spring security 自定义退出策略

项目需要，要求登录用户非空闲状态，不可退出。说白了就是，在退出的时候增加逻辑判断，如果状态为非空，就不让其退出。
仔细查看spring security文档，发现这个框架里维护了一个过滤器链，来提供服务。而我退出策略用的是LogoutFilter，框架默认提供的过滤器。代码如下：

<sec:http use-expressions="false" auto-config="true"
        entry-point-ref="loginUrlAuthenticationEntryPoint">
        <sec:intercept-url pattern='/**' access='ROLE_LOGIN' />

        **<sec:logout invalidate-session="true" logout-url="/logout" success-handler-ref="logoutSuccessHandler"
                    delete-cookies="JSESSIONID"/>**
        <sec:csrf disabled="true" />
        <sec:custom-filter position="CONCURRENT_SESSION_FILTER"
            ref="concurrencyFilter" />
        <sec:custom-filter before="FORM_LOGIN_FILTER" ref="authFilter" />
        <sec:session-management invalid-session-url="/sessionexpired"
            session-authentication-strategy-ref="sas" />
    </sec:http>

而框架提供过滤器链如下：

因此可以自定义过滤器，赶在LogoutFilter之前执行，配置如下：

before="LOGOUT_FILTER"
                           ref="cloudqLogoutFilter" />


id="cloudqLogoutFilter" class="com.raymon.cloudq.security.CloudqLogoutFilter">
        <property name="logoutUrl" value="/logout" />
    

filter代码如下

/**
 * 非空闲状态下，用户不能退出
 * Created by  on 2017/11/7.
 */
public class CloudqLogoutFilter extends GenericFilterBean {
    private org.slf4j.Logger logger = LoggerFactory.getLogger(getClass());
    private ObjectMapper mapper = new ObjectMapper();
    private String logoutUrl;
    @Autowired
    WindowCurrentStateMapper windowCurrentStateMapper

    @Override
    protected void initFilterBean() throws ServletException {
        super.initFilterBean();
        mapper.setPropertyNamingStrategy(new PropertyNamingStrategy.UpperCamelCaseStrategy());
    }

    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
        HttpServletRequest request = (HttpServletRequest) servletRequest;
        HttpServletResponse response = (HttpServletResponse) servletResponse;
        if (this.requiresLogout(request, response) && SecurityContextHolder.getContext() != null
                && SecurityContextHolder.getContext().getAuthentication() != null) {
            AuthUserDetails authUser = (AuthUserDetails) SecurityContextHolder.getContext().getAuthentication().getPrincipal();
            ClientEmp clientEmp = authUser.getClientEmpUser();
            Integer empId = clientEmp.getEmpId();
            Integer branchesId = clientEmp.getBranchesId();
            List windowEmpList = windowCurrentStateMapper.selectbyEmpId(branchesId, empId);
            if (windowEmpList != null && windowEmpList.size() > 0) {
                for (WindowsParticulars windowEmp : windowEmpList) {
                    if (Constants.WINDOW_CURRENT_STATE_CALL.equals(windowEmp.getCurrentState()) || Constants.WINDOW_CURRENT_STATE_IN_PROCESS.equals(windowEmp.getCurrentState())) {
                        logger.info("您的账号id='{}',name='{}',非空闲状态下，用户不能退出", clientEmp.getEmpId(), clientEmp.getEmpName());
                        printErrorMsg(servletResponse);
                       return;
                    }
                }
            }

        }
        filterChain.doFilter(servletRequest, servletResponse);

    }

    private void printErrorMsg(ServletResponse servletResponse) {
        servletResponse.setContentType("application/json");
        servletResponse.setCharacterEncoding("UTF-8");
        PrintWriter out = null;
        try {
            out = servletResponse.getWriter();
            Result result = new Result(StatusCode.ERROR_WINDOW_NOT_HANDLE, null, "非空闲状态下，用户不能退出");
            out.write(mapper.writeValueAsString(result));
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            if (out != null) {
                out.close();
            }
        }
    }

    /**
     * 判断请求路径是否是退出
     *
     * @param request
     * @param response
     * @return
     */
    private boolean requiresLogout(HttpServletRequest request, HttpServletResponse response) {
        if (StringUtils.isBlank(logoutUrl))
            return false;
        String path = request.getRequestURI();
        return path.contains(logoutUrl);
    }

    public void setLogoutUrl(String logoutUrl) {
        this.logoutUrl = logoutUrl;
    }
}

问题搞定！