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
    python | sumy,一个超酷的 用于文本摘要的 Python 库!
    查看>>
    python | tiler,一个不可思议的 图像切片重组 Python 库!
    查看>>
    python | tinydb,一个非常厉害的 关于数据库的 Python 库!
    查看>>
    python | tox,一个超强的 自动化测试工具 Python 库!
    查看>>
    python | ttkbootstrap,一个神奇的 Python 库!
    查看>>
    python | unoconv,一个超厉害的 Python 库!
    查看>>
    python | urllib3,一个超强的 Python 库!
    查看>>
    python | webassets,一个超强的 Python 库!
    查看>>
    python | werkzeug,一个不可思议的 Python 库!
    查看>>
    python | xlsxwriter,一个实用的 Python 库!
    查看>>
    python | xlwings,一个非常实用的 Excel 相关的 Python 库!
    查看>>
    python | xmltodict,一个非常厉害的 关于XML数据 Python 库!
    查看>>
    python | xonsh,一个超酷的 Python 库!
    查看>>
    python | yagmail,一个实用的 Python 库!
    查看>>
    python | 一文掌握Python的上下文管理器和with语句
    查看>>
    python | 一文看懂Python闭包机制与变量作用域规则
    查看>>
    python读取含中文的json
    查看>>
    python | 如何用Python锁避免并发错误?
    查看>>
    python | 提升代码迭代速度的Python重载方法
    查看>>
    python | 深入理解Python并发编程中的GIL限制与解决方案
    查看>>