小贝子编程

Spring托管对象始终为null.柳条框架



今天我遇到了一个令人愤怒的问题，如下所示：

我有一个基于wicket的应用程序，我使用spring来管理将应用程序连接到数据库的对象，过去这对我来说很好

我使用eclipse中内置的jetty服务器来运行应用程序，我注意到，当我在我要填充的类中的数据源方法中放置断点时，在启动时，似乎调用了setter，并且数据源对象具有我想要的数据。

然而，当我使用spring将其值注入其数据源对象的对象时，该对象返回null。

代码片段如下：

声明要由spring管理的类：

public class HomePage extends WebPage {
@SpringBean(name = "userImpl")
private UserImpl userImp;
/**
 * 
 */

我称这个对象的地方：

    protected void onSubmit() {
            super.onSubmit();
            try {
                Person returnedUser = userImp.findUser(model.getUsername(),
                        model.getPassword());
                setResponsePage(StudentPage.class);
                returnedUser.getEmail();
            } catch (Exception e) {

我的应用程序上下文文件：

<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"        xmlns:context="http://www.springframework.org/schema/context"
xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context-3.0.xsd">
<!-- the DataSource (parameterized for configuration via a PropertyPlaceHolderConfigurer) -->
<bean id="datasource" destroy-method="close"
    class="org.apache.commons.dbcp.BasicDataSource">
    <property name="driverClassName" value="com.mysql.jdbc.Driver" />
    <property name="url" value="jdbc:mysql://localhost:3306" />
    <property name="username" value="root" />
    <property name="password" value="admin" />
</bean>
<bean id="userImp" class="com.bascombe.persistance.UserImpl">
    <property name="datasource" ref="datasource" />
</bean>

我的web.xml：

<?xml version="1.0" encoding="ISO-8859-1"?>

http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"version="2.5">

<display-name>FinalYearProject</display-name>
<context-param>
    <param-name>contextConfigLocation</param-name>
    <param-value>classpath:applicationContext.xml</param-value>
</context-param>
<filter>
    <filter-name>wicket.FinalYearProject</filter-name>
    <filter-class>org.apache.wicket.protocol.http.WicketFilter</filter-class>
    <init-param>
        <param-name>applicationClassName</param-name>
        <param-value>com.bascombe.pages.WicketApplication</param-value>
    </init-param>
</filter>
<filter>
    <filter-name>springRequestContextFilter</filter-name>
    <filter-class>org.springframework.web.filter.RequestContextFilter</filter-class>
</filter>
<filter-mapping>
    <filter-name>wicket.FinalYearProject</filter-name>
    <url-pattern>/*</url-pattern>
</filter-mapping>
<listener>
    <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
</listener>

提交表单时的结果是一个空指针异常，如下所示：

java.lang.NullPointerException
at com.bascombe.pages.HomePage$1.onSubmit(HomePage.java:37)
at org.apache.wicket.markup.html.form.Form$9.component(Form.java:1246)
at org.apache.wicket.markup.html.form.Form$9.component(Form.java:1240)
at org.apache.wicket.util.visit.Visits.visitPostOrderHelper(Visits.java:274)
at org.apache.wicket.util.visit.Visits.visitPostOrder(Visits.java:245)
at org.apache.wicket.markup.html.form.Form.delegateSubmit(Form.java:1239)
at org.apache.wicket.markup.html.form.Form.process(Form.java:921)
at org.apache.wicket.markup.html.form.Form.onFormSubmitted(Form.java:767)
at org.apache.wicket.markup.html.form.Form.onFormSubmitted(Form.java:700)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at org.apache.wicket.RequestListenerInterface.internalInvoke(RequestListenerInterface.java:258)
at org.apache.wicket.RequestListenerInterface.invoke(RequestListenerInterface.java:216)
at org.apache.wicket.core.request.handler.ListenerInterfaceRequestHandler.invokeListener(ListenerInterfaceRequestHandler.java:240)
at org.apache.wicket.core.request.handler.ListenerInterfaceRequestHandler.respond(ListenerInterfaceRequestHandler.java:226)
at org.apache.wicket.request.cycle.RequestCycle$HandlerExecutor.respond(RequestCycle.java:840)
at org.apache.wicket.request.RequestHandlerStack.execute(RequestHandlerStack.java:64)
at org.apache.wicket.request.cycle.RequestCycle.execute(RequestCycle.java:254)
at org.apache.wicket.request.cycle.RequestCycle.processRequest(RequestCycle.java:211)
at org.apache.wicket.request.cycle.RequestCycle.processRequestAndDetach(RequestCycle.java:282)
at org.apache.wicket.protocol.http.WicketFilter.processRequestCycle(WicketFilter.java:244)
at org.apache.wicket.protocol.http.WicketFilter.processRequest(WicketFilter.java:188)
at org.apache.wicket.protocol.http.WicketFilter.doFilter(WicketFilter.java:267)
at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1332)
at org.eclipse.jetty.servlet.ServletHandler.doHandle(ServletHandler.java:477)
at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:119)
at org.eclipse.jetty.security.SecurityHandler.handle(SecurityHandler.java:524)
at org.eclipse.jetty.server.session.SessionHandler.doHandle(SessionHandler.java:227)
at org.eclipse.jetty.server.handler.ContextHandler.doHandle(ContextHandler.java:1031)
at org.eclipse.jetty.servlet.ServletHandler.doScope(ServletHandler.java:406)
at org.eclipse.jetty.server.session.SessionHandler.doScope(SessionHandler.java:186)
at org.eclipse.jetty.server.handler.ContextHandler.doScope(ContextHandler.java:965)
at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:117)
at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:111)
at org.eclipse.jetty.server.Server.handle(Server.java:348)
at org.eclipse.jetty.server.AbstractHttpConnection.handleRequest(AbstractHttpConnection.java:452)
at org.eclipse.jetty.server.BlockingHttpConnection.handleRequest(BlockingHttpConnection.java:47)
at org.eclipse.jetty.server.AbstractHttpConnection.content(AbstractHttpConnection.java:894)
at org.eclipse.jetty.server.AbstractHttpConnection$RequestHandler.content(AbstractHttpConnection.java:948)
at org.eclipse.jetty.http.HttpParser.parseNext(HttpParser.java:851)
at org.eclipse.jetty.http.HttpParser.parseAvailable(HttpParser.java:235)
at org.eclipse.jetty.server.BlockingHttpConnection.handle(BlockingHttpConnection.java:66)
at org.eclipse.jetty.server.bio.SocketConnector$ConnectorEndPoint.run(SocketConnector.java:254)
at org.eclipse.jetty.server.ssl.SslSocketConnector$SslConnectorEndPoint.run(SslSocketConnector.java:665)
at org.eclipse.jetty.util.thread.QueuedThreadPool.runJob(QueuedThreadPool.java:603)
at org.eclipse.jetty.util.thread.QueuedThreadPool$3.run(QueuedThreadPool.java:538)
at java.lang.Thread.run(Unknown Source)
java.lang.NullPointerException
at com.bascombe.pages.HomePage$1.onSubmit(HomePage.java:37)
at org.apache.wicket.markup.html.form.Form$9.component(Form.java:1246)
at org.apache.wicket.markup.html.form.Form$9.component(Form.java:1240)
at org.apache.wicket.util.visit.Visits.visitPostOrderHelper(Visits.java:274)
at org.apache.wicket.util.visit.Visits.visitPostOrder(Visits.java:245)
at org.apache.wicket.markup.html.form.Form.delegateSubmit(Form.java:1239)
at org.apache.wicket.markup.html.form.Form.process(Form.java:921)
at org.apache.wicket.markup.html.form.Form.onFormSubmitted(Form.java:767)
at org.apache.wicket.markup.html.form.Form.onFormSubmitted(Form.java:700)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at org.apache.wicket.RequestListenerInterface.internalInvoke(RequestListenerInterface.java:258)
at org.apache.wicket.RequestListenerInterface.invoke(RequestListenerInterface.java:216)
at org.apache.wicket.core.request.handler.ListenerInterfaceRequestHandler.invokeListener(ListenerInterfaceRequestHandler.java:240)
at org.apache.wicket.core.request.handler.ListenerInterfaceRequestHandler.respond(ListenerInterfaceRequestHandler.java:226)
at org.apache.wicket.request.cycle.RequestCycle$HandlerExecutor.respond(RequestCycle.java:840)
at org.apache.wicket.request.RequestHandlerStack.execute(RequestHandlerStack.java:64)
at org.apache.wicket.request.cycle.RequestCycle.execute(RequestCycle.java:254)
at org.apache.wicket.request.cycle.RequestCycle.processRequest(RequestCycle.java:211)
at org.apache.wicket.request.cycle.RequestCycle.processRequestAndDetach(RequestCycle.java:282)
at org.apache.wicket.protocol.http.WicketFilter.processRequestCycle(WicketFilter.java:244)
at org.apache.wicket.protocol.http.WicketFilter.processRequest(WicketFilter.java:188)
at org.apache.wicket.protocol.http.WicketFilter.doFilter(WicketFilter.java:267)
at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1332)
at org.eclipse.jetty.servlet.ServletHandler.doHandle(ServletHandler.java:477)
at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:119)
at org.eclipse.jetty.security.SecurityHandler.handle(SecurityHandler.java:524)
at org.eclipse.jetty.server.session.SessionHandler.doHandle(SessionHandler.java:227)
at org.eclipse.jetty.server.handler.ContextHandler.doHandle(ContextHandler.java:1031)
at org.eclipse.jetty.servlet.ServletHandler.doScope(ServletHandler.java:406)
at org.eclipse.jetty.server.session.SessionHandler.doScope(SessionHandler.java:186)
at org.eclipse.jetty.server.handler.ContextHandler.doScope(ContextHandler.java:965)
at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:117)
at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:111)
at org.eclipse.jetty.server.Server.handle(Server.java:348)
at org.eclipse.jetty.server.AbstractHttpConnection.handleRequest(AbstractHttpConnection.java:452)
at org.eclipse.jetty.server.BlockingHttpConnection.handleRequest(BlockingHttpConnection.java:47)
at org.eclipse.jetty.server.AbstractHttpConnection.content(AbstractHttpConnection.java:894)
at org.eclipse.jetty.server.AbstractHttpConnection$RequestHandler.content(AbstractHttpConnection.java:948)
at org.eclipse.jetty.http.HttpParser.parseNext(HttpParser.java:851)
at org.eclipse.jetty.http.HttpParser.parseAvailable(HttpParser.java:235)
at org.eclipse.jetty.server.BlockingHttpConnection.handle(BlockingHttpConnection.java:66)
at org.eclipse.jetty.server.bio.SocketConnector$ConnectorEndPoint.run(SocketConnector.java:254)
at org.eclipse.jetty.server.ssl.SslSocketConnector$SslConnectorEndPoint.run(SslSocketConnector.java:665)
at org.eclipse.jetty.util.thread.QueuedThreadPool.runJob(QueuedThreadPool.java:603)
at org.eclipse.jetty.util.thread.QueuedThreadPool$3.run(QueuedThreadPool.java:538)
at java.lang.Thread.run(Unknown Source)
java.lang.NullPointerException
at com.bascombe.pages.HomePage$1.onSubmit(HomePage.java:37)
at org.apache.wicket.markup.html.form.Form$9.component(Form.java:1246)
at org.apache.wicket.markup.html.form.Form$9.component(Form.java:1240)
at org.apache.wicket.util.visit.Visits.visitPostOrderHelper(Visits.java:274)
at org.apache.wicket.util.visit.Visits.visitPostOrder(Visits.java:245)
at org.apache.wicket.markup.html.form.Form.delegateSubmit(Form.java:1239)
at org.apache.wicket.markup.html.form.Form.process(Form.java:921)
at org.apache.wicket.markup.html.form.Form.onFormSubmitted(Form.java:767)
at org.apache.wicket.markup.html.form.Form.onFormSubmitted(Form.java:700)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at org.apache.wicket.RequestListenerInterface.internalInvoke(RequestListenerInterface.java:258)
at org.apache.wicket.RequestListenerInterface.invoke(RequestListenerInterface.java:216)
at org.apache.wicket.core.request.handler.ListenerInterfaceRequestHandler.invokeListener(ListenerInterfaceRequestHandler.java:240)
at org.apache.wicket.core.request.handler.ListenerInterfaceRequestHandler.respond(ListenerInterfaceRequestHandler.java:226)
at org.apache.wicket.request.cycle.RequestCycle$HandlerExecutor.respond(RequestCycle.java:840)
at org.apache.wicket.request.RequestHandlerStack.execute(RequestHandlerStack.java:64)
at org.apache.wicket.request.cycle.RequestCycle.execute(RequestCycle.java:254)
at org.apache.wicket.request.cycle.RequestCycle.processRequest(RequestCycle.java:211)
at org.apache.wicket.request.cycle.RequestCycle.processRequestAndDetach(RequestCycle.java:282)
at org.apache.wicket.protocol.http.WicketFilter.processRequestCycle(WicketFilter.java:244)
at org.apache.wicket.protocol.http.WicketFilter.processRequest(WicketFilter.java:188)
at org.apache.wicket.protocol.http.WicketFilter.doFilter(WicketFilter.java:267)
at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1332)
at org.eclipse.jetty.servlet.ServletHandler.doHandle(ServletHandler.java:477)
at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:119)
at org.eclipse.jetty.security.SecurityHandler.handle(SecurityHandler.java:524)
at org.eclipse.jetty.server.session.SessionHandler.doHandle(SessionHandler.java:227)
at org.eclipse.jetty.server.handler.ContextHandler.doHandle(ContextHandler.java:1031)
at org.eclipse.jetty.servlet.ServletHandler.doScope(ServletHandler.java:406)
at org.eclipse.jetty.server.session.SessionHandler.doScope(SessionHandler.java:186)
at org.eclipse.jetty.server.handler.ContextHandler.doScope(ContextHandler.java:965)
at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:117)
at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:111)
at org.eclipse.jetty.server.Server.handle(Server.java:348)
at org.eclipse.jetty.server.AbstractHttpConnection.handleRequest(AbstractHttpConnection.java:452)
at org.eclipse.jetty.server.BlockingHttpConnection.handleRequest(BlockingHttpConnection.java:47)
at org.eclipse.jetty.server.AbstractHttpConnection.content(AbstractHttpConnection.java:894)
at org.eclipse.jetty.server.AbstractHttpConnection$RequestHandler.content(AbstractHttpConnection.java:948)
at org.eclipse.jetty.http.HttpParser.parseNext(HttpParser.java:851)
at org.eclipse.jetty.http.HttpParser.parseAvailable(HttpParser.java:235)
at org.eclipse.jetty.server.BlockingHttpConnection.handle(BlockingHttpConnection.java:66)
at org.eclipse.jetty.server.bio.SocketConnector$ConnectorEndPoint.run(SocketConnector.java:254)
at org.eclipse.jetty.server.ssl.SslSocketConnector$SslConnectorEndPoint.run(SslSocketConnector.java:665)
at org.eclipse.jetty.util.thread.QueuedThreadPool.runJob(QueuedThreadPool.java:603)
at org.eclipse.jetty.util.thread.QueuedThreadPool$3.run(QueuedThreadPool.java:538)
at java.lang.Thread.run(Unknown Source)

调试后，我发现我调用findUser的对象为null。

有什么想法吗？

如果bean id"userImp"只是你问题中的一个拼写错误，那么：你还没有激活注释配置，所以你的注释@SpringBean没有效果。

您必须将其添加到您的应用程序上下文中：

<context:annotation-config/>

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