org.apache.metamodel.xml

Class XmlSaxDataContext

java.lang.Object

org.apache.metamodel.AbstractDataContext

org.apache.metamodel.QueryPostprocessDataContext

org.apache.metamodel.xml.XmlSaxDataContext

All Implemented Interfaces:

HasReadTypeConverters, DataContext

public class XmlSaxDataContext
extends QueryPostprocessDataContext

XML datacontext which uses SAX parsing for fast and memory effecient reading of XML files. The DataContext requires the user to specify a set of (simplified) XPaths to define which elements are row delimitors and which elements or attributes are value/column definitions.

Field Summary

Fields

Modifier and Type	Field and Description
static String	COLUMN_NAME_ROW_ID

Fields inherited from class org.apache.metamodel.QueryPostprocessDataContext

INFORMATION_SCHEMA_NAME, SYSTEM_PROPERTY_CREATE_DEFAULT_TABLE_ALIAS

Constructor Summary

Constructors

Constructor and Description
XmlSaxDataContext(File file, XmlSaxTableDef... tableDefs)
XmlSaxDataContext(Resource resource, Collection<XmlSaxTableDef> tableDefs)
XmlSaxDataContext(Resource resource, XmlSaxTableDef... tableDefs)
XmlSaxDataContext(Supplier<InputSource> inputSourceRef, Collection<XmlSaxTableDef> tableDefs) Constructs an XML DataContext based on SAX parsing.
XmlSaxDataContext(Supplier<InputSource> inputSourceRef, XmlSaxTableDef... tableDefs)

Method Summary

Modifier and Type	Method and Description
protected Schema	getMainSchema()
protected String	getMainSchemaName()
protected DataSet	materializeMainSchemaTable(Table table, List<Column> columns, int maxRows) Executes a simple one-table query against a table in the main schema of the subclasses of this class.

Methods inherited from class org.apache.metamodel.QueryPostprocessDataContext

addConverter, executeCountQuery, executePrimaryKeyLookupQuery, executeQuery, getDefaultSchemaName, getSchemaByNameInternal, getSchemaNamesInternal, isMainSchemaTable, isScalarFunctionMaterialized, materializeFromItem, materializeMainSchemaTable, materializeMainSchemaTable, materializeMainSchemaTableSelect, materializeTable

Methods inherited from class org.apache.metamodel.AbstractDataContext

compileQuery, executeQuery, executeQuery, getColumnByQualifiedLabel, getDefaultSchema, getSchemaByName, getSchemaNames, getSchemas, getTableByQualifiedLabel, isQualifiedPathDelim, onSchemaCacheRefreshed, parseQuery, query, refreshSchemas

Methods inherited from class java.lang.Object

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

Field Detail

COLUMN_NAME_ROW_ID

public static final String COLUMN_NAME_ROW_ID

See Also:

Constant Field Values

Constructor Detail

XmlSaxDataContext

public XmlSaxDataContext(Supplier<InputSource> inputSourceRef,
                         Collection<XmlSaxTableDef> tableDefs)

Constructs an XML DataContext based on SAX parsing.

Parameters:

inputSourceRef - a factory reference for the input source to read the XML from. The ref will be repeatedly called for each access to the file!

tableDefs - a collection of table definitions, which provide instructions as to the xpaths to apply to the document.

See Also:

XmlSaxTableDef

XmlSaxDataContext

public XmlSaxDataContext(Supplier<InputSource> inputSourceRef,
                         XmlSaxTableDef... tableDefs)

XmlSaxDataContext

public XmlSaxDataContext(Resource resource,
                         XmlSaxTableDef... tableDefs)

XmlSaxDataContext

public XmlSaxDataContext(Resource resource,
                         Collection<XmlSaxTableDef> tableDefs)

XmlSaxDataContext

public XmlSaxDataContext(File file,
                         XmlSaxTableDef... tableDefs)

Method Detail

getMainSchema

protected Schema getMainSchema()
                        throws MetaModelException

Specified by:

getMainSchema in class QueryPostprocessDataContext

Returns:

the main schema that subclasses of this class produce

Throws:

MetaModelException

getMainSchemaName

protected String getMainSchemaName()
                            throws MetaModelException

Specified by:

getMainSchemaName in class QueryPostprocessDataContext

Returns:

the name of the main schema that subclasses of this class produce

Throws:

MetaModelException

materializeMainSchemaTable

protected DataSet materializeMainSchemaTable(Table table,
                                             List<Column> columns,
                                             int maxRows)

Description copied from class: QueryPostprocessDataContext

Executes a simple one-table query against a table in the main schema of the subclasses of this class.

Specified by:

materializeMainSchemaTable in class QueryPostprocessDataContext

Parameters:

table - the table to query

columns - the columns of the table to query

maxRows - the maximum amount of rows needed or -1 if all rows are wanted.

Returns:

a dataset with the raw table/column content.