java Struts2框架下实现文件上传功能

<?xml version="1.0" encoding="UTF-8"?>
<web-app version="2.5"
  xmlns="http://java.sun.com/xml/ns/javaee"
  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xsi:schemaLocation="http://java.sun.com/xml/ns/javaee
  http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd">
 <display-name></display-name>
  <filter>
  <filter-name>struts2</filter-name>
  <filter-class>org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter</filter-class>
 </filter>
 <filter-mapping>
  <filter-name>struts2</filter-name>
  <url-pattern>/*</url-pattern>
 </filter-mapping>
</web-app>

<?xml version="1.0" encoding="UTF-8"?>
<web-app version="2.5"
xmlns="http://java.sun.com/xml/ns/javaee"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://java.sun.com/xml/ns/javaee
http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd">
<display-name></display-name>
<filter>
<filter-name>struts2</filter-name>
<filter-class>org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter</filter-class>
</filter>
<filter-mapping>
<filter-name>struts2</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>
</web-app>

package com.xmgc.sc.action;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import org.apache.struts2.ServletActionContext;
public class MyUpLoadAction {
  private String title;
  private File upload;//与form表单中的file文件类型的名字是一样的
  private String uploadContentType;//前缀必须要是上面的upload
  private String uploadFileName;
  public String getTitle() {
    return title;
  }
  public void setTitle(String title) {
    this.title = title;
  }
  public File getUpload() {
    return upload;
  }
  public void setUpload(File upload) {
    this.upload = upload;
  }
  public String getUploadContentType() {
    return uploadContentType;
  }
  public void setUploadContentType(String uploadContentType) {
    this.uploadContentType = uploadContentType;
  }
  public String getUploadFileName() {
    return uploadFileName;
  }
  public void setUploadFileName(String uploadFileName) {
    this.uploadFileName = uploadFileName;
  }
/* public String getSavePath() {
    //ServletContext cxt=ServletActionContext.getServletContext();
    //String path=cxt.getRealPath("/");
    //这个获取的path为：http://localhost:8080/sc   
    //上传以后变为E:\software\apache-tomcat-6.0.45\webapps\sc
    return savePath;
  }
  public void setSavePath(String savePath) {
    //E:\software\apache-tomcat-6.0.45\webapps\sc/myupload
    this.savePath = ServletActionContext.getServletContext().getRealPath("/myupload");
  }*/
  public String execute() throws IOException{
    System.out.println(title);//标题
    System.out.println(uploadContentType);//准备上传的文件的文件类型
    System.out.println(uploadFileName);//准备上传的文件的文件名,记住还有扩展名
    System.out.println(upload);
    String realPath=ServletActionContext.getServletContext().getRealPath("/");
    String path=realPath+"myupload/"+uploadFileName;
    System.out.println(realPath);
    System.out.println(path);
    FileInputStream fis=new FileInputStream(upload);
    FileOutputStream fos=new FileOutputStream(path);
    byte[] bytes=new byte[1024];//定义一个1024大小的字节数组
    int len=-1;//用来做标志位
    while((len=fis.read(bytes))>0){
      fos.write(bytes, 0, len);
    }
    return null;
  }
}

<%@ page contentType="text/html;charset=utf-8"%>
<!-- enctype="multipart/form-data",这个是最重要的配置 -->
<form action="myupload.action" enctype="multipart/form-data" method="post">
   文件名：<input type="text" name="title"/><br/>
     上传：<input type="file" name="upload"/><br/>
    <input type="submit" value="上传"/>
</form>