Method changeSessionIdMethod = ReflectionUtils.findMethod(HttpServletRequest.class, "changeSessionId");

        if(changeSessionIdMethod == null) {

            throw new IllegalStateException("HttpServletRequest.changeSessionId is undefined. Are you using a Servlet 3.1+ environment?");

        }

        System.out.println(changeSessionIdMethod);

TimeUnit.MILLISECONDS.sleep(1000);

private static final PropertyPlaceholderHelper helper = new PropertyPlaceholderHelper("@{", "}", ":", false);

    private static final PlaceholderResolver placeholderResolver=new PlaceholderResolver(){

        @Override

        public String resolvePlaceholder(String key) {

            return System.getProperty(key);

        }

    };

String[] methods = Wrapper.getWrapper(interfaceClass).getMethodNames();

        String template="test1={0},test2={1},test3={2}";

        Object[] objects=new Object[]{0,1,"test2"};

        String emailContent = MessageFormat.format(template, objects);

        System.out.println(emailContent);

    @Override

    protected void doFilterInternal(HttpServletRequest request, HttpServletResponse response, FilterChain filterChain)

            throws ServletException, IOException {

        HttpServletRequest requestToUse = request;

        if ("POST".equals(request.getMethod()) && request.getAttribute(WebUtils.ERROR_EXCEPTION_ATTRIBUTE) == null) {

            String paramValue = request.getParameter(this.methodParam);

            if (StringUtils.hasLength(paramValue)) {

                requestToUse = new HttpMethodRequestWrapper(request, paramValue);

            }

        }

        filterChain.doFilter(requestToUse, response);

    }

        if (ClassUtils.isPresent(REACTIVE_WEB_ENVIRONMENT_CLASS, null)

                && !ClassUtils.isPresent(MVC_WEB_ENVIRONMENT_CLASS, null)) {

            return WebApplicationType.REACTIVE;

        }

        for (String className : WEB_ENVIRONMENT_CLASSES) {

            if (!ClassUtils.isPresent(className, null)) {

                return WebApplicationType.NONE;

            }

        }

    public static void main(String[] args) throws Exception {

        Enumeration<URL> urls = ClassLoader.getSystemResources("META-INF/services/ch.qos.logback.classic.spi.Configurator");

        while (urls.hasMoreElements()) {

            URL url = urls.nextElement();

            System.out.println(url.getPath());

        }

    }
    // 从url 读取文件内容
BufferedReader reader = new BufferedReader(new InputStreamReader(resourceURL.openStream(), "utf-8"));　　

public class FileUtil {

    public static File getFile(String path,String fileName) throws IOException{

        File directory=new File(path);

        String filePath=directory.getCanonicalPath();

        return new File(filePath+"/"+fileName);

    }

}

    public static byte[] subBytes(byte[] src, int begin, int count) {

        byte[] bs = new byte[count];

        System.arraycopy(src, begin, bs, 0, count);

        return bs;

    }

if (!StringUtil.isNullOrEmpty(po.getContent())){

            byte[] contentB= new byte[0];

            try {

                contentB = po.getContent().getBytes("utf-8");

                if (contentB.length>1024){

                    po.setContent(new String(StringUtil.subBytes(contentB,0,1024),"utf-8"));

                }

            } catch (UnsupportedEncodingException e) {

                String result="content bytes length > 1024，convert error";

                po.setContent(result);

                log.error(result,e);

            }

        }

    private Class<?> deduceMainApplicationClass() {

        try {

            StackTraceElement[] stackTrace = new RuntimeException().getStackTrace();

            for (StackTraceElement stackTraceElement : stackTrace) {

                if ("main".equals(stackTraceElement.getMethodName())) {

                    return Class.forName(stackTraceElement.getClassName());

                }

            }

        }

        catch (ClassNotFoundException ex) {

            // Swallow and continue

        }

        return null;

    }