“ Bean名称'loginCommand'的BindingResult或普通目标对象都不可用作请求属性”
我一直收到此Binding结果错误，而我尝试过的所有操作似乎都无法停止它。我已经看过其他有关此问题的帖子，但它们似乎都无法解决我遇到的任何问题。
这是我的新项目的第一个控制器，我在使xml平方消失时遇到一些问题。我认为这是固定的，但如果一切正常，我认为问题可能在那里。奇怪的是，所有这些代码几乎都是从我拥有的另一个项目中直接复制过来的，并且工作得很好。
如果那很重要的话，我也正在玻璃鱼上奔跑。预先感谢！
编辑：该网页是/morencore/login.jsp。我尝试去登录login.html并假设它可以启动它，但是它似乎仅在我进入login.jsp时才起作用。我相信我尝试将控制器更改为映射到jsp，但这没有用。
这是我的login.jsp页面：
<form:form method="post" modelAttribute="loginCommand">
<form:errors cssClass="error" element="p" />
<table border="0">
<tr>
<td align="right">Username:</td>
<td><form:input path="userName" /> <form:errors path="userName" cssClass="error" /></td>
</tr>
<tr>
<td align="right">Password:</td>
<td><form:password path="password" /> <form:errors path="password" cssClass="error" /></td>
</tr>
<tr>
<td colspan="2" align="center"><input type="submit" id="submit" name="submit" value="Log In" disabled="disabled"></td>
</tr>
</table>
</form:form>
这是我的控制器：
@Controller
@ControllerAdvice
@RequestMapping("/login.html")
public class LoginController {
protected final Logger logger = LogManager.getLogger(getClass());
@Autowired
protected LoginValidator loginValidator;
@RequestMapping(method= RequestMethod.GET)
protected String initializeForm(@ModelAttribute("loginCommand")LoginCommand loginCommand,
BindingResult result,
ModelMap model)
{
logger.info("INITIALIZING LOGIN FORM");
model.addAttribute("loginCommand", new LoginCommand());
return "login";
}
@InitBinder("loginCommand")
protected void initBinder(ServletRequestDataBinder binder) throws Exception
{
binder.addValidators(loginValidator);
}
@RequestMapping(method=RequestMethod.POST)
protected String onSubmit(@ModelAttribute("loginCommand")LoginCommand loginCommand,
BindingResult result,
HttpServletRequest request) throws Exception
{
logger.info("validating login input");
loginValidator.validate(loginCommand, result);
if (result.hasErrors())
{
result.reject("login.failure");
return "login";
}
UserDao userDao = new UserDao();
User user = userDao.by_name(loginCommand.getUserName());
if (user == null
|| !user.getName().equals(loginCommand.getUserName())
|| !user.getPassword().equals(loginCommand.getPassword()))
{
result.reject("login.failure");
return "login";
}
return "redirect:main.html";
}
}
这是我的LoginCommand类：
@XmlRootElement
public class LoginCommand
{
private String userName;
private String password;
/** blah blah blah getters and setters*/
}
这是请求的完整堆栈跟踪：
Neither BindingResult nor plain target object for bean name 'loginCommand' available as request attribute
java.lang.IllegalStateException: Neither BindingResult nor plain target object for bean name 'loginCommand' available as request attribute
at org.springframework.web.servlet.support.BindStatus.<init>(BindStatus.java:142)
at org.springframework.web.servlet.tags.form.AbstractDataBoundFormElementTag.getBindStatus(AbstractDataBoundFormElementTag.java:168)
at org.springframework.web.servlet.tags.form.AbstractDataBoundFormElementTag.getPropertyPath(AbstractDataBoundFormElementTag.java:188)
at org.springframework.web.servlet.tags.form.AbstractDataBoundFormElementTag.getName(AbstractDataBoundFormElementTag.java:154)
at org.springframework.web.servlet.tags.form.AbstractDataBoundFormElementTag.autogenerateId(AbstractDataBoundFormElementTag.java:141)
at org.springframework.web.servlet.tags.form.AbstractDataBoundFormElementTag.resolveId(AbstractDataBoundFormElementTag.java:132)
at org.springframework.web.servlet.tags.form.AbstractDataBoundFormElementTag.writeDefaultAttributes(AbstractDataBoundFormElementTag.java:116)
at org.springframework.web.servlet.tags.form.AbstractHtmlElementTag.writeDefaultAttributes(AbstractHtmlElementTag.java:422)
at org.springframework.web.servlet.tags.form.InputTag.writeTagContent(InputTag.java:142)
at org.springframework.web.servlet.tags.form.AbstractFormTag.doStartTagInternal(AbstractFormTag.java:84)
at org.springframework.web.servlet.tags.RequestContextAwareTag.doStartTag(RequestContextAwareTag.java:80)
at org.apache.jsp.login_jsp._jspx_meth_form_input_0(login_jsp.java:233)
at org.apache.jsp.login_jsp._jspService(login_jsp.java:126)
at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:111)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:791)
at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:411)
at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:473)
at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:377)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:791)
at org.apache.catalina.core.StandardWrapper.service(StandardWrapper.java:1580)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:338)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
at org.glassfish.tyrus.servlet.TyrusServletFilter.doFilter(TyrusServletFilter.java:305)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:250)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:256)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:160)
at org.apache.catalina.core.StandardPipeline.doInvoke(StandardPipeline.java:652)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:591)
at com.sun.enterprise.web.WebPipeline.invoke(WebPipeline.java:99)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:155)
at org.apache.catalina.connector.CoyoteAdapter.doService(CoyoteAdapter.java:371)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:238)
at com.sun.enterprise.v3.services.impl.ContainerMapper$HttpHandlerCallable.call(ContainerMapper.java:463)
at com.sun.enterprise.v3.services.impl.ContainerMapper.service(ContainerMapper.java:168)
at org.glassfish.grizzly.http.server.HttpHandler.runService(HttpHandler.java:206)
at org.glassfish.grizzly.http.server.HttpHandler.doHandle(HttpHandler.java:180)
at org.glassfish.grizzly.http.server.HttpServerFilter.handleRead(HttpServerFilter.java:242)
at org.glassfish.grizzly.filterchain.ExecutorResolver$9.execute(ExecutorResolver.java:119)
at org.glassfish.grizzly.filterchain.DefaultFilterChain.executeFilter(DefaultFilterChain.java:284)
at org.glassfish.grizzly.filterchain.DefaultFilterChain.executeChainPart(DefaultFilterChain.java:201)
at org.glassfish.grizzly.filterchain.DefaultFilterChain.execute(DefaultFilterChain.java:133)
at org.glassfish.grizzly.filterchain.DefaultFilterChain.process(DefaultFilterChain.java:112)
at org.glassfish.grizzly.ProcessorExecutor.execute(ProcessorExecutor.java:77)
at org.glassfish.grizzly.nio.transport.TCPNIOTransport.fireIOEvent(TCPNIOTransport.java:539)
at org.glassfish.grizzly.strategies.AbstractIOStrategy.fireIOEvent(AbstractIOStrategy.java:112)
at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy.run0(WorkerThreadIOStrategy.java:117)
答案 0 :(得分：0)
在其他事情中，似乎您的映射需要修改。这是我会尝试的。调整很多，因此无法保证它是否会完全正常运行，但它应该为您提供正确的方向。
@Controller
public class LoginController {
protected final Logger logger = LogManager.getLogger(getClass()); //look at SLF4J instead. Then you're not tied to a specific logger and you use a facade.
@Autowired //may want to use constructor wiring instead on these
private LoginValidator loginValidator;
@Autowired
private UserDao userDao; //this should be wired and not simply instantiated - Spring won't know about it otherwise
@Autowired
private LoginValidator loginValidator;
@GetMapping("/login")
public String initializeForm(Model model) {
logger.info("INITIALIZING LOGIN FORM");
model.addAttribute("loginCommand", new LoginCommand());
return "login";
}
@PostMapping("/loginPost")
public String onSubmit(@ModelAttribute("loginCommand") LoginCommand loginCommand,
BindingResult result) throws Exception {
logger.info("validating login input");
loginValidator.validate(loginCommand, result);
if (result.hasErrors()) {
result.reject("login.failure");
return "login";
}
User user = userDao.by_name(loginCommand.getUserName());
if (user == null
|| !user.getName().equals(loginCommand.getUserName())
|| !user.getPassword().equals(loginCommand.getPassword())) { //you should really refactor this and move it outside of your controller. Just keep routing code in your controller, not logic
result.reject("login.failure");
return "login";
}
return "main"; //you should return just "main" or redirect:/main depending on what you're trying to do - you want the JSP to be processed. Leaving off the extension allows you to change frameworks without changing the server-side code and allows the page to be compiled. You could switch to Thymeleaf, for example, and not touch any of this code.
}
}
向表单添加操作：
<form:errors cssClass="error" element="p" />
<table border="0">
<tr>
<td align="right">Username:</td>
<td><form:input path="userName" /> <form:errors path="userName" cssClass="error" /></td>
</tr>
<tr>
<td align="right">Password:</td>
<td><form:password path="password" /> <form:errors path="password" cssClass="error" /></td>
</tr>
<tr>
<td colspan="2" align="center"><input type="submit" id="submit" name="submit" value="Log In"></td>
</tr>
</table>
对于下一个阅读您的代码的开发人员，我将LoginCommand重命名为更接近其实际名称的名称，例如UserDetailsAdapter或类似的名称。我假设LoginCommand将使用Spring Security来实现UserDetails。
您可能还想考虑更新您的UserDao，使其具有名为findOneByUsername的方法，而不是by_name。以后使用Spring Repositories时，命名约定可以为您提供帮助。
最后，在Project Lombok中查找您的bean。它将为您节省很多头痛。