How can I generate report bytes?

[jcatubay]

I'm using

JasperReport jasperReport = JasperCompileManager.compileReport(reportFile.getPath());

bytes = JasperRunManager.runReportToPdf(

jasperReport,

parameters);

return bytes;

for some reason it returns a null value. What are the conditions so I can use this version of the runReportToPdf. I'm using hibernate and spring

Thanks!

[wegnerk]

I am not sure, but i think it must be a byte-array, byte[] pdfFile for example.

 

I also needed byte-arrays to fill an outputstream for a webapplication and in my case, it works.

[jcatubay]

How did you generate your byte array? Did you have a query in your application to get the data? That is what I'm doing right now, I create a JRDatasource in my application the fill it report with the data. I'm currently using:

 

bytes = JasperRunManager.runReportToPdf(

JasperReport jasperReport,

Map parameters,

JRDatasource ds

)

 

But I want to get away with queries in my code and just use the queries stored in my reports. I want to do something like this

 

bytes = JasperRunManager.runReportToPdf(

JasperReport jasperReport,

Map parameters);

 

But for some reason it returns a null value for my bytes.

Thanks!

[wegnerk]

i have my data in a database and i give the jasperFillManager a DB-connection.

 

my code looks like this:

Code:

try {
Connection conn = getConnection();
jasperReport = JasperCompileManager.compileReport("reports/Gesamt_Monat.jrxml"«»);
jasperPrint = JasperFillManager.fillReport(jasperReport, new HashMap(), conn);

closeDB(conn);

byte[] outputFile = JasperExportManager.exportReportToPdf(jasperPrint);

} catch (Exception e) {
	e.printStackTrace();
}

and this byte[] ouputFile, i can use for streams.

 

But if you don't want to have queries in your code, did you try with JREmptyDataSource?

 

I really dont know, if this helps you in any way, but i don't have experience with hibernate/spring...

[jcatubay]

I dont like to have queries in my code but I still want to be able to fill me report using the reports query. Would JREmptyDataSource give empty report. The program right now is using the parameters, my program generates a resultset by executing the queries in my program, then make that into a JRDataSource. After getting the JRDataSource, together with jrxml file, I pass them to a method that generates my byte[].This is the method:

public byte[] generatePDFReport(File reportFile, Map parameters, JRDataSource ds) {

byte[] bytes = null;

try {

JasperReport jasperReport = JasperCompileManager.compileReport(reportFile.getPath());

bytes = JasperRunManager.runReportToPdf(

jasperReport,

parameters,

ds);

} catch (JRException e) {

e.printStackTrace();

}

return bytes;

}

After I get the bytes, I pass it to another method:

public void sendToPDFResponse(byte[] bytes){

HttpServletResponse response = (HttpServletResponse) FacesContext.getCurrentInstance().getExternalContext().getResponse();

response.setContentType("application/pdf");

sendToResponse(response, bytes);

}

to publish it in the web.

What I want to do now is bypass the method where I get my JRDataSource using my programs query. I want to find a way to just use the query in my xml to get my data and generate byte[]. I saw a method in my JasperManager that have this interface:

bytes = JasperRunManager.runReportToPdf(

jasperReport,

parameters);

return bytes;

So it uses just the parameters and jasperreport but when I use it it generates just a null byte[].What are the precondition for me to be able to use this method and generate my data?

Thanks a lot for helping with this, I'm new to JasperReport but I think it's cool and I want to learn more about it....

[lucianc]

If you want to use the report query to retrieve data, you need to pass the data connection to the report in one of the following ways:

If the query is SQL and you are using JDBC to execute it, by calling

Code:

JasperRunManager.runReportToPdf(jasperReport, parameters, jdbcConnection);

In the general case, the connection parameter should be included in the parameters map, e.g.

Code:

[code]//for SQL queries parameters.put(JRParameter.REPORT_CONNECTION, jdbcConnection); //or for HQL queries parameters.put(JRHibernateQueryExecuterFactory.PARAMETER_HIBERNATE_SESSION, hibernateSession); //etc

[/ul]

 

HTH,

Lucian

[jcatubay]

Thanks, that helps!

[jcatubay]

Thanks a lot!