaderEnabled
```
public boolean isFastReaderEnabled()
```
  - getFastReaderBuilder
```
public FastReaderBuilder getFastReaderBuilder()
```
  - createDatumReader
```
public DatumReader createDatumReader(Schema schema)
```
    Returns a DatumReader for this kind of data.
  - createDatumReader
```
public DatumReader createDatumReader(Schema writer,
                                     Schema reader)
```
    Returns a DatumReader for this kind of data.
  - createDatumWriter
```
public DatumWriter createDatumWriter(Schema schema)
```
    Returns a DatumWriter for this kind of data.
  - validate
```
public boolean validate(Schema schema,
                        Object datum)
```
    Returns true if a Java datum matches a schema.
  - toString
```
public String toString(Object datum)
```
    Renders a Java datum as JSON.
  - toString
```
protected void toString(Object datum,
                        StringBuilder buffer,
                        IdentityHashMap<Object,Object> seenObjects)
```
    Renders a Java datum as JSON.
  - induce
```
public Schema induce(Object datum)
```
    Create a schema given an example datum.
  - setField
```
public void setField(Object record,
                     String name,
                     int position,
                     Object value)
```
    Called by GenericDatumReader.readRecord(java.lang.Object, org.apache.avro.Schema, org.apache.avro.io.ResolvingDecoder) to set a record fields value to a record instance. The default implementation is for IndexedRecord.
  - getField
```
public Object getField(Object record,
                       String name,
                       int position)
```
    Called by GenericDatumReader.readRecord(java.lang.Object, org.apache.avro.Schema, org.apache.avro.io.ResolvingDecoder) to retrieve a record field value from a reused instance. The default implementation is for IndexedRecord.
  - getRecordState
```
protected Object getRecordState(Object record,
                                Schema schema)
```
    Produce state for repeated calls to getField(Object,String,int,Object) and setField(Object,String,int,Object,Object) on the same record.
  - setField
```
protected void setField(Object record,
                        String name,
                        int position,
                        Object value,
                        Object state)
```
    Version of setField(java.lang.Object, java.lang.String, int, java.lang.Object) that has state.
  - getField
```
protected Object getField(Object record,
                          String name,
                          int pos,
                          Object state)
```
    Version of getField(java.lang.Object, java.lang.String, int) that has state.
  - resolveUnion
```
public int resolveUnion(Schema union,
                        Object datum)
```
    Return the index for a datum within a union. Implemented with Schema.getIndexNamed(String) and getSchemaName(Object).
  - getSchemaName
```
protected String getSchemaName(Object datum)
```
    Return the schema full name for a datum. Called by resolveUnion(Schema,Object).
  - instanceOf
```
protected boolean instanceOf(Schema schema,
                             Object datum)
```
    Called by resolveUnion(Schema,Object). May be overridden for alternate data representations.
  - isArray
```
protected boolean isArray(Object datum)
```
    Called by the default implementation of instanceOf(org.apache.avro.Schema, java.lang.Object).
  - getArrayAsCollection
```
protected Collection getArrayAsCollection(Object datum)
```
    Called to access an array as a collection.
  - isRecord
```
protected boolean isRecord(Object datum)
```
    Called by the default implementation of instanceOf(org.apache.avro.Schema, java.lang.Object).
  - getRecordSchema
```
protected Schema getRecordSchema(Object record)
```
    Called to obtain the schema of a record. By default calls {GenericContainer#getSchema(). May be overridden for alternate record representations.
  - isEnum
```
protected boolean isEnum(Object datum)
```
    Called by the default implementation of instanceOf(org.apache.avro.Schema, java.lang.Object).
  - getEnumSchema
```
protected Schema getEnumSchema(Object enu)
```
    Called to obtain the schema of a enum. By default calls {GenericContainer#getSchema(). May be overridden for alternate enum representations.
  - isMap
```
protected boolean isMap(Object datum)
```
    Called by the default implementation of instanceOf(org.apache.avro.Schema, java.lang.Object).
  - isFixed
```
protected boolean isFixed(Object datum)
```
    Called by the default implementation of instanceOf(org.apache.avro.Schema, java.lang.Object).
  - getFixedSchema
```
protected Schema getFixedSchema(Object fixed)
```
    Called to obtain the schema of a fixed. By default calls {GenericContainer#getSchema(). May be overridden for alternate fixed representations.
  - isString
```
protected boolean isString(Object datum)
```
    Called by the default implementation of instanceOf(org.apache.avro.Schema, java.lang.Object).
  - isBytes
```
protected boolean isBytes(Object datum)
```
    Called by the default implementation of instanceOf(org.apache.avro.Schema, java.lang.Object).
  - isInteger
```
protected boolean isInteger(Object datum)
```
    Called by the default implementation of instanceOf(org.apache.avro.Schema, java.lang.Object).
  - isLong
```
protected boolean isLong(Object datum)
```
    Called by the default implementation of instanceOf(org.apache.avro.Schema, java.lang.Object).
  - isFloat
```
protected boolean isFloat(Object datum)
```
    Called by the default implementation of instanceOf(org.apache.avro.Schema, java.lang.Object).
  - isDouble
```
protected boolean isDouble(Object datum)
```
    Called by the default implementation of instanceOf(org.apache.avro.Schema, java.lang.Object).
  - isBoolean
```
protected boolean isBoolean(Object datum)
```
    Called by the default implementation of instanceOf(org.apache.avro.Schema, java.lang.Object).
  - hashCode
```
public int hashCode(Object o,
                    Schema s)
```
    Compute a hash code according to a schema, consistent with compare(Object,Object,Schema).
  - hashCodeAdd
```
protected int hashCodeAdd(int hashCode,
                          Object o,
                          Schema s)
```
    Add the hash code for an object into an accumulated hash code.
  - compare
```
public int compare(Object o1,
                   Object o2,
                   Schema s)
```
    Compare objects according to their schema. If equal, return zero. If greater-than, return 1, if less than return -1. Order is consistent with that of BinaryData.compare(byte[], int, byte[], int, Schema).
  - compare
```
protected int compare(Object o1,
                      Object o2,
                      Schema s,
                      boolean equals)
```
    Comparison implementation. When equals is true, only checks for equality, not for order.
  - getDefaultValue
```
public Object getDefaultValue(Schema.Field field)
```
    Gets the default value of the given field, if any.
    
    Parameters:
    
    field - the field whose default value should be retrieved.
    
    Returns:
    
    the default value associated with the given field, or null if none is specified in the schema.
  - deepCopy
```
public <T> T deepCopy(Schema schema,
                      T value)
```
    Makes a deep copy of a value given its schema.
    Logical types are converted to raw types, copied, then converted back.
    
    Parameters:
    
    schema - the schema of the value to deep copy.
    
    value - the value to deep copy.
    
    Returns:
    
    a deep copy of the given value.
  - createFixed
```
public Object createFixed(Object old,
                          Schema schema)
```
    Called to create an fixed value. May be overridden for alternate fixed representations. By default, returns GenericFixed.
  - createFixed
```
public Object createFixed(Object old,
                          byte[] bytes,
                          Schema schema)
```
    Called to create an fixed value. May be overridden for alternate fixed representations. By default, returns GenericFixed.
  - createEnum
```
public Object createEnum(String symbol,
                         Schema schema)
```
    Called to create an enum value. May be overridden for alternate enum representations. By default, returns a GenericEnumSymbol.
  - newRecord
```
public Object newRecord(Object old,
                        Schema schema)
```
    Called to create new record instances. Subclasses may override to use a different record implementation. The returned instance must conform to the schema provided. If the old object contains fields not present in the schema, they should either be removed from the old object, or it should create a new instance that conforms to the schema. By default, this returns a GenericData.Record.
  - createString
```
public Object createString(Object value)
```
    Called to create an string value. May be overridden for alternate string representations.
  - newArray
```
public Object newArray(Object old,
                       int size,
                       Schema schema)
```
  - newMap
```
public Object newMap(Object old,
                     int size)
```
    Called to create new array instances. Subclasses may override to use a different map implementation. By default, this returns a HashMap.
  - getNewRecordSupplier
```
public GenericData.InstanceSupplier getNewRecordSupplier(Schema schema)
```
    create a supplier that allows to get new record instances for a given schema in an optimized way

Class GenericData

Nested Class Summary

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

STRING_PROP

STRING_TYPE_STRING

FAST_READER_PROP

Constructor Detail

GenericData

GenericData

Method Detail

setStringType

get

getClassLoader

getConversions

addLogicalTypeConversion

getConversionByClass

getConversionByClass

getConversionFor

setFastReaderEnabled

isFastReaderEnabled

getFastReaderBuilder

createDatumReader

createDatumReader

createDatumWriter

validate

toString

toString

induce

setField

getField

getRecordState

setField

getField

resolveUnion

getSchemaName

instanceOf

isArray

getArrayAsCollection

isRecord

getRecordSchema

isEnum

getEnumSchema

isMap

isFixed

getFixedSchema

isString

isBytes

isInteger

isLong

isFloat

isDouble

isBoolean

hashCode

hashCodeAdd

compare

compare

getDefaultValue

deepCopy

createFixed

createFixed

createEnum

newRecord

createString

newArray

newMap

getNewRecordSupplier