Filter过滤器例外URL设置-蒲公英云

Filter过滤器例外URL设置

在web.xml声明的一个filter中：

<!– session过滤filter –>

<filter>    
<filter-name>SessionFilter</filter-name>    
<filter-class>    
com.iqbon.jcms.web.util.SessionFilter     
</filter-class>    
<init-param>    
<param-name>excludedPages</param-name>    
<param-value>/admin/login.do</param-value>    
</init-param>    
</filter>    
<filter-mapping>    
<filter-name>SessionFilter</filter-name>    
<url-pattern>/admin/*</url-pattern>    
</filter-mapping>

可以看到url-pattern的设置里面过滤的url规则是/admin/*，如果要把/admin/login.do排除在过滤url之外。

可以结合init-param的初始化参数和HttpServletRequest的getServletPath()方法来判断。

<init-param>    
<param-name>excludedPages</param-name>    
<param-value>/admin/login.do</param-value>    
</init-param>

其次在filter的 Java 代码中加上判断：

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;     
import org.apache.commons.lang3.StringUtils;     
import com.iqbon.jcms.util.KeyConstant;     
/**   
* session过滤器   
*/    
public class SessionFilter implements Filter {     
/**   
* 需要排除的页面   
*/    
private String excludedPages;       
private String[] excludedPageArray;     
/**   
* @see Filter#destroy()   
*/    
public void destroy() {     
return;     
}     
/**   
* 对session进行判断当前访问是否有登录   
*/    
public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {     
boolean isExcludedPage = false;     
for (String page : excludedPageArray) {//判断是否在过滤url之外     
if(((HttpServletRequest) request).getServletPath().equals(page)){     
isExcludedPage = true;     
break;     
}     
}     
if (isExcludedPage) {//在过滤url之外     
chain.doFilter(request, response);     
} else {//不在过滤url之外，判断session是否存在     
HttpSession session = ((HttpServletRequest) request).getSession();     
if (session == null || session.getAttribute(KeyConstant.SESSION_KEY_USER) == null) {     
((HttpServletResponse) response).sendRedirect(“/login.htm”);     
} else {     
chain.doFilter(request, response);     
}     
}     
}     
/**   
* 初始化函数，获取需要排除在外的url   
*/    
public void init(FilterConfig fConfig) throws ServletException {     
excludedPages = fConfig.getInitParameter(“excludedPages”);     
if (StringUtils.isNotEmpty(excludedPages)) {     
excludedPageArray = excludedPages.split(“,”);     
}     
return;     
}     
}