springMVC4.0图片显示与文件下载

@RequestMapping(value = "/download")
@ResponseBody
public void download(
String id,String type,@RequestParam(value = DEFAULT_JQUERY_JSONP_CALLBACK_PARAM_NAME, required = false) String callbackName,
HttpServletResponse response) throws IOException {
if (StringUtils.isNotEmpty(id) && StringUtils.isNotEmpty(type)) {
HttpHeaders headers = new HttpHeaders();
File file = null;
if ("real".equals(type)) {
com.miracle.mby.core.entity.File fileModel = fileService.getFilesByMd5(id);
if (null != fileModel) {
Dict dict = fileService.getUploadFileDict();
headers.setContentDispositionFormData("attachment", new String(fileModel.getOrginName().getBytes("UTF-8"), "ISO8859-1"));
file = new File(dict.getValue() + fileModel.getPath());

}
} else if ("temp".equals(type)) {
file = FileUtils.getTempUploadFile(id);
if (file == null) {
logger.warn("资源不存在%s", id);
} else {
headers.setContentDispositionFormData("attachment", new String(file.getName().getBytes("gbk"), "ISO8859-1"));
}
}
if (FileUtils.isImage(file)) {
response.setHeader("Accept-Ranges", "bytes");
response.setHeader("Pragma", "no-cache");
response.setHeader("Cache-Control", "no-cache");
response.setDateHeader("Expires", 0);

}else{
response.setContentType("application/octet-stream");
response.setHeader("Accept-Ranges", "bytes");
response.setHeader("Content-Disposition", "attachment;fileName=" + new String(file.getName().getBytes("gbk"), "ISO8859-1"));

}
if(file.exists()){
FileInputStream inputStream = new FileInputStream(file);
response.setHeader("Content-Length", String.valueOf(file.length()));
byte[] bos = IOUtils.read(inputStream);
OutputStream out = null;
out = response.getOutputStream();
out.write(bos);
out.flush();
out.close();
inputStream.close();
}

}
}

public static boolean isImage(File file){
if(file.isDirectory()){
return false;
}
String fileName = file.getName();
int len = fileName.indexOf(".");
String imagesPattern  = fileName.substring(len+1,fileName.length()).toLowerCase();
if("jpg".equals(imagesPattern)){
return true;
}else if("bmp".equals(imagesPattern)){
return true;
}else if("gif".equals(imagesPattern)){
return true;
}else if("psd".equals(imagesPattern)){
return true;
}else if("pcx".equals(imagesPattern)){
return true;
}else if("png".equals(imagesPattern)){
return true;
}else if("dxf".equals(imagesPattern)){
return true;
}else if("cdr".equals(imagesPattern)){
return true;
}else if("ico".equals(imagesPattern)){
return true;
}else if("bmp".equals(imagesPattern)){
return true;
}else if("jpeg".equals(imagesPattern)){
return true;
}else if("svg".equals(imagesPattern)){
return true;
}else if("wmf".equals(imagesPattern)){
return true;
}else if("emf".equals(imagesPattern)){
return true;
}else if("eps".equals(imagesPattern)){
return true;
}else if("tga".equals(imagesPattern)){
return true;
}else if("nef".equals(imagesPattern)){
return true;
}else if("tif".equals(imagesPattern)){
return true;
}else if("tiff".equals(imagesPattern)){
return true;
}else{
return false;
}

}