RelatorioBase.java

import java.io.ByteArrayInputStream;
import java.io.InputStream;
import java.util.Map;

import javax.faces.context.FacesContext;
import javax.servlet.ServletContext;

import net.sf.jasperreports.engine.JRDataSource;
import net.sf.jasperreports.engine.JasperExportManager;
import net.sf.jasperreports.engine.JasperFillManager;
import net.sf.jasperreports.engine.JasperPrint;

import org.springframework.stereotype.Component;

@Component
public class RelatorioBase {
	
	public InputStream geraRelatorioPDF(Map<String, Object> mapaParametros, String nomeJasper, JRDataSource dataSource) throws Exception{
		FacesContext context = FacesContext.getCurrentInstance();
		ServletContext servletContext = (ServletContext) context.getExternalContext().getContext();
		String pathRel = servletContext.getRealPath("/reports/"+nomeJasper+".jasper");
//		JasperCompileManager.compileReport(pathRel);
		JasperPrint print = JasperFillManager.fillReport(pathRel,mapaParametros,dataSource);
		byte[] bytes = JasperExportManager.exportReportToPdf(print);
		return new ByteArrayInputStream(bytes);
	}
}