我正在学习如何使用JSF的事件.出于某种原因,当我更改下拉菜单的值时,程序不会更改文本字段中的值.页面加载并显示"德国",但不会将文本字段更改为"DE".有什么建议？
的index.xhtml:
<?xml version='1.0' encoding='UTF-8' ?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml"
xmlns:f="http://java.sun.com/jsf/core"
xmlns:h="http://java.sun.com/jsf/html">
<h:head>
<title>Facelet Title</title>
</h:head>
<h:body>
<f:view>
<h:form>
<h:selectOneMenu value="#{Bean.selectedItem}" valueChangeListener="#{Bean.changeEvent}" onchange="submit()" >
<f:selectItems value="#{Bean.itemsList}" />
</h:selectOneMenu>
<br />
<h:inputText value="#{Bean.selectedItem}" />
</h:form>
</f:view>
</h:body>
MyBean.java
import javax.faces.bean.ManagedBean;
import javax.faces.bean.RequestScoped;
import java.util.ArrayList;
import javax.faces.model.SelectItem;
import javax.faces.event.ValueChangeEvent;
@ManagedBean (name = "Bean")
@RequestScoped
public class MyBean {
private static ArrayList menuItems;
private String selectedItem = "EN";
static {
menuItems = new ArrayList();
menuItems.add(new SelectItem("EN", "English")); …我从Spring Boot的1.5.2版中收到以下错误。在跟踪中，它提取了tomcat版本8.5.11，而我正在使用javax.servlet版本3.1。我到处看都说版本3.1应该可以解决此问题，但是即使删除.m2目录下的存储库，我仍然可以使用它。
java.util.concurrent.ExecutionException: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Tomcat].StandardHost[localhost].TomcatEmbeddedContext[]]
at java.util.concurrent.FutureTask.report(FutureTask.java:122) [na:1.8.0_66]
at java.util.concurrent.FutureTask.get(FutureTask.java:192) [na:1.8.0_66]
at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:939) ~[tomcat-embed-core-8.5.11.jar:8.5.11]
at org.apache.catalina.core.StandardHost.startInternal(StandardHost.java:872) [tomcat-embed-core-8.5.11.jar:8.5.11]
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150) [tomcat-embed-core-8.5.11.jar:8.5.11]
at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1419) [tomcat-embed-core-8.5.11.jar:8.5.11]
at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1409) [tomcat-embed-core-8.5.11.jar:8.5.11]
at java.util.concurrent.FutureTask.run(FutureTask.java:266) [na:1.8.0_66]
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142) [na:1.8.0_66]
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617) [na:1.8.0_66]
at java.lang.Thread.run(Thread.java:745) [na:1.8.0_66]
Caused by: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Tomcat].StandardHost[localhost].TomcatEmbeddedContext[]]
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:167) [tomcat-embed-core-8.5.11.jar:8.5.11]
... 6 common frames omitted
Caused by: org.apache.catalina.LifecycleException: Failed to start component [Pipeline[StandardEngine[Tomcat].StandardHost[localhost].TomcatEmbeddedContext[]]]
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:167) [tomcat-embed-core-8.5.11.jar:8.5.11]
at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5099) ~[tomcat-embed-core-8.5.11.jar:8.5.11]
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150) [tomcat-embed-core-8.5.11.jar:8.5.11]
... 6 common frames omitted …