JavaのFilter

27609 ワード
filter
filterフィルタは、主にフロントからバックグラウンドにデータを渡すフィルタ操作に使用されます.程度は簡単で説明しないで、直接いくつかのすでに書いたコードをあげます:
 
一、ブラウザがページをキャッシュしないようにするフィルタ
import javax.servlet.*;

import javax.servlet.http.HttpServletResponse;

import java.io.IOException;



public class ForceNoCacheFilter implements Filter {

 public void doFilter(ServletRequest request, ServletResponse response, FilterChain filterChain) throws IOException, ServletException

 {



  ((HttpServletResponse) response).setHeader("Cache-Control","no-cache");



  ((HttpServletResponse) response).setHeader("Pragma","no-cache");



  ((HttpServletResponse) response).setDateHeader ("Expires", -1);



  filterChain.doFilter(request, response);



 }



 public void destroy()

 {

 }



 public void init(FilterConfig filterConfig) throws ServletException

 {

 }

}

二、ユーザーが登録したかどうかを検出するフィルタ
import javax.servlet.*;

import javax.servlet.http.HttpServletRequest;

import javax.servlet.http.HttpServletResponse;

import javax.servlet.http.HttpSession;

import java.util.List;

import java.util.ArrayList;

import java.util.StringTokenizer;

import java.io.IOException;

 

public class CheckLoginFilter implements Filter

{

 protected FilterConfig filterConfig = null;

 private String redirectURL = null;

 private List notCheckURLList = new ArrayList();

 private String sessionKey = null;



 public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException

 {



  HttpServletRequest request = (HttpServletRequest) servletRequest;

  HttpServletResponse response = (HttpServletResponse) servletResponse;

  HttpSession session = request.getSession();



  if(sessionKey == null)

  {

   filterChain.doFilter(request, response);

   return;

  }



  if((!checkRequestURIIntNotFilterList(request)) && session.getAttribute(sessionKey) == null)

  {

   response.sendRedirect(request.getContextPath() + redirectURL);

   return;

  }



  filterChain.doFilter(servletRequest, servletResponse);

 }



 public void destroy()

 {

  notCheckURLList.clear();

 }



 private boolean checkRequestURIIntNotFilterList(HttpServletRequest request)

 {

  String uri = request.getServletPath() + (request.getPathInfo() == null ? "" : request.getPathInfo());

  return notCheckURLList.contains(uri);

 }



 public void init(FilterConfig filterConfig) throws ServletException

 {

  this.filterConfig = filterConfig;

  redirectURL = filterConfig.getInitParameter("redirectURL");

  sessionKey = filterConfig.getInitParameter("checkSessionKey"); 



  String notCheckURLListStr = filterConfig.getInitParameter("notCheckURLList");



  if(notCheckURLListStr != null)

  {

   StringTokenizer st = new StringTokenizer(notCheckURLListStr, ";");

   notCheckURLList.clear();

   while(st.hasMoreTokens())

   {

    notCheckURLList.add(st.nextToken());

   }

  }

 }

}

三、文字コードのフィルタ
import javax.servlet.*;

import java.io.IOException;



public class CharacterEncodingFilter implements Filter

{

 protected FilterConfig filterConfig = null;

 protected String encoding = "";



 public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException

 {

  if(encoding != null)

    servletRequest.setCharacterEncoding(encoding);

  filterChain.doFilter(servletRequest, servletResponse);

 } 



 public void destroy()

 {

  filterConfig = null;

  encoding = null;

 }


 public void init(FilterConfig filterConfig) throws ServletException

 {

        this.filterConfig = filterConfig;

        this.encoding = filterConfig.getInitParameter("encoding");

 }

}

四、ユーザーのアクセス操作器を記録する
package com.qwserv.itm.pfl.log.svr;



import java.io.IOException;

import javax.servlet.Filter;

import javax.servlet.FilterChain;

import javax.servlet.FilterConfig;

import javax.servlet.ServletException;

import javax.servlet.ServletRequest;

import javax.servlet.ServletResponse;

import java.text.SimpleDateFormat;

import javax.servlet.http.HttpServletRequest;

import com.qwserv.itm.api.pfl.sm.vo.Person;

import java.sql.*;

import com.qwserv.itm.api.ServiceAccess;

import com.qwserv.itm.util.toolkit.DebugUtil;



public class ObserveFilter implements Filter {

    protected static DebugUtil log = DebugUtil.getInstances("pfl-log", ObserveFilter.class);

    public void destroy() {

    }



    public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException,

            ServletException {

        //         

        HttpServletRequest request1 = (HttpServletRequest)request;

        StringBuffer url = request1.getRequestURL();



        // url    ，   js/css/image      

        if (judgeFile(url.toString())){

            String operTime = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss").format(new java.util.Date());

            String hostIp = request.getRemoteAddr();

            String sessionId = request1.getRequestedSessionId();

            String userId = "";

            Person person = (Person)request1.getSession().getAttribute("userObj");

            if (null != person && null != person.getUser()){

                userId = person.getUser().getId();

            }

            String queryString = request1.getQueryString();

            if (null != queryString) {

                url.append('?');

                url.append(queryString);

            }



            //       

            saveToDb(userId,hostIp,sessionId,url.toString(),operTime,"");

        }

        // Pass control on to the next filter

        chain.doFilter(request, response);

    }



    public void init(FilterConfig filterConfig) throws ServletException {

    }



    public boolean judgeFile(String url){

        if (url.endsWith(".gif") || url.endsWith(".jpg") || url.endsWith(".png")

            || url.endsWith(".bmp") || url.endsWith(".css") || url.endsWith(".js")

                || url.endsWith(".jsx")){

            return false;

        } else {

            return true;

        }

    }



    public int saveToDb(String userId, String hostIp,String sessionId,String url,

                         String operTime,String desc){

            //              

            Connection conn = null;

            Statement st = null;



            try {

                //  sql   ，        

                conn = ServiceAccess.getSystemSupportService().getDefaultConnection();

                st = conn.createStatement();

                String sql = "insert into LOG_OBSERVE_HISTORY(USERID,URL,Detail,SessionID,HostName,StartDate)   values('"+

                        userId + "','" + url + "','" + desc + "','" + sessionId

                        + "','" + hostIp + "','" + operTime + "')";

                if (ServiceAccess.getSystemSupportService().getConnectionType(conn)==ServiceAccess.getSystemSupportService().JCA_TYPE_ORACLE){

                    sql = "insert into LOG_OBSERVE_HISTORY(Id,USERID,URL,Detail,SessionID,HostName,StartDate)  values(LOG_OBSERVE_SEQ.nextval,'"+

                        userId + "','" + url + "','" + desc + "','" + sessionId

                        + "','" + hostIp + "',TO_DATE('" + operTime

                        + "','YYYY-MM-DD HH24:MI:SS'))";

                }

                st.executeUpdate(sql);

            } catch (Exception e) {

                e.printStackTrace();

                log.error("--------------------The url String is:" + url + "-------------------------------");

                return 1;  //      

            } finally {

                if (null != st)

                {

                    try{

                        st.close();

                    }

                    catch(Exception e)

                    {

                        e.printStackTrace();

                    }



                    st = null;

                }



                if (conn != null) {

                    try {

                        conn.close();

                    } catch (Exception e) {

                        e.printStackTrace();

                    }

                    conn = null;

                }

            }



            return 0;  //      

    }

}

  
    <filter>

        <filter-name>ObserveFilter</filter-name>

        <filter-class>com.qwserv.itm.pfl.log.svr.ObserveFilter</filter-class>

    </filter>

    <filter-mapping>

        <filter-name>ObserveFilter</filter-name>

        <url-pattern>/*</url-pattern>

    </filter-mapping>

 
五.Filterは、ユーザーが許可されていないリソースにアクセスすることを防止します.
package com.drp.util.filter;     

import java.io.IOException;      

import javax.servlet.Filter;   

import javax.servlet.FilterChain;   

import javax.servlet.FilterConfig;   

import javax.servlet.ServletException;   

import javax.servlet.ServletRequest;   

import javax.servlet.ServletResponse;   

import javax.servlet.http.HttpServletRequest;   

import javax.servlet.http.HttpServletResponse;   

import javax.servlet.http.HttpSession;   

      

public class AuthFilter implements Filter {        

  public void destroy() {       

  }   

      

  public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {

//1,doFilter         ServletRequest  。                （      、cookie HTTP   ）     。

//      ServletResponse，               。       FilterChain，       servlet JSP 。       

    HttpServletRequest request = (HttpServletRequest)servletRequest;//    HTTP  ，        getHeader getCookies  ServletRequest        ，    request     HttpServletRequest   

    HttpServletResponse response = (HttpServletResponse)servletResponse。   

      

    String currentURL = request.getRequestURI();//             :   

    String targetURL = currentURL.substring(currentURL.indexOf("/", 1), currentURL.length());  //               

    HttpSession session = request.getSession(false);   

         

    if (!"/login.jsp".equals(targetURL)) {//                    ，      session   ，          

      if (session == null || session.getAttribute("user") == null) {//*           session   

        System.out.println("request.getContextPath()=" + request.getContextPath());   

        response.sendRedirect(request.getContextPath() + "/login.jsp");//  session               login.jsp     

        return;   

      }   

    }   

    //  filter          

    filterChain.doFilter(request, response);//.  FilterChain   doFilter  。Filter   doFilter     FilterChain          。       doFilter   ，           。           servlet JSP    ， servlet JSP     。       

  }   

      

  public void init(FilterConfig filterConfig) throws ServletException {        

  }   

}

  
 <filter>

   <filter-name>AuthFilter</filter-name>

   <filter-class>com.drp.util.filter.AuthFilter</filter-class>

 </filter>

  

 <filter-mapping>

   <filter-name>AuthFilter</filter-name>

   <url-pattern>*.jsp</url-pattern> <!--     jsp    -->

 </filter-mapping>

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