我一直在试图找出如何在
Spring MVC中填充一个下拉框.有一些关于这个问题的线程,但我没有找到帮助我,所以我希望有人可以帮助我.
这是我的控制器：
@Controller
@RequestMapping("/document-revision")
public class DocumentRevisionController {
@Autowired
private DocumentRevisionService documentRevisionService;
private DocumentService documentService;
@RequestMapping(value="/list",method=RequestMethod.GET)
public String getDocumentRevisionList(Model model) {
List<DocumentRevision> documentRevisions = documentRevisionService.retrieveAllDocumentRevisions();
model.addAttribute("documentRevisions",documentRevisions);
return "document-revision";
}
@RequestMapping(value="/add",method=RequestMethod.GET)
public String getDocumentRevision(Model model) {
DocumentRevision documentRevision = new DocumentRevision();
model.addAttribute("documentRevisionAttribute",documentRevision);
return "new-documnent-revision";
}
@RequestMapping(value="/add",method=RequestMethod.POST)
public String postDocumentRevision(@modelattribute("documentRevisionAttribute") @Valid DocumentRevision documentRevision,BindingResult result) {
if(result.hasErrors()){
return "new-document-revision";
}
documentRevisionService.createDocumentRevision(documentRevision);
return "redirect:/testapp/document-revision/list";
}
}
这里是jsp页面：
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<%@ taglib uri="http://www.springframework.org/tags/form" prefix="form" %>
<html>
<head>
<Meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Insert title here</title>
<style>
.error { color: red; }
</style>
</head>
<body>
<h1>Create New Document Revision</h1>
<c:url var="saveUrl" value="/testapp/document-revision/add" />
<form:form modelAttribute="documentRevisionAttribute" method="POST" action="${saveUrl}">
<table>
<tr>
<td>DocumentNumber</td>
<td><form:select path="document_number">
<form:option value="NONE" label="--- Select ---" />
<form:options items="${documentNumberList}" />
</form:select>
</td>
<td><form:errors path="document_number" cssClass="error" /></td>
</tr>
<tr>
<td><form:label path="documentRState">Document R-State</form:label></td>
<td><form:input path="documentRState"/></td>
<td><form:errors path="documentRState" cssClass="error"/></td>
</tr>
</table>
<input type="submit" value="Save" />
</form:form>
</body>
</html>
我已经尝试添加一个@modelattribute方法来检索文档编号,
@modelattribute public List<Document> documentNumberList(){ return documentService.retrieveAllDocumentNumbers(); }
但它给了我错误.有没有人知道应该怎么做？
感谢您的时间
/ D
编辑我以为我会澄清,我的愿望是为documentService检索的文档编号有一个下拉框.
编辑2这是根据请求的错误日志：
java.lang.NullPointerException testapp.controller.DocumentRevisionController.documentNumberList(DocumentRevisionController.java:33) sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57) sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) java.lang.reflect.Method.invoke(Method.java:601) org.springframework.web.method.support.InvocableHandlerMethod.invoke(InvocableHandlerMethod.java:212) org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:126) org.springframework.web.method.annotation.ModelFactory.invokeModelAttributeMethods(ModelFactory.java:123) org.springframework.web.method.annotation.ModelFactory.initModel(ModelFactory.java:97) org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:614) org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:578) org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:80) org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:900) org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:827) org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:882) org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:778) javax.servlet.http.HttpServlet.service(HttpServlet.java:621) javax.servlet.http.HttpServlet.service(HttpServlet.java:722)
解决方案我以为我会添加完整的控制器代码,以防其他人可以从中受益：
@Controller
@RequestMapping("/document-revision")
public class DocumentRevisionController {
@Autowired
private DocumentRevisionService documentRevisionService;
@Autowired
private DocumentService documentService;
@RequestMapping(value="/list",documentRevision);
model.addAttribute("documentNumberList",documentService.retrieveAllDocumentNumbers());
return "new-documnent-revision";
}
@RequestMapping(value="/add",BindingResult result) {
if(result.hasErrors()){
return "new-document-revision";
}
documentRevisionService.createDocumentRevision(documentRevision);
return "redirect:/testapp/document-revision/list";
}
}
