springboot拦截器过滤token,并返回结果及异常处理操作

1.springboot 拦截器处理过滤token，并且返回结果

import org.apache.commons.lang3.StringUtils;
import org.apache.shiro.subject.Subject;
import org.springframework.lang.Nullable;
import org.springframework.stereotype.Component;
import org.springframework.web.servlet.HandlerInterceptor;
import org.springframework.web.servlet.ModelAndView;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.io.PrintWriter;
import java.util.Map;

@Component
public class ECInterceptor implements HandlerInterceptor {
  /**
   * @Description 在业务处理器处理请求之前被调用。预处理，可以进行编码、安全控制等处理；
   * @Date 2019/5/14 16:04
   * @Version 1.0
   */
  @Override
  public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
    System.out.println(request.getRequestURL()+"===========preHandle===========");
    String token = request.getParameter("token");
    if(StringUtils.isNotEmpty(token)){
      Subject subject = ShiroUtil.getSubject(token);
      if(subject != null && subject.isAuthenticated()){
        return true;
      } else{
        //返回校验token结果
        returnJson(response);
        // return false; //我做的时候返回数据后忘记return false了，所以导致异常
      }
    }
    return true;
  }

  @Override
  public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, @Nullable ModelAndView modelAndView) throws Exception {
    System.out.println(request.getContextPath()+"============postHandle==========");
  }
  /**
   * @Description 在DispatcherServlet完全处理完请求后被调用，也就是说视图渲染已经完毕或者调用者已经拿到结果
   * @Date 2019/5/14 16:05
   * @Version 1.0
   */
  @Override
  public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, @Nullable Exception ex) throws Exception {
    System.out.println(request.getContextPath()+"============afterCompletion==========");
  }
  private void returnJson(HttpServletResponse response){
    PrintWriter writer = null;
    response.setCharacterEncoding("UTF-8");
    response.setContentType("application/json; charset=utf-8");
    try {
      writer = response.getWriter();
      Map result = PackageReturnResult.returnJson(400, "用户令牌token无效");
      result.put("data", null);
      writer.print(result);
    } catch (IOException e){
      LoggerUtil.logError(ECInterceptor.class, "拦截器输出流异常"+e);
    } finally {
      if(writer != null){
        writer.close();
      }
    }
  }
}

2.java.lang.IllegalStateException: getWriter() has already been called for this response异常

我再做拦截器处理response数据后忘记return false返回，导致拦截器被调用两次，报java.lang.IllegalStateException: getWriter() has already been called for this response异常，犯这样低级错误花了很长时间才解决，谨记！！！

[2019-05-27 09:27:17.690] [http-nio-8080-exec-1        ] [ERROR] [o.a.c.c.C.[.[.[.[dispatcherServlet] :175 ] - Servlet.service() for servlet [dispatcherServlet] in context with path [] threw exception [Request processing failed; nested exception is java.lang.IllegalStateException: getWriter() has already been called for this response] with root cause
java.lang.IllegalStateException: getWriter() has already been called for this response
	at org.apache.catalina.connector.Response.getOutputStream(Response.java:548)
	at org.apache.catalina.connector.ResponseFacade.getOutputStream(ResponseFacade.java:210)
	at javax.servlet.ServletResponseWrapper.getOutputStream(ServletResponseWrapper.java:105)
	at org.springframework.http.server.ServletServerHttpResponse.getBody(ServletServerHttpResponse.java:83)
	at org.springframework.http.converter.json.AbstractJackson2HttpMessageConverter.writeInternal(AbstractJackson2HttpMessageConverter.java:255)
	at org.springframework.http.converter.AbstractGenericHttpMessageConverter.write(AbstractGenericHttpMessageConverter.java:103)
	at org.springframework.web.servlet.mvc.method.annotation.AbstractMessageConverterMethodProcessor.writeWithMessageConverters(AbstractMessageConverterMethodProcessor.java:290)
	at org.springframework.web.servlet.mvc.method.annotation.RequestResponseBodyMethodProcessor.handleReturnValue(RequestResponseBodyMethodProcessor.java:180)
	at com.uufund.ecapi.config.returnvalue.HandlerMethodReturnValueHandlerProxy.handleReturnValue(HandlerMethodReturnValueHandlerProxy.java:40)
	at org.springframework.web.method.support.HandlerMethodReturnValueHandlerComposite.handleReturnValue(HandlerMethodReturnValueHandlerComposite.java:82)
	at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:119)
	at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:892)
	at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:797)
	at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:87)
	at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:1038)
	at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:942)
	at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:1005)
	at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:897)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:634)
	at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:882)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:741)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
	at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
	at org.apache.shiro.web.servlet.AbstractShiroFilter.executeChain(AbstractShiroFilter.java:449)
	at org.apache.shiro.web.servlet.AbstractShiroFilter$1.call(AbstractShiroFilter.java:365)
	at org.apache.shiro.subject.support.SubjectCallable.doCall(SubjectCallable.java:90)
	at org.apache.shiro.subject.support.SubjectCallable.call(SubjectCallable.java:83)
	at org.apache.shiro.subject.support.DelegatingSubject.execute(DelegatingSubject.java:387)
	at org.apache.shiro.web.servlet.AbstractShiroFilter.doFilterInternal(AbstractShiroFilter.java:362)
	at org.apache.shiro.web.servlet.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:125)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
	at com.uufund.ecapi.config.filter.ECWebFilter.doFilter(ECWebFilter.java:24)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
	at org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:99)
	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
	at org.springframework.web.filter.FormContentFilter.doFilterInternal(FormContentFilter.java:92)
	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
	at org.springframework.web.filter.HiddenHttpMethodFilter.doFilterInternal(HiddenHttpMethodFilter.java:93)
	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
	at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:200)
	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
	at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:200)
	at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96)
	at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:490)
	at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:139)
	at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:92)
	at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:74)
	at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:343)
	at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:408)
	at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:66)
	at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:834)
	at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1415)
	at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
	at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
	at java.lang.Thread.run(Thread.java:748)

补充知识：springboot 拦截器过滤权限和错误处理

先说异常处理，增加一个异常处理的类MyControllerAdvice就可以了，不需要其他地方使用，注意使用注解@ControllerAdvice

@ControllerAdvice
public class MyControllerAdvice {
  @Resource
  GetRootPath getRootPath;
  private static final Logger logger = LoggerFactory.getLogger(MyControllerAdvice.class);

  public void output(Object json, HttpServletRequest request, HttpServletResponse response) throws IOException {
    String header = request.getHeader("Origin");
    response.setContentType("application/json;charset=UTF-8;");
    PrintWriter out = response.getWriter();
    out.println(json);
    out.flush();
    out.close();
  }

  /***
   * 404处理
   * @param e
   * @return
   */
  @ExceptionHandler(NoHandlerFoundException.class)
  public void notFountHandler(HttpServletRequest request, HttpServletResponse response, Model model, NoHandlerFoundException e) throws IOException, JSONException {
    JSONObject json = new JSONObject();
    json.put("code", 500);
    json.put("content", null);
    json.put("msg", "未找到路径："+request.getServletPath());
    output(json,request,response);
  }

  /**
   * 运行时异常
   *
   * @param exception
   * @return
   */
  @ExceptionHandler({RuntimeException.class})
  @ResponseStatus(HttpStatus.OK)
  public void processException(HttpServletRequest request, HttpServletResponse response, Model model, RuntimeException exception) throws JSONException, IOException {
    JSONObject json = new JSONObject();
    json.put("code", 500);
    json.put("content", null);
    json.put("msg", exception.getMessage());
    output(json,request,response);
  }

  /**
   * Excepiton异常
   *
   * @param exception
   * @return
   */
  @ExceptionHandler({Exception.class})
  @ResponseStatus(HttpStatus.OK)
  public void processException(HttpServletRequest request, HttpServletResponse response, Model model, Exception exception) throws JSONException, IOException {
    JSONObject json = new JSONObject();
    json.put("code", 500);
    json.put("content", null);
    json.put("msg", exception.getMessage());
    output(json,request,response);
  }
}

再来权限验证的，接手的项目框架中只有验证是否登录的，没有验收权限的，增加一个类WebMvcConfig，注意使用注解@Configuration， 不需要在其他地方引用即可起作用，并注意使用excludePathPatterns去掉不需要拦截的部分，否则会拦截掉静态资源。

@Configuration
public class WebMvcConfig implements WebMvcConfigurer {
 
  /**
   * 添加拦截器
   */
  @Override
  public void addInterceptors(InterceptorRegistry registry) {
    //静态资源不拦截
    registry.addInterceptor(new LoginInterceptor()).addPathPatterns("/**").excludePathPatterns("/static/**");
  }
}

增加拦截器类LoginInterceptor

public class LoginInterceptor extends HandlerInterceptorAdapter {

  /**
   * 检查是否已经登录
   */
  @Override
  public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
    Object username = request.getSession().getAttribute(Constants.LOGIN_USER);
    String servletPath = request.getServletPath();
    String type = request.getHeader("X-Requested-With") == null ? "" : request.getHeader("X-Requested-With");

    if (username != null) {
      //检查页面访问的权限
      if (!"XMLHttpRequest".equals(type)) {
        int userId = Integer.valueOf(request.getSession().getAttribute(Constants.LOGIN_USERID).toString());
        List moduleList = (List) request.getSession().getAttribute(Constants.USER_MODULE);
        boolean chkResult = methodPermissionLimit(moduleList, servletPath);
        if(!chkResult){
          JSONObject outputMSg = new JSONObject();
          outputMSg.put("code", 500);
          outputMSg.put("content", "");
          outputMSg.put("msg", "没有权限");
          output(outputMSg, request, response);
          return false;
        }else{
          return true;
        }
      } else {
        //如果是json访问，则不做检查
        return true;
      }
    } else {
      //检查是否登录允许
      if (methodLoginLimit(handler)) {
        return true;
      } else {
        if ("XMLHttpRequest".equals(type)) {
          JSONObject outputMSg = new JSONObject();
          outputMSg.put("code", 500);
          outputMSg.put("content", "");
          outputMSg.put("msg", "登录过期，请重新登陆");
          output(outputMSg, request, response);
          return false;
        } else {
          String redirectUrl = request.getContextPath() + "/login";
          response.sendRedirect(redirectUrl);
          return false;
        }
      }
    }
  }

  public boolean methodLoginLimit(Object handler) {
    HandlerMethod method = (HandlerMethod) handler;
    //获取当前方法PermessionLimit
    LoginLimit loginLimit = method.getMethodAnnotation(LoginLimit.class);
    if (loginLimit == null) {
      //获取控制器的PermessionLimit
      loginLimit = method.getMethod().getDeclaringClass().getAnnotation(LoginLimit.class);
    }
    if (loginLimit != null && !loginLimit.limit()) {
      return true;
    } else {
      return false;
    }
  }

  /**
   * 检查权限
   *
   * @param moduleList
   * @param path
   * @return
   */
  public boolean methodPermissionLimit(List moduleList, String path) {
    boolean havePermission = moduleList.stream().anyMatch(f->f.getPath().toLowerCase().equals(path.toLowerCase()));
    return havePermission;
  }

  public void output(Object json, HttpServletRequest request, HttpServletResponse response) throws IOException {
    String header = request.getHeader("Origin");
    response.setContentType("application/json;charset=UTF-8;");
    PrintWriter out = response.getWriter();
    out.println(json);
    out.flush();
    out.close();
  }
}

这样的拦截器只对页面地址进行拦截，对ajax提交的数据不做处理，做普通项目的权限过滤是可以了。

以上这篇springboot拦截器过滤token,并返回结果及异常处理操作就是小编分享给大家的全部内容了，希望能给大家一个参考，也希望大家多多支持脚本之家。