SMM框架添加自定义filter

首先在web.xml中添加myFilter，可以在init-param中根据自己的需求添加一些自定义的参数

<filter>
<filter-name>myFilter</filter-name>
<filter-class>com.is.common.filter.MyFilter</filter-class>
<init-param>
<!--添加一些例外的路径，准备让过滤器放行-->
<param-name>exceptPath</param-name>
<param-value>
/,*.js,*.html,*.css,*.png,*.jpg,*.ico,*.gif,
*login,*index.html
</param-value>
</init-param>
</filter>
<filter-mapping>
<filter-name>myFilter</filter-name>
<!--所有的请求将经过filter -->
<url-pattern>/*</url-pattern>
</filter-mapping>

<!--配置springMVC 的转发器 -->
<servlet>
<servlet-name>springMVC</servlet-name>
<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
<init-param>
<param-name>contextConfigLocation</param-name>
<param-value>classpath:spring-mvc.xml</param-value>
</init-param>
<load-on-startup>1</load-on-startup>
</servlet>
<servlet-mapping>
<servlet-name>springMVC</servlet-name>
<!-- *.do的请求将经过DispatcherServlet转发 -->
<url-pattern>*.do</url-pattern>
</servlet-mapping>

MyFilter类实现servlet的Filter接口，在启动tomcat的时候会加载init方法，可在init中初始化一些参数，每次请求时会执行doFilter，在doFilter中写入自己的逻辑进行过滤

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.lang.StringUtils;

public class MyFilter implements Filter {
// 例外路径，不做拦截
String[] exceptStrs;

@Override
public void destroy() {
//      System.out.println("-------destory filter------");
}

@Override
public void doFilter(ServletRequest req, ServletResponse resp, FilterChain chain)
throws IOException, ServletException {
//      System.out.println("-------do filter------");
HttpServletRequest hreq = (HttpServletRequest) req;
HttpServletResponse hresp = (HttpServletResponse) resp;
String path = hreq.getRequestURI();
//      System.out.println("-------requset url:" + path + "------");
toDoFilter(isExceptPath(path), hreq, hresp, chain);//执行具体的过滤
}

@Override
public void init(FilterConfig config) throws ServletException {
//      System.out.println("-------init filter------");
//获取xml中配置的inin-param
exceptStrs = config.getInitParameter("exceptPath").replace(" ", "").replace("   ", "").replace("\n", "").replace("\r\n", "").split(",");
}

/**
*
* @Title: isExceptPath
* @Desc: 判断请求路径是否例外
*
* @param path
* @return 参数
*
*/
private boolean isExceptPath(String path) {
if (StringUtils.isEmpty(path)) {
return true;
}
for (String e : exceptStrs) {
if (e.startsWith("*")) {//含前通配符
if (StringUtils.endsWith(path, e.substring(1))) {
return true;
}
} else if (e.endsWith("*")) {//含后通配符
if (StringUtils.startsWith(path, e.substring(0, e.length() - 1))) {
return true;
}
} else {
if (path.equals(e)) {//不含通配符
return true;
}
}
}
return false;
}

/**
*
* @Title: toDoFilter
* @Desc: 过滤请求
*
*  @param isExcept
*  @param req
*  @param resp
*  @param chain
*  @throws IOException 参数
* @throws ServletException
*
*/
private void toDoFilter(boolean isExcept, HttpServletRequest req, HttpServletResponse resp, FilterChain chain)
throws IOException, ServletException {
HttpSession session = req.getSession();
if (!isExcept) {//非例外的路径，进行自定义过滤
//根据session判断用户是否已经登录
if (session == null || session.getAttribute("user") == null){
resp.sendRedirect("/index.html");//未登录，则跳转到登录页面
return;
}
}

//........其他的过滤逻辑

chain.doFilter(req, resp);//继续执行过滤链，不写则只能得到空白的页面
}

}

controller中用户登录验证后将信息写入session

/**
*
* @Title: login
* @Desc: 用户登录
*
* @param user
* @param request
* @return 参数
*
*/
@ResponseBody
@RequestMapping(value = "/login", method = RequestMethod.POST)
public JSONObject login(User user, HttpServletRequest request,HttpServletResponse response) {
// 验证用户和密码
User u = userService.login(user);
JSONObject jsonObject = new JSONObject();
if (u != null) {//查询到用户
//将用户信息写入session
request.getSession().setAttribute("user", u);
jsonObject.put("result", Constant.SUCCESS);
} else {
jsonObject.put("result", Constant.FAIL);
}
return jsonObject;
}

到此，一个简单的自定义filter就实现了，可以进行登录的过滤，其他的过滤逻辑根据自己的需求添加即可。