Jsf PrimeFaces<；p:commandButton>；无法更新<；h：输出文本>；并引发org.primefaces.expression.ComponentNotFoundException：

在提交文本框中的值并单击按钮时更新元素时出现异常，该按钮应更新Id显示的另一个元素，但会引发异常。 我理解异常，但仍然无法确定如何解决它

我的pom.xml文件：

****<project xmlns="http://maven.apache.org/POM/4.0.0"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>jsftesting</groupId>
<artifactId>jsf</artifactId>
<packaging>war</packaging>
<version>0.0.1-SNAPSHOT</version>
<name>jsf Maven Webapp</name>
<url>http://maven.apache.org</url>
<dependencies>
    <dependency>
        <groupId>junit</groupId>
        <artifactId>junit</artifactId>
        <version>3.8.1</version>
        <scope>test</scope>
    </dependency>
    <dependency>
        <groupId>com.sun.faces</groupId>
        <artifactId>jsf-api</artifactId>
        <version>2.1.7</version>
    </dependency>
    <dependency>
        <groupId>org.primefaces</groupId>
        <artifactId>primefaces</artifactId>
        <version>7.0</version>
    </dependency>
    <dependency>
        <groupId>com.sun.faces</groupId>
        <artifactId>jsf-impl</artifactId>
        <version>2.1.7</version>
    </dependency>
</dependencies>
<build>
    <finalName>jsf</finalName>

    <plugins>
        <plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-compiler-plugin</artifactId>
            <version>2.3.1</version>

            <configuration>
                <source>1.6</source>
                <target>1.6</target>
            </configuration>
        </plugin>
    </plugins>
</build>
</project>

我得到的例外情况

SEVERE: Error Rendering View[/views/home.xhtml]
org.primefaces.expression.ComponentNotFoundException: Cannot find component for expression "display" referenced from "j_idt4".
    at org.primefaces.expression.SearchExpressionFacade.cannotFindComponent(SearchExpressionFacade.java:720)
    at org.primefaces.expression.SearchExpressionFacade.resolveClientIds(SearchExpressionFacade.java:259)
    at org.primefaces.util.AjaxRequestBuilder.addExpressions(AjaxRequestBuilder.java:136)
    at org.primefaces.util.AjaxRequestBuilder.update(AjaxRequestBuilder.java:129)
    at org.primefaces.renderkit.CoreRenderer.buildAjaxRequest(CoreRenderer.java:412)
    at org.primefaces.renderkit.CoreRenderer.buildAjaxRequest(CoreRenderer.java:399)
    at org.primefaces.component.commandbutton.CommandButtonRenderer.buildRequest(CommandButtonRenderer.java:145)
    at org.primefaces.component.commandbutton.CommandButtonRenderer.encodeMarkup(CommandButtonRenderer.java:78)
    at org.primefaces.component.commandbutton.CommandButtonRenderer.encodeEnd(CommandButtonRenderer.java:63)
    at javax.faces.component.UIComponentBase.encodeEnd(UIComponentBase.java:875)
    at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1786)
    at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1782)
    at com.sun.faces.application.view.FaceletViewHandlingStrategy.renderView(FaceletViewHandlingStrategy.java:402)
    at com.sun.faces.application.view.MultiViewHandler.renderView(MultiViewHandler.java:125)
    at com.sun.faces.lifecycle.RenderResponsePhase.execute(RenderResponsePhase.java:121)
    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:594)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
    at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:202)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96)
    at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:526)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:139)
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:92)
    at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:678)
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:74)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:343)
    at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:367)
    at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:65)
    at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:860)
    at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1591)
    at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)
    at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
    at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
    at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
    at java.base/java.lang.Thread.run(Unknown Source)

我无法确定为什么commandButton不能更新上面提到的Id的元素。虽然它非常基本，但仍然需要澄清，为什么它不能更新元素

---

提前感谢

您将JSF 2.2 XHTML名称空间与

http://xmlns.jcp.org

域，但您使用的是Mojarra 2.1.7，实际上使用的是近8年的JSF 2.1实现。JSF2.2名称空间仅在JSF2.2或更高版本的实现中受支持。实际上，您的

实际上并没有被执行，而是被解释为纯模板文本

如果从PrimeFaces

标记中删除

update=“display”

，则页面将加载良好，但当您检查生成的HTML源代码时，仍然会看到所有核心JSF标记在那里未被解析。这就解释了PrimeFaces标签的问题。它确实找不到组件，因为未正确识别

名称空间

您可以通过从

http://xmlns.jcp.org

至

http://java.sun.com

域，但不建议这样做。最好的办法就是让你们的图书馆保持最新。这些天，你可以在小组中找到莫哈拉，目前（2019年12月）是2.3.14

替换

<dependency>
    <groupId>com.sun.faces</groupId>
    <artifactId>jsf-api</artifactId>
    <version>2.1.7</version>
</dependency>
<dependency>
    <groupId>com.sun.faces</groupId>
    <artifactId>jsf-impl</artifactId>
    <version>2.1.7</version>
</dependency>

com.sun.faces

我又检查了一遍，一切正常，你们中有人能试着编译并运行这段代码吗？@BalusC你说得对，我为这个错误的信息感到抱歉。我以为我也遇到过同样的问题，但我的问题不同。我想我尝试了所有方法，但这段代码似乎很好，它在其他地方失败了。@BalusC你有机会运行上面的代码吗？或者发现了什么？我被困在这里了。是的。Mojara是核心JSF（来自
http://xmlns.jcp.org/jsf/*
名称空间）。如果没有核心JSF impl，您就无法运行JSF（目前有两种可用：Mojarra和MyFaces，您目前正在使用Mojarra）。PrimeFaces只是一个JSF扩展（来自
http://primefaces.org/*
名称空间）。您使用的是史前版本的Mojarra 2.1.7。您需要删除它的两个
com.sun.faces::
依赖项，并用
org.glassfish:jakarta.faces
中提供的最新版本2.3.14替换它。
SEVERE: Error Rendering View[/views/home.xhtml]
org.primefaces.expression.ComponentNotFoundException: Cannot find component for expression "display" referenced from "j_idt4".
    at org.primefaces.expression.SearchExpressionFacade.cannotFindComponent(SearchExpressionFacade.java:720)
    at org.primefaces.expression.SearchExpressionFacade.resolveClientIds(SearchExpressionFacade.java:259)
    at org.primefaces.util.AjaxRequestBuilder.addExpressions(AjaxRequestBuilder.java:136)
    at org.primefaces.util.AjaxRequestBuilder.update(AjaxRequestBuilder.java:129)
    at org.primefaces.renderkit.CoreRenderer.buildAjaxRequest(CoreRenderer.java:412)
    at org.primefaces.renderkit.CoreRenderer.buildAjaxRequest(CoreRenderer.java:399)
    at org.primefaces.component.commandbutton.CommandButtonRenderer.buildRequest(CommandButtonRenderer.java:145)
    at org.primefaces.component.commandbutton.CommandButtonRenderer.encodeMarkup(CommandButtonRenderer.java:78)
    at org.primefaces.component.commandbutton.CommandButtonRenderer.encodeEnd(CommandButtonRenderer.java:63)
    at javax.faces.component.UIComponentBase.encodeEnd(UIComponentBase.java:875)
    at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1786)
    at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1782)
    at com.sun.faces.application.view.FaceletViewHandlingStrategy.renderView(FaceletViewHandlingStrategy.java:402)
    at com.sun.faces.application.view.MultiViewHandler.renderView(MultiViewHandler.java:125)
    at com.sun.faces.lifecycle.RenderResponsePhase.execute(RenderResponsePhase.java:121)
    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:594)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
    at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:202)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96)
    at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:526)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:139)
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:92)
    at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:678)
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:74)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:343)
    at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:367)
    at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:65)
    at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:860)
    at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1591)
    at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)
    at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
    at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
    at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
    at java.base/java.lang.Thread.run(Unknown Source)



<dependency>
    <groupId>com.sun.faces</groupId>
    <artifactId>jsf-api</artifactId>
    <version>2.1.7</version>
</dependency>
<dependency>
    <groupId>com.sun.faces</groupId>
    <artifactId>jsf-impl</artifactId>
    <version>2.1.7</version>
</dependency>

<dependency>
    <groupId>org.glassfish</groupId>
    <artifactId>jakarta.faces</artifactId>
    <version>2.3.14</version>
</dependency>