java - 如何防止 Validator 以不相关的 ModelAttribute 为目标？

Question

我正在使用 Spring 框架的自定义 validator 来验证 Employee 实体的用户输入。如果没有错误，我想直接转到一个 html 页面供用户创建一个新的 LeaveRecord。

Controller :

    @Autowired
    private EmployeeValidator eValidator;

    @InitBinder
    protected void initBinder(WebDataBinder binder) {
        binder.addValidators(eValidator);
    }

    @RequestMapping(path = "/authenticate", method = RequestMethod.POST)
    public ModelAndView authenticate(@Valid @ModelAttribute Employee user, BindingResult bindingResult) {

        if (bindingResult.hasErrors()) {
            return new ModelAndView("redirect:/");
        }

        ModelAndView mav = new ModelAndView("LeaveForm");
        mav.addObject("leave", new LeaveRecord());
        return mav;
    }

validator :

@Component
public class EmployeeValidator implements Validator{

    private LeaveServiceIF lService;

    @Autowired
    public void setlService(LeaveServiceIF lService) {
        this.lService = lService;
    }

    @Override
    public boolean supports(Class<?> clazz) {
        return Employee.class.equals(clazz);
    }

    @Override
    public void validate(Object obj, Errors e) {
        Employee emp = (Employee) obj;
        if (lService.authenticate(emp.getEmpId(), emp.getPwd()) == null) {
            e.rejectValue(null, "invalidEmpIdOrPwd");
        }
    }
}

依赖项(pom.xml):

<dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-jpa</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-thymeleaf</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <scope>runtime</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework.session</groupId>
            <artifactId>spring-session-core</artifactId>
        </dependency>
    </dependencies>

但是，当 Employee 实体没有错误时，我会得到以下异常。

java.lang.IllegalStateException: Invalid target for Validator [sg.edu.nus.laps.validator.EmployeeValidator@3404e5c4]: LeaveRecord [lType=null, startDate=null, endDate=null, numOfDays=0.0, reason=null, lStatus=null, employee=null]
    at org.springframework.validation.DataBinder.assertValidators(DataBinder.java:542) ~[spring-context-5.1.6.RELEASE.jar:5.1.6.RELEASE]
    at org.springframework.validation.DataBinder.addValidators(DataBinder.java:553) ~[spring-context-5.1.6.RELEASE.jar:5.1.6.RELEASE]
    at sg.edu.nus.laps.controller.LeaveController.initBinder(LeaveController.java:38) ~[classes/:na]
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_212]
    at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source) ~[na:1.8.0_212]
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) ~[na:1.8.0_212]
    at java.lang.reflect.Method.invoke(Unknown Source) ~[na:1.8.0_212]
    at org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:189) ~[spring-web-5.1.6.RELEASE.jar:5.1.6.RELEASE]
    at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:138) ~[spring-web-5.1.6.RELEASE.jar:5.1.6.RELEASE]
    at org.springframework.web.method.annotation.InitBinderDataBinderFactory.initBinder(InitBinderDataBinderFactory.java:68) ~[spring-web-5.1.6.RELEASE.jar:5.1.6.RELEASE]
    at org.springframework.web.bind.support.DefaultDataBinderFactory.createBinder(DefaultDataBinderFactory.java:60) ~[spring-web-5.1.6.RELEASE.jar:5.1.6.RELEASE]
    at org.springframework.web.method.annotation.ModelFactory.updateBindingResult(ModelFactory.java:214) ~[spring-web-5.1.6.RELEASE.jar:5.1.6.RELEASE]
    at org.springframework.web.method.annotation.ModelFactory.updateModel(ModelFactory.java:200) ~[spring-web-5.1.6.RELEASE.jar:5.1.6.RELEASE]
    at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.getModelAndView(RequestMappingHandlerAdapter.java:1001) ~[spring-webmvc-5.1.6.RELEASE.jar:5.1.6.RELEASE]
    at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:897) ~[spring-webmvc-5.1.6.RELEASE.jar:5.1.6.RELEASE]
    at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:797) ~[spring-webmvc-5.1.6.RELEASE.jar:5.1.6.RELEASE]
    at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:87) ~[spring-webmvc-5.1.6.RELEASE.jar:5.1.6.RELEASE]
    at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:1038) ~[spring-webmvc-5.1.6.RELEASE.jar:5.1.6.RELEASE]
    at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:942) ~[spring-webmvc-5.1.6.RELEASE.jar:5.1.6.RELEASE]
    at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:1005) ~[spring-webmvc-5.1.6.RELEASE.jar:5.1.6.RELEASE]
    at org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:908) ~[spring-webmvc-5.1.6.RELEASE.jar:5.1.6.RELEASE]
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:660) ~[tomcat-embed-core-9.0.17.jar:9.0.17]
    at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:882) ~[spring-webmvc-5.1.6.RELEASE.jar:5.1.6.RELEASE]
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:741) ~[tomcat-embed-core-9.0.17.jar:9.0.17]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231) ~[tomcat-embed-core-9.0.17.jar:9.0.17]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.17.jar:9.0.17]
    at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53) ~[tomcat-embed-websocket-9.0.17.jar:9.0.17]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-9.0.17.jar:9.0.17]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.17.jar:9.0.17]
    at org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:99) ~[spring-web-5.1.6.RELEASE.jar:5.1.6.RELEASE]
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) ~[spring-web-5.1.6.RELEASE.jar:5.1.6.RELEASE]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-9.0.17.jar:9.0.17]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.17.jar:9.0.17]
    at org.springframework.web.filter.FormContentFilter.doFilterInternal(FormContentFilter.java:92) ~[spring-web-5.1.6.RELEASE.jar:5.1.6.RELEASE]
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) ~[spring-web-5.1.6.RELEASE.jar:5.1.6.RELEASE]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-9.0.17.jar:9.0.17]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.17.jar:9.0.17]
    at org.springframework.web.filter.HiddenHttpMethodFilter.doFilterInternal(HiddenHttpMethodFilter.java:93) ~[spring-web-5.1.6.RELEASE.jar:5.1.6.RELEASE]
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) ~[spring-web-5.1.6.RELEASE.jar:5.1.6.RELEASE]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-9.0.17.jar:9.0.17]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.17.jar:9.0.17]
    at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:200) ~[spring-web-5.1.6.RELEASE.jar:5.1.6.RELEASE]
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) ~[spring-web-5.1.6.RELEASE.jar:5.1.6.RELEASE]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-9.0.17.jar:9.0.17]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.17.jar:9.0.17]
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:200) ~[tomcat-embed-core-9.0.17.jar:9.0.17]
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96) [tomcat-embed-core-9.0.17.jar:9.0.17]
    at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:490) [tomcat-embed-core-9.0.17.jar:9.0.17]
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:139) [tomcat-embed-core-9.0.17.jar:9.0.17]
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:92) [tomcat-embed-core-9.0.17.jar:9.0.17]
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:74) [tomcat-embed-core-9.0.17.jar:9.0.17]
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:343) [tomcat-embed-core-9.0.17.jar:9.0.17]
    at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:408) [tomcat-embed-core-9.0.17.jar:9.0.17]
    at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:66) [tomcat-embed-core-9.0.17.jar:9.0.17]
    at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:834) [tomcat-embed-core-9.0.17.jar:9.0.17]
    at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1415) [tomcat-embed-core-9.0.17.jar:9.0.17]
    at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49) [tomcat-embed-core-9.0.17.jar:9.0.17]
    at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source) [na:1.8.0_212]
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source) [na:1.8.0_212]
    at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) [tomcat-embed-core-9.0.17.jar:9.0.17]
    at java.lang.Thread.run(Unknown Source) [na:1.8.0_212]

EmployeeValidator 似乎以我传递给 html View 的 LeaveRecord 实体为目标，因此导致了异常。

有什么方法可以避免这种情况，还是我做得对？

Answer 1

看起来您的 Validator 类可能有问题。你能告诉我们代码吗？

这可能有帮助:

Prevent "IllegalStateException: Invalid target for Validator" error