Spring Boot控制器问题[重复]答案

【问题标题】：Spring boot controller issue [duplicate]Spring Boot控制器问题[重复]
【发布时间】：2018-02-18 06:55:14
【问题描述】：

我正在使用过滤器检查用户是否已连接（令牌有效），如果令牌无效，我设置了一个名为“error”的属性，其中包含错误的详细信息，这是我的控制器

@RestController
public class HomeController {


@RequestMapping(value = "secure/info", method = RequestMethod.POST)

public Object login(@RequestBody User user,@RequestAttribute(name="error") AppError error)  {

    if(error!=null) return error ;
    return "information";

}

这是我的过滤器：

        @Override
        public void doFilter(final ServletRequest req, final ServletResponse res, final FilterChain chain)
                throws IOException, ServletException {

            final HttpServletRequest request = (HttpServletRequest) req;
            final HttpServletResponse response = (HttpServletResponse) res;
            final String authHeader = request.getHeader("authorization");

            if ("OPTIONS".equals(request.getMethod())) {
                response.setStatus(HttpServletResponse.SC_OK);

                chain.doFilter(request, response);
            } else {

                if (authHeader == null || !authHeader.startsWith("Bearer ")) {
                    AppError error = new AppError("0001","Invalid bearer token.");
                    request.setAttribute("error", error);
                    chain.doFilter(request, response);
                }

                final String token = authHeader.substring(7);

                try {
                    final Claims claims = Jwts.parser().setSigningKey("secretkey").parseClaimsJws(token).getBody();
                    request.setAttribute("claims", claims);
                } catch (final SignatureException e) {
                    AppError error = new AppError("0002","Invalid token signature.");
                    request.setAttribute("error", error);
                    chain.doFilter(request, response);
                }
                 catch (final ExpiredJwtException e) {
                     AppError error = new AppError("0003","Expired token.");
                     request.setAttribute("error", error);
                     chain.doFilter(request, response);

                 }

                 catch (final MalformedJwtException e) {
                     AppError error = new AppError("0004","Malformed token.");
                     request.setAttribute("error", error);
                     chain.doFilter(request, response);
                     //return ;
                 }



                chain.doFilter(req, res);
            }
        }

这是我得到的例外：

java.lang.IllegalStateException：无法调用 sendError() 在已提交响应在 org.apache.catalina.connector.ResponseFacade.sendError（ResponseFacade.java:472） ~[tomcat-embed-core-8.5.16.jar:8.5.16] 在 org.springframework.web.servlet.mvc.support.DefaultHandlerExceptionResolver.handleHttpMessageNotReadable(DefaultHandlerExceptionResolver.java:386) ~[spring-webmvc-4.3.10.RELEASE.jar:4.3.10.RELEASE] 在 ... …… 在 com.inconso.LoginFilter.doFilter(LoginFilter.java:67) [classes/:na]

【问题讨论】：

标签： spring servlets spring-boot servlet-filters

【解决方案1】：

在条件为真的else 块中：authHeader == null || !authHeader.startsWith("Bearer ") 您正在调用chain.doFilter() 两次。

曾在此区块中：

if (authHeader == null || !authHeader.startsWith("Bearer ")) {
    AppError error = new AppError("0001","Invalid bearer token.");
    request.setAttribute("error", error);
    chain.doFilter(request, response);
}

第二次在else 块的末尾：

else {

    ...

    chain.doFilter(req, res);
}

一次就足够了，所以要么从 else 块的底部删除最后一个 chain.doFilter(request, response)，要么从该块其他地方的 if 和 catch 子句中删除 chain.doFilter(request, response)。

【讨论】：

【解决方案2】：

在第一个 chain.doFilter(request, response); 之后添加退货声明 -- 提前退货方法

                if (authHeader == null || !authHeader.startsWith("Bearer ")) {
                    AppError error = new AppError("0001","Invalid bearer token.");
                    request.setAttribute("error", error);
                    chain.doFilter(request, response);

                    // ADD a RETURN STATEMENT HERE
                }

OR（IF-ELSE 阶梯法）

// START: MOVE THIS inside AN ELSE Block

                final String token = authHeader.substring(7);

                try {
                    final Claims claims = Jwts.parser().setSigningKey("secretkey").parseClaimsJws(token).getBody();
                    request.setAttribute("claims", claims);
                } catch (final SignatureException e) {
                    AppError error = new AppError("0002","Invalid token signature.");
                    request.setAttribute("error", error);
                    chain.doFilter(request, response);
                }
                 catch (final ExpiredJwtException e) {
                     AppError error = new AppError("0003","Expired token.");
                     request.setAttribute("error", error);
                     chain.doFilter(request, response);

                 }

                 catch (final MalformedJwtException e) {
                     AppError error = new AppError("0004","Malformed token.");
                     request.setAttribute("error", error);
                     chain.doFilter(request, response);
                     //return ;
                 }
// END: MOVE THIS inside AN ELSE Block

【讨论】：