Spring MVC中的对象绑定列表

Question

public class Contact {

    private String firstname;
    private String lastname;
    private String email;
    private String phone;

    public Contact() {
    }

    public Contact(String firstname, String lastname, String email, String phone) {
        this.firstname = firstname;
        this.lastname = lastname;
        this.email = email;
        this.phone = phone;
    }

    public String getFirstname() {
        return firstname;
    }

    public void setFirstname(String firstname) {
        this.firstname = firstname;
    }

    public String getLastname() {
        return lastname;
    }

    public void setLastname(String lastname) {
        this.lastname = lastname;
    }

    public String getEmail() {
        return email;
    }

    public void setEmail(String email) {
        this.email = email;
    }

    public String getPhone() {
        return phone;
    }

    public void setPhone(String phone) {
        this.phone = phone;
    }
}

公共类ContactForm {

    private List<Contact> contacts;

    public List<Contact> getContacts() {
        return contacts;
    }

    public void setContacts(List<Contact> contacts) {
        this.contacts = contacts;
    }
}

这是我的控制器课

@Controller
public class ContactController {

    private List<Contact> list = new ArrayList<Contact>();

    @RequestMapping(value = "/save", method = RequestMethod.POST)
    public ModelAndView save(@ModelAttribute("contactForm") ContactForm contactForm) {
        System.out.println(contactForm);
        System.out.println(contactForm.getContacts());
        List<Contact> contacts = contactForm.getContacts();

        if(null != contacts && contacts.size() > 0) {
            for (Contact contact : contacts) {
                System.out.printf(contact.getFirstname());
            }
        }

        return new ModelAndView("showContact", "contactForm", contactForm);
    }
}

下面是我的jsp

<%@taglib uri="http://www.springframework.org/tags" prefix="spring"%>
<%@taglib uri="http://www.springframework.org/tags/form" prefix="form"%>
<%@taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c"%> 

<h2>Spring MVC Multiple Row Form Submit example</h2>
<form:form method="post" action="save.html" modelattribute="contactForm">
    <c:forEach items="${contactForm.contacts}" var="contact" varStatus="status">
       </c:forEach><table>
    <tbody><tr>
        <th>No.</th>
        <th>Name</th>
        <th>Lastname</th>
        <th>Email</th>
        <th>Phone</th>
    </tr>
    <tr>
            <td align="center">${status.count}</td>
            <td><input name="contact[${status.index}].firstname" value="${contact.firstname}"></td>
            <td><input name="contact[${status.index}].lastname" value="${contact.lastname}"></td>
            <td><input name="contact[${status.index}].email" value="${contact.email}"></td>
            <td><input name="contact[${status.index}].phone" value="${contact.phone}"></td>
        </tr>

</tbody></table>  

<br>
<input type="submit" value="Save">

</form:form>

我从viralpatel的博客获得了此代码，但对我不起作用...如果我输入值，它将引发错误。 以下是完整的堆栈跟踪

SEVERE: Servlet.service() for servlet [MVC-Dispatcher] in context with path [/SpringMVC] threw exception [Request processing failed; nested exception is org.springframework.beans.InvalidPropertyException: Invalid property 'contacts[]' of bean class [com.sharique.beans.ContactForm]: Invalid index in property path 'contacts[]'; nested exception is java.lang.NumberFormatException: For input string: ""] with root cause
java.lang.NumberFormatException: For input string: ""
    at java.lang.NumberFormatException.forInputString(Unknown Source)
    at java.lang.Integer.parseInt(Unknown Source)
    at java.lang.Integer.parseInt(Unknown Source)
    at org.springframework.beans.BeanWrapperImpl.getPropertyValue(BeanWrapperImpl.java:793)
    at org.springframework.beans.BeanWrapperImpl.getNestedBeanWrapper(BeanWrapperImpl.java:571)
    at org.springframework.beans.BeanWrapperImpl.getBeanWrapperForPropertyPath(BeanWrapperImpl.java:548)
    at org.springframework.beans.BeanWrapperImpl.setPropertyValue(BeanWrapperImpl.java:916)
    at org.springframework.beans.AbstractPropertyAccessor.setPropertyValues(AbstractPropertyAccessor.java:95)
    at org.springframework.validation.DataBinder.applyPropertyValues(DataBinder.java:749)
    at org.springframework.validation.DataBinder.doBind(DataBinder.java:645)
    at org.springframework.web.bind.WebDataBinder.doBind(WebDataBinder.java:189)
    at org.springframework.web.bind.ServletRequestDataBinder.bind(ServletRequestDataBinder.java:106)
    at org.springframework.web.servlet.mvc.method.annotation.ServletModelAttributeMethodProcessor.bindRequestParameters(ServletModelAttributeMethodProcessor.java:150)
    at org.springframework.web.method.annotation.ModelAttributeMethodProcessor.resolveArgument(ModelAttributeMethodProcessor.java:110)
    at org.springframework.web.method.support.HandlerMethodArgumentResolverComposite.resolveArgument(HandlerMethodArgumentResolverComposite.java:77)
    at org.springframework.web.method.support.InvocableHandlerMethod.getMethodArgumentValues(InvocableHandlerMethod.java:162)
    at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:129)
    at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:110)
    at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandleMethod(RequestMappingHandlerAdapter.java:777)
    at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:706)
    at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:85)
    at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:943)
    at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:877)
    at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:966)
    at org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:868)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:641)
    at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:842)
    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(Unknown Source)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
    at java.lang.Thread.run(Unknown Source)

Answer 1

如错误所指定，您的表单在应为contacts [0] .firstname时发送参数contacts []。firstname。

我建议您使用类似于Firebug的工具检查请求，以了解如何在请求中发送表单。

希望这可以帮助您找到解决问题的正确方法。