com.goldencode.p2j.persist.serial

Class JsonImport

java.lang.Object

com.goldencode.p2j.persist.serial.Importer

com.goldencode.p2j.persist.serial.JsonImport

All Implemented Interfaces:

TableReader

public final class JsonImport
extends Importer
implements TableReader

An implementation of the 4GL READ-JSON method, which parses a JSON stream and reads the content into a temp-table.

Runtime support is partial at this time; not all modes and features are supported. PRODATASET is not supported at this time.

Nested Class Summary

Nested classes/interfaces inherited from class com.goldencode.p2j.persist.serial.Importer

Importer.FieldMaker, Importer.ImportContext

Field Summary

Fields

Modifier and Type	Field and Description
private static CentralLogger	LOG Logger.
private com.fasterxml.jackson.core.JsonParser	parser JSON parser
private P2JIndex	primaryIndex The primary index which drives the duplicate resolution, in case the read mode is REPLACE.

Fields inherited from class com.goldencode.p2j.persist.serial.Importer

b4tables, bufMan, childFieldsByChild, ctx, ds, inferredRelations, loader, peerMapping, readingBefore, readMode, savedCtx, source, tables

Constructor Summary

Constructors

Constructor and Description
JsonImport(SourceData source, java.lang.String mode) Constructor which immediately performs the import of a DATASET or a TEMP-TABLE.

Method Summary

Modifier and Type	Method and Description
private void	addField(TempTableBuilder ttb, java.lang.String name, java.lang.Object val) Add field to the temp-table.
static boolean	createDatasetStructure(DataSet ds, SourceData source) Validates the source and create the dataset structure by building all temp-tables according to source JsonObject.
static java.lang.Boolean	createTableStructure(TempTableBuilder builder, SourceData source) Validates the source and create the table structure for builder temp-table.
private static P2JField	inferFieldType(java.lang.String name, java.lang.Object value) TBA
private boolean	parseRecord(boolean addLinkToParent) Parse JSON record to retrieve fields' data, prepare table and populate the first record
boolean	readDataset(DataSet ds) Read JSON data from the input source and store it in each temp-table of the dataset.
private boolean	readDataSetContent() Reads the content of a dataset, by populating its whole set of tables.
private boolean	readDataSetContent(java.lang.String name) Reads the content of an empty dynamic dataset, by inferring its structure and populating its whole set of tables.
private boolean	readDatasetFromJsonObject(JsonObject source) Iterates the JsonObject source and populates the tables matching the properties.
private boolean	readNested(java.lang.String name) Read nested table.
private boolean	readRecord(boolean addLinkToParent) Read JSON content from the stream corresponding with a single data record and store it in the temp-table.
private boolean	readRowFromJsonObject(TempTableSchema schema, JsonObject jsonObject) Creates a new record in target temp-table, iterates the JsonObject source and populates the new records with data extracted from the source JsonObject.
boolean	readTable(java.lang.String tableName, TempTableBuilder table, java.util.function.BiConsumer<RecordBuffer,Record> loader) Read JSON data from the input source and store it in the just created empty TEMP-TABLE which is a part of a DATA-SET.
boolean	readTable(TemporaryBuffer buffer, java.util.function.BiConsumer<RecordBuffer,Record> loader) Read JSON data from the input source and store it in the temp-table.
boolean	readTable(TempTableBuilder table, java.util.function.BiConsumer<RecordBuffer,Record> loader) Read JSON data from the input source and store it in the just created empty TEMP-TABLE.
private boolean	readTableContent() Read JSON content from reader and import records into the temp-table.
private boolean	readTableFromJsonArray(TempTableSchema schema, JsonArray jsonArray) Iterates the JsonArray source and for each element creates a new row in the target temp-table.
protected ParmType	typeOf(java.lang.Object val) Get an inferred type of the value.

Methods inherited from class com.goldencode.p2j.persist.serial.Importer

fillFromParent, getColumn, peekContext, persist, popContext, populateRecord, processHiddenFk, processId, processRowState, pushContext, setField, setField, setField, setParentValues, setupDataset

Methods inherited from class java.lang.Object

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

Field Detail

LOG

private static final CentralLogger LOG

Logger.

primaryIndex

private P2JIndex primaryIndex

The primary index which drives the duplicate resolution, in case the read mode is REPLACE.

parser

private com.fasterxml.jackson.core.JsonParser parser

JSON parser

Constructor Detail

JsonImport

public JsonImport(SourceData source,
                  java.lang.String mode)

Constructor which immediately performs the import of a DATASET or a TEMP-TABLE.

Parameters:

source - Data source which normalizes access of various media to an input stream.

mode - Read mode to determine how records are stored and how non-unique records are handled. Not currently honored, except temp-table records are deleted if mode is EMPTY.

Method Detail

createDatasetStructure

public static boolean createDatasetStructure(DataSet ds,
                                             SourceData source)

Validates the source and create the dataset structure by building all temp-tables according to source JsonObject.

Parameters:

ds - The Dataset to be populated with fields and finally prepared.

source - The data source.

Returns:

true if operation is successful and false otherwise.

createTableStructure

public static java.lang.Boolean createTableStructure(TempTableBuilder builder,
                                                     SourceData source)

Validates the source and create the table structure for builder temp-table.

Parameters:

builder - The TempTableBuilder to be populated with fields and finally prepared.

source - The data source.

Returns:

true if operation is successful, false on failure, or null if source is not JSONOBJECT or JSONARRAY.

inferFieldType

private static P2JField inferFieldType(java.lang.String name,
                                       java.lang.Object value)

TBA

readTable

public boolean readTable(TempTableBuilder table,
                         java.util.function.BiConsumer<RecordBuffer,Record> loader)
                  throws PersistenceException

Read JSON data from the input source and store it in the just created empty TEMP-TABLE.

Parameters:

table - TEMP-TABLE to be loaded.

loader - A BiConsumer which helps loading a Record into the buffer.

Returns:

true on success.

Throws:

PersistenceException - if there is any error reading or storing JSON data.

readTable

public boolean readTable(java.lang.String tableName,
                         TempTableBuilder table,
                         java.util.function.BiConsumer<RecordBuffer,Record> loader)
                  throws PersistenceException

Read JSON data from the input source and store it in the just created empty TEMP-TABLE which is a part of a DATA-SET.

Specified by:

readTable in interface TableReader

Parameters:

tableName - table name

table - TEMP-TABLE to be loaded.

loader - A BiConsumer which helps loading a Record into the buffer.

Returns:

true on success.

Throws:

PersistenceException - if there is any error reading or storing JSON data.

readTable

public boolean readTable(TemporaryBuffer buffer,
                         java.util.function.BiConsumer<RecordBuffer,Record> loader)
                  throws PersistenceException

Read JSON data from the input source and store it in the temp-table.

Parameters:

buffer - A buffer of a table in which data is stored.

loader - A BiConsumer which helps loading a Record into the buffer.

Returns:

true on success.

Throws:

PersistenceException - if there is any error reading or storing JSON data.

readDataset

public boolean readDataset(DataSet ds)
                    throws PersistenceException

Read JSON data from the input source and store it in each temp-table of the dataset.

Parameters:

ds - The DataSet in which data is stored.

Returns:

true on success.

Throws:

PersistenceException - if there is any error reading or storing JSON data.

readDataSetContent

private boolean readDataSetContent(java.lang.String name)
                            throws java.io.IOException,
                                   PersistenceException

Reads the content of an empty dynamic dataset, by inferring its structure and populating its whole set of tables.

Parameters:

name - dataset name.

Returns:

true on success.

Throws:

java.io.IOException - If an IO error occurred while getting the data.

PersistenceException - If an error occurred while persisting the read data.

readDataSetContent

private boolean readDataSetContent()
                            throws java.io.IOException,
                                   PersistenceException

Reads the content of a dataset, by populating its whole set of tables.

Returns:

true on success.

Throws:

java.io.IOException - If an IO error occurred while getting the data.

PersistenceException - If an error occurred while persisting the read data.

readTableContent

private boolean readTableContent()
                          throws java.io.IOException,
                                 PersistenceException

Read JSON content from reader and import records into the temp-table.

This version ensures that the group and decimal separators are ',' and '.' for the duration of the deserialization.

Throws:

java.io.IOException - if there is an error reading JSON content from the stream.

PersistenceException - if there is an error storing data in the temp-table.

parseRecord

private boolean parseRecord(boolean addLinkToParent)
                     throws java.io.IOException,
                            PersistenceException

Parse JSON record to retrieve fields' data, prepare table and populate the first record

Parameters:

addLinkToParent - flag indicating that a link to the parent must be added

Returns:

true on success.

Throws:

java.io.IOException - on I/O error

PersistenceException - on error.

typeOf

protected ParmType typeOf(java.lang.Object val)
                   throws PersistenceException

Get an inferred type of the value.

Specified by:

typeOf in class Importer

Parameters:

val - The value to be analyzed.

Returns:

the inferred type of the value.

Throws:

PersistenceException - when the type cannot be inferred from the provided value.

readRecord

private boolean readRecord(boolean addLinkToParent)
                    throws java.io.IOException,
                           PersistenceException

Read JSON content from the stream corresponding with a single data record and store it in the temp-table.

Parameters:

addLinkToParent - flag indicating that a link to the parent must be added.

Throws:

java.io.IOException - if there is an error reading JSON content from the stream.

PersistenceException - if there is an error storing data in the temp-table.

readNested

private boolean readNested(java.lang.String name)
                    throws PersistenceException,
                           java.io.IOException

Read nested table.

Parameters:

name - The name of the table to be read.

Returns:

true on success and false on fail.

Throws:

PersistenceException - on database error.

java.io.IOException - on file I/O error.

readDatasetFromJsonObject

private boolean readDatasetFromJsonObject(JsonObject source)
                                   throws PersistenceException

Iterates the JsonObject source and populates the tables matching the properties.

Parameters:

source - The source which contains the JsonObject source.

Returns:

true on success and false otherwise.

Throws:

PersistenceException - on unexpected events related to persistence.

readTableFromJsonArray

private boolean readTableFromJsonArray(TempTableSchema schema,
                                       JsonArray jsonArray)
                                throws PersistenceException

Iterates the JsonArray source and for each element creates a new row in the target temp-table.

Parameters:

schema - The schema of the temp-table.

jsonArray - The source which contains the JsonArray source.

Returns:

true on success and false otherwise.

Throws:

PersistenceException - on unexpected events related to persistence.

addField

private void addField(TempTableBuilder ttb,
                      java.lang.String name,
                      java.lang.Object val)
               throws PersistenceException

Add field to the temp-table.

Parameters:

ttb - The destination temp-table builder.

name - The name of the field to be added.

val - The value of field. It is used for inferring the type of the new field.

Throws:

PersistenceException - If the type of the field cannot be inferred from the provided value.

readRowFromJsonObject

private boolean readRowFromJsonObject(TempTableSchema schema,
                                      JsonObject jsonObject)
                               throws PersistenceException

Creates a new record in target temp-table, iterates the JsonObject source and populates the new records with data extracted from the source JsonObject.

Parameters:

schema - The schema of the temp-table.

jsonObject - The source which contains the JsonObject source.

Returns:

true on success and false otherwise.

Throws:

PersistenceException - on unexpected events related to persistence.