Web基礎知識ノート

    web        
webapps            hello
         WEB-INF     html  
WEB-INF             class          lib     web.xml
  tomcat   


tomcat      
tomcat confg    server.xml


     //              host    
      <Host name="localhost"  appBase="webapps"
            unpackWARs="true" autoDeploy="true">

       <Host/>

tomcat web.xml listing   true    webapps        

servlet     :

servlet    
          
         web.xml          servletname 
  servlet-name    servlet-class
  servlet
  init   init     init(servletConfig config)  config.getInitParams("") web.xml         
-  service   service         doget doPost  
  doxx  
    destroy  

web.xml load-on-startup   0                servlet


    
html    utf-8
tomcat config/server.xml  <Connector URIEncoding="UTF-8"/>(get             )
servlet      request.setCharacterEncoding("UTF-8")(post         )







   String str = "hello";
     out.println(str+"
");
  %>
   str%> out    


jsp     tomcat    servlet  tomcat  work    java  


jsp  java          import       


jsp     response.sendRedirct("    ")   response                      retrun（         ）       
      :<jsp:forward page="03.jsp"> <jsp:value:="gac" name="user"/> </jsp>       （         ）
         

                   
              

               ,req.getContextPath();//       


         

(    )@include file="/inc/top.jsp"%>                         ,                        ，           

(    )<jsp:include page="/inc/top.jsp"></jsp:include>                 html      

           ,               


        
request.setAttribute(String,Object)
request.getAttribute(String name)


jsp servlet          Atrribute  pageContext(Servlet    ) request(HttpRequest)  session(HttpSession) .application(ServletContext)
pageContext(      ,           )
request            ,                    
session                              session     
application             

    :    pageContext    request   session   session   application


filter             
//  post            
public class CharEncodingFilter implements Filter {
    String encoding;
    @Override
    public void init(FilterConfig filterConfig) throws ServletException {
        encoding = filterConfig.getInitParameter("encoding");//filter     servlet         
    }

    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
       System.out.println("before fileter");
        servletRequest.setCharacterEncoding(encoding);
       filterChain.doFilter(servletRequest,servletResponse);//     request response      
       System.out.println("end filter");
    }

    @Override
    public void destroy() {

    }
}

el     ${username}      pageContext  username,    
   request   ,       session   username,session       application