建立一个完整功能的Filter:
package com.tom.web.filter;
import com.tom.util.BaseUtil;
import com.tom.util.CacheHelper;
import com.tom.util.Constants;
import java.io.IOException;
import java.io.PrintWriter;
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 TomFilter
implements Filter
{
private String[] permitUrls = null;
public void init(FilterConfig config) throws ServletException
{
String permitUrls = config.getInitParameter("permitUrls");
if (BaseUtil.isNotEmpty(permitUrls)) {
this.permitUrls = permitUrls.split(";");
}
}
public void doFilter(ServletRequest request, ServletResponse response,
FilterChain chain)
throws IOException, ServletException
{
HttpServletRequest req = (HttpServletRequest)request;
HttpServletResponse res = (HttpServletResponse)response;
HttpSession session = req.getSession();
req.setAttribute("tm_base", Constants.getSiteBaseUrl(req));
boolean isPermit = isPermitUrl(req);
String uid = String.valueOf(session.getAttribute(
Constants.SESSION_USERID));
String sessionid = String.valueOf(session.getAttribute(
Constants.SESSION_SESSID));
if (BaseUtil.isEmpty(uid)) {
if (isPermit) {
chain.doFilter(req, res);
} else {
toLoginPage(req, res);
}
}
else
{
int checkcode = checkLoginStatus(uid, sessionid);
if (checkcode == 1) {
chain.doFilter(req, res);
} else {
if (checkcode == 0)
{
session.setAttribute(Constants.SESSION_USERID, null);
session.setAttribute(Constants.SESSION_USERNAME, null);
session.setAttribute(Constants.SESSION_USERTYPE, null);
session.setAttribute(Constants.SESSION_USERGID, null);
session.setAttribute(Constants.SESSION_SESSID, null);
toLoginPage(req, res);
return;
}
session.setAttribute(Constants.SESSION_USERID, null);
session.setAttribute(Constants.SESSION_USERNAME, null);
session.setAttribute(Constants.SESSION_USERTYPE, null);
session.setAttribute(Constants.SESSION_USERGID, null);
session.setAttribute(Constants.SESSION_SESSID, null);
toStatusExpiredPage(req, res);
return;
}
}
}
public void destroy()
{
permitUrls = null;
}
private int checkLoginStatus(String uid, String sessionid)
{
String cache_sessionid = (String)CacheHelper.getCache(
"SessionCache", "U" + uid);
if (BaseUtil.isEmpty(cache_sessionid)) {
return 0;
}
if (cache_sessionid.equals(sessionid)) {
return 1;
}
return -1;
}
private void toStatusExpiredPage(HttpServletRequest request,
HttpServletResponse response)
{
String path = request.getContextPath();
String html = "<script>top.location.href='" + path +
"/common/expired.thtml';</script>";
PrintWriter out = null;
response.setContentType("text/html");
response.setCharacterEncoding("UTF-8");
try {
out = response.getWriter();
request.setCharacterEncoding("UTF-8");
} catch (Exception e) {
e.printStackTrace();
}
out.println(html);
out.flush();
out.close();
}
private void toLoginPage(HttpServletRequest request, HttpServletResponse
response)
{
String path = request.getContextPath();
String html = "<script>top.location.href='" + path +
"/login.thtml';</script>";
PrintWriter out = null;
response.setContentType("text/html");
response.setCharacterEncoding("UTF-8");
try {
out = response.getWriter();
request.setCharacterEncoding("UTF-8");
} catch (Exception e) {
e.printStackTrace();
}
out.println(html);
out.flush();
out.close();
}
private boolean isPermitUrl(HttpServletRequest request) {
boolean isPermit = false;
String currentUrl = getCurrentURI(request);
if ((permitUrls != null) && (permitUrls.length > 0)) {
String[] arrayOfString;
int j = (arrayOfString = permitUrls).length;
for (int i = 0; i < j; i++)
{ String url = arrayOfString[i];
if (url.equals(currentUrl)) {
isPermit = true;
break;
}
}
}
return isPermit;
}
private String getCurrentURI(HttpServletRequest request) {
String path = request.getContextPath();
String uri = request.getRequestURI();
uri = uri.substring(path.length());
return uri;
}
}
/*
* Qualified Name: com.tom.web.filter.TomFilter
* Java Class Version: 6 (50.0)
* JD-Core Version: 0.7.1
*/
配置web.xml:
<filter>
<filter-name>encodingFilter</filter-name>
<filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class>
<init-param>
<param-name>encoding</param-name>
<param-value>UTF-8</param-value>
</init-param>
<init-param>
<param-name>forceEncoding</param-name>
<param-value>true</param-value>
</init-param>
</filter>
<filter-mapping>
<filter-name>encodingFilter</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>
<filter>
<filter-name>TomFilter</filter-name>
<filter-class>com.tom.web.filter.TomFilter</filter-class>
<init-param>
<param-name>permitUrls</param-name>
<param-value>/login.thtml;/common/login.do;/common/logout.do;/inc/checkcode.jsp;
/common/expired.thtml;/register.thtml;/common/register.do</param-value>
</init-param>
</filter>
<filter-mapping>
<filter-name>TomFilter</filter-name>
<url-pattern>*.thtml</url-pattern>
</filter-mapping>
<filter-mapping>
<filter-name>TomFilter</filter-name>
<url-pattern>*.do</url-pattern>
</filter-mapping>
注意区分
javax.servlet.Filter;
和
org.springframework.web.filter.*;
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