ServletContext瀵硅薄

Posted 2022-11-16

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姣忎竴涓猈eb宸ョ▼瀵瑰簲浜庝竴涓猄ervletContext瀵硅薄锛屾瀵硅薄浠ｈ〃web搴旂敤锛岀敱鏈嶅姟鍣ㄥ垱寤恒€傚彲浠ヨВ鍐充笉鍚岀敤鎴风殑鏁版嵁鍏变韩闂銆?/p>

1銆佺敓鍛藉懆鏈燂細

鍒涘缓锛歸eb搴旂敤琚姞杞藉埌鏈嶅姟鍣ㄦ垨鏈嶅姟鍣ㄥ紑鍚€?/p>

閿€姣侊細web搴旂敤琚Щ闄ゆ垨鏈嶅姟鍣ㄥ叧闂€?/p>

2銆佸璞＄殑鑾峰彇锛?/span>

锛?锛夊疄鐜癝ervlet鎺ュ彛鐨勭被鍐呴儴锛?/p>

   public void init(ServletConfig servletConfig) throws ServletException 
        ServletContext servletContext= servletConfig.getServletContext();
    

锛?锛?/p>

   protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException 
        ServletContext servletContext=getServletContext();
    

(3)閫氳繃Session鑾峰彇锛?/p>

 ServletContext servletContext=request.getSession().getServletContext();

3銆丼ervletContext瀵硅薄鐨勫簲鐢細

锛?锛夎幏寰楀垵濮嬪寲鍙傛暟锛坵eb.xml鐨勫叏灞€鏁版嵁锛夛細

  <servlet>
        <servlet-name>MyServlet</servlet-name>
        <servlet-class>ServletDemo</servlet-class>
    </servlet>
    <servlet-mapping>
        <servlet-name>MyServlet</servlet-name>
        <url-pattern>/abc</url-pattern>
    </servlet-mapping>
    <context-param>//涓€缁勬爣绛惧彧鑳藉瓨鍌ㄤ竴缁勯敭鍊煎
        <param-name>zhai</param-name>
        <param-value>zhai1997</param-value>
    </context-param>

    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException 
        ServletContext servletContext=getServletContext();
        String paramvalue=servletContext.getInitParameter("zhai");//鐢遍敭鑾峰彇鍊?
        System.out.println(paramvalue);
    

 濡傛灉鏁版嵁涓嶅瓨鍦紝杩斿洖NULL銆?/p>

 锛?锛夎幏寰楀伐绋嬪彂甯冨悗鐨勭粷瀵硅矾寰勶細

    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException 
        ServletContext servletContext=getServletContext();
        String realpath=servletContext.getRealPath("/web.text");
        System.out.println(realpath);
        String realpath1=servletContext.getRealPath("/WEB-INF/wen-inf.text");
        System.out.println(realpath1);
        String realpath2=servletContext.getRealPath("../宸ョ▼.text");
        System.out.println(realpath2);
    

 

 

 

getRealPath鐨勫弬鏁颁负鐩稿浜巜eb鐨勮矾寰勶紝鍥犱负鍙戝竷鍒版湇鍔″櫒鐨勬椂鍊欏彧鍙戝竷web鏂囦欢涓殑鍐呭锛屽洜姝わ細宸ョ▼.text鏂囦欢涓嶈兘琚闂埌銆?/p>

 锛?锛夊煙瀵硅薄锛堜綔鐢ㄨ寖鍥翠负鏁翠釜web搴旂敤锛?/span>

Servlet1锛氬垱寤篠ervletContext瀵硅薄璁剧疆閿拰鍊硷紙鏁版嵁瀛樺偍锛夛細

    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException 
        ServletContext servletContext=getServletContext();
        servletContext.setAttribute("name","zhai");
    

Servlet2锛氱敱閿幏鍙栧€硷細

   String attribute=(String)this.getServletContext().getAttribute("name");
     System.out.println(attribute);
    

闇€瑕佸厛璁块棶Servlet1璁剧疆閿拰鍊硷紝鍐嶅幓璁块棶Servlet2鑾峰彇鍊笺€傚鏋滀笉瀛樺湪杩斿洖NULL銆?/p>