org.apache.kafka.connect.data

Class SchemaBuilder

java.lang.Object

org.apache.kafka.connect.data.SchemaBuilder

All Implemented Interfaces:

Schema

public class SchemaBuilder
extends java.lang.Object
implements Schema

SchemaBuilder provides a fluent API for constructing Schema objects. It allows you to set each of the properties for the schema and each call returns the SchemaBuilder so the calls can be chained. When nested types are required, use one of the predefined schemas from Schema or use a second SchemaBuilder inline.

Here is an example of building a struct schema:

     Schema dateSchema = SchemaBuilder.struct()
         .name("com.example.CalendarDate").version(2).doc("A calendar date including month, day, and year.")
         .field("month", Schema.STRING_SCHEMA)
         .field("day", Schema.INT8_SCHEMA)
         .field("year", Schema.INT16_SCHEMA)
         .build();
     

Here is an example of using a second SchemaBuilder to construct complex, nested types:

     Schema userListSchema = SchemaBuilder.array(
         SchemaBuilder.struct().name("com.example.User").field("username", Schema.STRING_SCHEMA).field("id", Schema.INT64_SCHEMA).build()
     ).build();
     

Nested Class Summary

Nested classes/interfaces inherited from interface org.apache.kafka.connect.data.Schema

Schema.Type

Field Summary

Fields inherited from interface org.apache.kafka.connect.data.Schema

BOOLEAN_SCHEMA, BYTES_SCHEMA, FLOAT32_SCHEMA, FLOAT64_SCHEMA, INT16_SCHEMA, INT32_SCHEMA, INT64_SCHEMA, INT8_SCHEMA, OPTIONAL_BOOLEAN_SCHEMA, OPTIONAL_BYTES_SCHEMA, OPTIONAL_FLOAT32_SCHEMA, OPTIONAL_FLOAT64_SCHEMA, OPTIONAL_INT16_SCHEMA, OPTIONAL_INT32_SCHEMA, OPTIONAL_INT64_SCHEMA, OPTIONAL_INT8_SCHEMA, OPTIONAL_STRING_SCHEMA, STRING_SCHEMA

Constructor Summary

Constructors

Constructor and Description
SchemaBuilder(Schema.Type type)

Method Summary

Modifier and Type	Method and Description
static SchemaBuilder	array(Schema valueSchema)
static SchemaBuilder	bool()
Schema	build() Build the Schema using the current settings
static SchemaBuilder	bytes()
java.lang.Object	defaultValue()
SchemaBuilder	defaultValue(java.lang.Object value) Set the default value for this schema.
java.lang.String	doc()
SchemaBuilder	doc(java.lang.String doc) Set the documentation for this schema.
Field	field(java.lang.String fieldName) Get a field for this Schema by name.
SchemaBuilder	field(java.lang.String fieldName, Schema fieldSchema) Add a field to this struct schema.
java.util.List<Field>	fields() Get the list of fields for this Schema.
static SchemaBuilder	float32()
static SchemaBuilder	float64()
static SchemaBuilder	int16()
static SchemaBuilder	int32()
static SchemaBuilder	int64()
static SchemaBuilder	int8()
boolean	isOptional()
Schema	keySchema() Get the key schema for this map schema.
static SchemaBuilder	map(Schema keySchema, Schema valueSchema)
java.lang.String	name()
SchemaBuilder	name(java.lang.String name) Set the name of this schema.
SchemaBuilder	optional() Set this schema as optional.
SchemaBuilder	parameter(java.lang.String propertyName, java.lang.String propertyValue) Set a schema parameter.
java.util.Map<java.lang.String,java.lang.String>	parameters() Get a map of schema parameters.
SchemaBuilder	parameters(java.util.Map<java.lang.String,java.lang.String> props) Set schema parameters.
SchemaBuilder	required() Set this schema as required.
Schema	schema() Return a concrete instance of the Schema specified by this builder
static SchemaBuilder	string()
static SchemaBuilder	struct()
Schema.Type	type()
static SchemaBuilder	type(Schema.Type type) Create a SchemaBuilder for the specified type.
Schema	valueSchema() Get the value schema for this map or array schema.
java.lang.Integer	version() Get the optional version of the schema.
SchemaBuilder	version(java.lang.Integer version) Set the version of this schema.

Methods inherited from class java.lang.Object

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

Constructor Detail

SchemaBuilder

public SchemaBuilder(Schema.Type type)

Method Detail

isOptional

public boolean isOptional()

Specified by:

isOptional in interface Schema

Returns:

true if this field is optional, false otherwise

optional

public SchemaBuilder optional()

Set this schema as optional.

Returns:

the SchemaBuilder

required

public SchemaBuilder required()

Set this schema as required. This is the default, but this method can be used to make this choice explicit.

Returns:

the SchemaBuilder

defaultValue

public java.lang.Object defaultValue()

Specified by:

defaultValue in interface Schema

Returns:

the default value for this schema

defaultValue

public SchemaBuilder defaultValue(java.lang.Object value)

Set the default value for this schema. The value is validated against the schema type, throwing a SchemaBuilderException if it does not match.

Parameters:

value - the default value

Returns:

the SchemaBuilder

name

public java.lang.String name()

Specified by:

name in interface Schema

Returns:

the name of this schema

name

public SchemaBuilder name(java.lang.String name)

Set the name of this schema.

Parameters:

name - the schema name

Returns:

the SchemaBuilder

version

public java.lang.Integer version()

Description copied from interface: Schema

Get the optional version of the schema. If a version is included, newer versions *must* be larger than older ones.

Specified by:

version in interface Schema

Returns:

the version of this schema

version

public SchemaBuilder version(java.lang.Integer version)

Set the version of this schema. Schema versions are integers which, if provided, must indicate which schema is newer and which is older by their ordering.

Parameters:

version - the schema version

Returns:

the SchemaBuilder

doc

public java.lang.String doc()

Specified by:

doc in interface Schema

Returns:

the documentation for this schema

doc

public SchemaBuilder doc(java.lang.String doc)

Set the documentation for this schema.

Parameters:

doc - the documentation

Returns:

the SchemaBuilder

parameters

public java.util.Map<java.lang.String,java.lang.String> parameters()

Description copied from interface: Schema

Get a map of schema parameters.

Specified by:

parameters in interface Schema

Returns:

Map containing parameters for this schema, or null if there are no parameters

parameter

public SchemaBuilder parameter(java.lang.String propertyName,
                               java.lang.String propertyValue)

Set a schema parameter.

Parameters:

propertyName - name of the schema property to define

propertyValue - value of the schema property to define, as a String

Returns:

the SchemaBuilder

parameters

public SchemaBuilder parameters(java.util.Map<java.lang.String,java.lang.String> props)

Set schema parameters. This operation is additive; it does not remove existing parameters that do not appear in the set of properties pass to this method.

Parameters:

props - Map of properties to set

Returns:

the SchemaBuilder

type

public Schema.Type type()

Specified by:

type in interface Schema

Returns:

the type of this schema

type

public static SchemaBuilder type(Schema.Type type)

Create a SchemaBuilder for the specified type. Usually it will be simpler to use one of the variants like string() or struct(), but this form can be useful when generating schemas dynamically.

Parameters:

type - the schema type

Returns:

a new SchemaBuilder

int8

public static SchemaBuilder int8()

Returns:

a new Schema.Type.INT8 SchemaBuilder

int16

public static SchemaBuilder int16()

Returns:

a new Schema.Type.INT16 SchemaBuilder

int32

public static SchemaBuilder int32()

Returns:

a new Schema.Type.INT32 SchemaBuilder

int64

public static SchemaBuilder int64()

Returns:

a new Schema.Type.INT64 SchemaBuilder

float32

public static SchemaBuilder float32()

Returns:

a new Schema.Type.FLOAT32 SchemaBuilder

float64

public static SchemaBuilder float64()

Returns:

a new Schema.Type.FLOAT64 SchemaBuilder

bool

public static SchemaBuilder bool()

Returns:

a new Schema.Type.BOOLEAN SchemaBuilder

string

public static SchemaBuilder string()

Returns:

a new Schema.Type.STRING SchemaBuilder

bytes

public static SchemaBuilder bytes()

Returns:

a new Schema.Type.BYTES SchemaBuilder

struct

public static SchemaBuilder struct()

Returns:

a new Schema.Type.STRUCT SchemaBuilder

field

public SchemaBuilder field(java.lang.String fieldName,
                           Schema fieldSchema)

Add a field to this struct schema. Throws a SchemaBuilderException if this is not a struct schema.

Parameters:

fieldName - the name of the field to add

fieldSchema - the Schema for the field's value

Returns:

the SchemaBuilder

fields

public java.util.List<Field> fields()

Get the list of fields for this Schema. Throws a DataException if this schema is not a struct.

Specified by:

fields in interface Schema

Returns:

the list of fields for this Schema

field

public Field field(java.lang.String fieldName)

Description copied from interface: Schema

Get a field for this Schema by name. Throws a DataException if this schema is not a struct.

Specified by:

field in interface Schema

Parameters:

fieldName - the name of the field to look up

Returns:

the Field object for the specified field, or null if there is no field with the given name

array

public static SchemaBuilder array(Schema valueSchema)

Parameters:

valueSchema - the schema for elements of the array

Returns:

a new Schema.Type.ARRAY SchemaBuilder

map

public static SchemaBuilder map(Schema keySchema,
                                Schema valueSchema)

Parameters:

keySchema - the schema for keys in the map

valueSchema - the schema for values in the map

Returns:

a new Schema.Type.MAP SchemaBuilder

keySchema

public Schema keySchema()

Description copied from interface: Schema

Get the key schema for this map schema. Throws a DataException if this schema is not a map.

Specified by:

keySchema in interface Schema

Returns:

the key schema

valueSchema

public Schema valueSchema()

Description copied from interface: Schema

Get the value schema for this map or array schema. Throws a DataException if this schema is not a map or array.

Specified by:

valueSchema in interface Schema

Returns:

the value schema

build

public Schema build()

Build the Schema using the current settings

Returns:

the Schema

schema

public Schema schema()

Return a concrete instance of the Schema specified by this builder

Specified by:

schema in interface Schema

Returns:

the Schema