后台获取不到file

Question

JSP代码
<form action="add.action" id="f" method="post" enctype="multipart/form-data">
<input type="file" name="upload" id="formFile" />
struts2的代码
<action name="add" class="sdjx.action.back.PoliceAddAction">后台JAVA代码
package sdjx.action.back;import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import org.springframework.web.context.ServletContextAware;
import javax.servlet.ServletContext;public class PoliceAddAction implements ServletContextAware{  
  private File upload;
  private String uploadContextType;
private String uploadFileName;
private ServletContext application;
    public String execute()throws Exception{
     FileOutputStream fos=null;
FileInputStream fis=null;
try{
System.out.println(this.upload);
fis=new FileInputStream(this.upload);
byte[] bytes=new byte[10240];
String path=application.getRealPath("productImages");
System.out.println("lu jing wei:===="+path);

path=path+"/"+System.currentTimeMillis()+this.uploadFileName;
String filename=System.currentTimeMillis()+this.uploadFileName;
fos=new FileOutputStream(path);
while(fis.read(bytes)!=-1){
fos.write(bytes);
}
this.uploadFileName=filename;
}finally{
if(fos!=null){
fos.close();
}
if(fis!=null){
fis.close();
}

}
System.out.println("-----------------");
return "success";
    }

public File getUpload() {
return upload;
}
public void setUpload(File upload) {
this.upload = upload;
}
public String getUploadContextType() {
return uploadContextType;
}
public void setUploadContextType(String uploadContextType) {
this.uploadContextType = uploadContextType;
}
public String getUploadFileName() {
return uploadFileName;
}
public void setUploadFileName(String uploadFileName) {
this.uploadFileName = uploadFileName;
}

public ServletContext getApplication() {
return application;
}
public void setApplication(ServletContext application) {
this.application = application;
}
public void setServletContext(ServletContext application) {
this.application=application;
}

}
错误提示：
java.lang.NullPointerException
sdjx.action.back.PoliceAddAction.execute(PoliceAddAction.java:27)
sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
java.lang.reflect.Method.invoke(Unknown Source)
com.opensymphony.xwork2.DefaultActionInvocation.invokeAction(DefaultActionInvocation.java:441)
com.opensymphony.xwork2.DefaultActionInvocation.invokeActionOnly(DefaultActionInvocation.java:280)
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:243)
com.opensymphony.xwork2.interceptor.DefaultWorkflowInterceptor.doIntercept(DefaultWorkflowInterceptor.java:165)
com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:87)
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
com.opensymphony.xwork2.validator.ValidationInterceptor.doIntercept(ValidationInterceptor.java:252)
org.apache.struts2.interceptor.validation.AnnotationValidationInterceptor.doIntercept(AnnotationValidationInterceptor.java:68)
com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:87)
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
com.opensymphony.xwork2.interceptor.ConversionErrorInterceptor.intercept(ConversionErrorInterceptor.java:122)
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
com.opensymphony.xwork2.interceptor.ParametersInterceptor.doIntercept(ParametersInterceptor.java:195)
com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:87)
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
com.opensymphony.xwork2.interceptor.ParametersInterceptor.doIntercept(ParametersInterceptor.java:195)
com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:87)
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
com.opensymphony.xwork2.interceptor.StaticParametersInterceptor.intercept(StaticParametersInterceptor.java:179)
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
org.apache.struts2.interceptor.MultiselectInterceptor.intercept(MultiselectInterceptor.java:75)
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
org.apache.struts2.interceptor.CheckboxInterceptor.intercept(CheckboxInterceptor.java:94)
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
org.apache.struts2.interceptor.FileUploadInterceptor.intercept(FileUploadInterceptor.java:306)
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
com.opensymphony.xwork2.interceptor.ModelDrivenInterceptor.intercept(ModelDrivenInterceptor.java:89)
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
com.opensymphony.xwork2.interceptor.ScopedModelDrivenInterceptor.intercept(ScopedModelDrivenInterceptor.java:130)
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
org.apache.struts2.interceptor.debugging.DebuggingInterceptor.intercept(DebuggingInterceptor.java:267)
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
com.opensymphony.xwork2.interceptor.ChainingInterceptor.intercept(ChainingInterceptor.java:126)
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
com.opensymphony.xwork2.interceptor.PrepareInterceptor.doIntercept(PrepareInterceptor.java:138)
com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:87)
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
com.opensymphony.xwork2.interceptor.I18nInterceptor.intercept(I18nInterceptor.java:165)
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
org.apache.struts2.interceptor.ServletConfigInterceptor.intercept(ServletConfigInterceptor.java:164)
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
com.opensymphony.xwork2.interceptor.AliasInterceptor.intercept(AliasInterceptor.java:179)
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
com.opensymphony.xwork2.interceptor.ExceptionMappingInterceptor.intercept(ExceptionMappingInterceptor.java:176)
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
org.apache.struts2.impl.StrutsActionProxy.execute(StrutsActionProxy.java:52)
org.apache.struts2.dispatcher.Dispatcher.serviceAction(Dispatcher.java:488)
org.apache.struts2.dispatcher.ng.ExecuteOperations.executeAction(ExecuteOperations.java:77)
org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter.doFilter(StrutsPrepareAndExecuteFilter.java:91)
报错的代码是：String path=application.getRealPath("productImages");
控制台：D:\Tomcat6.0\work\Catalina\localhost\repeat\upload_4e9fa4ee_13eab18992c__7fff_00000006.tmp

Answer 1

application.getRealPath已经不建议使用这个方法了。改用ServletContext.getResourceAsStream或者getResource

Answer 2

我试了一下application确实为空，为什么会出现这个原因啊？求指教啊~

Answer 3

我想获取到的是图片上传的路径，需要存进数据库，如果用这个方法以后是不是还需要用别的方法转换出String路径来啊

Answer 4

没有初始化。application=this.getServletContext();

Answer 5

ServletActionContext.getServletContext();

Answer 6

好吧，我晕了，我这里写的应该是给application吧~

Answer 7

我试了一下application确实为空，为什么会出现这个原因啊？求指教啊~实现的接口应该初始化不了吧，你试试implements这个ApplicationAware接口