jar包启动后读取相对路径文件报异常：

Caused by: java.io.FileNotFoundException: class path resource [***.***] cannot be resolved to absolute

.***.jar/BOOT-INF/classes!/***.**

// /template/template.html是resource下面的文件

String template=readfile("/template/template.html");

//file 相对路径

 public  String readfile(String file){

        InputStream stream = this.getClass().getResourceAsStream(file);

        StringBuffer sb = new StringBuffer() ;

        BufferedReader br = null ;

        try {

            br = new BufferedReader(new InputStreamReader(stream,"UTF-8")) ;

            String s=null ;

            while((s=br.readLine()) !=null){

                sb.append(s) ;

            }

            br.close();

        } catch (FileNotFoundException e) {

            log.error("FileNotFoundException:"+e);

        } catch (IOException e) {

            log.error("IOException :"+e);

        }finally {

            if(br !=null){

                try {

                    br.close();

                } catch (IOException e) {

                    log.error("close br error:"+e);

                }

            }

        }

        return sb.toString();

    }