net.sf.jasperreports.engine.export

Class JRTextExporter

java.lang.Object

net.sf.jasperreports.engine.JRAbstractExporter

net.sf.jasperreports.engine.export.JRTextExporter

All Implemented Interfaces:

JRExporter

public class JRTextExporter
extends JRAbstractExporter

Exports filled reports in plain text format. The text exporter allows users to define a custom character resolution (the number of columns and rows in text format). Since the character resolution is mapped on the actual pixel resolution, every character corresponds to a rectangle of pixels. If a certain text element has a smaller size in pixels (width, height, or both) than the number of pixels that map to a character, the text element will not be rendered. Because of this, users must take some precautions when creating reports for text export. First, they must make sure the page size in characters is large enough to render the report, because if the report pages contain too much text, some of it may be rendered only partially. On the other hand, if the character resolution is too small compared to the pixel resolution (say, a height of 20 characters for a page 800 pixels tall) all texts with sizes smaller than the one needed to map to a character, will not be displayed (in the previous example, a text element needs to be at least 800/20 = 40 pixels tall in order to be rendered).

As a conclusion, the text exporter will yield the better results if the space needed for displaying a text is large. So users have to either design reports with few text or export to big text pages. Another good practice is to arrange text elements at design time as similar as possible to a grid.

Version:

$Id: JRTextExporter.java 4595 2011-09-08 15:55:10Z teodord $

Author:

Ionut Nedelcu (ionutned@users.sourceforge.net)

See Also:

JRExporterParameter

Nested Class Summary

Nested classes/interfaces inherited from class net.sf.jasperreports.engine.JRAbstractExporter

JRAbstractExporter.BaseExporterContext, JRAbstractExporter.ParameterOverriddenResolver, JRAbstractExporter.ParameterOverrideResolver, JRAbstractExporter.ParameterResolver

Field Summary

Fields

Modifier and Type	Field and Description
protected java.lang.String	betweenPagesText
protected float	charHeight
protected float	charWidth
protected java.lang.String	lineSeparator
protected int	pageHeightInChars
protected int	pageWidthInChars
protected JRExportProgressMonitor	progressMonitor
protected static java.lang.String	systemLineSeparator
protected java.io.Writer	writer

Fields inherited from class net.sf.jasperreports.engine.JRAbstractExporter

dateFormatCache, endPageIndex, filter, globalOffsetX, globalOffsetY, hyperlinkProducerFactory, isModeBatch, jasperPrint, jasperPrintList, numberFormatCache, parameters, PROPERTY_DEFAULT_FILTER_FACTORY, PROPERTY_SUFFIX_DEFAULT_FILTER_FACTORY, startPageIndex

Constructor Summary

Constructors

Constructor and Description
JRTextExporter()

Method Summary

Methods

Modifier and Type	Method and Description
protected void	exportElements(java.util.List<JRPrintElement> elements)
protected void	exportPage(JRPrintPage page) Exports a page to the output writer.
void	exportReport() Actually starts the export process.
protected void	exportReportToWriter()
protected void	exportText(JRPrintText element) Renders a text and places it in the output matrix.
protected java.lang.String	getExporterKey()
protected int	getHeightInChars(int height) Transforms height from pixel space to character space.
protected JRStyledText	getStyledText(JRPrintText textElement)
protected int	getWidthInChars(int width) Transforms width from pixel space to character space.
void	setReportParameters()

Methods inherited from class net.sf.jasperreports.engine.JRAbstractExporter

createFilter, defaultParseNumber, getBooleanCellValue, getBooleanParameter, getCharacterParameter, getCustomHandler, getDateCellValue, getDateFormat, getFloatParameter, getHyperlinkProducer, getIntegerParameter, getLocale, getNumberCellValue, getNumberFormat, getOffsetX, getOffsetY, getParameter, getParameterResolver, getParameters, getReportContext, getStringArrayParameter, getStringParameter, getStringParameterOrDefault, getStyledText, getTextFormatFactoryClass, getTextLocale, getTextTimeZone, getTextValue, getTextValueString, reset, resetClassLoader, resetExportContext, restoreElementOffsets, setClassLoader, setExportContext, setFrameElementsOffset, setHyperlinkProducerFactory, setInput, setJasperPrint, setOffset, setOffset, setOutput, setPageRange, setParameter, setParameters, setReportContext

Methods inherited from class java.lang.Object

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

Field Detail

pageWidthInChars

protected int pageWidthInChars

pageHeightInChars

protected int pageHeightInChars

charWidth

protected float charWidth

charHeight

protected float charHeight

progressMonitor

protected JRExportProgressMonitor progressMonitor

writer

protected java.io.Writer writer

betweenPagesText

protected java.lang.String betweenPagesText

lineSeparator

protected java.lang.String lineSeparator

systemLineSeparator

protected static final java.lang.String systemLineSeparator

Constructor Detail

JRTextExporter

public JRTextExporter()

Method Detail

exportReport

public void exportReport()
                  throws JRException

Description copied from interface: JRExporter

Actually starts the export process.

Specified by:

exportReport in interface JRExporter

Specified by:

exportReport in class JRAbstractExporter

Throws:

JRException

setReportParameters

public void setReportParameters()
                         throws JRException

Throws:

JRException

exportReportToWriter

protected void exportReportToWriter()
                             throws JRException,
                                    java.io.IOException

Throws:

JRException

java.io.IOException

exportPage

protected void exportPage(JRPrintPage page)
                   throws java.io.IOException

Exports a page to the output writer. Only text elements within the page are considered. For each page, the engine creates a matrix of characters and each rendered text element is placed at the appropiate position in the matrix. After all texts are parsed, the character matrix is sent to the output writer.

Throws:

java.io.IOException

exportElements

protected void exportElements(java.util.List<JRPrintElement> elements)

exportText

protected void exportText(JRPrintText element)

Renders a text and places it in the output matrix.

getHeightInChars

protected int getHeightInChars(int height)

Transforms height from pixel space to character space.

getWidthInChars

protected int getWidthInChars(int width)

Transforms width from pixel space to character space.

getStyledText

protected JRStyledText getStyledText(JRPrintText textElement)

Overrides:

getStyledText in class JRAbstractExporter

getExporterKey

protected java.lang.String getExporterKey()

Specified by:

getExporterKey in class JRAbstractExporter