spring boot 优雅的处理拦截响应

超、凢脫俗 2022-10-02 10:59 133阅读 0赞

如何在拦截器中验证用户未登录时给予优雅提示？  
首先打开创建拦截器加入以下代码：

import java.util.Map;
    import java.util.concurrent.ConcurrentHashMap;
    
    import javax.servlet.http.HttpServletRequest;
    import javax.servlet.http.HttpServletResponse;
    import javax.servlet.http.HttpSession;
    
    import org.apache.shiro.SecurityUtils;
    import org.springframework.stereotype.Component;
    import org.springframework.web.servlet.HandlerInterceptor;
    import org.springframework.web.servlet.ModelAndView;
    
    import com.alibaba.fastjson.JSONObject;
    import com.changdao.domain.SysUser;
    import com.changdao.util.InterceptUtil;
    
    /** 
    * @author  作者 : 小布
    * @version 创建时间 : 2019年6月17日 上午11:25:53 
    * @explain 类说明 : 拦截器
    */
    @Component
    public class ApiInterceptor implements HandlerInterceptor {
    	    
    		//请求前
    		@Override    
    		public boolean preHandle(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, Object o) throws Exception {
    			if (httpServletRequest.getMethod().equals("OPTIONS")){//处理预请求
    				httpServletResponse.setStatus(HttpServletResponse.SC_OK);
    	            return true;
    	        }
    			HttpSession session = httpServletRequest.getSession();
    			SysUser sysUser = (SysUser) SecurityUtils.getSubject().getPrincipal();
    			if(session.getAttribute("user") != null && sysUser != null) {
    				return true;    
    			}else {
    				Map<String, Object> object = new ConcurrentHashMap<>();
    				object.put("msg","请重新登录");
    				String jsonObjectStr = JSONObject.toJSONString(object);
    				InterceptUtil.returnJson(httpServletResponse,jsonObjectStr);
    				return false;    
    			}
    		}   
    		
    		//请求时   
    		@Override    
    		public void postHandle(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, Object o, ModelAndView modelAndView) throws Exception {
    			
    		}    
    		
    		//请求完成
    		@Override 
    		public void afterCompletion(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, Object o, Exception e) throws Exception {
    			
    		}
    		
    }

创建一个相应页面的工具类InterceptUtil：

import java.io.IOException;
    import java.io.PrintWriter;
    
    import javax.servlet.http.HttpServletResponse;
    
    /** 
    * @author  作者 : 小布
    * @version 创建时间 : 2019年6月17日 上午11:41:21 
    * @explain 类说明 : 
    */
    public class InterceptUtil {
    
    	public static void returnJson(HttpServletResponse response, String json) throws Exception{
            PrintWriter writer = null;
            response.setCharacterEncoding("UTF-8");
            response.setContentType("application/json;charset=utf-8");
            try {
                writer = response.getWriter();
                writer.print(json);
            } catch (IOException e) {
                //由于统一拦截了异常所以不需要抛出
            } finally {
                if (writer != null) {
                	writer.close();
                }
            }
        }
    	
    }

配合前端之后的效果：  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80MjExODI4NA_size_16_color_FFFFFF_t_70]  
![在这里插入图片描述][20190618155426825.png]

[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80MjExODI4NA_size_16_color_FFFFFF_t_70]: /images/20220112/53edc59bd1c44175b5f7daf229f0403a.png
[20190618155426825.png]: /images/20220112/ff3a93c6ebae45f48cfaee6e478b8296.png