今天,我遇到了一个令人恼火的问题,如下:
我有一个基于wicket的应用程序,其中我使用spring来管理将应用程序连接到数据库的对象,在过去,这对我来说工作得很好。
我正在使用eclipse中内置的jetty服务器来运行应用程序,并且我注意到,当我将断点放入我正在填充的类的数据源方法中时,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。
但是,当我使用spring已经将其值注入到其数据源对象中的对象时,它返回该对象为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;
/**
*
*/
在我调用这个对象的地方:
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>
表单提交时的结果是空指针异常,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,我发现我正在调用findUser的对象为空。
有什么想法吗?
发布于 2013-05-18 22:22:28
如果bean id "userImp“只是您问题中的一个打字错误,那么:您没有激活注释配置,因此您的注释@SpringBean没有任何效果。
您必须将其添加到您的应用程序上下文中:
<context:annotation-config/>
https://stackoverflow.com/questions/16628874
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