在Struts 2中实现单文件上传

实现原理

Struts 2是通过Commons FileUpload文件上传。Commons FileUpload通过将HTTP的数据保存到临时文件夹，然后Struts使用fileUpload拦截器将文件绑定到Action的实例中。从而我们就能够以本地文件方式的操作浏览器上传的文件。

其次是FileUploadAction.java代码：

 

package tutorial;

import java.io.BufferedInputStream;

import java.io.BufferedOutputStream;

import java.io.File;

import java.io.FileInputStream;

import java.io.FileOutputStream;

import java.io.InputStream;

import java.io.OutputStream;

import java.util.Date;

import org.apache.struts2.ServletActionContext;

import com.opensymphony.xwork2.ActionSupport;

public class FileUploadAction extends ActionSupport {

     private static final long serialVersionUID = 572146812454l ;

     private static final int BUFFER_SIZE = 16 * 1024 ;

    

     private File myFile;

     private String contentType;

     private String fileName;

     private String imageFileName;

     private String caption;

    

      public void setMyFileContentType(String contentType) {

         this .contentType = contentType;

    } 

    

      public void setMyFileFileName(String fileName) {

         this .fileName = fileName;

    } 

        

      public void setMyFile(File myFile) {

         this .myFile = myFile;

    } 

    

      public String getImageFileName() {

         return imageFileName;

    } 

    

      public String getCaption() {

         return caption;

    } 

      public void setCaption(String caption) {

         this .caption = caption;

    } 

    

      private static void copy(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();

        } 

    } 

    

      private static String getExtention(String fileName) {

         int pos = fileName.lastIndexOf( " . " );

         return fileName.substring(pos);

    } 

    @Override

      public String execute()      {        

        imageFileName = new Date().getTime() + getExtention(fileName);

        File imageFile = new File(ServletActionContext.getServletContext().getRealPath( " /UploadImages " ) + " / " + imageFileName);

        copy(myFile, imageFile);

         return SUCCESS;

    } 

    

}