-1
我想跟隨一個非常基本的JSF教程，但我得到一個空指針在我的第二頁（test.xhtml），如果我嘗試讀取用戶名，但找不到在這裏我做錯了什麼。JSF - Managed Bean = null重定向後
這是我的豆：
import java.io.Serializable;
import javax.faces.bean.ManagedBean;
import javax.faces.bean.SessionScoped;
@ManagedBean
@SessionScoped
public class User implements Serializable {
private static final long serialVersionUID = 1L;
private String name;
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
}
這是我出發的facelet：
<!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:ui="http://java.sun.com/jsf/facelets"
xmlns:f="http://java.sun.com/jsf/core"
xmlns:h="http://java.sun.com/jsf/html">
<h:head></h:head>
<body>
<h:form>
<h:inputText value="#{user.name}" />
<h:commandLink action="test" value="go" />
</h:form>
</body>
</html>
而且我想在此的facelet打印名稱：
<!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:ui="http://java.sun.com/jsf/facelets"
xmlns:f="http://java.sun.com/jsf/core"
xmlns:h="http://java.sun.com/jsf/html">
<h:head></h:head>
<body>
<h:form>
<h:outputText value="#{user.name}" />
</h:form>
</body>
</html>
請告訴我錯誤這裏？
編輯：堆棧跟蹤：
00:09:04,468 ERROR [io.undertow.request] (default task-8) UT005023: Exception handling request to /TestJSF/index.xhtml;jsessionid=WmQDd1vj88TJk7m3GC8DuHSo.xxx: javax.servlet.ServletException: /index.xhtml @10,39 value="#{user.name}": Target Unreachable, identifier 'user' resolved to null
at javax.faces.webapp.FacesServlet.service(FacesServlet.java:659)
at io.undertow.servlet.handlers.ServletHandler.handleRequest(ServletHandler.java:86)
at io.undertow.servlet.handlers.security.ServletSecurityRoleHandler.handleRequest(ServletSecurityRoleHandler.java:62)
at io.undertow.servlet.handlers.ServletDispatchingHandler.handleRequest(ServletDispatchingHandler.java:36)
at org.wildfly.extension.undertow.security.SecurityContextAssociationHandler.handleRequest(SecurityContextAssociationHandler.java:78)
at io.undertow.server.handlers.PredicateHandler.handleRequest(PredicateHandler.java:43)
at io.undertow.servlet.handlers.security.SSLInformationAssociationHandler.handleRequest(SSLInformationAssociationHandler.java:131)
at io.undertow.servlet.handlers.security.ServletAuthenticationCallHandler.handleRequest(ServletAuthenticationCallHandler.java:57)
at io.undertow.server.handlers.PredicateHandler.handleRequest(PredicateHandler.java:43)
at io.undertow.security.handlers.AbstractConfidentialityHandler.handleRequest(AbstractConfidentialityHandler.java:46)
at io.undertow.servlet.handlers.security.ServletConfidentialityConstraintHandler.handleRequest(ServletConfidentialityConstraintHandler.java:64)
at io.undertow.security.handlers.AuthenticationMechanismsHandler.handleRequest(AuthenticationMechanismsHandler.java:58)
at io.undertow.servlet.handlers.security.CachedAuthenticatedSessionHandler.handleRequest(CachedAuthenticatedSessionHandler.java:70)
at io.undertow.security.handlers.NotificationReceiverHandler.handleRequest(NotificationReceiverHandler.java:50)
at io.undertow.security.handlers.SecurityInitialHandler.handleRequest(SecurityInitialHandler.java:76)
at io.undertow.server.handlers.PredicateHandler.handleRequest(PredicateHandler.java:43)
at org.wildfly.extension.undertow.security.jacc.JACCContextIdHandler.handleRequest(JACCContextIdHandler.java:61)
at io.undertow.server.handlers.PredicateHandler.handleRequest(PredicateHandler.java:43)
at io.undertow.server.handlers.PredicateHandler.handleRequest(PredicateHandler.java:43)
at io.undertow.servlet.handlers.ServletInitialHandler.handleFirstRequest(ServletInitialHandler.java:278)
at io.undertow.servlet.handlers.ServletInitialHandler.dispatchRequest(ServletInitialHandler.java:255)
at io.undertow.servlet.handlers.ServletInitialHandler.access$000(ServletInitialHandler.java:80)
at io.undertow.servlet.handlers.ServletInitialHandler$1.handleRequest(ServletInitialHandler.java:174)
at io.undertow.server.Connectors.executeRootHandler(Connectors.java:199)
at io.undertow.server.HttpServerExchange$1.run(HttpServerExchange.java:774)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
at java.lang.Thread.run(Thread.java:744)
Caused by: javax.el.PropertyNotFoundException: /index.xhtml @10,39 value="#{user.name}": Target Unreachable, identifier 'user' resolved to null
at com.sun.faces.facelets.el.TagValueExpression.getType(TagValueExpression.java:100)
at com.sun.faces.renderkit.html_basic.HtmlBasicInputRenderer.getConvertedValue(HtmlBasicInputRenderer.java:95)
at javax.faces.component.UIInput.getConvertedValue(UIInput.java:1045)
at javax.faces.component.UIInput.validate(UIInput.java:975)
at javax.faces.component.UIInput.executeValidate(UIInput.java:1248)
at javax.faces.component.UIInput.processValidators(UIInput.java:712)
at javax.faces.component.UIForm.processValidators(UIForm.java:253)
at javax.faces.component.UIComponentBase.processValidators(UIComponentBase.java:1260)
at javax.faces.component.UIViewRoot.processValidators(UIViewRoot.java:1195)
at com.sun.faces.lifecycle.ProcessValidationsPhase.execute(ProcessValidationsPhase.java:76)
at com.sun.faces.lifecycle.Phase.doPhase(Phase.java:101)
at com.sun.faces.lifecycle.LifecycleImpl.execute(LifecycleImpl.java:198)
at javax.faces.webapp.FacesServlet.service(FacesServlet.java:646)
... 27 more
Caused by: javax.el.PropertyNotFoundException: Target Unreachable, identifier 'user' resolved to null
at com.sun.el.parser.AstValue.getTarget(AstValue.java:174)
at com.sun.el.parser.AstValue.getType(AstValue.java:86)
at com.sun.el.ValueExpressionImpl.getType(ValueExpressionImpl.java:201)
at org.jboss.weld.el.WeldValueExpression.getType(WeldValueExpression.java:93)
at org.jboss.weld.el.WeldValueExpression.getType(WeldValueExpression.java:93)
at com.sun.faces.facelets.el.TagValueExpression.getType(TagValueExpression.java:98)
... 39 more
編輯2：在faces-config.xml只是看起來像：
<?xml version="1.0" encoding="UTF-8"?>
<faces-config version="2.2" xmlns="http://xmlns.jcp.org/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-facesconfig_2_2.xsd">
</faces-config>
的web.xml文件：
HTTP ：//xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd「> 面臨的Servlet javax.faces.webapp.FacesServlet 面孔的Servlet * .xhtml
<!-- Date Converter use system time zone instead of UTC -->
<context-param>
<param-name>javax.faces.DATETIMECONVERTER_DEFAULT_TIMEZONE_IS_SYSTEM_TIMEZONE</param-name>
<param-value>true</param-value>
</context-param>
<!-- Do not send XML comments to the client -->
<context-param>
<param-name>javax.faces.FACELETS_SKIP_COMMENTS</param-name>
<param-value>true</param-value>
</context-param>
<!-- Process zero-length input strings as null values -->
<context-param>
<param-name>javax.faces.INTERPRET_EMPTY_STRING_SUBMITTED_VALUES_AS_NULL</param-name>
<param-value>true</param-value>
</context-param>
<!-- Use development mode -->
<context-param>
<param-name>javax.faces.PROJECT_STAGE</param-name>
<param-value>Development</param-value>
</context-param>
<context-param>
<param-name>facelets.DEVELOPMENT</param-name>
<param-value>true</param-value>
</context-param>
<!-- Welcome page -->
<welcome-file-list>
<welcome-file>index.xhtml</welcome-file>
</welcome-file-list>
</web-app>
也許使用''。 –
DavidS
發佈空指針的堆棧跟蹤。 –
你可以添加你的「faces-config.xml」嗎？ –