net.sf.jasperreports.engine.data

Class JRXmlDataSource

java.lang.Object

net.sf.jasperreports.engine.data.JRAbstractTextDataSource

net.sf.jasperreports.engine.data.JRXmlDataSource

All Implemented Interfaces:

JRDataSource, JRRewindableDataSource

public class JRXmlDataSource
extends JRAbstractTextDataSource
implements JRRewindableDataSource

XML data source implementation that allows to access the data from a xml document using XPath expressions.

The data source is constructed around a node set (record set) selected by an XPath expression from the xml document.

Each field can provide an additional XPath expresion that will be used to select its value. This expression must be specified using the "fieldDescription" element of the field. The expression is evaluated in the context of the current node thus the expression should be relative to the current node.

To support subreports, sub data sources can be created. There are two different methods for creating sub data sources. The first one allows to create a sub data source rooted at the current node. The current node can be seen as a new document around which the sub data source is created. The second method allows to create a sub data source that is rooted at the same document that is used by the data source but uses a different XPath select expression.

Example:

 <A>
        <B id="0">
                <C>
                <C>
        </B>
        <B id="1">
                <C>
                <C>
        </B>
        <D id="3">
                <E>
                <E>
        </D>
 </A>
 

Data source creation

• new JRXmlDataSource(document, "/A/B") - creates a data source with two nodes of type /A/B
• new JRXmlDataSource(document, "/A/D") - creates a data source with two nodes of type /A/D

Field selection

• @id - will select the "id" attribute from the current node
• C - will select the value of the first node of type C under the current node.

Sub data source creation

• "((net.sf.jasperreports.engine.data.JRXmlDataSource)$P{REPORT_DATA_SOURCE}).subDataSource("/B/C") - in the context of the node B, creates a data source with elements of type /B/C
• "((net.sf.jasperreports.engine.data.JRXmlDataSource)$P{REPORT_DATA_SOURCE}).dataSource("/A/D") - creates a data source with elements of type /A/D

Generally the full power of XPath expression is available. As an example, "/A/B[@id > 0"] will select all the nodes of type /A/B having the id greater than 0. You'll find a short XPath tutorial here.

Note on performance. Due to the fact that all the XPath expression are interpreted the data source performance is not great. For the cases where more speed is required, consider implementing a custom data source that directly accesses the Document through the DOM API.

Version:

$Id: JRXmlDataSource.java 5397 2012-05-21 01:10:02Z teodord $

Author:

Peter Severin (peter_p_s@sourceforge.net, contact@jasperassistant.com)

See Also:

JRXPathExecuterUtils

Constructor Summary

Constructors

Constructor and Description
JRXmlDataSource(Document document)
JRXmlDataSource(Document document, String selectExpression)
JRXmlDataSource(File file)
JRXmlDataSource(File file, String selectExpression)
JRXmlDataSource(InputStream in)
JRXmlDataSource(InputStream in, String selectExpression)
JRXmlDataSource(JasperReportsContext jasperReportsContext, Document document) Creates the data source by parsing the xml document from the given file.
JRXmlDataSource(JasperReportsContext jasperReportsContext, Document document, String selectExpression) Creates the data source by parsing the xml document from the given file.
JRXmlDataSource(JasperReportsContext jasperReportsContext, File file) Creates the data source by parsing the xml document from the given file.
JRXmlDataSource(JasperReportsContext jasperReportsContext, File file, String selectExpression) Creates the data source by parsing the xml document from the given file.
JRXmlDataSource(JasperReportsContext jasperReportsContext, InputStream in) Creates the data source by parsing the xml document from the given input stream.
JRXmlDataSource(JasperReportsContext jasperReportsContext, InputStream in, String selectExpression) Creates the data source by parsing the xml document from the given input stream.
JRXmlDataSource(JasperReportsContext jasperReportsContext, String uri) Creates the data source by parsing the xml document from the given system identifier (URI).
JRXmlDataSource(JasperReportsContext jasperReportsContext, String uri, String selectExpression) Creates the data source by parsing the xml document from the given system identifier (URI).
JRXmlDataSource(String uri)
JRXmlDataSource(String uri, String selectExpression)

Method Summary

Methods

Modifier and Type	Method and Description
void	close() Closes the reader.
JRXmlDataSource	dataSource() Creates a sub data source using as root document the document used by "this" data source.
JRXmlDataSource	dataSource(String selectExpr) Creates a sub data source using as root document the document used by "this" data source.
Object	getFieldValue(JRField jrField) Gets the field value for the current position.
String	getText(Node node) Return the text that a node contains.
void	moveFirst() Moves back to the first element in the data source.
boolean	next() Tries to position the cursor on the next element in the data source.
JRXmlDataSource	subDataSource() Creates a sub data source using the current node (record) as the root of the document.
JRXmlDataSource	subDataSource(String selectExpr) Creates a sub data source using the current node (record) as the root of the document.
Document	subDocument() Creates a document using the current node as root.

Methods inherited from class net.sf.jasperreports.engine.data.JRAbstractTextDataSource

convertNumber, convertStringValue, getConvertBean, getDatePattern, getFormattedDate, getFormattedNumber, getLocale, getNumberPattern, getTimeZone, setDatePattern, setLocale, setLocale, setNumberPattern, setTextAttributes, setTimeZone, setTimeZone

Methods inherited from class java.lang.Object

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

Constructor Detail

JRXmlDataSource

public JRXmlDataSource(JasperReportsContext jasperReportsContext,
               Document document)
                throws JRException

Creates the data source by parsing the xml document from the given file. The data source will contain exactly one record consisting of the document node itself.

Parameters:

document - the document

Throws:

JRException - if the data source cannot be created

JRXmlDataSource

public JRXmlDataSource(Document document)
                throws JRException

Throws:

JRException

See Also:

JRXmlDataSource(JasperReportsContext, Document).

JRXmlDataSource

public JRXmlDataSource(JasperReportsContext jasperReportsContext,
               Document document,
               String selectExpression)
                throws JRException

Creates the data source by parsing the xml document from the given file. An additional XPath expression specifies the select criteria that produces the nodes (records) for the data source.

Parameters:

document - the document

selectExpression - the XPath select expression

Throws:

JRException - if the data source cannot be created

JRXmlDataSource

public JRXmlDataSource(Document document,
               String selectExpression)
                throws JRException

Throws:

JRException

See Also:

JRXmlDataSource(JasperReportsContext, Document, String)

JRXmlDataSource

public JRXmlDataSource(JasperReportsContext jasperReportsContext,
               InputStream in)
                throws JRException

Creates the data source by parsing the xml document from the given input stream.

Parameters:

in - the input stream

Throws:

JRException

See Also:

JRXmlDataSource(Document)

JRXmlDataSource

public JRXmlDataSource(InputStream in)
                throws JRException

Throws:

JRException

See Also:

JRXmlDataSource(JasperReportsContext, InputStream)

JRXmlDataSource

public JRXmlDataSource(JasperReportsContext jasperReportsContext,
               InputStream in,
               String selectExpression)
                throws JRException

Creates the data source by parsing the xml document from the given input stream.

Throws:

JRException

See Also:

JRXmlDataSource(InputStream), JRXmlDataSource(Document, String)

JRXmlDataSource

public JRXmlDataSource(InputStream in,
               String selectExpression)
                throws JRException

Throws:

JRException

See Also:

JRXmlDataSource(JasperReportsContext, InputStream, String)

JRXmlDataSource

public JRXmlDataSource(JasperReportsContext jasperReportsContext,
               String uri)
                throws JRException

Creates the data source by parsing the xml document from the given system identifier (URI).

If the system identifier is a URL, it must be full resolved.

Parameters:

uri - the system identifier

Throws:

JRException

See Also:

JRXmlDataSource(Document)

JRXmlDataSource

public JRXmlDataSource(String uri)
                throws JRException

Throws:

JRException

See Also:

JRXmlDataSource(JasperReportsContext, String)

JRXmlDataSource

public JRXmlDataSource(JasperReportsContext jasperReportsContext,
               String uri,
               String selectExpression)
                throws JRException

Creates the data source by parsing the xml document from the given system identifier (URI).

Throws:

JRException

See Also:

JRXmlDataSource(String), JRXmlDataSource(Document, String)

JRXmlDataSource

public JRXmlDataSource(String uri,
               String selectExpression)
                throws JRException

Throws:

JRException

See Also:

JRXmlDataSource(JasperReportsContext, String, String)

JRXmlDataSource

public JRXmlDataSource(JasperReportsContext jasperReportsContext,
               File file)
                throws JRException

Creates the data source by parsing the xml document from the given file.

Parameters:

file - the file

Throws:

JRException

See Also:

JRXmlDataSource(Document)

JRXmlDataSource

public JRXmlDataSource(File file)
                throws JRException

Throws:

JRException

See Also:

JRXmlDataSource(JasperReportsContext, File)

JRXmlDataSource

public JRXmlDataSource(JasperReportsContext jasperReportsContext,
               File file,
               String selectExpression)
                throws JRException

Creates the data source by parsing the xml document from the given file.

Throws:

JRException

See Also:

JRXmlDataSource(File), JRXmlDataSource(Document, String)

JRXmlDataSource

public JRXmlDataSource(File file,
               String selectExpression)
                throws JRException

Throws:

JRException

See Also:

JRXmlDataSource(JasperReportsContext, File, String)

Method Detail

moveFirst

public void moveFirst()
               throws JRException

Description copied from interface: JRRewindableDataSource

Moves back to the first element in the data source.

Specified by:

moveFirst in interface JRRewindableDataSource

Throws:

JRException

next

public boolean next()

Description copied from interface: JRDataSource

Tries to position the cursor on the next element in the data source.

Specified by:

next in interface JRDataSource

Returns:

true if there is a next record, false otherwise

getFieldValue

public Object getFieldValue(JRField jrField)
                     throws JRException

Description copied from interface: JRDataSource

Gets the field value for the current position.

Specified by:

getFieldValue in interface JRDataSource

Returns:

an object containing the field value. The object type must be the field object type.

Throws:

JRException

subDataSource

public JRXmlDataSource subDataSource(String selectExpr)
                              throws JRException

Creates a sub data source using the current node (record) as the root of the document. An additional XPath expression specifies the select criteria applied to this new document and that produces the nodes (records) for the data source.

Parameters:

selectExpr - the XPath select expression

Returns:

the xml sub data source

Throws:

JRException - if the sub data source couldn't be created

See Also:

JRXmlDataSource(Document, String)

subDataSource

public JRXmlDataSource subDataSource()
                              throws JRException

Creates a sub data source using the current node (record) as the root of the document. The data source will contain exactly one record consisting of the document node itself.

Returns:

the xml sub data source

Throws:

JRException - if the data source cannot be created

See Also:

subDataSource(String), JRXmlDataSource(Document)

subDocument

public Document subDocument()
                     throws JRException

Creates a document using the current node as root.

Returns:

a document having the current node as root

Throws:

JRException

dataSource

public JRXmlDataSource dataSource(String selectExpr)
                           throws JRException

Creates a sub data source using as root document the document used by "this" data source. An additional XPath expression specifies the select criteria applied to this document and that produces the nodes (records) for the data source.

Parameters:

selectExpr - the XPath select expression

Returns:

the xml sub data source

Throws:

JRException - if the sub data source couldn't be created

See Also:

JRXmlDataSource(Document, String)

dataSource

public JRXmlDataSource dataSource()
                           throws JRException

Creates a sub data source using as root document the document used by "this" data source. The data source will contain exactly one record consisting of the document node itself.

Returns:

the xml sub data source

Throws:

JRException - if the data source cannot be created

See Also:

dataSource(String), JRXmlDataSource(Document)

getText

public String getText(Node node)

Return the text that a node contains. This routine:

• Ignores comments and processing instructions.
• Concatenates TEXT nodes, CDATA nodes, and the results of recursively processing EntityRef nodes.
• Ignores any element nodes in the sublist. (Other possible options are to recurse into element sublists or throw an exception.)

Parameters:

node - a DOM node

Returns:

a String representing node contents or null

close

public void close()

Closes the reader. Users of this data source should close it after usage.