java后台导出pdf

新页面打开wpf

@RequestMapping("/showPdf")
public String getpic( HttpServletRequest request, HttpServletResponse response) throws IOException {
File file = new File("C://Users//Administrator//Desktop//hello.pdf");
if (!file.exists()) {
request.setAttribute("error", "附件已删除或不存在");
// return "/error";
}
InputStream in = null;
OutputStream os = null;
try {
response.setContentType("application/pdf"); // 设置返回内容格式
in = new FileInputStream(file); //用该文件创建一个输入流
os = response.getOutputStream(); //创建输出流
byte[] b = new byte[1024];
while (in.read(b) != -1) {
os.write(b);
}
in.close();
os.flush();
os.close();
} catch (Exception e) {
try {
if (null != in) {
in.close();
}
} catch (IOException e1) {
e1.printStackTrace();
}
try {
if (null != os) {
os.close();
}
} catch (IOException e2) {
e2.printStackTrace();
}

}
return null;

}