Package io.deephaven.parquet.table

Class ParquetSchemaReader

java.lang.Object

io.deephaven.parquet.table.ParquetSchemaReader

public class ParquetSchemaReader
extends Object

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static interface	ParquetSchemaReader.ColumnDefinitionConsumer
static final class	ParquetSchemaReader.ParquetMessageDefinition

Constructor Summary

Constructors

Constructor	Description
ParquetSchemaReader()

Method Summary

Modifier and Type	Method	Description
static Optional<TableInfo>	parseMetadata(@NotNull Map<String,String> keyValueMetadata)
static ParquetInstructions	readParquetSchema(@NotNull String filePath, @NotNull ParquetInstructions readInstructions, @NotNull ParquetSchemaReader.ColumnDefinitionConsumer consumer, @NotNull BiFunction<String,Set<String>,String> legalizeColumnNameFunc)	Obtain schema information from a parquet file
static ParquetInstructions	readParquetSchema(@NotNull org.apache.parquet.schema.MessageType schema, @NotNull Map<String,String> keyValueMetadata, @NotNull ParquetInstructions readInstructions, @NotNull ParquetSchemaReader.ColumnDefinitionConsumer consumer, @NotNull BiFunction<String,Set<String>,String> legalizeColumnNameFunc)	Obtain schema information from a parquet file

Methods inherited from class java.lang.Object

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

Constructor Details

ParquetSchemaReader

public ParquetSchemaReader()

Method Details

readParquetSchema

public static ParquetInstructions readParquetSchema(@NotNull
 @NotNull String filePath,
 @NotNull
 @NotNull ParquetInstructions readInstructions,
 @NotNull
 @NotNull ParquetSchemaReader.ColumnDefinitionConsumer consumer,
 @NotNull
 @NotNull BiFunction<String,Set<String>,String> legalizeColumnNameFunc)
                                             throws IOException

Obtain schema information from a parquet file

Parameters:

filePath - Location for input parquet file

readInstructions - Parquet read instructions specifying transformations like column mappings and codecs. Note a new read instructions based on this one may be returned by this method to provide necessary transformations, eg, replacing unsupported characters like ' ' (space) in column names.

consumer - A ColumnDefinitionConsumer whose accept method would be called for each column in the file

Returns:

Parquet read instructions, either the ones supplied or a new object based on the supplied with necessary transformations added.

Throws:

IOException

parseMetadata

public static Optional<TableInfo> parseMetadata(@NotNull
 @NotNull Map<String,String> keyValueMetadata)

readParquetSchema

public static ParquetInstructions readParquetSchema(@NotNull
 @NotNull org.apache.parquet.schema.MessageType schema,
 @NotNull
 @NotNull Map<String,String> keyValueMetadata,
 @NotNull
 @NotNull ParquetInstructions readInstructions,
 @NotNull
 @NotNull ParquetSchemaReader.ColumnDefinitionConsumer consumer,
 @NotNull
 @NotNull BiFunction<String,Set<String>,String> legalizeColumnNameFunc)

Obtain schema information from a parquet file

Parameters:

schema - Parquet schema. DO NOT RELY ON ParquetMetadataConverter FOR THIS! USE ParquetFileReader!

keyValueMetadata - Parquet key-value metadata map

readInstructions - Parquet read instructions specifying transformations like column mappings and codecs. Note a new read instructions based on this one may be returned by this method to provide necessary transformations, eg, replacing unsupported characters like ' ' (space) in column names.

consumer - A ColumnDefinitionConsumer whose accept method would be called for each column in the file

Returns:

Parquet read instructions, either the ones supplied or a new object based on the supplied with necessary transformations added.