java 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;     
}     
}   

http://blog.csdn.net/Error_case/article/details/41946449

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;
}
}