t：JSF中的inputFileUpload在myBean.submit（）上抛出NullPointerException

时间：2011-03-18 21:06:35

标签： jsf upload nullpointerexception

从昨天开始，我很难在jsf web应用程序中上传文件。我找到的教程（一个来自balusC，另一个来自一些官方java教程页面）非常好，但不知何故它仍然无法运行。我猜web.xml有问题，因为这是我在google上找到的答案，但对我来说仍然没有好结果。 现在详细说明： 首先：我建立一个新项目只是为了测试上传，所以如果有太多的库（如果有这样的s.th.），请告诉我。 其次：这是我大学的课程项目，所以我必须使用一些东西，比如h2-database和glassfish应用服务器。

我使用的库：
commons-el-1.0.jar
commons-fileupload.1.2.1.jar
commons-io-1.3.2.jar
commons-logging.1.1.1.jar
tomahawk20-1.1.10.jar
h2-1.2.141.jar
jboss-el-2.0.1.GA.jar
jstl-1.2.jar
jsf-api.jar

我的web.xml 

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns="http://java.sun.com/xml/ns/javaee" xmlns:web="http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"
xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"
id="WebApp_ID" version="2.5">

<display-name>Test</display-name>

<session-config>
    <session-timeout>15</session-timeout>
</session-config>

<servlet>
    <servlet-name>FacesServlet</servlet-name>
    <servlet-class>
        javax.faces.webapp.FacesServlet
    </servlet-class>
    <load-on-startup>1</load-on-startup>
</servlet>

<servlet-mapping>
    <servlet-name>FacesServlet</servlet-name>
    <url-pattern>/faces/*</url-pattern>
</servlet-mapping>

<servlet-mapping>
    <servlet-name>FacesServlet</servlet-name>
    <url-pattern>*.faces</url-pattern>
</servlet-mapping>

<filter>
    <filter-name>ExtensionsFilter</filter-name>
    <filter-class>
        org.apache.myfaces.webapp.filter.ExtensionsFilter
    </filter-class>
    <init-param>
        <param-name>uploadMaxFileSize</param-name>
        <param-value>10m</param-value>
    </init-param>
    <init-param>
        <param-name>uploadThresholdSize</param-name>
        <param-value>100k</param-value>
    </init-param>
</filter>

<filter-mapping>
    <filter-name>ExtensionsFilter</filter-name>
    <servlet-name>FacesServlet</servlet-name>
</filter-mapping>

<welcome-file-list>
    <welcome-file>index.html</welcome-file>
</welcome-file-list>

<!-- JBoss EL allows method parameters -->
<context-param>
    <param-name>com.sun.faces.expressionFactory</param-name>
    <param-value>org.jboss.el.ExpressionFactoryImpl</param-value>
</context-param>

my test.xthml 

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN""http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
  <ui:composition xmlns="http://www.w3.org/1999/xhtml"
  xmlns:ui="http://java.sun.com/jsf/facelets"
  xmlns:h="http://java.sun.com/jsf/html"
  xmlns:f="http://java.sun.com/jsf/core"
  xmlns:t="http://myfaces.apache.org/tomahawk"
  xmlns:sf="http://www.springframework.org/tags/faces"
  xmlns:x="http://myfaces.apache.org/extensions"
  template="template.xhtml">

<ui:define name="header">
    <h1>List of Matches</h1>
</ui:define>

<ui:define name="content">
<f:view>
<html lang="en">
    <head>
        <title>File upload test</title>
    </head>
    <body>
        <h:form id="uploadForm" enctype="multipart/form-data">
            <h:panelGrid columns="3">
                <h:outputLabel for="file" value="Select file" />
                <t:inputFileUpload id="file" value="#{myBean.uploadedFile}" storage="file" required="true" />
                <h:message for="file" style="color: red;" />

                <h:panelGroup />
                <h:commandButton value="Submit" action="#{myBean.submit()}" />
                <h:message for="uploadForm" infoStyle="color: green;" errorStyle="color: red;" />
            </h:panelGrid>
        </h:form>

        <h:outputLink value="file/#{myBean.fileName}" rendered="#{myBean.fileName != null}">
            Download back
        </h:outputLink>
    </body>
</html>
</f:view>
</ui:define>
</ui:composition>

MyBean.java 

package managedbean;

import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStream;

import javax.faces.application.FacesMessage;
import javax.faces.context.FacesContext;

import javax.faces.bean.ManagedBean;
import org.apache.commons.io.FilenameUtils;
import org.apache.commons.io.IOUtils; 
import org.apache.myfaces.custom.fileupload.UploadedFile;

@ManagedBean (name = "myBean")
public class MyBean {

private UploadedFile uploadedFile;
private String fileName;

public void submit() {

    String prefix = FilenameUtils.getBaseName(uploadedFile.getName());
    String suffix = FilenameUtils.getExtension(uploadedFile.getName());

    File file = null;
    OutputStream output = null;

    try {
        file = File.createTempFile(prefix + "_", "." + suffix, new File("/Users/"));
        output = new FileOutputStream(file);
        IOUtils.copy(uploadedFile.getInputStream(), output);
        fileName = file.getName();


    } catch (IOException e) {

        if (file != null) file.delete();

        e.printStackTrace();
    } finally {
        IOUtils.closeQuietly(output);
    }
}


public UploadedFile getUploadedFile() {
    return uploadedFile;
}

public String getFileName() {
    return fileName;
}


public void setUploadedFile(UploadedFile uploadedFile) {
       this.uploadedFile = uploadedFile;
}

}

当我提交

时，我的完整堆栈跟踪 
[#|2011-03-18T22:00:08.768+0100|WARNING|oracle-glassfish3.1|javax.enterprise.resource.webcontainer.jsf.lifecycle|_ThreadID=19;_ThreadName=http-thread-pool-8080(4);|#{myBean.submit()}: java.lang.NullPointerException
javax.faces.FacesException: #{myBean.submit()}: java.lang.NullPointerException
    at com.sun.faces.application.ActionListenerImpl.processAction(ActionListenerImpl.java:118)
    at javax.faces.component.UICommand.broadcast(UICommand.java:315)
    at javax.faces.component.UIViewRoot.broadcastEvents(UIViewRoot.java:794)
    at javax.faces.component.UIViewRoot.processApplication(UIViewRoot.java:1259)
    at com.sun.faces.lifecycle.InvokeApplicationPhase.execute(InvokeApplicationPhase.java:81)
    at com.sun.faces.lifecycle.Phase.doPhase(Phase.java:101)
    at com.sun.faces.lifecycle.LifecycleImpl.execute(LifecycleImpl.java:118)
    at javax.faces.webapp.FacesServlet.service(FacesServlet.java:409)
    at org.apache.catalina.core.StandardWrapper.service(StandardWrapper.java:1534)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:343)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:215)
    at org.apache.myfaces.webapp.filter.ExtensionsFilter.doFilter(ExtensionsFilter.java:349)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:256)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:215)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:279)
    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:680)
Caused by: javax.faces.el.EvaluationException: java.lang.NullPointerException
    at javax.faces.component.MethodBindingMethodExpressionAdapter.invoke(MethodBindingMethodExpressionAdapter.java:102)
    at com.sun.faces.application.ActionListenerImpl.processAction(ActionListenerImpl.java:102)
    ... 37 more
Caused by: java.lang.NullPointerException
    at managedbean.MyBean.submit(Unknown Source)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
    at java.lang.reflect.Method.invoke(Method.java:597)
    at org.jboss.el.util.ReflectionUtil.invokeMethod(ReflectionUtil.java:329)
    at org.jboss.el.util.ReflectionUtil.invokeMethod(ReflectionUtil.java:274)
    at org.jboss.el.parser.AstMethodSuffix.getValue(AstMethodSuffix.java:59)
    at org.jboss.el.parser.AstMethodSuffix.invoke(AstMethodSuffix.java:65)
    at org.jboss.el.parser.AstValue.invoke(AstValue.java:96)
    at org.jboss.el.MethodExpressionImpl.invoke(MethodExpressionImpl.java:276)
    at com.sun.faces.facelets.el.TagMethodExpression.invoke(TagMethodExpression.java:105)
    at javax.faces.component.MethodBindingMethodExpressionAdapter.invoke(MethodBindingMethodExpressionAdapter.java:88)
    ... 38 more
|#]

[#|2011-03-18T22:00:08.774+0100|WARNING|oracle-glassfish3.1|javax.enterprise.system.container.web.com.sun.enterprise.web|_ThreadID=84;_ThreadName=http-thread-pool-8080(4);|StandardWrapperValve[FacesServlet]: PWC1406: Servlet.service() for servlet FacesServlet threw exception
javax.faces.el.EvaluationException: java.lang.NullPointerException
    at javax.faces.component.MethodBindingMethodExpressionAdapter.invoke(MethodBindingMethodExpressionAdapter.java:102)
    at com.sun.faces.application.ActionListenerImpl.processAction(ActionListenerImpl.java:102)
    at javax.faces.component.UICommand.broadcast(UICommand.java:315)
    at javax.faces.component.UIViewRoot.broadcastEvents(UIViewRoot.java:794)
    at javax.faces.component.UIViewRoot.processApplication(UIViewRoot.java:1259)
    at com.sun.faces.lifecycle.InvokeApplicationPhase.execute(InvokeApplicationPhase.java:81)
    at com.sun.faces.lifecycle.Phase.doPhase(Phase.java:101)
    at com.sun.faces.lifecycle.LifecycleImpl.execute(LifecycleImpl.java:118)
    at javax.faces.webapp.FacesServlet.service(FacesServlet.java:409)
    at org.apache.catalina.core.StandardWrapper.service(StandardWrapper.java:1534)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:343)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:215)
    at org.apache.myfaces.webapp.filter.ExtensionsFilter.doFilter(ExtensionsFilter.java:349)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:256)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:215)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:279)
    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:680)
Caused by: java.lang.NullPointerException
    at managedbean.MyBean.submit(Unknown Source)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
    at java.lang.reflect.Method.invoke(Method.java:597)
    at org.jboss.el.util.ReflectionUtil.invokeMethod(ReflectionUtil.java:329)
    at org.jboss.el.util.ReflectionUtil.invokeMethod(ReflectionUtil.java:274)
    at org.jboss.el.parser.AstMethodSuffix.getValue(AstMethodSuffix.java:59)
    at org.jboss.el.parser.AstMethodSuffix.invoke(AstMethodSuffix.java:65)
    at org.jboss.el.parser.AstValue.invoke(AstValue.java:96)
    at org.jboss.el.MethodExpressionImpl.invoke(MethodExpressionImpl.java:276)
    at com.sun.faces.facelets.el.TagMethodExpression.invoke(TagMethodExpression.java:105)
    at javax.faces.component.MethodBindingMethodExpressionAdapter.invoke(MethodBindingMethodExpressionAdapter.java:88)
    ... 38 more
|#]

就像我说的，这只是我放在一起的教程;文件的名称显示在文本字段中，但是当点击提交时，只有例外。

提前致谢。

编辑：我只是觉得知道使用1.6.0jdk工作可能会有用。

1 个答案:

答案 0 :(得分：0)

我遇到了同样的问题，但在Linux中工作并在Windows中失败。为了解决这个问题，我找到了这个解决方案： 不要忘记将“enctype”属性添加到表单中，并将此属性设置为“multipart / form-data”。 

<h:form enctype="multipart/form-data">

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