How to take advantage of the consultation in two separate layouts reports?

Question

I have two reports in Jasper for different views on the same mass of data. So much so that the parameters and query are exactly the same.

Is there any method, inherent to Jasper Reports, that allows me to write this query/these parameters only once and take advantage in both .jrxmls? Or should I make myself some textual substitution method to allow this?

Answer 1

jasperreports has the concept of Datasources, where you can assemble the data source of your report from various formats and send it to your reports.

You need to execute a code that returns some interface implementation Jrdatasource

There are some implementations of this class depending on how you want to pass your data, following examples:

1. Jrresultsetdatasource If you want to work with a Resultset
2. Jrbeancollectiondatasource If you want to pass any Collection as List, Set, etc
3. Jrxlsdatasource If you want to use an Excel file as a data source.

Basically, instead of mounting the query in the report and having it run the query you pass the data source to the fillReport method, follow example:

InputStream isDesignRelatorio = this.getClass().getResourceAsStream("path/to/report.jasper");
JRDataSource dataSource = new JRResultSetDataSource(this.getResultSet());
JasperPrint print = JasperFillManager.fillReport(isDesignRelatorio,this.getParametros(), dataSource);
ByteArrayOutputStream pdfStream = new ByteArrayOutputStream();  

JRPdfExporter exporter = new JRPdfExporter();
exporter.setExporterInput(SimpleExporterInput.getInstance(Arrays.asList(print)));
exporter.setExporterOutput(new SimpleOutputStreamExporterOutput(pdfStream));
SimplePdfExporterConfiguration configuration = new SimplePdfExporterConfiguration() ;
configuration.setCreatingBatchModeBookmarks(true);
exporter.setConfiguration(configuration);
exporter.exportReport(); 

Some comments on this code snippet:

This example assumes that you have a jrxml file already compiled in format. Jasper, I compile the report by the design tool so that the code does not "waste time" doing this, however you can also choose to compile at runtime. In this case add a line compiling the report, for example:

 JasperReport report = JasperCompileManager.compileReport(isDesignRelatorio);

The method this.getResultSet() is to represent your data source that in this case would be a Resultset, but as I explained earlier may even be a Collection of a DTO assembled by you or even a bank entity. In this case change the implmentation of the source date of new JRResultSetDataSource(this.getResultSet()); for something like new JRBeanCollectionDataSource(this.getCollection());

This example writes the export output on a ByteArrayOutputStream, if you are working with a web system you can write directly to outputstream.

There is also the possibility to generate the output in a physical file, just explore the export forms.