我正在使用 JSF 2.0 和 PrimeFaces。我有一个 selectOneMenu 和一个 selectManyCheckbox。我想实现这个场景:
当用户选择时:
- option1(PieChart),然后允许用户勾选最多一个checkbox
- option2(BarChart),然后允许用户勾选最多两个复选框
这是我到目前为止的尝试, View :
<h:selectOneMenu value="#{bean.chartType}">
<f:selectItem itemValue="PieChart" itemLabel="PieChart" />
<f:selectItem itemValue="BarChart" itemLabel="BarChart" />
<p:ajax event="keyup" update="checkbox" listener="#{bean.checkboxHandler}" />
</h:selectOneMenu>
<h:selectManyCheckbox id="checkbox" value="#{bean.selectedItemscheckbox}">
<f:selectItem itemValue="priority" itemLabel="By priority" />
<f:selectItem itemValue="project" itemLabel="By project" />
<f:selectItem itemValue="issuetype" itemLabel="By IssueType" />
<f:selectItem itemValue="group" itemLabel="By group" />
</h:selectManyCheckbox>
(注意:我不确定 <p:ajax event>
是否正确)
bean :
public void checkboxHandler() {
Iterator it1 = selectedItemscheckbox.iterator();
if (chartType.equals("PieChart")) {
while (it1.hasNext()) {
if (selectedItemscheckbox.size() > 1) {
// Here should be somthing that shows a message to the user.
}
}
}
}
在尝试了BalusC的解决方案后,出现了这个错误:
java.lang.InstantiationException: DAOKPI.TestAjax$MyCheckboxValidator
at java.lang.Class.newInstance0(Class.java:340)
at java.lang.Class.newInstance(Class.java:308)
at com.sun.faces.application.ApplicationImpl.newThing(ApplicationImpl.java:1699)
at com.sun.faces.application.ApplicationImpl.createValidator(ApplicationImpl.java:1557)
at com.sun.faces.facelets.tag.jsf.ValidatorTagHandlerDelegateImpl.createValidator(ValidatorTag HandlerDelegateImpl.java:238)
at com.sun.faces.facelets.tag.jsf.ValidatorTagHandlerDelegateImpl.applyAttachedObject(Validato rTagHandlerDelegateImpl.java:132)
at com.sun.faces.facelets.tag.jsf.ValidatorTagHandlerDelegateImpl.applyNested(ValidatorTagHand lerDelegateImpl.java:205)
at com.sun.faces.facelets.tag.jsf.ValidatorTagHandlerDelegateImpl.apply(ValidatorTagHandlerDel egateImpl.java:87)
at javax.faces.view.facelets.DelegatingMetaTagHandler.apply(DelegatingMetaTagHandler.java:120)
at javax.faces.view.facelets.CompositeFaceletHandler.apply(CompositeFaceletHandler.java:98)
at javax.faces.view.facelets.DelegatingMetaTagHandler.applyNextHandler(DelegatingMetaTagHandle r.java:137)
at com.sun.faces.facelets.tag.jsf.ComponentTagHandlerDelegateImpl.apply(ComponentTagHandlerDel egateImpl.java:188)
at javax.faces.view.facelets.DelegatingMetaTagHandler.apply(DelegatingMetaTagHandler.java:120)
at javax.faces.view.facelets.CompositeFaceletHandler.apply(CompositeFaceletHandler.java:98)
at javax.faces.view.facelets.DelegatingMetaTagHandler.applyNextHandler(DelegatingMetaTagHandler.java:137)
at com.sun.faces.facelets.tag.jsf.ComponentTagHandlerDelegateImpl.apply(ComponentTagHandlerDelegateImpl.java:188)
at javax.faces.view.facelets.DelegatingMetaTagHandler.apply(DelegatingMetaTagHandler.java:120)
at javax.faces.view.facelets.CompositeFaceletHandler.apply(CompositeFaceletHandler.java:98)
at javax.faces.view.facelets.DelegatingMetaTagHandler.applyNextHandler(DelegatingMetaTagHandler.java:137)
at com.sun.faces.facelets.tag.jsf.ComponentTagHandlerDelegateImpl.apply(ComponentTagHandlerDelegateImpl.java:188)
at javax.faces.view.facelets.DelegatingMetaTagHandler.apply(DelegatingMetaTagHandler.java:120)
at javax.faces.view.facelets.DelegatingMetaTagHandler.applyNextHandler(DelegatingMetaTagHandler.java:137)
at com.sun.faces.facelets.tag.jsf.ComponentTagHandlerDelegateImpl.apply(ComponentTagHandlerDelegateImpl.java:188)
at javax.faces.view.facelets.DelegatingMetaTagHandler.apply(DelegatingMetaTagHandler.java:120)
at javax.faces.view.facelets.CompositeFaceletHandler.apply(CompositeFaceletHandler.java:98)
at javax.faces.view.facelets.DelegatingMetaTagHandler.applyNextHandler(DelegatingMetaTagHandler.java:137)
at com.sun.faces.facelets.tag.jsf.ComponentTagHandlerDelegateImpl.apply(ComponentTagHandlerDelegateImpl.java:188)
at javax.faces.view.facelets.DelegatingMetaTagHandler.apply(DelegatingMetaTagHandler.java:120)
at javax.faces.view.facelets.CompositeFaceletHandler.apply(CompositeFaceletHandler.java:98)
at com.sun.faces.facelets.compiler.NamespaceHandler.apply(NamespaceHandler.java:93)
at javax.faces.view.facelets.CompositeFaceletHandler.apply(CompositeFaceletHandler.java:98)
at com.sun.faces.facelets.compiler.EncodingHandler.apply(EncodingHandler.java:86)
at com.sun.faces.facelets.impl.DefaultFacelet.apply(DefaultFacelet.java:152)
at com.sun.faces.application.view.FaceletViewHandlingStrategy.buildView(FaceletViewHandlingStrategy.java:769)
at com.sun.faces.lifecycle.RenderResponsePhase.execute(RenderResponsePhase.java:100)
at com.sun.faces.lifecycle.Phase.doPhase(Phase.java:101)
at com.sun.faces.lifecycle.LifecycleImpl.render(LifecycleImpl.java:139)
at javax.faces.webapp.FacesServlet.service(FacesServlet.java:410)
at org.apache.catalina.core.StandardWrapper.service(StandardWrapper.java:1534)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:281)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:175)
at org.apache.catalina.core.StandardPipeline.doInvoke(StandardPipeline.java:655)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:595)
at com.sun.enterprise.web.WebPipeline.invoke(WebPipeline.java:98)
at com.sun.enterprise.web.PESessionLockingStandardPipeline.invoke(PESessionLockingStandardPipeline.java:91)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:162)
at org.apache.catalina.connector.CoyoteAdapter.doService(CoyoteAdapter.java:326)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:227)
at com.sun.enterprise.v3.services.impl.ContainerMapper.service(ContainerMapper.java:170)
at com.sun.grizzly.http.ProcessorTask.invokeAdapter(ProcessorTask.java:822)
at com.sun.grizzly.http.ProcessorTask.doProcess(ProcessorTask.java:719)
at com.sun.grizzly.http.ProcessorTask.process(ProcessorTask.java:1013)
at com.sun.grizzly.http.DefaultProtocolFilter.execute(DefaultProtocolFilter.java:225)
at com.sun.grizzly.DefaultProtocolChain.executeProtocolFilter(DefaultProtocolChain.java:137)
at com.sun.grizzly.DefaultProtocolChain.execute(DefaultProtocolChain.java:104)
at com.sun.grizzly.DefaultProtocolChain.execute(DefaultProtocolChain.java:90)
at com.sun.grizzly.http.HttpProtocolChain.execute(HttpProtocolChain.java:79)
at com.sun.grizzly.ProtocolChainContextTask.doCall(ProtocolChainContextTask.java:54)
at com.sun.grizzly.SelectionKeyContextTask.call(SelectionKeyContextTask.java:59)
at com.sun.grizzly.ContextTask.run(ContextTask.java:71)
at com.sun.grizzly.util.AbstractThreadPool$Worker.doWork(AbstractThreadPool.java:532)
at com.sun.grizzly.util.AbstractThreadPool$Worker.run(AbstractThreadPool.java:513)
at java.lang.Thread.run(Thread.java:662)
更新
谢谢问题解决:)
最佳答案
您需要一个自定义 Validator
抛出 ValidatorException
当复选框包含太多选中的项目时。这Validator
需要附加到复选框组件并且应该有一个 <h:message>
或 <h:messages>
View 中某处可以显示验证错误的组件。
ajax 事件错误。在下拉列表中,您想 Hook change
事件代替。在您想要 Hook 的复选框或单选按钮内 click
事件代替。当您离开 event
时,这两者都已经是默认设置了属性为默认值。每个组件应该依次 ajax 提交自己和另一个组件,最后重新呈现消息组件以反射(reflect)验证错误。
为了在自定义 validator 中显示选定的下拉值,最简洁的方法是将整个下拉组件设置为复选框组件的自定义属性。这可以通过将下拉列表绑定(bind)到 View 来实现 binding
属性并将其指定为 <f:attribute>
的值在复选框内。然后可以在自定义 validator 中获取下拉组件及其值。
总而言之,下面的启动示例应该有效(请注意,我使用了 <f:ajax>
,因为 <p:ajax>
在这种特殊情况下没有增加额外的优势,我承认无法从头顶判断它如何以及是否有效):
<h:selectOneMenu id="chartType" binding="#{chartType}" value="#{bean.chartType}">
<f:selectItem itemValue="PieChart" itemLabel="PieChart" />
<f:selectItem itemValue="BarChart" itemLabel="BarChart" />
<f:ajax execute="chartType checkbox" render="checkboxmessage" />
</h:selectOneMenu>
<h:selectManyCheckbox id="checkbox" value="#{bean.selectedItemscheckbox}">
<f:selectItem itemValue="priority" itemLabel="By priority" />
<f:selectItem itemValue="project" itemLabel="By project" />
<f:selectItem itemValue="issuetype" itemLabel="By IssueType" />
<f:selectItem itemValue="group" itemLabel="By group" />
<f:validator validatorId="myCheckboxValidator" />
<f:attribute name="chartType" value="#{chartType}" />
<f:ajax execute="chartType checkbox" render="checkboxmessage" />
</h:selectManyCheckbox>
<h:message id="checkboxmessage" for="checkbox" />
与
@FacesValidator("myCheckboxValidator")
public class MyCheckboxValidator implements Validator {
@Override
public void validate(FacesContext context, UIComponent component, Object value) throws ValidatorException {
UIInput chartTypeComponent = (UIInput) component.getAttributes().get("chartType");
String chartType = (String) chartTypeComponent.getValue();
List<String> selectedItemscheckbox = (List<String>) value;
if ("PieChart".equals(chartType) && selectedItemscheckbox.size() > 1) {
throw new ValidatorException(new FacesMessage("Max 1 item allowed"));
}
else if ("BarChart".equals(chartType) && selectedItemscheckbox.size() > 2) {
throw new ValidatorException(new FacesMessage("Max 2 items allowed"));
}
}
}
请注意,我假设 #{bean.selectedItemscheckbox}
成为List<String>
.如果它实际上是 String[]
,那么您需要相应地更改 validator 代码。
关于java - 如何根据 selectOneMenu 的当前选择验证 selectManyCheckbox 的最大选中值数量?,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/6827675/