WEB页面加载优化-JS、CSS等多静态文件合并

@RequestMapping(value="/merge",method={RequestMethod.GET,RequestMethod.POST})
public void getJS(HttpServletRequest request, HttpServletResponse response){
    PrintWriter writer = null;
    String fileNames = request.getParameter("fileNames");
    try {
        String jsContent = getStaticResource(fileNames);
        response.reset();
        response.setBufferSize(2048);
        response.setCharacterEncoding("utf-8");
        response.setContentLength(jsContent.getBytes("utf-8").length);
        response.setContentType("application/javascript");
        if(fileNames != null && !"".equals(fileNames)) {
            String[] fileNamesArr = fileNames.split(",");
            if(fileNamesArr!=null && fileNamesArr.length>0){
                if(fileNamesArr[0].endsWith(".css") || fileNamesArr[0].endsWith(".CSS")){
                    response.setContentType("text/css");
                }
            }
        }
        response.setStatus(HttpServletResponse.SC_OK);
        writer = response.getWriter();
        writer.print(jsContent);
        writer.flush();
    } catch (Exception e) {
        System.out.println("获取js文件失败："+e.getMessage());
        try {
            response.sendError(HttpServletResponse.SC_INTERNAL_SERVER_ERROR,e.getMessage());
        } catch (IOException e1) {
            System.out.println(e1.getMessage());
        }
    }finally{
        if(writer != null){
            writer.close();
        }
    }
}

//合并静态文件
private  String getStaticResource(String fileNames) {
    if(fileNames != null && !"".equals(fileNames)){
        String[] fileNamesArr = fileNames.split(",");
        StringBuffer sb_result = new StringBuffer(";");
        if(fileNamesArr != null && fileNamesArr.length>0){
            for(String fileName:fileNamesArr){
                //读取文件
                String fileContent = null;
                try{
                    InputStream is = new FileInputStream(Paths.get(staticpath, fileName).toFile());
                    ByteArrayOutputStream baos=new ByteArrayOutputStream();
                    byte[] buffer = new byte[2048];
                    int len = 0;
                    while((len=is.read(buffer))!=-1){
                        baos.write(buffer, 0, len);
                    }
                    is.close();
                    baos.close();
                    fileContent = baos.toString();
                }catch(Exception e){
                    e.printStackTrace();
                }
                if(StringUtils.isEmpty(fileContent)){
                    continue;
                }
                sb_result.append(fileContent+";");
            }
            return sb_result.toString();
        }else{
            return ";";
        }
    }else{
        return ";";
    }
}