博客
关于我
JavaWeb快速入门--Filter&Listener
阅读量:60 次
发布时间:2019-02-25

本文共 3615 字,大约阅读时间需要 12 分钟。

JavaWeb ???????????

???

????JavaWeb????????????????????????????????????????????????????????????????????????????????????????

????????

  • ????

    ???????????????????

    • REQUEST??????????
    • FORWARD???RequestDispatcher#forward()???????
    • INCLUDE???RequestDispatcher#include()???????
    • ERROR???????????????????
  • ????

    ?????????????????

    • ???????/index.jsp
    • ???/user/*
    • ????*.jsp
    • ?????/*
  • ????????

    ???????????

    • init(FilterConfig)????????????????
    • doFilter(ServletRequest, ServletResponse, FilterChain)?????????????
    • destroy()????????????
  • ????????????

    @WebFilter("/*")public class CharacterFilter implements Filter {    @Override    public void doFilter(ServletRequest req, ServletResponse res, FilterChain chain) throws IOException, ServletException {        HttpServletRequest request = (HttpServletRequest) req;        HttpServletResponse response = (HttpServletResponse) res;                if (request.getMethod().equalsIgnoreCase("post")) {            request.setCharacterEncoding("utf-8");        }        response.setContentType("text/html;charset=utf-8");                chain.doFilter(request, response);    }}

    ???????????

    @WebFilter("/*")public class SensitiveWordsFilter implements Filter {    private List
    sensitiveWords = new ArrayList<>(); @Override public void init(FilterConfig config) throws ServletException { try { ServletContext servletContext = config.getServletContext(); String path = servletContext.getRealPath("/WEB-INF/classes/sensitiveWords.txt"); BufferedReader br = new BufferedReader(new FileReader(path)); while ((line = br.readLine()) != null) { sensitiveWords.add(line); } br.close(); } catch (Exception e) { e.printStackTrace(); } } @Override public void doFilter(ServletRequest req, ServletResponse resp, FilterChain chain) throws ServletException, IOException { ServletRequest proxyRequest = new Proxy(req) { @Override public String getParameter() { String value = super.getParameter(); if (value != null) { for (String word : sensitiveWords) { if (value.contains(word)) { value = value.replaceAll(word, "***"); } } } return value; } }; chain.doFilter(proxyRequest, resp); }}

    ???

    ????JavaWeb???????????Web????????????????????Servlet??8?????????????????

  • ServletContextListener???ServletContext?????????
  • SessionListener???session???????
  • RequestListener???request???????
  • ??????ServletContextListener

    @WebListenerpublic class ContextLoaderListener implements ServletContextListener {    @Override    public void contextInitialized(ServletContextEvent event) {        ServletContext servletContext = event.getServletContext();        String contextConfigLocation = servletContext.getInitParameter("contextConfigLocation");        String realPath = servletContext.getRealPath(contextConfigLocation);        try {            FileInputStream fis = new FileInputStream(realPath);            System.out.println("ServletContext????????????" + realPath);        } catch (IOException e) {            e.printStackTrace();        }    }    @Override    public void contextDestroyed(ServletContextEvent event) {        System.out.println("ServletContext??????");    }}

    ????????

    • ServletContextListener?????????????????
    • SessionListener?????????????????????????
    • RequestListener??????????????????????????????

    ????????????????????JavaWeb???????????????

    转载地址:http://uim.baihongyu.com/

    你可能感兴趣的文章
    PC端稳定性测试探索
    查看>>
    PC端编辑 但能在PC端模拟移动端预览的富文本编辑器
    查看>>
    PDB文件:每个开发人员都必须知道的
    查看>>
    springMVC学习(二)
    查看>>
    Pdfkit页眉和页脚
    查看>>
    PDF中的Pandoc语法突出显示不起作用
    查看>>
    pdf从结构新建书签_在PDF文件中怎样创建书签
    查看>>
    pdf做成翻页电子书_第一弹:常见BOOX电子书阅读器问题解答,这些技能你都会吗?...
    查看>>
    PDF工具箱-分割提取合并
    查看>>
    pdf打印骑缝章
    查看>>
    PDF文字识/编辑?这个工具真的很强大!
    查看>>
    pdf文档出现乱码如何修改
    查看>>
    pdf根据模板导出
    查看>>
    PDF调出本来存在的书签面板
    查看>>
    pdf转图片
    查看>>
    pdf转图片、提取pdf文本、提取pdf图片
    查看>>
    springMvc 3.0 使用基本原理
    查看>>
    springCloud整合RabbitMQ实现消息中间件
    查看>>
    pdo sqlserver
    查看>>
    SpringCloud实战(十一)-更优的分布式配置解决方案(Apollo)
    查看>>