[How to write conditional sql query for ireport parameter?]

I am new to Ireport and jasperreport What I am trying is, I have a select dropdown in html shows groups once select a group and click submit it should generate report of all vehicles under that group. in dropdown I have a value All , If i select that it should generate report of all vehicle under perticuler user. So I have created parameters in I report as follow ,

 

    $P{querycontroler}==>default value is :$P{gp}.equals("All")?$P{byuser}:$P{bygrp}

    $P{bygroup}==>default value is:"SELECT * FROM vehicle_details where client_id=$P{user} and group_name=$P{gp}"

   $P{byuser}==>default value is:"SELECT * FROM vehicle_details where client_id=$P{user}"

    $P{gp}==>promts to enter group(selected dropdown value )

   $P{user}==>promts to enter user(user who logged in application)

 

   and when I write a report query as $P!{group} , it doesnt reads fields of table instead it just shows `Error:null`. How to solve this please help me in this.

[How to display pdf report in jsp?]

I have a link in one jsp as,

 

<form action="VehicleReports">

<a href="vehicleReport.jsp">Vehicle Report</a>

</form>

 

I have writen VehicleReports servlet as,

 

 

protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

 

Connection con=null;

try{

 

response.setContentType("application/pdf"); 

 

con=VehicleDetails.getConnection();

InputStream inputStream = new FileInputStream ("E:/ReportFld/report4.jrxml");

 

Map parameters = new HashMap();

 

JasperDesign jasperDesign = JRXmlLoader.load(inputStream);

JasperReport jasperReport = JasperCompileManager.compileReport(jasperDesign);

@SuppressWarnings("unchecked")

JasperPrint jasperPrint = JasperFillManager.fillReport(jasperReport, parameters, con);

 

JasperExportManager.exportReportToPdfFile(jasperPrint, "D:/reports/vehicle2_jasper.pdf");

 

JasperExportManager.exportReportToPdfFile(jasperPrint, "D:/reports/vehicle2_jasper.pdf");

 

 

   int len = (int)new File("D:/reports/vehicle2_jasper.pdf").length(); 

response.setContentLength(len); 

byte[] buf = new byte[len]; 

FileInputStream pdfin = new FileInputStream("D:/reports/vehicle2_jasper.pdf"); 

pdfin.read(buf); 

pdfin.close(); 

OutputStream pdfout = response.getOutputStream(); 

pdfout.write(buf,0,len); 

pdfout.flush();  

 

request.getRequestDispatcher("/vehicleReport.jsp").forward(request, response);

 

 

}

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

finally{

try {

con.close();

} catch (SQLException e) {

// TODO Auto-generated catch block

e.printStackTrace();

}

}

}

 

and in vehicleReport.jsp I am trying to display the report as,

<object data="D:/reports/vehicle2_jasper.pdf" type="application/pdf">

<embed src="D:/reports/vehicle2_jasper.pdf" type="application/pdf">

</object>

 

but its not showing anything. .  How to solve this. can anyone help me in this.