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

1. import java.io.IOException;
2. import javax.servlet.Filter;
3. import javax.servlet.FilterChain;
4. import javax.servlet.FilterConfig;
5. import javax.servlet.ServletException;
6. import javax.servlet.ServletRequest;
7. import javax.servlet.ServletResponse;
8. import javax.servlet.http.HttpServletRequest;
9. import javax.servlet.http.HttpServletResponse;
10. import javax.servlet.http.HttpSession;
11. import org.apache.commons.lang3.StringUtils;
12. import com.iqbon.jcms.util.KeyConstant;
13. /**
14. * session过滤器
15. */
16. public class SessionFilter implements Filter {
17. /**
18. * 需要排除的页面
19. */
20. private String excludedPages;
21. private String[] excludedPageArray;
22. /**
23. * @see Filter#destroy()
24. */
25. public void destroy() {
26. return;
27. }
28. /**
29. * 对session进行判断当前访问是否有登录
30. */
31. public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
32. boolean isExcludedPage = false;
33. for (String page : excludedPageArray) {//判断是否在过滤url之外
34. if(((HttpServletRequest) request).getServletPath().equals(page)){
35. isExcludedPage = true;
36. break;
37. }
38. }
39. if (isExcludedPage) {//在过滤url之外
40. chain.doFilter(request, response);
41. } else {//不在过滤url之外，判断session是否存在
42. HttpSession session = ((HttpServletRequest) request).getSession();
43. if (session == null || session.getAttribute(KeyConstant.SESSION_KEY_USER) == null) {
44. ((HttpServletResponse) response).sendRedirect(“/login.htm”);
45. } else {
46. chain.doFilter(request, response);
47. }
48. }
49. }
50. /**
51. * 初始化函数，获取需要排除在外的url
52. */
53. public void init(FilterConfig fConfig) throws ServletException {
54. excludedPages = fConfig.getInitParameter(“excludedPages”);
55. if (StringUtils.isNotEmpty(excludedPages)) {
56. excludedPageArray = excludedPages.split(“,”);
57. }
58. return;
59. }
60. }