PDFController.java

package com.cs.controller;

import org.springframework.http.MediaType;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServletResponse;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.nio.Buffer;
import java.nio.ByteBuffer;

@RestController
public class PDFController {

    @RequestMapping("/pdf")
    public byte[] pdf(HttpServletResponse response) throws Exception{
        ByteArrayOutputStream stream = new ByteArrayOutputStream();
        ServletOutputStream outputStream = response.getOutputStream();
        File file = new File("Z:\\1.pdf");
//        stream.writeTo(fileInputStream);
//        outputStream.write(stream.toByteArray());
        response.setContentType(MediaType.APPLICATION_PDF_VALUE);
        return stream.toByteArray();
    }
}