struts2中文件上传的实现

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1.struts文件上传步骤：

1)在WEB-INF/lib下加入commons-fileupload-1.2.1.jar、commons-io-1.3.2.jar。

2)把form表的enctype设置为:"multipart/form-data"，并把method改为post。如下：
<form enctype="multipart/form-data" action="${pageContext.request.contextPath}/xxx.action" method="post">
<input type="file" name="uploadImage">
</form>

3)在Action类中添加以下属性

public class HelloWorldAction extends ActionSupport{

private File uploadImage;//得到上传的文件，如果是多个文件上传，可以改为List,必须是泛型。
private String uploadImageContentType;//得到文件的类型，uploadImage必须为file的文件名，ContentType是struts2的规范，必须这样写
private String uploadImageFileName;//得到文件的名称，uploadImage必须为file的文件名，FileName是struts2的规范，必须这样写
//这里略省了属性的getter/setter方法

public String upload() throws Exception{
   String realpath = ServletActionContext.getServletContext().getRealPath("/images");
   File file = new File(realpath);
   if(!file.exists()) file.mkdirs();
   FileUtils.copyFile(uploadImage, new File(file, uploadImageFileName));
   return "success";

}}

2.如何限制上传文件大小

在struts2中默认的上传文件大小为2M，如果我们想修改可以加常量：



<constant name="struts.multipart.maxSize" value="10701096"/>

3.单个文件上传

ublic class Image extends ActionSupport{

   private File image;
   private String imageFileName;
   private String imageContentType;



   public String getImageContentType() {
       return imageContentType;
   }

   public void setImageContentType(String imageContentType) {
       this.imageContentType = imageContentType;
   }

   public File getImage() {
       return image;
   }

   public String getImageFileName() {
       return imageFileName;
   }

   public void setImageFileName(String imageFileName) {
       this.imageFileName = imageFileName;
   }
   public void setImage(File image) {
       this.image = image;
   }


   @Override
   public String execute() throws Exception {

       //1.得到要上传文件夹的绝对路径
       String realpath=ServletActionContext.getServletContext().getRealPath("/images");
       if(image!=null){
           File dir=new File(realpath);
           if(!dir.exists()) dir.mkdirs();
           File file=new File(realpath,imageFileName);
           FileUtils.copyFile(image, file);
           System.out.println(imageContentType+"=filetype");
       }

       return SUCCESS;
   }

}

2.多文件上传

public class MultiUp extends ActionSupport{


   private ArrayList<File> image;
   private ArrayList imageFileName;



   public ArrayList getImageFileName() {
       return imageFileName;
   }
   public ArrayList<File> getImage() {
       return image;
   }
   public void setImage(ArrayList<File> image) {
       this.image = image;
   }
   public void setImageFileName(ArrayList imageFileName) {
       this.imageFileName = imageFileName;
   }


   @Override
   public String execute() throws Exception {
       // TODO Auto-generated method stub

       //先得到路径的决定路径
       String realpath=ServletActionContext.getServletContext().getRealPath("/images");
       if(image!=null){
           File dir=new File(realpath);
           if(!dir.exists()){
               dir.mkdirs();
           }
           for (int i = 0; i < image.size(); i++) {
               File file=new File(dir,(String)imageFileName.get(i));
               FileUtils.copyFile(image.get(i), file);
           }
       }
       return SUCCESS;
   }
}
//实现复制文件的方法
private static void copyFile(File src, File dst) {
       try {
           InputStream in = null;
           OutputStream out = null;
           try {
               in = new BufferedInputStream(new FileInputStream(src),
                       BUFFER_SIZE);
               out = new BufferedOutputStream(new FileOutputStream(dst),
                       BUFFER_SIZE);
               byte[] buffer = new byte[BUFFER_SIZE];
               while (in.read(buffer) > 0) {
                   out.write(buffer);
               }
           } finally {
               if (null != in) {
                   in.close();
               }
               if (null != out) {
                   out.close();
               }
           }
       } catch (Exception e) {
           e.printStackTrace();
       }

   }