dynamicresports and jasperreport within vaadin streamresource - vaadin

Question

STACKOVERFLOW is my final destination for my questions. Vaadin forum is really quiet and dynamicreports has no forum.
I have a problem integrating dynamicreports which is based on jasperreport with vaadin class named "Embedded". The "Embedded" class needs StreamResource object and all will be ended implementing getStream() function which is, in my case, never get called.
Here is my code:
//
//
//
public void build(Application app) throws IOException, DRException {
final JasperReportBuilder report = DynamicReports.report();
report.addColumn(Columns.column("Item", "item", DataTypes.stringType()));
report.addColumn(Columns.column("Quantity", "quantity", DataTypes.integerType()));
report.addColumn(Columns.column("Unit price", "unitprice", DataTypes.bigDecimalType()));
report.addTitle(Components.text("Getting started"));
report.addPageFooter(Components.pageXofY());
report.setDataSource(createDataSource());
StreamResource.StreamSource resstream = new filePDF(report);
StreamResource ress = new StreamResource(resstream, "abc.pdf", app);
//
ress.setMIMEType("application/pdf");
//
Embedded c = new Embedded("Title", ress);
c.setSource(ress);
c.setMimeType("application/pdf");
c.setType(Embedded.TYPE_BROWSER);
c.setSizeFull();
c.setHeight("800px");
c.setParameter("Content-Disposition", "attachment; filename=" + ress.getFilename());
//
app.getMainWindow().removeAllComponents();
app.getMainWindow().addComponent(c);
}
//
//
//
private JRDataSource createDataSource() {
DataSource dataSource = new DataSource("item", "quantity", "unitprice");
dataSource.add("Notebook", 1, new BigDecimal(500));
dataSource.add("DVD", 5, new BigDecimal(30));
dataSource.add("DVD", 1, new BigDecimal(28));
dataSource.add("DVD", 5, new BigDecimal(32));
dataSource.add("Book", 3, new BigDecimal(11));
dataSource.add("Book", 1, new BigDecimal(15));
dataSource.add("Book", 5, new BigDecimal(10));
dataSource.add("Book", 8, new BigDecimal(9));
return (JRDataSource) dataSource;
}
And this is "filePDF" class:
/**
*
*/
package com.example.postgrekonek;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.util.HashMap;
import net.sf.dynamicreports.jasper.builder.JasperReportBuilder;
import net.sf.dynamicreports.report.exception.DRException;
import net.sf.jasperreports.engine.JRException;
import net.sf.jasperreports.engine.JasperRunManager;
import com.vaadin.Application;
import com.vaadin.terminal.StreamResource;
/**
* #author hehehe
*
*/
public class filePDF implements StreamResource.StreamSource {
private JasperReportBuilder report;
//
public filePDF(final JasperReportBuilder rpt) {
report = rpt;
}
#Override
public InputStream getStream() {
//
ByteArrayOutputStream os = new ByteArrayOutputStream();
//
//os.write(JasperRunManager.runReportToPdf(report.toJasperReport(), new HashMap()));
try {
report.toPdf(os);
try {
os.flush();
} catch (IOException e) {
//
e.printStackTrace();
}
} catch (DRException e) {
//
e.printStackTrace();
}
return new ByteArrayInputStream(os.toByteArray());
}
}
And this is "Datasource" class:
/* Dynamic reports - Free Java reporting library for creating reports dynamically
*
* (C) Copyright 2010 Ricardo Mariaca
*
* http://dynamicreports.sourceforge.net
*
* This library is free software; you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License as published by
* the Free Software Foundation; either version 3 of the License, or
* (at your option) any later version.
*
* This library is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
* or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
* License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
* USA.
*/
package net.sf.dynamicreports.examples;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import net.sf.jasperreports.engine.JRDataSource;
import net.sf.jasperreports.engine.JRException;
import net.sf.jasperreports.engine.JRField;
/**
* #author Ricardo Mariaca (dynamicreports#gmail.com)
*/
public class DataSource implements JRDataSource {
private String[] columns;
private List<Map<String, Object>> values;
private Iterator<Map<String, Object>> iterator;
private Map<String, Object> currentRecord;
public DataSource(String ...columns) {
this.columns = columns;
this.values = new ArrayList<Map<String, Object>>();
}
public void add(Object ...values) {
Map<String, Object> row = new HashMap<String, Object>();
for (int i = 0; i < values.length; i++) {
row.put(columns[i], values[i]);
}
this.values.add(row);
}
public Object getFieldValue(JRField field) throws JRException {
return currentRecord.get(field.getName());
}
public boolean next() throws JRException {
if (iterator == null) {
this.iterator = values.iterator();
}
boolean hasNext = iterator.hasNext();
if (hasNext) {
currentRecord = iterator.next();
}
return hasNext;
}
}

Answer 1

Maybe this is browser cache issue.
Have you been try with ress.setCacheTime(1)?
For more effective streaming you should look at http://ostermiller.org/convert_java_outputstream_inputstream.html
Shortly add producer thread to handle report output and use circular buffer for host it as input.