说明:当使用拦截器出现“请求转发”无限循环或者“重定向”次数过多这种问题的时候,一般都是 拦截器 设置错了
情况一:请求转发时没有配置排除拦截路径,就是说你访问的路径都拦截了,导致一直转发,从而产生java.lang.*Error
错误
情况二:重定向时没有配置排除拦截路径,会导致一直重定向/重定向次数过多
解决办法:正确添加拦截路径,正确排除拦截路径
Spring Boot中我因疏忽导致的错误(参考):
错误写法:
@Override
public void addInterceptors(InterceptorRegistry registry) {
registry.addInterceptor(new LoginHandlerInterceptor())
// addPathPatterns 用于添加拦截规则
// excludePathPatterns 用于排除拦截
//注:因为疏忽下方的index.html前面未加/,转发多次-->*Error
.addPathPatterns("/**").excludePathPatterns("index.html","/","/login","/user/login",
"/assets/**","/assets/brand/**","/assets/dist/css/**","/assets/dist/js/**");
}
正确写法:
自定义的实现了WebMvcConfigurer接口的配置类,并重写addInterceptors方法
@Override
public void addInterceptors(InterceptorRegistry registry) {
registry.addInterceptor(new LoginHandlerInterceptor())
// addPathPatterns 用于添加拦截规则
// excludePathPatterns 用于排除拦截
.addPathPatterns("/**").excludePathPatterns("/index.html","/","/login","/user/login",
"/assets/**","/assets/brand/**","/assets/dist/css/**","/assets/dist/js/**");
}
拦截器:
public class LoginHandlerInterceptor implements HandlerInterceptor {
@Override
public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
//登陆成功之后,获取用户的session
Object loginUser = request.getSession().getAttribute("loginUser");
if (loginUser==null){//未登录
System.out.println(request.getRequestURI());
request.getRequestDispatcher("index.html").forward(request,response);
// response.sendRedirect("index.html");
return false;
}else {
return true;
}
}
}