我使用的是Spring Boot。我想创建一个用于测试输入的网页，但我对thymelaf有一个问题。我有一个带有新客户页面按钮的索引页面。在新客户页面中，有一个表格需要填写和保存。单击按钮时，控制器类中的方法应该捕获PostMapping(/savecustomer(。在执行处理器"org.thymelaf.spring5.processor.SpringInputGeneralFieldTagProcessor"期间，无法打开页面newcustomer，它显示Whitelabel错误页面，控制台显示错误只有当我删除所有th:field属性时，它才能打开。
我看过一些关于这个话题的帖子，但对我没有帮助。我试过：处理器执行期间出错'；org.thymelaf.spring5.processer.SpringInputGeneralFieldTagProcessor'；(模板："索引"-第93行，第69列(和无法使用th:field of thymelaf不起作用。如果你能解释错误在哪里，或者如果你知道的话，这个论坛的正确答案在哪里，我将不胜感激。
index.html
<html xmlns:th = "http://www.thymeleaf.org">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
</head>
<body>
<h1>TITLE</h1>
<form action = "/newcustomer">
<div>
<input type = "submit" value = "New customer" />
</div>
</form>
</body>
</html>
newcustomer.html
<!DOCTYPE html>
<html xmlns:th = "http://www.thymeleaf.org">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
</head><body>
<h1>Unesi novog korisnika</h1>
<form th:action = "@{/savecustomer}" th:object = "${customerDTO}" method = "POST">
<div class = "editform">
<div class = "textboxes">
<label>Paypal Adress: </label> <input type = "text" name = "paypalAdress" th:field = "*{paypalAdress}"></input><br/><br/>
<label>Paypal Username: </label> <input type = "text" name = "paypalUsername" th:field = "*{paypalUsername}"></input><br/><br/>
<label>Active: </label> <input type = "checkbox" name = "isActive" th:field = "*{isActive}" checked></input><br/><br/>
<label>Date: </label> <input type = "date" name = "date" th:field = "*{date}"></input><br/><br/>
<label>Currency: </label> <input type = "text" name = "currency" th:field = "*{currency}"></input><br/><br/>
<label>Old/Other Username: </label> <input type = "text" name = "oldOtherUsername" th:field = "*{oldOtherUsername}"></input><br/><br/>
<label>Charge Back: </label> <input type = "checkbox" name = "isChargeBack" th:field = "*{isChargeBack}" checked></input><br/><br/>
</div>
<div>
<input type = "submit" value = "Save" />
</div>
</div>
</form>
</body>
</html>
控制器类
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.ModelAttribute;
import org.springframework.web.bind.annotation.PostMapping;
import dto.CustomerDTO;
@Controller
public class MitogamesController
{
@GetMapping("/index")
public String homePage()
{
return "index";
}
@GetMapping("/newcustomer")
public String newCustomer()
{
return "newcustomer";
}
@PostMapping("/savecustomer")
public String saveCustomer(@ModelAttribute CustomerDTO customerDTO)
{
return "newcustomer";
}
}
客户DTO类
import java.util.Date;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;
import javax.persistence.Table;
@Entity
@Table(name = "customers")
public class CustomerDTO
{
@Id
@GeneratedValue
@Column(name = "id_customer")
private int idCustomer;
@Column(name = "paypal_adress")
private String paypalAdress;
@Column(name = "paypal_username")
private String paypalUsername;
@Column(name = "is_active")
private boolean isActive;
@Column(name = "date")
private Date date;
@Column(name = "currency")
private String currency;
@Column(name = "old_other_username")
private String oldOtherUsername;
@Column(name = "charge_back")
private boolean isChargeBack;
public int getIdCustomer()
{
return idCustomer;
}
public void setIdCustomer(int idCustomer)
{
this.idCustomer = idCustomer;
}
public String getPaypalAdress()
{
return paypalAdress;
}
public void setPaypalAdress(String paypalAdress)
{
this.paypalAdress = paypalAdress;
}
public String getPaypalUsername()
{
return paypalUsername;
}
public void setPaypalUsername(String paypalUsername)
{
this.paypalUsername = paypalUsername;
}
public boolean isActive()
{
return isActive;
}
public void setActive(boolean isActive)
{
this.isActive = isActive;
}
public Date getDate()
{
return date;
}
public void setDate(Date date)
{
this.date = date;
}
public String getCurrency()
{
return currency;
}
public void setCurrency(String currency)
{
this.currency = currency;
}
public String getOldOtherUsername()
{
return oldOtherUsername;
}
public void setOldOtherUsername(String oldOtherUsername)
{
this.oldOtherUsername = oldOtherUsername;
}
public boolean isChargeBack()
{
return isChargeBack;
}
public void setChargeBack(boolean isChargeBack)
{
this.isChargeBack = isChargeBack;
}
}
这里还有完整的日志：
org.thymeleaf.exceptions.TemplateProcessingException: Error during execution of processor 'org.thymeleaf.spring5.processor.SpringInputGeneralFieldTagProcessor' (template: "newcustomer" - line 15, col 80)
at org.thymeleaf.processor.element.AbstractAttributeTagProcessor.doProcess(AbstractAttributeTagProcessor.java:117) ~[thymeleaf-3.0.11.RELEASE.jar:3.0.11.RELEASE]
at org.thymeleaf.processor.element.AbstractElementTagProcessor.process(AbstractElementTagProcessor.java:95) ~[thymeleaf-3.0.11.RELEASE.jar:3.0.11.RELEASE]
at org.thymeleaf.util.ProcessorConfigurationUtils$ElementTagProcessorWrapper.process(ProcessorConfigurationUtils.java:633) ~[thymeleaf-3.0.11.RELEASE.jar:3.0.11.RELEASE]
at org.thymeleaf.engine.ProcessorTemplateHandler.handleStandaloneElement(ProcessorTemplateHandler.java:918) ~[thymeleaf-3.0.11.RELEASE.jar:3.0.11.RELEASE]
at org.thymeleaf.engine.StandaloneElementTag.beHandled(StandaloneElementTag.java:228) ~[thymeleaf-3.0.11.RELEASE.jar:3.0.11.RELEASE]
at org.thymeleaf.engine.TemplateModel.process(TemplateModel.java:136) ~[thymeleaf-3.0.11.RELEASE.jar:3.0.11.RELEASE]
at org.thymeleaf.engine.TemplateManager.parseAndProcess(TemplateManager.java:661) ~[thymeleaf-3.0.11.RELEASE.jar:3.0.11.RELEASE]
at org.thymeleaf.TemplateEngine.process(TemplateEngine.java:1098) ~[thymeleaf-3.0.11.RELEASE.jar:3.0.11.RELEASE]
at org.thymeleaf.TemplateEngine.process(TemplateEngine.java:1072) ~[thymeleaf-3.0.11.RELEASE.jar:3.0.11.RELEASE]
at org.thymeleaf.spring5.view.ThymeleafView.renderFragment(ThymeleafView.java:362) ~[thymeleaf-spring5-3.0.11.RELEASE.jar:3.0.11.RELEASE]
at org.thymeleaf.spring5.view.ThymeleafView.render(ThymeleafView.java:189) ~[thymeleaf-spring5-3.0.11.RELEASE.jar:3.0.11.RELEASE]
at org.springframework.web.servlet.DispatcherServlet.render(DispatcherServlet.java:1394) ~[spring-webmvc-5.3.2.jar:5.3.2]
at org.springframework.web.servlet.DispatcherServlet.processDispatchResult(DispatcherServlet.java:1139) ~[spring-webmvc-5.3.2.jar:5.3.2]
at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:1078) ~[spring-webmvc-5.3.2.jar:5.3.2]
at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:961) ~[spring-webmvc-5.3.2.jar:5.3.2]
at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:1006) ~[spring-webmvc-5.3.2.jar:5.3.2]
at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:898) ~[spring-webmvc-5.3.2.jar:5.3.2]
at javax.servlet.http.HttpServlet.service(HttpServlet.java:626) ~[tomcat-embed-core-9.0.41.jar:4.0.FR]
at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:883) ~[spring-webmvc-5.3.2.jar:5.3.2]
at javax.servlet.http.HttpServlet.service(HttpServlet.java:733) ~[tomcat-embed-core-9.0.41.jar:4.0.FR]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231) ~[tomcat-embed-core-9.0.41.jar:9.0.41]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.41.jar:9.0.41]
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53) ~[tomcat-embed-websocket-9.0.41.jar:9.0.41]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-9.0.41.jar:9.0.41]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.41.jar:9.0.41]
at org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:100) ~[spring-web-5.3.2.jar:5.3.2]
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) ~[spring-web-5.3.2.jar:5.3.2]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-9.0.41.jar:9.0.41]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.41.jar:9.0.41]
at org.springframework.web.filter.FormContentFilter.doFilterInternal(FormContentFilter.java:93) ~[spring-web-5.3.2.jar:5.3.2]
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) ~[spring-web-5.3.2.jar:5.3.2]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-9.0.41.jar:9.0.41]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.41.jar:9.0.41]
at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:201) ~[spring-web-5.3.2.jar:5.3.2]
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) ~[spring-web-5.3.2.jar:5.3.2]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-9.0.41.jar:9.0.41]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.41.jar:9.0.41]
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:202) ~[tomcat-embed-core-9.0.41.jar:9.0.41]
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:97) ~[tomcat-embed-core-9.0.41.jar:9.0.41]
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:542) ~[tomcat-embed-core-9.0.41.jar:9.0.41]
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:143) ~[tomcat-embed-core-9.0.41.jar:9.0.41]
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:92) ~[tomcat-embed-core-9.0.41.jar:9.0.41]
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:78) ~[tomcat-embed-core-9.0.41.jar:9.0.41]
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:343) ~[tomcat-embed-core-9.0.41.jar:9.0.41]
at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:374) ~[tomcat-embed-core-9.0.41.jar:9.0.41]
at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:65) ~[tomcat-embed-core-9.0.41.jar:9.0.41]
at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:888) ~[tomcat-embed-core-9.0.41.jar:9.0.41]
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1597) ~[tomcat-embed-core-9.0.41.jar:9.0.41]
at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49) ~[tomcat-embed-core-9.0.41.jar:9.0.41]
at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128) ~[na:na]
at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628) ~[na:na]
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) ~[tomcat-embed-core-9.0.41.jar:9.0.41]
at java.base/java.lang.Thread.run(Thread.java:830) ~[na:na]
Caused by: java.lang.IllegalStateException: Neither BindingResult nor plain target object for bean name 'customerDTO' available as request attribute
at org.springframework.web.servlet.support.BindStatus.<init>(BindStatus.java:153) ~[spring-webmvc-5.3.2.jar:5.3.2]
at org.springframework.web.servlet.support.RequestContext.getBindStatus(RequestContext.java:903) ~[spring-webmvc-5.3.2.jar:5.3.2]
at org.thymeleaf.spring5.context.webmvc.SpringWebMvcThymeleafRequestContext.getBindStatus(SpringWebMvcThymeleafRequestContext.java:227) ~[thymeleaf-spring5-3.0.11.RELEASE.jar:3.0.11.RELEASE]
at org.thymeleaf.spring5.util.FieldUtils.getBindStatusFromParsedExpression(FieldUtils.java:306) ~[thymeleaf-spring5-3.0.11.RELEASE.jar:3.0.11.RELEASE]
at org.thymeleaf.spring5.util.FieldUtils.getBindStatus(FieldUtils.java:253) ~[thymeleaf-spring5-3.0.11.RELEASE.jar:3.0.11.RELEASE]
at org.thymeleaf.spring5.util.FieldUtils.getBindStatus(FieldUtils.java:227) ~[thymeleaf-spring5-3.0.11.RELEASE.jar:3.0.11.RELEASE]
at org.thymeleaf.spring5.processor.AbstractSpringFieldTagProcessor.doProcess(AbstractSpringFieldTagProcessor.java:174) ~[thymeleaf-spring5-3.0.11.RELEASE.jar:3.0.11.RELEASE]
at org.thymeleaf.processor.element.AbstractAttributeTagProcessor.doProcess(AbstractAttributeTagProcessor.java:74) ~[thymeleaf-3.0.11.RELEASE.jar:3.0.11.RELEASE]
... 52 common frames omitted
2020-12-21 04:44:34.812 ERROR 18224 --- [nio-8080-exec-2] o.a.c.c.C.[.[.[/].[dispatcherServlet] : Servlet.service() for servlet [dispatcherServlet] in context with path [] threw exception [Request processing failed; nested exception is org.thymeleaf.exceptions.TemplateProcessingException: Error during execution of processor 'org.thymeleaf.spring5.processor.SpringInputGeneralFieldTagProcessor' (template: "newcustomer" - line 15, col 80)] with root cause
java.lang.IllegalStateException: Neither BindingResult nor plain target object for bean name 'customerDTO' available as request attribute
at org.springframework.web.servlet.support.BindStatus.<init>(BindStatus.java:153) ~[spring-webmvc-5.3.2.jar:5.3.2]
at org.springframework.web.servlet.support.RequestContext.getBindStatus(RequestContext.java:903) ~[spring-webmvc-5.3.2.jar:5.3.2]
at org.thymeleaf.spring5.context.webmvc.SpringWebMvcThymeleafRequestContext.getBindStatus(SpringWebMvcThymeleafRequestContext.java:227) ~[thymeleaf-spring5-3.0.11.RELEASE.jar:3.0.11.RELEASE]
at org.thymeleaf.spring5.util.FieldUtils.getBindStatusFromParsedExpression(FieldUtils.java:306) ~[thymeleaf-spring5-3.0.11.RELEASE.jar:3.0.11.RELEASE]
at org.thymeleaf.spring5.util.FieldUtils.getBindStatus(FieldUtils.java:253) ~[thymeleaf-spring5-3.0.11.RELEASE.jar:3.0.11.RELEASE]
at org.thymeleaf.spring5.util.FieldUtils.getBindStatus(FieldUtils.java:227) ~[thymeleaf-spring5-3.0.11.RELEASE.jar:3.0.11.RELEASE]
at org.thymeleaf.spring5.processor.AbstractSpringFieldTagProcessor.doProcess(AbstractSpringFieldTagProcessor.java:174) ~[thymeleaf-spring5-3.0.11.RELEASE.jar:3.0.11.RELEASE]
at org.thymeleaf.processor.element.AbstractAttributeTagProcessor.doProcess(AbstractAttributeTagProcessor.java:74) ~[thymeleaf-3.0.11.RELEASE.jar:3.0.11.RELEASE]
at org.thymeleaf.processor.element.AbstractElementTagProcessor.process(AbstractElementTagProcessor.java:95) ~[thymeleaf-3.0.11.RELEASE.jar:3.0.11.RELEASE]
at org.thymeleaf.util.ProcessorConfigurationUtils$ElementTagProcessorWrapper.process(ProcessorConfigurationUtils.java:633) ~[thymeleaf-3.0.11.RELEASE.jar:3.0.11.RELEASE]
at org.thymeleaf.engine.ProcessorTemplateHandler.handleStandaloneElement(ProcessorTemplateHandler.java:918) ~[thymeleaf-3.0.11.RELEASE.jar:3.0.11.RELEASE]
at org.thymeleaf.engine.StandaloneElementTag.beHandled(StandaloneElementTag.java:228) ~[thymeleaf-3.0.11.RELEASE.jar:3.0.11.RELEASE]
at org.thymeleaf.engine.TemplateModel.process(TemplateModel.java:136) ~[thymeleaf-3.0.11.RELEASE.jar:3.0.11.RELEASE]
at org.thymeleaf.engine.TemplateManager.parseAndProcess(TemplateManager.java:661) ~[thymeleaf-3.0.11.RELEASE.jar:3.0.11.RELEASE]
at org.thymeleaf.TemplateEngine.process(TemplateEngine.java:1098) ~[thymeleaf-3.0.11.RELEASE.jar:3.0.11.RELEASE]
at org.thymeleaf.TemplateEngine.process(TemplateEngine.java:1072) ~[thymeleaf-3.0.11.RELEASE.jar:3.0.11.RELEASE]
at org.thymeleaf.spring5.view.ThymeleafView.renderFragment(ThymeleafView.java:362) ~[thymeleaf-spring5-3.0.11.RELEASE.jar:3.0.11.RELEASE]
at org.thymeleaf.spring5.view.ThymeleafView.render(ThymeleafView.java:189) ~[thymeleaf-spring5-3.0.11.RELEASE.jar:3.0.11.RELEASE]
at org.springframework.web.servlet.DispatcherServlet.render(DispatcherServlet.java:1394) ~[spring-webmvc-5.3.2.jar:5.3.2]
at org.springframework.web.servlet.DispatcherServlet.processDispatchResult(DispatcherServlet.java:1139) ~[spring-webmvc-5.3.2.jar:5.3.2]
at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:1078) ~[spring-webmvc-5.3.2.jar:5.3.2]
at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:961) ~[spring-webmvc-5.3.2.jar:5.3.2]
at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:1006) ~[spring-webmvc-5.3.2.jar:5.3.2]
at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:898) ~[spring-webmvc-5.3.2.jar:5.3.2]
at javax.servlet.http.HttpServlet.service(HttpServlet.java:626) ~[tomcat-embed-core-9.0.41.jar:4.0.FR]
at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:883) ~[spring-webmvc-5.3.2.jar:5.3.2]
at javax.servlet.http.HttpServlet.service(HttpServlet.java:733) ~[tomcat-embed-core-9.0.41.jar:4.0.FR]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231) ~[tomcat-embed-core-9.0.41.jar:9.0.41]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.41.jar:9.0.41]
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53) ~[tomcat-embed-websocket-9.0.41.jar:9.0.41]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-9.0.41.jar:9.0.41]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.41.jar:9.0.41]
at org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:100) ~[spring-web-5.3.2.jar:5.3.2]
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) ~[spring-web-5.3.2.jar:5.3.2]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-9.0.41.jar:9.0.41]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.41.jar:9.0.41]
at org.springframework.web.filter.FormContentFilter.doFilterInternal(FormContentFilter.java:93) ~[spring-web-5.3.2.jar:5.3.2]
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) ~[spring-web-5.3.2.jar:5.3.2]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-9.0.41.jar:9.0.41]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.41.jar:9.0.41]
at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:201) ~[spring-web-5.3.2.jar:5.3.2]
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) ~[spring-web-5.3.2.jar:5.3.2]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-9.0.41.jar:9.0.41]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.41.jar:9.0.41]
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:202) ~[tomcat-embed-core-9.0.41.jar:9.0.41]
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:97) ~[tomcat-embed-core-9.0.41.jar:9.0.41]
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:542) ~[tomcat-embed-core-9.0.41.jar:9.0.41]
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:143) ~[tomcat-embed-core-9.0.41.jar:9.0.41]
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:92) ~[tomcat-embed-core-9.0.41.jar:9.0.41]
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:78) ~[tomcat-embed-core-9.0.41.jar:9.0.41]
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:343) ~[tomcat-embed-core-9.0.41.jar:9.0.41]
at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:374) ~[tomcat-embed-core-9.0.41.jar:9.0.41]
at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:65) ~[tomcat-embed-core-9.0.41.jar:9.0.41]
at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:888) ~[tomcat-embed-core-9.0.41.jar:9.0.41]
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1597) ~[tomcat-embed-core-9.0.41.jar:9.0.41]
at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49) ~[tomcat-embed-core-9.0.41.jar:9.0.41]
at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128) ~[na:na]
at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628) ~[na:na]
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) ~[tomcat-embed-core-9.0.41.jar:9.0.41]
at java.base/java.lang.Thread.run(Thread.java:830) ~[na:na]
您在初始渲染或页面中使用了模型属性，但您没有将该属性添加到@GetMapping中的模型中
@GetMapping("/newcustomer")
public String newCustomer() {
return "newcustomer";
}
相反，您应该将CustomerDTO添加到您的模型中。为此，添加Model作为方法参数，并在其中放入模型属性
@GetMapping("/newcustomer")
public String newCustomer(Model model) {
model.addAttribute(new CustomerDTO());
return "newcustomer";
}
另一种解决方案是在控制器中添加一个@ModelAttribute注释方法，该方法将在每次请求时自动将该模型属性添加到模型中。
@ModelAttribute
public CustomerDTO prepareModel() {
return new CustomerDTO();
}
注意，这将为每个请求处理方法添加它，甚至为您的index页面添加它，从而增加开销。您可以将该方法移动到其自己的控制器中以避免这种情况(或者使用视图控制器(。