Crosstab misuse or memory leak?

[marciopd]

I'm using crosstabs in a possibly pretty large report.

I designed the report so that the data didn't get all loaded together into memory. Well,  tried :D
The thing is that it seems that there's a problem with jasperreports' crosstab report filling engine (JRFillCrosstab).

Using  a eclipse plugin (http://www.eclipse.org/mat/) to analyse the heap dump on out of memory error, i get that

JRFillCrossTab stores the data in a arraylist that keeps growing and growing...

Code to reproduce the issue is attached.
Class ReportServiceImpl has the main method to be executed.
You should modify the constant ReportServiceImpl.TMP_DIR_PATH to a temporary path in your file system.


Any help please?

Post Edited by marciopd at 07/17/2010 05:04

[marciopd]

Someone?

[marciopd]

I reported this issue as a bug. Please vote:

http://jasperforge.org/projects/jasperreports/tracker/view.php?id=4785

[marciopd]

class that generates the report: ReportServiceImpl.java

Code:

package report;import java.util.HashMap;import java.util.Map;import model.QueryLazyList;import net.sf.jasperreports.engine.JREmptyDataSource;import net.sf.jasperreports.engine.JRException;import net.sf.jasperreports.engine.JRParameter;import net.sf.jasperreports.engine.JRVirtualizer;import net.sf.jasperreports.engine.JasperExportManager;import net.sf.jasperreports.engine.JasperFillManager;import net.sf.jasperreports.engine.JasperPrint;import net.sf.jasperreports.engine.JasperReport;import net.sf.jasperreports.engine.fill.JRSwapFileVirtualizer;import net.sf.jasperreports.engine.util.JRSwapFile;import ar.com.fdvs.dj.core.DJConstants;import ar.com.fdvs.dj.core.DynamicJasperHelper;import ar.com.fdvs.dj.core.layout.ClassicLayoutManager;import ar.com.fdvs.dj.domain.DJCalculation;import ar.com.fdvs.dj.domain.DJCrosstab;import ar.com.fdvs.dj.domain.DynamicReport;import ar.com.fdvs.dj.domain.Style;import ar.com.fdvs.dj.domain.builders.CrosstabBuilder;import ar.com.fdvs.dj.domain.builders.DynamicReportBuilder;import ar.com.fdvs.dj.domain.constants.Border;public class ReportServiceImpl {	/**	 * Tmp dir path.	 */	private static final String TMP_DIR_PATH = "/tmp";	/**	 * Generates test report.	 * @return	 * @throws JRException erro	 */	public byte[] generateCrossTabReport() throws JRException {		DynamicReportBuilder drb = new DynamicReportBuilder();;		DJCrosstab djcross = new CrosstabBuilder().setHeight(200).setWidth(500)				.setDatasource("sr",						DJConstants.DATA_SOURCE_ORIGIN_PARAMETER,						DJConstants.DATA_SOURCE_TYPE_COLLECTION,						true)				.setUseFullWidth(true)				.setAutomaticTitle(false)				.setCellBorder(Border.THIN)				.addColumn("State", "state", String.class.getName(), false)				.addRow("City", "city", String.class.getName(),false)				.addMeasure("amount", String.class.getName(),						DJCalculation.NOTHING, "Amount", new Style())				.setCellDimension(17, 60)				.setColumnHeaderHeight(30)				.setRowHeaderWidth(80)				.build();		drb.addHeaderCrosstab(djcross);		DynamicReport dr = drb.build();		// put a collection in the parameters map to be used by the crosstab		Map<String, Object> reportParams = new HashMap<String, Object>();		reportParams.put("sr", getTestDataLazyList());		// set a swap file virtualizer		JRSwapFile swapFile = new JRSwapFile(TMP_DIR_PATH, 1024, 10);		JRVirtualizer virtualizer = new JRSwapFileVirtualizer(1024, swapFile, true);		reportParams.put(JRParameter.REPORT_VIRTUALIZER, virtualizer);		// generates jasper report		JasperReport jasperReport = DynamicJasperHelper.generateJasperReport(dr,			new ClassicLayoutManager(), reportParams);		// fills report and generates jasperprint		JasperPrint jasperPrint = JasperFillManager.fillReport(jasperReport,			reportParams, new JREmptyDataSource());		// export to pdf bytes		return JasperExportManager.exportReportToPdf(jasperPrint);	}	/**	 * returns test data.	 * @return test data	 */	private QueryLazyList getTestDataLazyList() {		return new QueryLazyList(1000);	}	public static void main(String[] args) throws JRException {		byte[] result = new ReportServiceImpl().generateCrossTabReport();		System.out.println(result.length);	}}

[marciopd]

AbstractLazyList.java

Code:

package model;import java.util.AbstractList;import java.util.HashMap;import java.util.List;import java.util.Map;/** * Lazy list to a generic type. */public abstract class AbstractLazyList<T> extends AbstractList<T> {	/**	 * Already loaded data.	 */	private final Map<Integer, T> loadedData;	/**	 * How much itens shoud be retrieved at a query.	 */	private final int pageSize;	/**	 * Constructor with page size.	 * @param pageSize page size	 */	public AbstractLazyList(int pageSize) {		super();		this.pageSize = pageSize;		this.loadedData = new HashMap<Integer, T>(pageSize);	}	@Override	public T get(int position) {		if (!loadedData.containsKey(position)) {			loadedData.clear();			List<T> results = queryPage(position, pageSize);			int index = position;			for (T item : results) {				loadedData.put(index, item);				index++;			}		}		return loadedData.get(position);	}	@Override	public int size() {		return getTotalQueryResultsSize();	}	/**	 * Queries the new page.	 * @param position initial position	 * @param pageSize page size	 * @return results from position to page size	 */	public abstract List<T> queryPage(int position, int pageSize);	/**	 * Returns the total results returned by the query.	 * @return total number of results	 */	public abstract int getTotalQueryResultsSize();}

[marciopd]

QueryLazyList.java

Code:

/** * */package model; import java.util.ArrayList;import java.util.List; /** * Test implementation for a lazy list. */public class QueryLazyList extends AbstractLazyList<CrossTabDataVO> {    /**     * Total number of results.     */    int totalNumberResults = Integer.MAX_VALUE;     public QueryLazyList(int pageSize) {        super(pageSize);    }     @Override    public int getTotalQueryResultsSize() {        return totalNumberResults;    }     @Override    public List<CrossTabDataVO> queryPage(int position, int pageSize) {        List<CrossTabDataVO> resultsPage = new ArrayList<CrossTabDataVO>(pageSize);        for(int i = position; i < position + pageSize; i++) {            CrossTabDataVO crossTabDataVO = new CrossTabDataVO();            crossTabDataVO.setState("State " + i);            crossTabDataVO.setCity("City " + i);            crossTabDataVO.setAmount(i + ",00");            resultsPage.add(crossTabDataVO);        }        return resultsPage;    }}

[marciopd]

CrossTabDataVO.java

Code:

package model; import java.io.Serializable; /** * Data to be used inside crosstab. */public class CrossTabDataVO implements Serializable {     /** serial. */    private static final long serialVersionUID = 3785582945804552430L;     private String state;     private String city;     private String amount;     public String getState() {        return state;    }     public void setState(String state) {        this.state = state;    }     public String getCity() {        return city;    }     public void setCity(String city) {        this.city = city;    }     public String getAmount() {        return amount;    }     public void setAmount(String amount) {        this.amount = amount;    }}

[lucianc]

Crosstabs were meant to present concise aggregated data.  The aggregation is performed in-memory, and it is scalable wrt large data volumes as long as the data falls into a small number of buckets.

Therefore crosstabs do not suit the case of creating large tables.  What exactly do you want to display in your crosstab?

Regards,

Lucian

[marciopd]

In my case, i'm dealing with large tables.

I used crosstabs because it deals well with dynamic columns and when theses columns gets larger than the page width.

 

Can I design a report so that its columns are dynamic and jasper will deal automatically with column breaks?

 

Thanks for helping

[lucianc]

marciopd
Wrote:

In my case, i'm dealing with large tables. I used crosstabs because it deals well with dynamic columns and when theses columns gets larger than the page width. Can I design a report so that its columns are dynamic and jasper will deal automatically with column breaks? Thanks for helping

Follow-up at http://jasperforge.org/plugins/espforum/view.php?group_id=102&forumid=103&topicid=77084