com.pushtechnology.diffusion.datatype.recordv2.schema

Interface SchemaBuilder

public interface SchemaBuilder

Used to build an immutable Schema.

A schema defines the records and fields that may occur in a RecordV2 topic value.

The schema must declare at least one record type and every record must have at least one field type declared.

Every record type and field type has a 'multiplicity' which defines the number of times that the record or field may occur within the data. Multiplicity is specified as a 'minimum' and 'maximum' number of occurrences or where the minimum and maximum are the same (fixed multiplicity) then the multiplicity may be specified as a single 'occurs' value. If the minimum and maximum are different, this is referred to a 'variable' multiplicity. Only the last record declared or the last field within a record may have variable multiplicity. The maximum value may be declared as -1 to indicate that the record or field can have an unlimited number of occurrences.

The builder is used to add a record definition followed by the fields within it. After all fields have been added to a record another may then be added, and so on, and then finally build() is called to create an immutable schema object.

Every call returns the builder instance allowing calls to be chained, for example:

 Schema schema = builder.record("R1").string("S1").string("S2", 1, 5)
     .record("R2", 0, -1).decimal("D", 5).build();
 

A builder is obtained using the RecordV2DataType.schemaBuilder() method.

Since:

6.0

Author:

DiffusionData Limited

Method Summary

Modifier and Type	Method and Description
Schema	build() Build an immutable Schema.
SchemaBuilder	decimal(String name, int scale) Add a single occurrence decimal field to the current record.
SchemaBuilder	decimal(String name, int scale, int occurs) Add a fixed multiplicity decimal field to the current record.
SchemaBuilder	decimal(String name, int scale, int min, int max) Add a decimal field to the current record.
SchemaBuilder	integer(String name) Add a single occurrence integer field to the current record.
SchemaBuilder	integer(String name, int occurs) Add a fixed multiplicity integer field to the current record.
SchemaBuilder	integer(String name, int min, int max) Add an integer field to the current record.
SchemaBuilder	record(String name) Add a new single occurrence record to the schema.
SchemaBuilder	record(String name, int occurs) Add a new fixed multiplicity record to the schema.
SchemaBuilder	record(String name, int min, int max) Add a new record to the schema.
SchemaBuilder	string(String name) Add a single occurrence string field to the current record.
SchemaBuilder	string(String name, int occurs) Add a fixed multiplicity string field to the current record.
SchemaBuilder	string(String name, int min, int max) Add a string field to the current record.

Method Detail

record

SchemaBuilder record(String name)
              throws SchemaViolationException

Add a new single occurrence record to the schema.

This is the equivalent to calling record(name, 1)

Parameters:

name - the record name

Returns:

this builder

Throws:

SchemaViolationException - if schema rules are violated

record

SchemaBuilder record(String name,
                     int occurs)
              throws SchemaViolationException

Add a new fixed multiplicity record to the schema.

This is the equivalent to calling record(name, occurs, occurs) .

Parameters:

name - the record name

occurs - the number of times the record is to occur. This must be a positive value.

Returns:

this builder

Throws:

SchemaViolationException - if schema rules are violated

record

SchemaBuilder record(String name,
                     int min,
                     int max)
              throws SchemaViolationException

Add a new record to the schema.

The record added must not have the same name as a previously added record.

A record may not be added after a record with variable multiplicity.

A record may not be added directly after another record which has had no fields added.

Parameters:

name - the record name

min - the minimum number of occurrences of the record. This must not be negative.

max - the maximum number of occurrences of the record. This must either be -1 to indicate an unlimited number or it must be a positive number greater than or equal to min.

Returns:

this builder

Throws:

SchemaViolationException - if schema rules are violated

string

SchemaBuilder string(String name)
              throws SchemaViolationException

Add a single occurrence string field to the current record.

This is the equivalent of calling string(name, 1).

Parameters:

name - field name

Returns:

this builder

Throws:

SchemaViolationException - if schema rules are violated

string

SchemaBuilder string(String name,
                     int occurs)
              throws SchemaViolationException

Add a fixed multiplicity string field to the current record.

This is the equivalent of calling string(name, occurs, occurs).

Parameters:

name - field name

occurs - the fixed number of times the field should occur within the record. This must be positive.

Returns:

this builder

Throws:

SchemaViolationException - if schema rules are violated

string

SchemaBuilder string(String name,
                     int min,
                     int max)
              throws SchemaViolationException

Add a string field to the current record.

A field may not be added after a field that has variable multiplicity (min != max).

Parameters:

name - field name. This must not be the same as any field already added to the record.

min - the minimum number of times the field may occur within the record. This must not be negative.

max - the maximum number of times that the field may occur within the record. This must either be -1 (indicating no upper limit) or a positive value that is not less than min.

Returns:

this builder

Throws:

SchemaViolationException - if schema rules are violated

integer

SchemaBuilder integer(String name)
               throws SchemaViolationException

Add a single occurrence integer field to the current record.

This is the equivalent of calling integer(name, 1).

Parameters:

name - field name

Returns:

this builder

Throws:

SchemaViolationException - if schema rules are violated

integer

SchemaBuilder integer(String name,
                      int occurs)
               throws SchemaViolationException

Add a fixed multiplicity integer field to the current record.

This is the equivalent of calling integer(name, occurs, occurs).

Parameters:

name - field name

occurs - the fixed number of times the field should occur within the record. This must be positive.

Returns:

this builder

Throws:

SchemaViolationException - if schema rules are violated

integer

SchemaBuilder integer(String name,
                      int min,
                      int max)
               throws SchemaViolationException

Add an integer field to the current record.

A field may not be added after a field that has variable multiplicity (min != max).

Parameters:

name - field name. This must not be the same as any field already added to the record.

min - the minimum number of times the field may occur within the record. This must not be negative.

max - the maximum number of times that the field may occur within the record. This must either be -1 (indicating no upper limit) or a positive value that is not less than min.

Returns:

this builder

Throws:

SchemaViolationException - if schema rules are violated

decimal

SchemaBuilder decimal(String name,
                      int scale)
               throws SchemaViolationException

Add a single occurrence decimal field to the current record.

This is the equivalent of calling decimal(name, scale, 1).

Parameters:

name - field name

scale - the scale of the field (the number of decimal places). This must be a positive value.

Returns:

this builder

Throws:

SchemaViolationException - if schema rules are violated

decimal

SchemaBuilder decimal(String name,
                      int scale,
                      int occurs)
               throws SchemaViolationException

Add a fixed multiplicity decimal field to the current record.

This is the equivalent of calling decimal(name, scale, occurs, occurs).

Parameters:

name - field name

scale - the scale of the field (the number of decimal places). This must be a positive value.

occurs - the fixed number of times the field should occur within the record. This must be positive.

Returns:

this builder

Throws:

SchemaViolationException - if schema rules are violated

decimal

SchemaBuilder decimal(String name,
                      int scale,
                      int min,
                      int max)
               throws SchemaViolationException

Add a decimal field to the current record.

A field may not be added after a field that has variable multiplicity (min != max).

Parameters:

name - field name. This must not be the same as any field already added to the builder.

scale - the scale of the field (the number of decimal places). This must be a positive value.

min - the minimum number of times the field may occur within the record. This must not be negative.

max - the maximum number of times that the field may occur within the record. This must either be -1 (indicating no upper limit) or a positive value that is not less than min.

Returns:

the builder

Throws:

SchemaViolationException - if schema rules are violated

build

Schema build()
      throws SchemaViolationException

Build an immutable Schema.

At least one record with at least one field must have been added to the builder.

Returns:

a new immutable schema object representing the current state of the builder

Throws:

SchemaViolationException - if no record have been specified to the builder.