目录
为了实现用户登录拦截你是否写过如下代码呢?
1. 基于Filter
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.HttpSession;
public class AuthenticationFilter implements Filter {
private FilterConfig filterConfig;
private String onErrorUrl;
public void init(FilterConfig filterConfig) throws ServletException {
// 从 filterConfig 中的得到错误页
this.filterConfig = filterConfig;
this.onErrorUrl = filterConfig.getInitParameter("onError");
if(this.onErrorUrl == null || "".equals(this.onErrorUrl))
this.onErrorUrl = "onError";
}
public void doFilter(ServletRequest request, ServletResponse response,
FilterChain chain) throws IOException, ServletException {
HttpServletRequest httpRequest = (HttpServletRequest)request;
session = httpRequest.getSession();
if(null == session.getAttribute("_LOGIN_USER_") && !"/login".equals(httpRequest.getServletPath())) {
httpRequest.getRequestDispatcher("/"+this.onErrorUrl).forward(request, response);
}else{
chain.doFilter(request, response);
}
}
public void destroy() {
}
}
2. 基于Struts
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import org.apache.struts2.ServletActionContext;
import com.opensymphony.xwork2.ActionInvocation;
import com.opensymphony.xwork2.interceptor.AbstractInterceptor;
@SuppressWarnings("serial")
public class LoginInterceptor extends AbstractInterceptor {
@Override
public String intercept(ActionInvocation invocation) throws Exception {
String currentUser="currentUser";
HttpServletRequest request=ServletActionContext.getRequest();
HttpServletResponse response=ServletActionContext.getResponse();
HttpSession session=request.getSession();
if(request.getRequestURI().endsWith("login.action")){
return invocation.invoke();
} else {
if(session.getAttribute(currentUser)!=null){
return invocation.invoke();
}else{
response.sendRedirect(request.getContextPath()+"/login.jsp");
}
}
return null;
}
}
3. 基于SpringMVC
import javax.servlet.RequestDispatcher;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.springframework.web.servlet.HandlerInterceptor;
import org.springframework.web.servlet.ModelAndView;
import cn.edu.hdc.util.Constants;
/**
* @ClassName: LoginInterceptor
* @Description: 登录拦截器
* @author loweir hbloweir@163.com
* @date 2016年4月27日 上午8:06:11
*/
public class LoginInterceptor implements HandlerInterceptor {
/**
* 在目标方法前被调用，返回 true 继续
*/
@Override
public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object obj) throws Exception {
try {
String url = request.getRequestURI();
// 如果不是登录操作 判断 session
if (!url.endsWith("login")) {
if (request.getSession().getAttribute(Constants.CURRENT_USER) == null) {
response.sendRedirect(request.getContextPath() + "/login.jsp");
return false;
}
} }
return true;
} catch (Exception e) {
e.printStackTrace();
return false;
}
}
@Override
public void afterCompletion(HttpServletRequest arg0, HttpServletResponse arg1, Object arg2, Exception arg3)
throws Exception {
}
@Override
public void postHandle(HttpServletRequest arg0, HttpServletResponse arg1, Object arg2, ModelAndView arg3)
throws Exception {
}
}
如何使用自定义注解完成自定义拦截呢？
登录注解
import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;
/**
* Created by loweir on 2017/5/14 17:19
* <p>
* author: 张瑀楠
* email: hbloweir@163.com
* 负责登录拦截
*/
@Retention(RetentionPolicy.RUNTIME)
@Target({ElementType.TYPE,ElementType.METHOD})
public @interface WebLoginRequired {
String value() default ""; // 未登录时需要跳转的路径
}
SpringMVC 拦截器设置
import com.ainsoft.globalshoperp.component.constant.WebLogin;
import org.apache.commons.lang3.StringUtils;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.springframework.web.method.HandlerMethod;
import org.springframework.web.servlet.HandlerInterceptor;
import org.springframework.web.servlet.ModelAndView;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
/**
* Created by loweir on 2017/5/14 17:14
* <p>
* author: 张瑀楠
* email: hbloweir@163.com
*/
public class LoginInterceptor implements HandlerInterceptor {
private static Log logger = LogFactory.getLog(LoginInterceptor.class);
public boolean preHandle(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, Object handler) throws Exception {
if (logger.isDebugEnabled()) {
logger.debug("拦截器启动");
}
/*
* 判断是否为 HandlerMethod.class
* 如果不是说明当前请求并不是 SpringMVC 管理，
* 如果不是再自行根据业务做响应操作，这里直接返回 true
*/
if (HandlerMethod.class.isInstance(handler)) {
HandlerMethod handlerMethod = (HandlerMethod) handler;
// 判断该 handler 是否有WebLoginRequired注解
WebLoginRequired webLoginRequired = handlerMethod.getMethod().getDeclaredAnnotation(WebLoginRequired.class);
// 如果该 handler 没有WebLoginRequired注解，判断所属Controller 是否包含注解
if (null == webLoginRequired) {
webLoginRequired = handlerMethod.getBeanType().getAnnotation(WebLoginRequired.class);
}
// 如果需要 WebLoginRequired 判断 session
if (null != webLoginRequired) {
if (httpServletRequest.getSession().getAttribute(WebLogin.CURRENTUSER) == null) {
String executeURL = webLoginRequired.value();
if (StringUtils.isBlank(executeURL)) {
executeURL = WebLogin.LOGIN;
}
httpServletResponse.sendRedirect(httpServletRequest.getContextPath() + executeURL);
return false;
}
}
}
return true;
}
public void postHandle(javax.servlet.http.HttpServletRequest httpServletRequest, javax.servlet.http.HttpServletResponse httpServletResponse, Object o, ModelAndView modelAndView) throws Exception {
if (logger.isDebugEnabled()) {
logger.debug("postHandler");
}
}
public void afterCompletion(javax.servlet.http.HttpServletRequest httpServletRequest, javax.servlet.http.HttpServletResponse httpServletResponse, Object o, Exception e) throws Exception {
if (logger.isDebugEnabled()) {
logger.debug("afterCompletion");
}
}
}
最终 controller 写法
1. 不需要登录权限的
类和方法都不需要注解
@Controller
@RequestMapping("auth")
public class AuthController {
@RequestMapping("login")
public String login() {
return "login";
}
}
2. 整个 controller 内都需要登录权限
在类上添加注解即可
@Controller
@WebLoginRequired
@RequestMapping("order")
public class OrderController {
@RequestMapping("index")
public String index() {
return "index";
}
}
3. controller 某个方法需要登录权限
只在需要登录权限的方法上添加注解
在注解上可以指定需要重定向的链接
如果不指定则默认到 login
@Controller
@RequestMapping("order")
public class OrderController {
@RequestMapping("index")
public String index() {
return "index";
}
// 需要登录
@WebLoginRequired
@RequestMapping("add")
public String index() {
return "index";
}
// 需要登录,如果未登录跳到 error
@WebLoginRequired("error")
@RequestMapping("delete")
public String index() {
return "index";
}
}