Output an Excel file from JAX RS

Output an Excel file from JAX-RS : Produces an excel(.xlsx) file and output is prompted to the user.

package com.homedepot.ta.wh.md.service;

import java.io.File;
import java.io.FileOutputStream;

import javax.ws.rs.GET;
import javax.ws.rs.Path;
import javax.ws.rs.Produces;
import javax.ws.rs.core.Response;
import javax.ws.rs.core.Response.ResponseBuilder;

import org.apache.poi.ss.usermodel.Workbook;
import org.apache.poi.xssf.usermodel.XSSFWorkbook;


@Path("/excel")

//Output an Excel file from JAX-RS
public class excelgenerator  {
 @GET
 // mime type for excel output
 @Produces("application/vnd.ms-excel")
 @Path("/get")
 

    ResponseBuilder rb=null;
 
 /*
  * Method which generates an excel file
  * Writes to an output stream
  * Appends the file in a response
  * Builds the response so as to produce an .xlsx file
  * 
  */
 public Response getExcel() {
 
  File file = new File("Excel.xlsx"); 
          try{
            Workbook wb = new XSSFWorkbook();
      FileOutputStream fos = new FileOutputStream(file);
            wb.write(fos);
            fos.close();
            rb = Response.ok((Object) file);
         rb.header("Content-Disposition","attachment; filename=Excel.xlsx");
 } catch (Exception e) {
   System.out.println(e.getMessage());
 }
    return rb.build();      
 }
  }