0

我这里有代码：

@Controller
@RequestMapping(value="/guestbook")
public class GuestBookController {


     @Autowired
     GuestBookServiceIF guestBookServiceIF; 



     @ModelAttribute("messagesModel")
     public List<UserMessage> getMessagesModel() {
          return guestBookServiceIF.fetchAllService();
        }


     @RequestMapping(method = RequestMethod.GET)
     public String renderGuestBook(Model model) {
         GuestBookBackObject guestBookBackObject = new GuestBookBackObject();
         model.addAttribute("guestBookBackObject", guestBookBackObject);
         return "book";
        }



        @RequestMapping(method=RequestMethod.POST)
        public String saveGuestBookMessage(@ModelAttribute(value="guestBookBackObject") GuestBookBackObject guestBookBackObject, 
                                                                                                    BindingResult buindingResult) {


            guestBookBackObject.setIsNameExist(guestBookServiceIF.isUserInDBService(guestBookBackObject.getUser().getUserName()));

            GuestBookValidation validator = new GuestBookValidation();
            validator.validate(guestBookBackObject, buindingResult);
            if(buindingResult.hasErrors()) {    
                return "book";      
            } else {

            guestBookBackObject.getUserMessage().setTheUser(guestBookBackObject.getUser());
            guestBookServiceIF.saveMessageService(guestBookBackObject.getUserMessage());

            return "redirect:/guestbook";

            }
     }

在saveGuestBookMessage()执行其余代码之前应该进行一些验证。我验证的重点是它检查数据库中是否存在相同的用户名，如果数据库中存在用户名，那么在 jsp 页面上应该呈现一些错误消息，例如：“选择不同的名称”例如为此目的是 isUserInDBService() 方法.

这是我的验证器代码：

@Component
public class GuestBookValidation implements Validator{


    @SuppressWarnings("rawtypes")
    @Override
    public boolean supports(Class clazz) {
        return GuestBookBackObject.class.isAssignableFrom(clazz);
    }


    @Override
    public void validate(Object obj, Errors error) {


        GuestBookBackObject guestBookBackObject = (GuestBookBackObject)obj;

        if(guestBookBackObject.equals(obj)) {

            ValidationUtils.rejectIfEmpty(error, "user.userName", "", "\u041D\u0435\u043E\u0431\u0445\u043E\u0434\u0438\u043C\u043E \u0432\u0432\u0435\u0441\u0442\u0438 \u0438\u043C\u044F");
            ValidationUtils.rejectIfEmptyOrWhitespace(error, "userMessage.theMessage", "", "\u042D\u0442\u043E \u043F\u043E\u043B\u0435 \u043D\u0435 \u043C\u043E\u0436\u0435\u0442 \u0431\u044B\u0442\u044C \u043F\u0443\u0441\u0442\u044B\u043C");


            if(guestBookBackObject.getIsNameExist()== null) {

                ValidationUtils.rejectIfEmpty(error, "user.userName", "", "Please choose different user name");

            }

        } else {

            try {
                throw new Exception("Object of referance variable obj not equal referance variable guestBookBackObject");
            } catch (Exception e) {
                e.printStackTrace();
            }

        }       

    }

基本上它应该可以正常工作，但它给出了错误：

Hibernate: insert into USER_DESC (USER_NAME) values (?)
WARN : org.hibernate.engine.jdbc.spi.SqlExceptionHelper - SQL Error: 1062, SQLState: 23000
ERROR: org.hibernate.engine.jdbc.spi.SqlExceptionHelper - Duplicate entry 'we' for key 'UK_ok6uvp3eyniad0xua3xdt5icw'
Oct 01, 2013 9:27:04 AM org.apache.catalina.core.StandardWrapperValve invoke
SEVERE: Servlet.service() for servlet [appServlet] in context with path [/web] threw exception [Request processing failed; nested exception is org.hibernate.exception.ConstraintViolationException: could not execute statement] with root cause
com.mysql.jdbc.exceptions.jdbc4.MySQLIntegrityConstraintViolationException: Duplicate entry 'we' for key 'UK_ok6uvp3eyniad0xua3xdt5icw'
    at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
    at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:57)
    at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
    at java.lang.reflect.Constructor.newInstance(Constructor.java:526)
    at com.mysql.jdbc.Util.handleNewInstance(Util.java:411)
    at com.mysql.jdbc.Util.getInstance(Util.java:386)
    at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:1041)
    at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:4190)
    at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:4122)
    at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:2570)
    at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:2731)
    at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2818)
    at com.mysql.jdbc.PreparedStatement.executeInternal(PreparedStatement.java:2157)
    at com.mysql.jdbc.PreparedStatement.executeUpdate(PreparedStatement.java:2460)
    at com.mysql.jdbc.PreparedStatement.executeUpdate(PreparedStatement.java:2377)
    at com.mysql.jdbc.PreparedStatement.executeUpdate(PreparedStatement.java:2361)
    at com.mchange.v2.c3p0.impl.NewProxyPreparedStatement.executeUpdate(NewProxyPreparedStatement.java:105)
    at org.hibernate.engine.jdbc.internal.ResultSetReturnImpl.executeUpdate(ResultSetReturnImpl.java:133)
    at org.hibernate.id.IdentityGenerator$GetGeneratedKeysDelegate.executeAndExtract(IdentityGenerator.java:96)
    at org.hibernate.id.insert.AbstractReturningDelegate.performInsert(AbstractReturningDelegate.java:58)
    at org.hibernate.persister.entity.AbstractEntityPersister.insert(AbstractEntityPersister.java:2975)
    at org.hibernate.persister.entity.AbstractEntityPersister.insert(AbstractEntityPersister.java:3487)
    at org.hibernate.action.internal.EntityIdentityInsertAction.execute(EntityIdentityInsertAction.java:81)
    at org.hibernate.engine.spi.ActionQueue.execute(ActionQueue.java:377)
    at org.hibernate.engine.spi.ActionQueue.addResolvedEntityInsertAction(ActionQueue.java:214)
    at org.hibernate.engine.spi.ActionQueue.addInsertAction(ActionQueue.java:194)
    at org.hibernate.engine.spi.ActionQueue.addAction(ActionQueue.java:178)
    at org.hibernate.event.internal.AbstractSaveEventListener.addInsertAction(AbstractSaveEventListener.java:321)
    at org.hibernate.event.internal.AbstractSaveEventListener.performSaveOrReplicate(AbstractSaveEventListener.java:286)
    at org.hibernate.event.internal.AbstractSaveEventListener.performSave(AbstractSaveEventListener.java:192)
    at org.hibernate.event.internal.AbstractSaveEventListener.saveWithGeneratedId(AbstractSaveEventListener.java:125)
    at org.hibernate.event.internal.DefaultSaveOrUpdateEventListener.saveWithGeneratedOrRequestedId(DefaultSaveOrUpdateEventListener.java:206)
    at org.hibernate.event.internal.DefaultSaveOrUpdateEventListener.entityIsTransient(DefaultSaveOrUpdateEventListener.java:191)
    at org.hibernate.event.internal.DefaultSaveOrUpdateEventListener.performSaveOrUpdate(DefaultSaveOrUpdateEventListener.java:114)
    at org.hibernate.event.internal.DefaultSaveOrUpdateEventListener.onSaveOrUpdate(DefaultSaveOrUpdateEventListener.java:90)
    at org.hibernate.internal.SessionImpl.fireSaveOrUpdate(SessionImpl.java:735)
    at org.hibernate.internal.SessionImpl.saveOrUpdate(SessionImpl.java:727)
    at org.hibernate.engine.spi.CascadingAction$5.cascade(CascadingAction.java:258)
    at org.hibernate.engine.internal.Cascade.cascadeToOne(Cascade.java:388)
    at org.hibernate.engine.internal.Cascade.cascadeAssociation(Cascade.java:331)
    at org.hibernate.engine.internal.Cascade.cascadeProperty(Cascade.java:209)
    at org.hibernate.engine.internal.Cascade.cascade(Cascade.java:166)
    at org.hibernate.event.internal.AbstractSaveEventListener.cascadeBeforeSave(AbstractSaveEventListener.java:424)
    at org.hibernate.event.internal.AbstractSaveEventListener.performSaveOrReplicate(AbstractSaveEventListener.java:263)
    at org.hibernate.event.internal.AbstractSaveEventListener.performSave(AbstractSaveEventListener.java:192)
    at org.hibernate.event.internal.AbstractSaveEventListener.saveWithGeneratedId(AbstractSaveEventListener.java:125)
    at org.hibernate.event.internal.DefaultSaveOrUpdateEventListener.saveWithGeneratedOrRequestedId(DefaultSaveOrUpdateEventListener.java:206)
    at org.hibernate.event.internal.DefaultSaveEventListener.saveWithGeneratedOrRequestedId(DefaultSaveEventListener.java:55)
    at org.hibernate.event.internal.DefaultSaveOrUpdateEventListener.entityIsTransient(DefaultSaveOrUpdateEventListener.java:191)
    at org.hibernate.event.internal.DefaultSaveEventListener.performSaveOrUpdate(DefaultSaveEventListener.java:49)
    at org.hibernate.event.internal.DefaultSaveOrUpdateEventListener.onSaveOrUpdate(DefaultSaveOrUpdateEventListener.java:90)
    at org.hibernate.internal.SessionImpl.fireSave(SessionImpl.java:764)
    at org.hibernate.internal.SessionImpl.save(SessionImpl.java:756)
    at org.hibernate.internal.SessionImpl.save(SessionImpl.java:752)
    at demidov.pkg.persistence.GuestBookDAOImpl.saveMessage(GuestBookDAOImpl.java:30)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:606)
    at org.springframework.aop.support.AopUtils.invokeJoinpointUsingReflection(AopUtils.java:317)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.invokeJoinpoint(ReflectiveMethodInvocation.java:183)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:150)
    at org.springframework.transaction.interceptor.TransactionInterceptor$1.proceedWithInvocation(TransactionInterceptor.java:96)
    at org.springframework.transaction.interceptor.TransactionAspectSupport.invokeWithinTransaction(TransactionAspectSupport.java:260)
    at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:94)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:172)
    at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:204)
    at com.sun.proxy.$Proxy8.saveMessage(Unknown Source)
    at demidov.pkg.service.GuestBookServiceImpl.saveMessageService(GuestBookServiceImpl.java:27)
    at demidov.pkg.web.GuestBookController.saveGuestBookMessage(GuestBookController.java:60)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:606)
    at org.springframework.web.method.support.InvocableHandlerMethod.invoke(InvocableHandlerMethod.java:219)
    at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:132)
    at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:104)
    at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandleMethod(RequestMappingHandlerAdapter.java:745)
    at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:686)
    at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:80)
    at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:925)
    at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:856)
    at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:936)
    at org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:838)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:641)
    at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:812)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:722)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:304)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:240)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:164)
    at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:462)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:164)
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:100)
    at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:562)
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:395)
    at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:250)
    at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:188)
    at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:302)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
    at java.lang.Thread.run(Thread.java:724)

这告诉数据库中存在值，并且该值应该是唯一的。好的！但是为什么验证器让先插入值而不检查它们？？？

我的背部对象（GuestBookBackObject）：

@Component
public class GuestBookBackObject {

    private UserMessage userMessage;

    public UserMessage getUserMessage() {
        return userMessage;
    }
    public void setUserMessage(UserMessage userMessage) {
        this.userMessage = userMessage;
    }


    private User user;

    public User getUser() {
        return user;
    }
    public void setUser(User user) {
        this.user = user;
    }


    private User isNameExist;

    public User getIsNameExist() {
        return isNameExist;
    }
    public void setIsNameExist(User isNameExist) {
        this.isNameExist = isNameExist;
    }

}

谢谢你。

4

2 回答 2

0

缺乏更多信息，例如GuestBookBackObject. 但根据你给的

只需抛出您得到的异常，因为您从未在数据库中检查您要插入的值是否存在于据说是唯一的列中。

在保存之前，您应该在验证器中或任何地方实现这一点。例如

boolean exists = guestBookServiceIF.isMessageExists(guestBookBackObject);

数据库找出您违反 a 约束的唯一方法是在执行该语句时。

于 2013-10-01T10:32:26.387 回答
0

要存储验证消息，您调用了错误的方法。

if(guestBookBackObject.getIsNameExist()== null) {
    ValidationUtils.rejectIfEmpty(error, "user.userName", "", "Please choose different user name");
}

如果设置了属性，但用户名不为空，则不会设置任何内容。您应该简单地调用对象reject上的方法Errors。

if(guestBookBackObject.getIsNameExist()== null) {
    errrors.reject("username.not.unique", "Please choose different user name");
}

接下来，您应该在您的Validator而不是您的控制器内部进行检查。这样，您就可以让 Spring 为您完成所有繁重的工作。

于 2013-10-01T10:51:05.610 回答