前端使用window.open即可

var url="file/preview.do?path="+response.path+"&fileName="+response.name;
top.window.open(url,response.name,"_blank");

接口代码如下

	@RequestMapping(value = "/file/preview.do")public @ResponseBody String preview(HttpServletRequest request, HttpServletResponse resp, String path, String fileName) throws IllegalStateException, IOException{InputStream inputStream = xxxx;//把需要预览的文件转成文件流OutputStream outputStream = resp.getOutputStream();String fileSuffix = fileName.substring(fileName.lastIndexOf(".") + 1).toLowerCase();//把doc文档转pdfif (fileSuffix.matches("doc|docx")){// spire.doc.freeDocument document = new Document();document.loadFromStream(inputStream);document.saveToStream(outputStream, FileFormat.PDF);}//把excel转pdfelse if (fileSuffix.matches("xls|xlsx")){//spire.xls.freeWorkbook workbook = new Workbook();workbook.loadFromStream(inputStream);workbook.saveToStream(outputStream, FileFormat.PDF);}else{if (!fileSuffix.matches("jpg|jpeg|png|gif|bmp|tiff|ai|cdr|eps|pdf")){resp.setContentType("application/octet-stream;charset=UTF-8");resp.addHeader("Content-Disposition", "attachment;filename=" + fileName);}byte[] b = new byte[1024];int length;while ((length = inputStream.read(b)) > 0){outputStream.write(b, 0, length);}}outputStream.flush();outputStream.close();inputStream.close();return null;}

如果需要把doc文档或者excel转为pdf，然后再进行预览的话需要引入spire.doc.free或者spire.xls.free的jar