Jstl foreach无法遍历页面对象进行分页

Question

我正试图在我的springboot应用程序中实现分页，我在互联网上看到了分页教程，并在存储库中添加了页面和可分页，在控制器中，我将可分页作为参数传递给了我的findall方法，它正在重新查询页面数据类型，这给我带来了错误。

2020-12-16 00:18:06.302 ERROR 7836 --- [nio-8080-exec-4] o.a.c.c.C.[.[.[/].[dispatcherServlet]    : Servlet.service() for servlet [dispatcherServlet] in context with path [] threw exception [An exception occurred processing [/WEB-INF/views/admin/doclist.jsp] at line [21]

18:     <th>Address</th>
19:     <th>Action</th>
20:   </tr>
21:  <c:forEach var="tempdoc" items="${doclist}">
22:  
23: 
24:   <tr>


Stacktrace:] with root cause

javax.servlet.jsp.JspTagException: Don't know how to iterate over supplied "items" in &lt;forEach&gt;
at org.apache.taglibs.standard.tag.common.core.ForEachSupport.toForEachIterator(ForEachSupport.java:274) ~[jstl-1.2.jar:1.2]
at org.apache.taglibs.standard.tag.common.core.ForEachSupport.supportedTypeForEachIterator(ForEachSupport.java:238) ~[jstl-1.2.jar:1.2]
at org.apache.taglibs.standard.tag.common.core.ForEachSupport.prepare(ForEachSupport.java:155) ~[jstl-1.2.jar:1.2]
at javax.servlet.jsp.jstl.core.LoopTagSupport.doStartTag(LoopTagSupport.java:256) ~[jstl-1.2.jar:1.2]
at org.apache.jsp.WEB_002dINF.views.admin.doclist_jsp._jspx_meth_c_005fforEach_005f0(doclist_jsp.java:265) ~[na:na]
at org.apache.jsp.WEB_002dINF.views.admin.doclist_jsp._jspService(doclist_jsp.java:212) ~[na:na]
at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:71) ~[tomcat-embed-jasper-9.0.39.jar:9.0.39]
at javax.servlet.http.HttpServlet.service(HttpServlet.java:733) ~[tomcat-embed-core-9.0.39.jar:4.0.FR]
at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:477) ~[tomcat-embed-jasper-9.0.39.jar:9.0.39]
at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:385) ~[tomcat-embed-jasper-9.0.39.jar:9.0.39]
at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:329) ~[tomcat-embed-jasper-9.0.39.jar:9.0.39]
at javax.servlet.http.HttpServlet.service(HttpServlet.java:733) ~[tomcat-embed-core-9.0.39.jar:4.0.FR]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231) ~[tomcat-embed-core-9.0.39.jar:9.0.39]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.39.jar:9.0.39]
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53) ~[tomcat-embed-websocket-9.0.39.jar:9.0.39]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-9.0.39.jar:9.0.39]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.39.jar:9.0.39]
at org.apache.catalina.core.ApplicationDispatcher.invoke(ApplicationDispatcher.java:712) ~[tomcat-embed-core-9.0.39.jar:9.0.39]
at org.apache.catalina.core.ApplicationDispatcher.processRequest(ApplicationDispatcher.java:459) ~[tomcat-embed-core-9.0.39.jar:9.0.39]
at org.apache.catalina.core.ApplicationDispatcher.doForward(ApplicationDispatcher.java:384) ~[tomcat-embed-core-9.0.39.jar:9.0.39]
at org.apache.catalina.core.ApplicationDispatcher.forward(ApplicationDispatcher.java:312) ~[tomcat-embed-core-9.0.39.jar:9.0.39]
at org.springframework.security.web.header.HeaderWriterFilter$HeaderWriterRequestDispatcher.forward(HeaderWriterFilter.java:172) ~[spring-security-web-5.2.7.RELEASE.jar:5.2.7.RELEASE]
at org.springframework.web.servlet.view.InternalResourceView.renderMergedOutputModel(InternalResourceView.java:171) ~[spring-webmvc-5.2.10.RELEASE.jar:5.2.10.RELEASE]
at org.springframework.web.servlet.view.AbstractView.render(AbstractView.java:316) ~[spring-webmvc-5.2.10.RELEASE.jar:5.2.10.RELEASE]
at org.springframework.web.servlet.DispatcherServlet.render(DispatcherServlet.java:1373) ~[spring-webmvc-5.2.10.RELEASE.jar:5.2.10.RELEASE]
at org.springframework.web.servlet.DispatcherServlet.processDispatchResult(DispatcherServlet.java:1118) ~[spring-webmvc-5.2.10.RELEASE.jar:5.2.10.RELEASE]
at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:1057) ~[spring-webmvc-5.2.10.RELEASE.jar:5.2.10.RELEASE]
at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:943) ~[spring-webmvc-5.2.10.RELEASE.jar:5.2.10.RELEASE]
at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:1006) ~[spring-webmvc-5.2.10.RELEASE.jar:5.2.10.RELEASE]
at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:898) ~[spring-webmvc-5.2.10.RELEASE.jar:5.2.10.RELEASE]
at javax.servlet.http.HttpServlet.service(HttpServlet.java:626) ~[tomcat-embed-core-9.0.39.jar:4.0.FR]
at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:883) ~[spring-webmvc-5.2.10.RELEASE.jar:5.2.10.RELEASE]
at javax.servlet.http.HttpServlet.service(HttpServlet.java:733) ~[tomcat-embed-core-9.0.39.jar:4.0.FR]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231) ~[tomcat-embed-core-9.0.39.jar:9.0.39]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.39.jar:9.0.39]
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53) ~[tomcat-embed-websocket-9.0.39.jar:9.0.39]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-9.0.39.jar:9.0.39]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.39.jar:9.0.39]
at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:320) ~[spring-security-web-5.2.7.RELEASE.jar:5.2.7.RELEASE]
at org.springframework.security.web.access.intercept.FilterSecurityInterceptor.invoke(FilterSecurityInterceptor.java:126) ~[spring-security-web-5.2.7.RELEASE.jar:5.2.7.RELEASE]
at org.springframework.security.web.access.intercept.FilterSecurityInterceptor.doFilter(FilterSecurityInterceptor.java:90) ~[spring-security-web-5.2.7.RELEASE.jar:5.2.7.RELEASE]
at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:334) ~[spring-security-web-5.2.7.RELEASE.jar:5.2.7.RELEASE]
at org.springframework.security.web.access.ExceptionTranslationFilter.doFilter(ExceptionTranslationFilter.java:118) ~[spring-security-web-5.2.7.RELEASE.jar:5.2.7.RELEASE]
at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:334) ~[spring-security-web-5.2.7.RELEASE.jar:5.2.7.RELEASE]
at org.springframework.security.web.session.SessionManagementFilter.doFilter(SessionManagementFilter.java:137) ~[spring-security-web-5.2.7.RELEASE.jar:5.2.7.RELEASE]
at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:334) ~[spring-security-web-5.2.7.RELEASE.jar:5.2.7.RELEASE]
at org.springframework.security.web.authentication.AnonymousAuthenticationFilter.doFilter(AnonymousAuthenticationFilter.java:111) ~[spring-security-web-5.2.7.RELEASE.jar:5.2.7.RELEASE]
at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:334) ~[spring-security-web-5.2.7.RELEASE.jar:5.2.7.RELEASE]
at org.springframework.security.web.servletapi.SecurityContextHolderAwareRequestFilter.doFilter(SecurityContextHolderAwareRequestFilter.java:158) ~[spring-security-web-5.2.7.RELEASE.jar:5.2.7.RELEASE]
at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:334) ~[spring-security-web-5.2.7.RELEASE.jar:5.2.7.RELEASE]
at org.springframework.security.web.savedrequest.RequestCacheAwareFilter.doFilter(RequestCacheAwareFilter.java:63) ~[spring-security-web-5.2.7.RELEASE.jar:5.2.7.RELEASE]
at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:334) ~[spring-security-web-5.2.7.RELEASE.jar:5.2.7.RELEASE]
at org.springframework.security.web.authentication.AbstractAuthenticationProcessingFilter.doFilter(AbstractAuthenticationProcessingFilter.java:200) ~[spring-security-web-5.2.7.RELEASE.jar:5.2.7.RELEASE]
at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:334) ~[spring-security-web-5.2.7.RELEASE.jar:5.2.7.RELEASE]
at org.springframework.security.web.authentication.logout.LogoutFilter.doFilter(LogoutFilter.java:116) ~[spring-security-web-5.2.7.RELEASE.jar:5.2.7.RELEASE]
at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:334) ~[spring-security-web-5.2.7.RELEASE.jar:5.2.7.RELEASE]
at org.springframework.security.web.header.HeaderWriterFilter.doHeadersAfter(HeaderWriterFilter.java:92) ~[spring-security-web-5.2.7.RELEASE.jar:5.2.7.RELEASE]
at org.springframework.security.web.header.HeaderWriterFilter.doFilterInternal(HeaderWriterFilter.java:77) ~[spring-security-web-5.2.7.RELEASE.jar:5.2.7.RELEASE]
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) ~[spring-web-5.2.10.RELEASE.jar:5.2.10.RELEASE]
at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:334) ~[spring-security-web-5.2.7.RELEASE.jar:5.2.7.RELEASE]
at org.springframework.security.web.context.SecurityContextPersistenceFilter.doFilter(SecurityContextPersistenceFilter.java:105) ~[spring-security-web-5.2.7.RELEASE.jar:5.2.7.RELEASE]
at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:334) ~[spring-security-web-5.2.7.RELEASE.jar:5.2.7.RELEASE]
at org.springframework.security.web.context.request.async.WebAsyncManagerIntegrationFilter.doFilterInternal(WebAsyncManagerIntegrationFilter.java:56) ~[spring-security-web-5.2.7.RELEASE.jar:5.2.7.RELEASE]
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) ~[spring-web-5.2.10.RELEASE.jar:5.2.10.RELEASE]
at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:334) ~[spring-security-web-5.2.7.RELEASE.jar:5.2.7.RELEASE]
at org.springframework.security.web.FilterChainProxy.doFilterInternal(FilterChainProxy.java:215) ~[spring-security-web-5.2.7.RELEASE.jar:5.2.7.RELEASE]
at org.springframework.security.web.FilterChainProxy.doFilter(FilterChainProxy.java:178) ~[spring-security-web-5.2.7.RELEASE.jar:5.2.7.RELEASE]
at org.springframework.web.filter.DelegatingFilterProxy.invokeDelegate(DelegatingFilterProxy.java:358) ~[spring-web-5.2.10.RELEASE.jar:5.2.10.RELEASE]
at org.springframework.web.filter.DelegatingFilterProxy.doFilter(DelegatingFilterProxy.java:271) ~[spring-web-5.2.10.RELEASE.jar:5.2.10.RELEASE]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-9.0.39.jar:9.0.39]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.39.jar:9.0.39]
at org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:100) ~[spring-web-5.2.10.RELEASE.jar:5.2.10.RELEASE]
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) ~[spring-web-5.2.10.RELEASE.jar:5.2.10.RELEASE]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-9.0.39.jar:9.0.39]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.39.jar:9.0.39]
at org.springframework.web.filter.FormContentFilter.doFilterInternal(FormContentFilter.java:93) ~[spring-web-5.2.10.RELEASE.jar:5.2.10.RELEASE]
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) ~[spring-web-5.2.10.RELEASE.jar:5.2.10.RELEASE]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-9.0.39.jar:9.0.39]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.39.jar:9.0.39]
at 

MY存储库代码

import org.springframework.data.domain.Page;
import org.springframework.data.domain.Pageable;
import org.springframework.data.jpa.repository.JpaRepository;
import com.abd.hospitalmgt.entity.Doctors;

public interface Doctorepo extends JpaRepository<Doctors, Integer>{
Page<Doctors> findAll(Pageable pgble); 

}

我的控制器方法

@GetMapping("/doclist/{page}")
public String doclist(@PathVariable("page") Integer page,Model model) {

Pageable pgable = PageRequest.of(page, 10);

Page<Doctors> doc = drepo.findAll(pgable);
model.addAttribute("doclist", doc);
model.addAttribute("curpage", page);
model.addAttribute("totalpage", doc.getTotalPages());
System.out.println(doc);
return "/admin/doclist";
}

我的Jsp页面

<%@ include file="header.jsp" %> 
<body>
<table class="table table-striped">
<tr>
<th>ID</th>
<th>Doctor Name</th> 
<th>Department</th>
<th>Experience</th>
<th>Fee</th>
<th>Address</th>
<th>Action</th>
</tr>
<c:forEach var="tempdoc" items="${doclist}">
<tr>

<td>${tempdoc.id}</td> 
<td>${tempdoc.name}</td>
<td>${tempdoc.dept}</td>
<td>${tempdoc.experience}</td>
<td>Rs. ${tempdoc.fee}</td>
<td>${tempdoc.pat.address}</td>


</tr>
</c:forEach>

</table>
</div>

<nav aria-label="Page navigation example">
<ul class="pagination">
<li class="page-item"><a class="page-link" href="#">Previous</a></li>
<li class="page-item"><a class="page-link" href="#">1</a></li>
<li class="page-item"><a class="page-link" href="#">2</a></li>
<li class="page-item"><a class="page-link" href="#">Next</a></li>
</ul>
</nav>
</body>
</html>

Answer 1

我错过了下面方法中的.getContent((，在看到这么多关于分页的参考教程后，我知道需要添加*obj.*getContent((。

@GetMapping("/doclist/{page}")
public String doclist(@PathVariable("page") Integer page,Model model) {

Pageable pgable = PageRequest.of(page, 10);

Page<Doctors> doc = drepo.findAll(pgable);
model.addAttribute("doclist", doc.getContent());
model.addAttribute("curpage", page);
model.addAttribute("totalpage", doc.getTotalPages());

System.out.println(doc);
return "/admin/doclist";
}