Apache Derby Database Engine and Embedded JDBC Driver 10.17.1.0 · org.apache.derby.iapi.types.XML

Modifier and Type	Field and Description
private static final int	BASE_MEMORY_USAGE
private boolean	containsTopLevelAttr
private SqlXmlUtil	tmpUtil
protected static final short	UTF8_IMPL_ID
public static final int	XML_DOC_ANY
public static final int	XML_SEQUENCE
private static String	xmlReqCheck
private SQLChar	xmlStringValue
public static final short	XQ_EMPTY_ON_EMPTY
public static final short	XQ_NULL_ON_EMPTY
public static final short	XQ_PASS_BY_REF
public static final short	XQ_PASS_BY_VALUE
public static final short	XQ_RETURN_CONTENT
public static final short	XQ_RETURN_SEQUENCE
private int	xType

Access	Constructor and Description
public	XML() Default constructor.
private	XML(SQLChar A SQLChar instance to clone and use for this XML value. val, int Qualified XML type for "val" xmlType, boolean Whether or not "val" corresponds to sequence with one or more top-level attribute nodes. seqWithAttr, boolean whether or not to force materialization of the underlying source data materialize) Private constructor used for the `cloneValue` method.

Method Summary

Modifier and Type	Method and Description
private static boolean	Returns: `true` if JAXP is installed, or `false` otherwise checkJAXPRequirement() Check if we have a JAXP implementation installed.
public static void	checkXMLRequirements() See if the required JAXP and Xalan classes are in the user's classpath.
private static boolean	Returns: `true` if XPath is supported, or `false` otherwise checkXPathRequirement() Check if XPath is supported on this platform.
public DataValueDescriptor	cloneValue(boolean any streams representing the data value will be materialized if `true`, the data value will be kept as a stream if possible if `false` forceMaterialization) Implements org.apache.derby.iapi.types.DataValueDescriptor.cloneValue. Clone this DataValueDescriptor.
public int	compare(DataValueDescriptor The Orderable to compare this one to. other) Implements org.apache.derby.iapi.types.DataValueDescriptor.compare. Compare two XML DataValueDescriptors.
public int	estimateMemoryUsage() Implements org.apache.derby.iapi.types.DataValueDescriptor.estimateMemoryUsage. Estimate the memory usage in bytes of the data value and the overhead of the class.
public int	getLength() Implements org.apache.derby.iapi.types.DataValueDescriptor.getLength. Gets the length of the data value.
public DataValueDescriptor	getNewNull() Implements org.apache.derby.iapi.types.DataValueDescriptor.getNewNull. Get a new null value of the same type as this data value.
public String	getString() Implements org.apache.derby.iapi.types.DataValueDescriptor.getString. Gets the value in the data value descriptor as a String.
public int	getTypeFormatId() Implements org.apache.derby.iapi.services.io.TypedFormat.getTypeFormatId. Get a universally unique identifier for the type of this object.
public String	getTypeName() Implements org.apache.derby.iapi.types.DataValueDescriptor.getTypeName. Get the SQL name of the datatype
public int	getXType() Implements org.apache.derby.iapi.types.XMLDataValue.getXType. Retrieve this XML value's qualified type.
public boolean	hasTopLevelAttr() Implements org.apache.derby.iapi.types.XMLDataValue.hasTopLevelAttr. Return whether or not this XML value represents a sequence that has one or more top-level attribute nodes.
public boolean	isNull() Implements org.apache.derby.iapi.services.io.Storable.isNull. Return whether the value is null or not.
public void	loadStream() Implements org.apache.derby.iapi.services.io.StreamStorable.loadStream. Set the value by reading the stream and converting it to an object form.
public void	markAsHavingTopLevelAttr() Implements org.apache.derby.iapi.types.XMLDataValue.markAsHavingTopLevelAttr. Take note of the fact this XML value represents an XML sequence that has one or more top-level attribute nodes.
public void	normalize(DataTypeDescriptor The type to normalize the source column to desiredType, DataValueDescriptor The value to normalize source) Overrides org.apache.derby.iapi.types.DataType.normalize. Implements org.apache.derby.iapi.types.DataValueDescriptor.normalize. Normalization method - this method will always be called when storing an XML value into an XML column, for example, when inserting/updating.
public void	readExternal(ObjectInput The stream from which we're reading. in) Implements java.io.Externalizable.readExternal. Read an XML value from an input stream.
public void	readExternalFromArray(ArrayInputStream The array stream positioned at the beginning of the byte stream to read from. in) Overrides org.apache.derby.iapi.types.DataType.readExternalFromArray. Implements org.apache.derby.iapi.types.DataValueDescriptor.readExternalFromArray. Read the DataValueDescriptor from the stream.
public void	restoreToNull() Implements org.apache.derby.iapi.services.io.Storable.restoreToNull. Restore this object to its (SQL)null value.
public InputStream	returnStream() Implements org.apache.derby.iapi.services.io.StreamStorable.returnStream. Return the on-disk stream state of the object.
protected void	setFrom(DataValueDescriptor The DataValueDescriptor that holds the value to which we want to set this DataValueDescriptor's value. theValue) Overrides org.apache.derby.iapi.types.DataType.setFrom. Set the value of this DataValueDescriptor based on the value of the specified DataValueDescriptor.
public void	setStream(InputStream The new stream to use newStream) Implements org.apache.derby.iapi.services.io.StreamStorable.setStream. sets the on-disk stream state for the object.
public final void	setValueFromResultSet(ResultSet The specified ResultSet. resultSet, int The 1-based column # into the resultSet. colNumber, boolean Whether or not the column is nullable (No need to call wasNull() if not) isNullable) Implements org.apache.derby.iapi.types.DataValueDescriptor.setValueFromResultSet. Set the value based on the value for the specified DataValueDescriptor from the specified ResultSet.
public void	setXType(int xtype) Implements org.apache.derby.iapi.types.XMLDataValue.setXType. Set this XML value's qualified type.
public int	typePrecedence() Overrides org.apache.derby.iapi.types.DataType.typePrecedence. Implements org.apache.derby.iapi.types.DataValueDescriptor.typePrecedence. Each built-in type in JSQL has a precedence.
public void	writeExternal(ObjectOutput The stream to which we're writing. out) Implements java.io.Externalizable.writeExternal. Write an XML value.
public BooleanDataValue	Returns: True if evaluation of the query expression stored in sqlxUtil returns at least one node for this XML value; unknown if the xml value is NULL; false otherwise. XMLExists(SqlXmlUtil Contains SQL/XML objects and util methods that facilitate execution of XML-related operations sqlxUtil) Implements org.apache.derby.iapi.types.XMLDataValue.XMLExists. The SQL/XML XMLExists operator.
public XMLDataValue	Returns: If 'text' constitutes a valid XML document, it has been stored in this XML value and this XML value is returned; otherwise, an exception is thrown. XMLParse(StringDataValue The string value to check. stringValue, boolean Whether or not to preserve ignorable whitespace. preserveWS, SqlXmlUtil Contains SQL/XML objects and util methods that facilitate execution of XML-related operations sqlxUtil) Implements org.apache.derby.iapi.types.XMLDataValue.XMLParse. Method to parse an XML string and, if it's valid, store the _serialized_ version locally and then return this XMLDataValue.
public XMLDataValue	Returns: An XMLDataValue whose content corresponds to the serialized version of the results from evaluation of the query expression. Note this XMLDataValue may not be storable into Derby XML columns. XMLQuery(SqlXmlUtil Contains SQL/XML objects and util methods that facilitate execution of XML-related operations sqlxUtil, XMLDataValue The result of a previous call to this method; null if not called yet. result) Implements org.apache.derby.iapi.types.XMLDataValue.XMLQuery. Evaluate the XML query expression contained within the received util object against this XML value and store the results into the received XMLDataValue "result" param (assuming "result" is non-null; else create a new XMLDataValue).
public StringDataValue	Returns: A serialized (to string) version of this XML object, in the form of a StringDataValue object. XMLSerialize(StringDataValue The result of a previous call to this method, null if not called yet. result, int The string type to which we want to serialize. targetType, int The width of the target type. targetWidth, int The collation type of the target type. targetCollationType) Implements org.apache.derby.iapi.types.XMLDataValue.XMLSerialize. The SQL/XML XMLSerialize operator.

BASE_MEMORY_USAGE	back to summary
private static final int BASE_MEMORY_USAGE

containsTopLevelAttr	back to summary
private boolean containsTopLevelAttr

tmpUtil	back to summary
private SqlXmlUtil tmpUtil

UTF8_IMPL_ID	back to summary
protected static final short UTF8_IMPL_ID

XML_DOC_ANY	back to summary
public static final int XML_DOC_ANY

XML_SEQUENCE	back to summary
public static final int XML_SEQUENCE

xmlReqCheck	back to summary
private static String xmlReqCheck

xmlStringValue	back to summary
private SQLChar xmlStringValue

XQ_EMPTY_ON_EMPTY	back to summary
public static final short XQ_EMPTY_ON_EMPTY

XQ_NULL_ON_EMPTY	back to summary
public static final short XQ_NULL_ON_EMPTY

XQ_PASS_BY_REF	back to summary
public static final short XQ_PASS_BY_REF

XQ_PASS_BY_VALUE	back to summary
public static final short XQ_PASS_BY_VALUE

XQ_RETURN_CONTENT	back to summary
public static final short XQ_RETURN_CONTENT

XQ_RETURN_SEQUENCE	back to summary
public static final short XQ_RETURN_SEQUENCE

xType	back to summary
private int xType

XML	back to summary
public XML() Default constructor.

XML	back to summary
private XML(SQLChar val, int xmlType, boolean seqWithAttr, boolean materialize) Private constructor used for the `cloneValue` method. Returns a new instance of XML whose fields are clones of the values received. Parameters val:SQLChar A SQLChar instance to clone and use for this XML value. xmlType:int Qualified XML type for "val" seqWithAttr:boolean Whether or not "val" corresponds to sequence with one or more top-level attribute nodes. materialize:boolean whether or not to force materialization of the underlying source data

Method Detail

checkJAXPRequirement back to summary

checkJAXPRequirement	back to summary
private static boolean checkJAXPRequirement() Check if we have a JAXP implementation installed. Returns:boolean `true` if JAXP is installed, or `false` otherwise

private static boolean checkJAXPRequirement()

Check if we have a JAXP implementation installed.

Returns:boolean: true if JAXP is installed, or false otherwise

checkXMLRequirements	back to summary
public static void checkXMLRequirements() throws StandardException See if the required JAXP and Xalan classes are in the user's classpath. Assumption is that we will always call this method before instantiating an instance of SqlXmlUtil, and thus we will never get a ClassNotFound exception caused by missing JAXP/Xalan classes. Instead, if either is missing we should throw an informative error indicating what the problem is. Note This method only does the checks necessary to allow successful instantiation of the SqlXmlUtil class. Further checks (esp. the presence of a JAXP _implementation_ in addition to the JAXP _interfaces_) are performed in the SqlXmlUtil constructor. Exceptions StandardException: thrown if the required classes cannot be located in the classpath.

checkXMLRequirements

back to summary

public static void checkXMLRequirements() throws StandardException

See if the required JAXP and Xalan classes are in the user's classpath. Assumption is that we will always call this method before instantiating an instance of SqlXmlUtil, and thus we will never get a ClassNotFound exception caused by missing JAXP/Xalan classes. Instead, if either is missing we should throw an informative error indicating what the problem is.

Note

This method only does the checks necessary to allow successful instantiation of the SqlXmlUtil class. Further checks (esp. the presence of a JAXP _implementation_ in addition to the JAXP _interfaces_) are performed in the SqlXmlUtil constructor.

Exceptions

StandardException:: thrown if the required classes cannot be located in the classpath.

checkXPathRequirement back to summary

checkXPathRequirement	back to summary
private static boolean checkXPathRequirement() Check if XPath is supported on this platform. Returns:boolean `true` if XPath is supported, or `false` otherwise

private static boolean checkXPathRequirement()

Check if XPath is supported on this platform.

Returns:boolean: true if XPath is supported, or false otherwise

cloneValue back to summary

cloneValue	back to summary
public DataValueDescriptor cloneValue(boolean forceMaterialization) Implements org.apache.derby.iapi.types.DataValueDescriptor.cloneValue. Doc from org.apache.derby.iapi.types.DataValueDescriptor.cloneValue. Clone this DataValueDescriptor. Results in a new object that has the same value as this but can be modified independently. Even though the objects can be modified independently regardless of the value of `forceMaterialization`, both the clone and the original may be dependent on the store state if `forceMaterialization` is set to `false`. An example is if you need to access the value you just read using `cloneValue` after the current transaction has ended, or after the source result set has been closed. Parameters forceMaterialization:boolean any streams representing the data value will be materialized if `true`, the data value will be kept as a stream if possible if `false` Returns:DataValueDescriptor A clone of the `DataValueDescriptor` with the same initial value as this. See Also `DataValueDescriptor#cloneValue`

public DataValueDescriptor cloneValue(boolean forceMaterialization)

Implements org.apache.derby.iapi.types.DataValueDescriptor.cloneValue.

Doc from org.apache.derby.iapi.types.DataValueDescriptor.cloneValue.

Clone this DataValueDescriptor. Results in a new object that has the same value as this but can be modified independently.

Even though the objects can be modified independently regardless of the value of forceMaterialization, both the clone and the original may be dependent on the store state if forceMaterialization is set to false. An example is if you need to access the value you just read using cloneValue after the current transaction has ended, or after the source result set has been closed.

Parameters

forceMaterialization:boolean: any streams representing the data value will be materialized if true, the data value will be kept as a stream if possible if false

Returns:DataValueDescriptor

A clone of the DataValueDescriptor with the same initial value as this.

See Also

DataValueDescriptor#cloneValue

compare back to summary

compare	back to summary
public int compare(DataValueDescriptor other) throws StandardException Implements org.apache.derby.iapi.types.DataValueDescriptor.compare. Compare two XML DataValueDescriptors. Note This method should only be used by the database store for the purpose of index positioning--comparisons of XML type are not allowed from the language side of things. That said, all store wants to do is order the NULLs, so we don't actually have to do a full comparison. Just return an order value based on whether or not this XML value and the other XML value are null. As mentioned in the "compare" method of DataValueDescriptor, nulls are considered equal to other nulls and less than all other values. An example of when this method might be used is if the user executed a query like: select i from x_table where x_col is not null Parameters other:DataValueDescriptor Doc from org.apache.derby.iapi.types.DataValueDescriptor.compare. The Orderable to compare this one to. Returns:int Doc from org.apache.derby.iapi.types.DataValueDescriptor.compare. <0 - this Orderable is less than other. 0 - this Orderable equals other. >0 - this Orderable is greater than other. The code should not explicitly look for -1, or 1. Exceptions StandardException: Doc from org.apache.derby.iapi.types.DataValueDescriptor.compare. Thrown on error See Also `DataValueDescriptor#compare`

public int compare(DataValueDescriptor other) throws StandardException

Implements org.apache.derby.iapi.types.DataValueDescriptor.compare.

Compare two XML DataValueDescriptors.

Note

This method should only be used by the database store for the purpose of index positioning--comparisons of XML type are not allowed from the language side of things. That said, all store wants to do is order the NULLs, so we don't actually have to do a full comparison. Just return an order value based on whether or not this XML value and the other XML value are null. As mentioned in the "compare" method of DataValueDescriptor, nulls are considered equal to other nulls and less than all other values. An example of when this method might be used is if the user executed a query like: select i from x_table where x_col is not null

Parameters

other:DataValueDescriptor

Doc from org.apache.derby.iapi.types.DataValueDescriptor.compare.

The Orderable to compare this one to.

Returns:int

Doc from org.apache.derby.iapi.types.DataValueDescriptor.compare.

<0 - this Orderable is less than other. 0 - this Orderable equals other. >0 - this Orderable is greater than other. The code should not explicitly look for -1, or 1.

Exceptions

StandardException:

Doc from org.apache.derby.iapi.types.DataValueDescriptor.compare.

Thrown on error

See Also

DataValueDescriptor#compare

estimateMemoryUsage back to summary

estimateMemoryUsage	back to summary
public int estimateMemoryUsage() Implements org.apache.derby.iapi.types.DataValueDescriptor.estimateMemoryUsage. Doc from org.apache.derby.iapi.types.DataValueDescriptor.estimateMemoryUsage. Estimate the memory usage in bytes of the data value and the overhead of the class. Returns:int the estimated memory usage See Also `DataValueDescriptor#estimateMemoryUsage`

public int estimateMemoryUsage()

Implements org.apache.derby.iapi.types.DataValueDescriptor.estimateMemoryUsage.

Doc from org.apache.derby.iapi.types.DataValueDescriptor.estimateMemoryUsage.

Estimate the memory usage in bytes of the data value and the overhead of the class.

Returns:int: the estimated memory usage
See Also: DataValueDescriptor#estimateMemoryUsage

getLength back to summary

getLength	back to summary
public int getLength() throws StandardException Implements org.apache.derby.iapi.types.DataValueDescriptor.getLength. Doc from org.apache.derby.iapi.types.DataValueDescriptor.getLength. Gets the length of the data value. The meaning of this is implementation-dependent. For string types, it is the number of characters in the string. For numeric types, it is the number of bytes used to store the number. This is the actual length of this value, not the length of the type it was defined as. For example, a VARCHAR value may be shorter than the declared VARCHAR (maximum) length. Returns:int The length of the data value Exceptions StandardException: On error See Also `DataValueDescriptor#getLength`

public int getLength() throws StandardException

Implements org.apache.derby.iapi.types.DataValueDescriptor.getLength.

Doc from org.apache.derby.iapi.types.DataValueDescriptor.getLength.

Gets the length of the data value. The meaning of this is implementation-dependent. For string types, it is the number of characters in the string. For numeric types, it is the number of bytes used to store the number. This is the actual length of this value, not the length of the type it was defined as. For example, a VARCHAR value may be shorter than the declared VARCHAR (maximum) length.

Returns:int

The length of the data value

Exceptions

StandardException:: On error

See Also

DataValueDescriptor#getLength

getNewNull back to summary

getNewNull	back to summary
public DataValueDescriptor getNewNull() Implements org.apache.derby.iapi.types.DataValueDescriptor.getNewNull. Doc from org.apache.derby.iapi.types.DataValueDescriptor.getNewNull. Get a new null value of the same type as this data value. See Also `DataValueDescriptor#getNewNull`

public DataValueDescriptor getNewNull()

Implements org.apache.derby.iapi.types.DataValueDescriptor.getNewNull.

Doc from org.apache.derby.iapi.types.DataValueDescriptor.getNewNull.

Get a new null value of the same type as this data value.

See Also: DataValueDescriptor#getNewNull

getString back to summary

getString	back to summary
public String getString() throws StandardException Implements org.apache.derby.iapi.types.DataValueDescriptor.getString. Doc from org.apache.derby.iapi.types.DataValueDescriptor.getString. Gets the value in the data value descriptor as a String. Throws an exception if the data value is not a string. Returns:String The data value as a String. Exceptions StandardException: Thrown on error See Also `DataValueDescriptor#getString`

public String getString() throws StandardException

Implements org.apache.derby.iapi.types.DataValueDescriptor.getString.

Doc from org.apache.derby.iapi.types.DataValueDescriptor.getString.

Gets the value in the data value descriptor as a String. Throws an exception if the data value is not a string.

Returns:String

The data value as a String.

Exceptions

StandardException:: Thrown on error

See Also

DataValueDescriptor#getString

getTypeFormatId back to summary

getTypeFormatId	back to summary
public int getTypeFormatId() Implements org.apache.derby.iapi.services.io.TypedFormat.getTypeFormatId. Doc from org.apache.derby.iapi.services.io.TypedFormat.getTypeFormatId. Get a universally unique identifier for the type of this object. Returns:int The identifier. (A UUID stuffed in an array of 16 bytes). See Also `From the engine's perspective, all XML implementations share the same format id.`

public int getTypeFormatId()

Implements org.apache.derby.iapi.services.io.TypedFormat.getTypeFormatId.

Doc from org.apache.derby.iapi.services.io.TypedFormat.getTypeFormatId.

Get a universally unique identifier for the type of this object.

Returns:int: The identifier. (A UUID stuffed in an array of 16 bytes).
See Also: From the engine's perspective, all XML implementations share the same format id.

getTypeName back to summary

getTypeName	back to summary
public String getTypeName() Implements org.apache.derby.iapi.types.DataValueDescriptor.getTypeName. Doc from org.apache.derby.iapi.types.DataValueDescriptor.getTypeName. Get the SQL name of the datatype Returns:String The SQL name of the datatype See Also `DataValueDescriptor#getTypeName`

public String getTypeName()

Implements org.apache.derby.iapi.types.DataValueDescriptor.getTypeName.

Doc from org.apache.derby.iapi.types.DataValueDescriptor.getTypeName.

Get the SQL name of the datatype

Returns:String: The SQL name of the datatype
See Also: DataValueDescriptor#getTypeName

getXType	back to summary
public int getXType() Implements org.apache.derby.iapi.types.XMLDataValue.getXType. Retrieve this XML value's qualified type.

getXType

back to summary

public int getXType()

Implements org.apache.derby.iapi.types.XMLDataValue.getXType.

Retrieve this XML value's qualified type.

hasTopLevelAttr	back to summary
public boolean hasTopLevelAttr() Implements org.apache.derby.iapi.types.XMLDataValue.hasTopLevelAttr. Return whether or not this XML value represents a sequence that has one or more top-level attribute nodes.

hasTopLevelAttr

back to summary

public boolean hasTopLevelAttr()

Implements org.apache.derby.iapi.types.XMLDataValue.hasTopLevelAttr.

Return whether or not this XML value represents a sequence that has one or more top-level attribute nodes.

isNull back to summary

isNull	back to summary
public boolean isNull() Implements org.apache.derby.iapi.services.io.Storable.isNull. Doc from org.apache.derby.iapi.services.io.Storable.isNull. Return whether the value is null or not. Returns:boolean true if the value is null and false otherwise. See Also `Storable#isNull`

public boolean isNull()

Implements org.apache.derby.iapi.services.io.Storable.isNull.

Doc from org.apache.derby.iapi.services.io.Storable.isNull.

Return whether the value is null or not.

Returns:boolean: true if the value is null and false otherwise.
See Also: Storable#isNull

loadStream back to summary

loadStream	back to summary
public void loadStream() throws StandardException Implements org.apache.derby.iapi.services.io.StreamStorable.loadStream. Doc from org.apache.derby.iapi.services.io.StreamStorable.loadStream. Set the value by reading the stream and converting it to an object form. Exceptions StandardException: on error See Also `StreamStorable#loadStream`

public void loadStream() throws StandardException

Implements org.apache.derby.iapi.services.io.StreamStorable.loadStream.

Doc from org.apache.derby.iapi.services.io.StreamStorable.loadStream.

Set the value by reading the stream and converting it to an object form.

Exceptions

StandardException:: on error

See Also

StreamStorable#loadStream

markAsHavingTopLevelAttr	back to summary
public void markAsHavingTopLevelAttr() Implements org.apache.derby.iapi.types.XMLDataValue.markAsHavingTopLevelAttr. Take note of the fact this XML value represents an XML sequence that has one or more top-level attribute nodes.

markAsHavingTopLevelAttr

back to summary

public void markAsHavingTopLevelAttr()

Implements org.apache.derby.iapi.types.XMLDataValue.markAsHavingTopLevelAttr.

Take note of the fact this XML value represents an XML sequence that has one or more top-level attribute nodes.

normalize	back to summary
public void normalize(DataTypeDescriptor desiredType, DataValueDescriptor source) throws StandardException Overrides org.apache.derby.iapi.types.DataType.normalize. Implements org.apache.derby.iapi.types.DataValueDescriptor.normalize. Normalization method - this method will always be called when storing an XML value into an XML column, for example, when inserting/updating. We always force normalization in this case because we need to make sure the qualified type of the value we're trying to store is XML_DOC_ANY--we don't allow anything else. Parameters desiredType:DataTypeDescriptor The type to normalize the source column to source:DataValueDescriptor The value to normalize Exceptions StandardException: Thrown if source is not XML_DOC_ANY.

normalize

back to summary

public void normalize(DataTypeDescriptor desiredType, DataValueDescriptor source) throws StandardException

Overrides org.apache.derby.iapi.types.DataType.normalize.

Implements org.apache.derby.iapi.types.DataValueDescriptor.normalize.

Normalization method - this method will always be called when storing an XML value into an XML column, for example, when inserting/updating. We always force normalization in this case because we need to make sure the qualified type of the value we're trying to store is XML_DOC_ANY--we don't allow anything else.

Parameters

desiredType:DataTypeDescriptor: The type to normalize the source column to
source:DataValueDescriptor: The value to normalize

Exceptions

StandardException:: Thrown if source is not XML_DOC_ANY.

readExternal	back to summary
public void readExternal(ObjectInput in) throws IOException Implements java.io.Externalizable.readExternal. Read an XML value from an input stream. Parameters in:ObjectInput The stream from which we're reading. Exceptions IOException: Doc from java.io.Externalizable.readExternal. if I/O errors occur

readExternal

back to summary

public void readExternal(ObjectInput in) throws IOException

Implements java.io.Externalizable.readExternal.

Read an XML value from an input stream.

Parameters

in:ObjectInput: The stream from which we're reading.

Exceptions

IOException:

Doc from java.io.Externalizable.readExternal.

if I/O errors occur

readExternalFromArray back to summary

readExternalFromArray	back to summary
public void readExternalFromArray(ArrayInputStream in) throws IOException Overrides org.apache.derby.iapi.types.DataType.readExternalFromArray. Implements org.apache.derby.iapi.types.DataValueDescriptor.readExternalFromArray. Doc from org.apache.derby.iapi.types.DataValueDescriptor.readExternalFromArray. Read the DataValueDescriptor from the stream. Initialize the data value by reading it's values from the ArrayInputStream. This interface is provided as a way to achieve possible performance enhancement when reading an array can be optimized over reading from a generic stream from readExternal(). Parameters in:ArrayInputStream The array stream positioned at the beginning of the byte stream to read from. Exceptions IOException: Usual error is if you try to read past limit on the stream. See Also `DataValueDescriptor#readExternalFromArray`

public void readExternalFromArray(ArrayInputStream in) throws IOException

Overrides org.apache.derby.iapi.types.DataType.readExternalFromArray.

Implements org.apache.derby.iapi.types.DataValueDescriptor.readExternalFromArray.

Doc from org.apache.derby.iapi.types.DataValueDescriptor.readExternalFromArray.

Read the DataValueDescriptor from the stream.

Initialize the data value by reading it's values from the ArrayInputStream. This interface is provided as a way to achieve possible performance enhancement when reading an array can be optimized over reading from a generic stream from readExternal().

Parameters

in:ArrayInputStream: The array stream positioned at the beginning of the byte stream to read from.

Exceptions

IOException:: Usual error is if you try to read past limit on the stream.

restoreToNull back to summary

restoreToNull	back to summary
public void restoreToNull() Implements org.apache.derby.iapi.services.io.Storable.restoreToNull. Doc from org.apache.derby.iapi.services.io.Storable.restoreToNull. Restore this object to its (SQL)null value. See Also `Storable#restoreToNull`

public void restoreToNull()

Implements org.apache.derby.iapi.services.io.Storable.restoreToNull.

Doc from org.apache.derby.iapi.services.io.Storable.restoreToNull.

Restore this object to its (SQL)null value.

See Also: Storable#restoreToNull

returnStream back to summary

returnStream	back to summary
public InputStream returnStream() Implements org.apache.derby.iapi.services.io.StreamStorable.returnStream. Doc from org.apache.derby.iapi.services.io.StreamStorable.returnStream. Return the on-disk stream state of the object. Returns:InputStream a stream to read the object state See Also `StreamStorable#returnStream`

public InputStream returnStream()

Implements org.apache.derby.iapi.services.io.StreamStorable.returnStream.

Doc from org.apache.derby.iapi.services.io.StreamStorable.returnStream.

Return the on-disk stream state of the object.

Returns:InputStream: a stream to read the object state
See Also: StreamStorable#returnStream

setFrom back to summary

setFrom	back to summary
protected void setFrom(DataValueDescriptor theValue) throws StandardException Overrides org.apache.derby.iapi.types.DataType.setFrom. Doc from org.apache.derby.iapi.types.DataType.setFrom. Set the value of this DataValueDescriptor based on the value of the specified DataValueDescriptor. Parameters theValue:DataValueDescriptor The DataValueDescriptor that holds the value to which we want to set this DataValueDescriptor's value. See Also `DataType#setFrom`

protected void setFrom(DataValueDescriptor theValue) throws StandardException

Overrides org.apache.derby.iapi.types.DataType.setFrom.

Doc from org.apache.derby.iapi.types.DataType.setFrom.

Set the value of this DataValueDescriptor based on the value of the specified DataValueDescriptor.

Parameters

theValue:DataValueDescriptor: The DataValueDescriptor that holds the value to which we want to set this DataValueDescriptor's value.

See Also

DataType#setFrom

setStream back to summary

setStream	back to summary
public void setStream(InputStream newStream) Implements org.apache.derby.iapi.services.io.StreamStorable.setStream. Doc from org.apache.derby.iapi.services.io.StreamStorable.setStream. sets the on-disk stream state for the object. Parameters newStream:InputStream The new stream to use See Also `StreamStorable#setStream`

public void setStream(InputStream newStream)

Implements org.apache.derby.iapi.services.io.StreamStorable.setStream.

Doc from org.apache.derby.iapi.services.io.StreamStorable.setStream.

sets the on-disk stream state for the object.

Parameters

newStream:InputStream: The new stream to use

See Also

StreamStorable#setStream

setValueFromResultSet back to summary

setValueFromResultSet	back to summary
public final void setValueFromResultSet(ResultSet resultSet, int colNumber, boolean isNullable) throws SQLException Implements org.apache.derby.iapi.types.DataValueDescriptor.setValueFromResultSet. Doc from org.apache.derby.iapi.types.DataValueDescriptor.setValueFromResultSet. Set the value based on the value for the specified DataValueDescriptor from the specified ResultSet. Parameters resultSet:ResultSet The specified ResultSet. colNumber:int The 1-based column # into the resultSet. isNullable:boolean Whether or not the column is nullable (No need to call wasNull() if not) Exceptions SQLException: Error accessing the result set See Also `DataValueDescriptor#setValueFromResultSet`

public final void setValueFromResultSet(ResultSet resultSet, int colNumber, boolean isNullable) throws SQLException

Implements org.apache.derby.iapi.types.DataValueDescriptor.setValueFromResultSet.

Doc from org.apache.derby.iapi.types.DataValueDescriptor.setValueFromResultSet.

Set the value based on the value for the specified DataValueDescriptor from the specified ResultSet.

Parameters

resultSet:ResultSet: The specified ResultSet.
colNumber:int: The 1-based column # into the resultSet.
isNullable:boolean: Whether or not the column is nullable (No need to call wasNull() if not)

Exceptions

SQLException:: Error accessing the result set

setXType	back to summary
public void setXType(int xtype) Implements org.apache.derby.iapi.types.XMLDataValue.setXType. Set this XML value's qualified type.

setXType

back to summary

public void setXType(int xtype)

Implements org.apache.derby.iapi.types.XMLDataValue.setXType.

Set this XML value's qualified type.

typePrecedence back to summary

typePrecedence	back to summary
public int typePrecedence() Overrides org.apache.derby.iapi.types.DataType.typePrecedence. Implements org.apache.derby.iapi.types.DataValueDescriptor.typePrecedence. Doc from org.apache.derby.iapi.types.DataValueDescriptor.typePrecedence. Each built-in type in JSQL has a precedence. This precedence determines how to do type promotion when using binary operators. For example, float has a higher precedence than int, so when adding an int to a float, the result type is float. The precedence for some types is arbitrary. For example, it doesn't matter what the precedence of the boolean type is, since it can't be mixed with other types. But the precedence for the number types is critical. The SQL standard requires that exact numeric types be promoted to approximate numeric when one operator uses both. Also, the precedence is arranged so that one will not lose precision when promoting a type. Returns:int The precedence of this type. See Also `DataValueDescriptor#typePrecedence`

public int typePrecedence()

Overrides org.apache.derby.iapi.types.DataType.typePrecedence.

Implements org.apache.derby.iapi.types.DataValueDescriptor.typePrecedence.

Doc from org.apache.derby.iapi.types.DataValueDescriptor.typePrecedence.

Each built-in type in JSQL has a precedence. This precedence determines how to do type promotion when using binary operators. For example, float has a higher precedence than int, so when adding an int to a float, the result type is float. The precedence for some types is arbitrary. For example, it doesn't matter what the precedence of the boolean type is, since it can't be mixed with other types. But the precedence for the number types is critical. The SQL standard requires that exact numeric types be promoted to approximate numeric when one operator uses both. Also, the precedence is arranged so that one will not lose precision when promoting a type.

Returns:int: The precedence of this type.
See Also: DataValueDescriptor#typePrecedence

writeExternal	back to summary
public void writeExternal(ObjectOutput out) throws IOException Implements java.io.Externalizable.writeExternal. Write an XML value. Parameters out:ObjectOutput The stream to which we're writing. Exceptions IOException: Doc from java.io.Externalizable.writeExternal. Includes any I/O exceptions that may occur

writeExternal

back to summary

public void writeExternal(ObjectOutput out) throws IOException

Implements java.io.Externalizable.writeExternal.

Write an XML value.

Parameters

out:ObjectOutput: The stream to which we're writing.

Exceptions

IOException:

Doc from java.io.Externalizable.writeExternal.

Includes any I/O exceptions that may occur

XMLExists	back to summary
public BooleanDataValue XMLExists(SqlXmlUtil sqlxUtil) throws StandardException Implements org.apache.derby.iapi.types.XMLDataValue.XMLExists. The SQL/XML XMLExists operator. Checks to see if evaluation of the query expression contained within the received util object against this XML value returns at least one item. Note For now, the query expression must be XPath only (XQuery not supported) because that's what Xalan supports. Parameters sqlxUtil:SqlXmlUtil Contains SQL/XML objects and util methods that facilitate execution of XML-related operations Returns:BooleanDataValue True if evaluation of the query expression stored in sqlxUtil returns at least one node for this XML value; unknown if the xml value is NULL; false otherwise. Exceptions StandardException: Thrown on error

XMLExists

back to summary

public BooleanDataValue XMLExists(SqlXmlUtil sqlxUtil) throws StandardException

Implements org.apache.derby.iapi.types.XMLDataValue.XMLExists.

The SQL/XML XMLExists operator. Checks to see if evaluation of the query expression contained within the received util object against this XML value returns at least one item.

Note

For now, the query expression must be XPath only (XQuery not supported) because that's what Xalan supports.

Parameters

sqlxUtil:SqlXmlUtil: Contains SQL/XML objects and util methods that facilitate execution of XML-related operations

Returns:BooleanDataValue

True if evaluation of the query expression stored in sqlxUtil returns at least one node for this XML value; unknown if the xml value is NULL; false otherwise.

Exceptions

StandardException:: Thrown on error

XMLParse	back to summary
public XMLDataValue XMLParse(StringDataValue stringValue, boolean preserveWS, SqlXmlUtil sqlxUtil) throws StandardException Implements org.apache.derby.iapi.types.XMLDataValue.XMLParse. Method to parse an XML string and, if it's valid, store the _serialized_ version locally and then return this XMLDataValue. Parameters stringValue:StringDataValue The string value to check. preserveWS:boolean Whether or not to preserve ignorable whitespace. sqlxUtil:SqlXmlUtil Contains SQL/XML objects and util methods that facilitate execution of XML-related operations Returns:XMLDataValue If 'text' constitutes a valid XML document, it has been stored in this XML value and this XML value is returned; otherwise, an exception is thrown. Exceptions StandardException: Thrown on error.

XMLParse

back to summary

public XMLDataValue XMLParse(StringDataValue stringValue, boolean preserveWS, SqlXmlUtil sqlxUtil) throws StandardException

Implements org.apache.derby.iapi.types.XMLDataValue.XMLParse.

Method to parse an XML string and, if it's valid, store the _serialized_ version locally and then return this XMLDataValue.

Parameters

stringValue:StringDataValue: The string value to check.
preserveWS:boolean: Whether or not to preserve ignorable whitespace.
sqlxUtil:SqlXmlUtil: Contains SQL/XML objects and util methods that facilitate execution of XML-related operations

Returns:XMLDataValue

If 'text' constitutes a valid XML document, it has been stored in this XML value and this XML value is returned; otherwise, an exception is thrown.

Exceptions

StandardException:: Thrown on error.

XMLQuery	back to summary
public XMLDataValue XMLQuery(SqlXmlUtil sqlxUtil, XMLDataValue result) throws StandardException Implements org.apache.derby.iapi.types.XMLDataValue.XMLQuery. Evaluate the XML query expression contained within the received util object against this XML value and store the results into the received XMLDataValue "result" param (assuming "result" is non-null; else create a new XMLDataValue). Parameters sqlxUtil:SqlXmlUtil Contains SQL/XML objects and util methods that facilitate execution of XML-related operations result:XMLDataValue The result of a previous call to this method; null if not called yet. Returns:XMLDataValue An XMLDataValue whose content corresponds to the serialized version of the results from evaluation of the query expression. Note this XMLDataValue may not be storable into Derby XML columns. Exceptions StandardException: thrown on error

XMLQuery

back to summary

public XMLDataValue XMLQuery(SqlXmlUtil sqlxUtil, XMLDataValue result) throws StandardException

Implements org.apache.derby.iapi.types.XMLDataValue.XMLQuery.

Evaluate the XML query expression contained within the received util object against this XML value and store the results into the received XMLDataValue "result" param (assuming "result" is non-null; else create a new XMLDataValue).

Parameters

sqlxUtil:SqlXmlUtil: Contains SQL/XML objects and util methods that facilitate execution of XML-related operations
result:XMLDataValue: The result of a previous call to this method; null if not called yet.

Returns:XMLDataValue

An XMLDataValue whose content corresponds to the serialized version of the results from evaluation of the query expression.

Note

this XMLDataValue may not be storable into Derby XML columns.

Exceptions

StandardException:: thrown on error

XMLSerialize

back to summary

public StringDataValue XMLSerialize(StringDataValue result, int targetType, int targetWidth, int targetCollationType) throws StandardException

Implements org.apache.derby.iapi.types.XMLDataValue.XMLSerialize.

The SQL/XML XMLSerialize operator. Serializes this XML value into a string with a user-specified character type, and returns that string via the received StringDataValue (if the received StringDataValue is non-null and of the correct type; else, a new StringDataValue is returned).

Parameters

result:StringDataValue

The result of a previous call to this method, null if not called yet.

targetType:int

The string type to which we want to serialize.

targetWidth:int

The width of the target type.

targetCollationType:int

Doc from org.apache.derby.iapi.types.XMLDataValue.XMLSerialize.

The collation type of the target type.

Returns:StringDataValue

A serialized (to string) version of this XML object, in the form of a StringDataValue object.

Exceptions

StandardException:: Thrown on error

public Class XML

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