JSF 2.2-文件上传返回java.lang.NullPointerException [英] JSF 2.2 - File upload return java.lang.NullPointerException
问题描述
<h:inputFile/>返回NullPointerException错误.我知道已经有很多关于此异常以及使用JSF上传文件的信息，但是我已经读完了所有内容，但未能成功诊断出该问题.
<h:inputFile/> return a NullPointerException error. I know there is already a lot of stuff about this exception and uploading files with JSF but I've read it all without any success to diagnose this problem.
我正在使用带有GlassFish 4.1.1的JSF 2.2，而没有PrimeFaces或Tomahawk，因为您可以使用JSF 2.2处理文件上传.正如我所读.
I am using JSF 2.2 with GlassFish 4.1.1, without PrimeFaces or Tomahawk since you can handle the file upload with JSF 2.2. as I read.
目标只是将图片上传到远程文件系统上，然后将路径复制到DB，以便稍后通过数据表进行检索.
The goal is just to upload a picture on the remote filesystem, and copy the path to the DB to retrieve it later through a datatable.
我已经检查过了:
1-我的表单具有enctype="multipart/form-data"属性.
1 - My form has the enctype="multipart/form-data" attribute.
2-我的表单虽然是<ui:composition/>的一部分，但并未嵌套在其他表单中.
2 - My form is not nested in another form though it is part of <ui:composition/>.
3-我已将所有适当的过滤器设置为处理multipart/form-data类型:
3 - I have set all proper filter to process multipart/form-data type :
<filter>
<filter-name>MyFacesExtensionsFilter</filter-name>
<filter-class>org.apache.myfaces.webapp.filter.ExtensionsFilter</filter-class>
</filter>
<filter-mapping>
<filter-name>MyFacesExtensionsFilter</filter-name>
<servlet-name>Faces Servlet</servlet-name>
</filter-mapping>
4-当我在create()方法中删除<h:inputFile/>标记及其部分时，发送数据毫无问题.
4 - When I remove the <h:inputFile/> tag and its part in the create() method, sending data works without any problem.
5-我试图将ManagedBean分别声明为@ApplicationScoped，@ViewScoped和@RequestScoped.
5 - I tried to state the ManagedBean as @ApplicationScoped, @ViewScoped and @RequestScoped without any change.
6-我试图使用抽象方法将initialize Part属性放入ManagedBean中，但没有成功.
6 - I tried to put the initialize Part attribute in the ManagedBean with abstract methods without any success.
这是我的表格:
<ui:composition xmlns="http://www.w3.org/1999/xhtml"
xmlns:f="http://xmlns.jcp.org/jsf/core"
xmlns:h="http://xmlns.jcp.org/jsf/html"
xmlns:ui="http://xmlns.jcp.org/jsf/facelets"
xmlns:c="http://xmlns.jcp.org/jsp/jstl/core"
xmlns:t="http://myfaces.apache.org/tomahawk">
<h:form enctype="multipart/form-data">
<h:outputLabel value="Marque : " />
<h:inputText value="#{carController.car.brand}" />
<br/>
few same inputText
<h:outputLabel value="Photo : " />
<h:inputFile value="#{carController.picture}" required="true" requiredMessage="No file selected."/>
<br/>
<h:commandButton value="Valider" action="#{carController.create}" />
</h:form>
</ui:composition>
这是我的ManagedBean，我已发表评论，因为这是处理我尝试过的图像上传的其他方式:
@Named(value = "carController")
@SessionScoped
public class CarController implements Serializable {
private static final long serialVersionUID = 1L;
@EJB
private CarFacade carFacade;
private Car car;
private Part picture;
private Collection<Car> carCollection;
public CarController() {car = new Car();}
public String create() throws IOException {
/*try ( InputStream inputStream = picture.getInputStream();
FileOutputStream outputStream = new FileOutputStream("D:" +
File.separator + "test" + File.separator +
picture.getSubmittedFileName())) {
int bytesRead = 0;
final byte[] chunck = new byte[1024];
while ((bytesRead = inputStream.read(chunck)) != -1) {
outputStream.write(chunck, 0, bytesRead);
}
}*/
/*Path folder = Paths.get("//resources//cars//");
String filename = FilenameUtils.getName(picture.getName());
String extension = FilenameUtils.getExtension(picture.getName());
Path file = Files.createTempFile(folder, filename + "-", "." + extension);
try (InputStream input = picture.getInputStream()) {
Files.copy(input, file, StandardCopyOption.REPLACE_EXISTING);
}*/
picture.write("\\resources\\cars\\"+picture.getSubmittedFileName()+"."+picture.getContentType());
car.setPicturePath(picture.getSubmittedFileName());
carFacade.create(car);
return "/index.xhtml";
}
这是例外:
Here is exception :
Caused by: java.lang.NullPointerException
at Controller.CarController.create(CarController.java:57)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:497)
at com.sun.el.parser.AstValue.invoke(AstValue.java:289)
at com.sun.el.MethodExpressionImpl.invoke(MethodExpressionImpl.java:304)
at org.jboss.weld.util.el.ForwardingMethodExpression.invoke(ForwardingMethodExpression.java:40)
at org.jboss.weld.el.WeldMethodExpression.invoke(WeldMethodExpression.java:50)
at com.sun.faces.facelets.el.TagMethodExpression.invoke(TagMethodExpression.java:105)
at javax.faces.component.MethodBindingMethodExpressionAdapter.invoke(MethodBindingMethodExpressionAdapter.java:87)
... 41 more
感谢您提供任何有用的想法.
Thank you for any idea that may help.
此错误的原因是:picture.write("\ resources \ cars \" + picture.getSubmittedFileName()+." + picture.getContentType());
THIS is responsible of the error : picture.write("\resources\cars\"+picture.getSubmittedFileName()+"."+picture.getContentType());
我尝试将其添加到web.xml中，但没有成功:
I've tried to add this to web.xml without any success :
<servlet>
<servlet-name>Faces Servlet</servlet-name>
<servlet-class>javax.faces.webapp.FacesServlet</servlet-class>
<load-on-startup>1</load-on-startup>
<multipart-config>
<location>\resources\cars\</location>
<max-file-size>1300000</max-file-size>
<max-request-size>20000000</max-request-size>
<file-size-threshold>50000</file-size-threshold>
</multipart-config>
</servlet>
推荐答案
删除MyFacesExtensionsFilter.仅当您使用<t:inputFileUpload>而不是<h:inputFile>时才需要.
Remove the MyFacesExtensionsFilter. That's only necessary when you're using <t:inputFileUpload> instead of <h:inputFile>.
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