理论上，单击提交后，应该调用登录方法并检查用户的用户名和密码是否匹配，并将其重定向到另一个 .jsp 页面，但是当我尝试加载 .jsp 页面时，出现以下错误.
我确定该错误与我的 .jsp 文件有关，但我不确定可能出了什么问题。
Jul 31, 2017 8:03:46 PM org.apache.catalina.core.StandardWrapperValve invoke
SEVERE: Servlet.service() for servlet [jsp] in context with path [/Atomicity] threw exception [An exception occurred processing JSP page [/login.jsp] at line [20]
17: class="register-form">
18: <table>
19: <tr>
20: <td><form:input path="username" /></td>
21: <td><form:errors path="username" /></td>
22: </tr>
23: <tr>
Stacktrace:] with root cause
java.lang.IllegalStateException: Neither BindingResult nor plain target object for bean name 'login' available as request attribute
at org.springframework.web.servlet.support.BindStatus.<init>(BindStatus.java:144)
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_005finput_005f0(login_jsp.java:298)
at org.apache.jsp.login_jsp._jspService(login_jsp.java:165)
at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:741)
at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:443)
at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:385)
at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:329)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:741)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:199)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:475)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:140)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:80)
at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:625)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:87)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:342)
at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:498)
at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:66)
at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:796)
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1372)
at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
at java.lang.Thread.run(Thread.java:745)
[登录.jsp]
<!DOCTYPE html>
<html>
<head>
<meta charset="ISO-8859-1">
<%@ taglib prefix="spring" uri="http://www.springframework.org/tags"%>
<%@ taglib prefix="form" uri="http://www.springframework.org/tags/form"%>
<link rel="shortcut icon" href="favicon1.ico" />
<title>Login page</title>
<link rel="stylesheet" href="css/normalize.css" />
<link rel="stylesheet" href="css/mystyle.css" />
</head>
<body>
<img id="logoImg2" src="img/atomicitylogo.png" alt="atomicity logo">
<div class="login-page">
<div class="form">
<form:form action="login" method="POST" commandName="login"
class="register-form">
<table>
<tr>
<td><form:input path="username" /></td>
<td><form:errors path="username" /></td>
</tr>
<tr>
<td><form:input path="password" /></td>
<td><form:errors path="password" /></td>
</tr>
<tr>
<td colspan="2"><input type="submit" value="Log In" />
<p class="message">
</tr>
</table>
<p>
Not registered? <a href="register.html">Create an account</a>
</p>
</form:form>
</div>
</div>
</body>
</html>
[LoginComponent.java]
package com.atomicity.components;
import javax.validation.constraints.NotNull;
import org.springframework.stereotype.Component;
@Component(value = "login")
public class LoginComponent {
@NotNull
private String username;
@NotNull
private String password;
public String getUsername() {
return username;
}
public void setUsername(String username) {
this.username = username;
}
public String getPassword() {
return password;
}
public void setPassword(String password) {
this.password = password;
}
}
[LoginController.java]
package com.atomicity.controllers;
import javax.validation.Valid;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.AbstractApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.validation.BindingResult;
import org.springframework.web.bind.annotation.ModelAttribute;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import com.atomicity.components.LoginComponent;
import com.atomicity.dao.UsersDAO;
import com.atomicity.domain.Users;
@Controller
public class LoginController {
@RequestMapping(value = "/loggingIn", method = RequestMethod.POST)
public String login(@Valid @ModelAttribute("login") LoginComponent login, BindingResult br, Model m) {
ApplicationContext appCon = new ClassPathXmlApplicationContext("beans.xml");
UsersDAO uDAO = (UsersDAO) appCon.getBean("usersDAO");
Users user = uDAO.getUserByName(login.getUsername());
if (user != null) {
// Check if password is correct
if (user.getPassword().equals(login.getPassword())) {
m.addAttribute("firstname", user.getFirstName());
m.addAttribute("lastname", user.getLastName());
m.addAttribute("email", user.getEmail());
m.addAttribute("username", login.getUsername());
((AbstractApplicationContext) appCon).close();
return "account";
} else {
// Wrong Password
}
} else {
// User/Password does not exists
}
((AbstractApplicationContext) appCon).close();
return null;
}
}
欢迎任何帮助。
[编辑]删除login.jsp中的表允许页面显示，所以我认为问题可能存在(或不存在)。
最佳答案
java.lang.IllegalStateException: Neither BindingResult nor plain target object for bean name 'login' available as request attribute
查看堆栈跟踪，它表明您尚未将登录对象传递给 View 。因此 JSP 无法正确呈现..
@GetMapping("/login")
public String login(Model m) {
//Use model to expose the LoginComponent object
m.addAttribute("login", new LoginComponent());
return "login";
}
您可以在此处找到更详细的演练:https://spring.io/guides/gs/handling-form-submission/
关于java.lang.IllegalStateException : Neither BindingResult nor plain target object for bean name 'login' available as request attribute，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/45427067/