这篇文章主要介绍了SpringMVC 如何使用注解完成登录拦截，帮助大家更好的理解和学习使用springMVC，感兴趣的朋友可以了解下

为了实现用户登录拦截你是否写过如下代码呢?

    1. 基于Filter

    2. 基于Struts

    3. 基于SpringMVC

如何使用自定义注解完成自定义拦截呢？

    登录注解

    SpringMVC 拦截器设置

    最终 controller 写法

        1. 不需要登录权限的

        2. 整个 controller 内都需要登录权限

        3. controller 某个方法需要登录权限

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

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";
 }
}

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";
 }
}

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";
 }
}

以上就是SpringMVC 如何使用注解完成登录拦截的详细内容

SpringMVC 如何使用注解完成登录拦截

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

2. 基于Struts

3. 基于SpringMVC

登录注解

SpringMVC 拦截器设置

最终 controller 写法

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