Package org.apache.juneau.marshall.marshaller

Class Parquet

java.lang.Object

org.apache.juneau.marshall.marshaller.Marshaller

org.apache.juneau.marshall.marshaller.StreamMarshaller

org.apache.juneau.marshall.marshaller.Parquet

public class Parquet
extends StreamMarshaller

A pairing of ParquetSerializer and ParquetParser for Apache Parquet binary format.

Examples:

// Serialize a list of beans to Parquet bytes List<MyBean> beans = List.of(new MyBean(...), new MyBean(...)); byte[] bytes = Parquet.of(beans); // Parse Parquet bytes back into a list of beans List<MyBean> parsed = Parquet.to(bytes, MyBean.class);

// Using instance methods Parquet m = Parquet.DEFAULT; bytes = m.write(beans); parsed = m.read(bytes, MyBean.class);

Output is binary (byte[]), Apache Parquet columnar format.

Note: Parquet is collection-oriented. The serializer accepts a Collection or array of beans (each bean is one row). A single bean is automatically wrapped in a one-element list. The parser always returns a List<T>, never a bare T.

// Using static shortcuts. MyPojo myPojo = Parquet.to(bytes, MyPojo.class); byte[] bytes = Parquet.of(myPojo);

See Also:

• Parquet Basics
• {doc jm.Marshallers}

Field Summary

Fields

Modifier and Type	Field	Description
static final Parquet	DEFAULT	Default reusable instance.

Constructor Summary

Constructors

Constructor	Description
Parquet()	Constructor using default serializer and parser.
Parquet(ParquetSerializer s, ParquetParser p)	Constructor.

Method Summary

Modifier and Type	Method	Description
static byte[]	of(Object object)	Serializes a POJO to a byte[] using the DEFAULT marshaller.
static void	of(Object object, OutputStream output)	Serializes a POJO to the specified OutputStream using the DEFAULT marshaller.
static RecordWriter	ofArrayRecords(Object output)	Opens a RecordWriter that wraps each written value as one element of a top-level wire array using the DEFAULT marshaller.
static RecordWriter	ofRecords(Object output)	Opens a low-level RecordWriter cursor over the specified output using the DEFAULT marshaller.
static <T> T	to(byte[] input, Class<T> type)	Parses an input into the specified object type using the DEFAULT marshaller.
static <T> T	to(byte[] input, Type type, Type... args)	Parses an input into the specified parameterized object type using the DEFAULT marshaller.
static <T> T	to(InputStream input, Class<T> type)	Parses the contents of an InputStream into the specified object type using the DEFAULT marshaller.
static <T> T	to(InputStream input, Type type, Type... args)	Parses the contents of an InputStream into the specified parameterized object type using the DEFAULT marshaller.
static RecordReader	toArrayRecords(Object input)	Opens a RecordReader that yields each element of a top-level wire array using the DEFAULT marshaller.
static RecordReader	toRecords(Object input)	Opens a low-level RecordReader cursor over the specified input using the DEFAULT marshaller.

Methods inherited from class org.apache.juneau.marshall.marshaller.StreamMarshaller

read, read, write

Methods inherited from class org.apache.juneau.marshall.marshaller.Marshaller

getParser, getSerializer, read, read, readArrayRecords, readRecords, readTokens, write, writeArrayRecords, writeRecords, writeTokens

Methods inherited from class java.lang.Object

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

Field Details

DEFAULT

public static final Parquet DEFAULT

Default reusable instance.

Constructor Details

Parquet

public Parquet()

Constructor using default serializer and parser.

Parquet

public Parquet(ParquetSerializer s,
 ParquetParser p)

Constructor.

Parameters:

s - The serializer.

p - The parser.

Method Details

of

public static byte[] of(Object object)
                 throws SerializeException

Serializes a POJO to a byte[] using the DEFAULT marshaller.

A shortcut for calling DEFAULT.write(object).

Parameters:

object - The object to serialize.

Returns:

The serialized object.

Throws:

SerializeException - If a problem occurred trying to convert the output.

to

public static <T> T to(byte[] input,
 Class<T> type)
                throws ParseException

Parses an input into the specified object type using the DEFAULT marshaller.

A shortcut for calling DEFAULT.read(input, type).

Type Parameters:

T - The class type of the object being created.

Parameters:

input - The input.

type - The object type to create.

Returns:

The parsed object.

Throws:

ParseException - Malformed input encountered.

to

public static <T> T to(byte[] input,
 Type type,
 Type... args)
                throws ParseException

Parses an input into the specified parameterized object type using the DEFAULT marshaller.

A shortcut for calling DEFAULT.read(input, type, args).

Type Parameters:

T - The class type of the object to create.

Parameters:

input - The input.

type - The object type to create.

args - The type arguments of the class if it's a collection or map.

Returns:

The parsed object.

Throws:

ParseException - Malformed input encountered.

to

public static <T> T to(InputStream input,
 Class<T> type)
                throws ParseException

Parses the contents of an InputStream into the specified object type using the DEFAULT marshaller.

A shortcut for calling DEFAULT.read(input, type) that catches any IOException from the underlying stream and rethrows it as an unchecked ParseException, so the caller is not burdened with a checked exception.

Type Parameters:

T - The class type of the object being created.

Parameters:

input - The input stream.

type - The object type to create.

Returns:

The parsed object.

Throws:

ParseException - Malformed input encountered or an I/O error occurred on the underlying stream.

to

public static <T> T to(InputStream input,
 Type type,
 Type... args)
                throws ParseException

Parses the contents of an InputStream into the specified parameterized object type using the DEFAULT marshaller.

A shortcut for calling DEFAULT.read(input, type, args) that catches any IOException from the underlying stream and rethrows it as an unchecked ParseException, so the caller is not burdened with a checked exception.

Type Parameters:

T - The class type of the object to create.

Parameters:

input - The input stream.

type - The object type to create.

args - The type arguments of the class if it's a collection or map.

Returns:

The parsed object.

Throws:

ParseException - Malformed input encountered or an I/O error occurred on the underlying stream.

of

public static void of(Object object,
 OutputStream output)
               throws SerializeException

Serializes a POJO to the specified OutputStream using the DEFAULT marshaller.

A shortcut for calling DEFAULT.write(object, output) that catches any IOException from the underlying stream and rethrows it as an unchecked SerializeException, so the caller is not burdened with a checked exception.

Parameters:

object - The object to serialize.

output - The output stream to serialize to.

Throws:

SerializeException - If a problem occurred trying to convert the output or an I/O error occurred on the underlying stream.

toRecords

public static RecordReader toRecords(Object input)
                              throws IOException

Opens a low-level RecordReader cursor over the specified input using the DEFAULT marshaller.

A shortcut for calling DEFAULT.readRecords(input).

Parameters:

input - The input.

Returns:

A new RecordReader.

Throws:

IOException - If a problem occurred opening the underlying input.

ofRecords

public static RecordWriter ofRecords(Object output)
                              throws IOException

Opens a low-level RecordWriter cursor over the specified output using the DEFAULT marshaller.

A shortcut for calling DEFAULT.writeRecords(output).

Parameters:

output - The output.

Returns:

A new RecordWriter.

Throws:

IOException - If a problem occurred opening the underlying output.

toArrayRecords

public static RecordReader toArrayRecords(Object input)
                                   throws IOException

Opens a RecordReader that yields each element of a top-level wire array using the DEFAULT marshaller.

A shortcut for calling DEFAULT.readArrayRecords(input).

Parameters:

input - The input.

Returns:

A new RecordReader.

Throws:

IOException - If a problem occurred opening the underlying input.

ofArrayRecords

public static RecordWriter ofArrayRecords(Object output)
                                   throws IOException

Opens a RecordWriter that wraps each written value as one element of a top-level wire array using the DEFAULT marshaller.

A shortcut for calling DEFAULT.writeArrayRecords(output).

Parameters:

output - The output.

Returns:

A new RecordWriter.

Throws:

IOException - If a problem occurred opening the underlying output.