【SSI开发总结.8】Struts2中实现文件上传功能

 

1.编写上传表单

...............................

<s:form name="f1" action="upload!add.htm" method="post" enctype="multipart/form-data">

<s:file name="upload"/><input type="submit" name="Submit" value="上传" />

</s:form>

................................

1.编写Action

package action.game.editor.windows;

import com.opensymphony.xwork2.ActionSupport;

import org.apache.struts2.ServletActionContext;

import java.io.File;

import java.io.FileInputStream;

import java.io.FileOutputStream;

import java.text.DateFormat;   

import java.text.SimpleDateFormat;   

import java.util.Date;   

import java.util.Random;

public class UploadAction extends ActionSupport {
private File upload;//与表单文件域Name属性相同

private String uploadContentType;//表单文件域Name+"ContentType"

private String uploadFileName;//表单文件域Name+"FileName"

private String savePath="/uploadFiles";//保存路径

private String allowTypes="image/pjpeg,image/gif,image/bmp,image/x-png";//允许的文件类型

private String getSavePath() throws Exception

    {

            return ServletActionContext.getRequest().getRealPath(savePath);

    }

//上传文件对应文件内容的setter

public void setUpload(File upload)

{

   this.upload = upload;

}

//上传文件的文件类型的setter

public void setUploadContentType(String uploadContentType)

{

   this.uploadContentType = uploadContentType;

}

public String getUploadContentType() {

   return uploadContentType;

}

//上传文件的文件名的setter

public void setUploadFileName(String uploadFileName)

{

   this.uploadFileName = uploadFileName;

}

  

//得到随机文件名

    private String generateFileName(String fileName) {   

        DateFormat format = new SimpleDateFormat("yyMMddHHmmss");   

        String formatDate = format.format(new Date());   

           

        int random = new Random().nextInt(10000);   

           

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

        String extension = fileName.substring(position);   

           

        return formatDate + random + extension;   

    }   

public String execute(){

   

    return SUCCESS;

    }

//添加本地图片

    public String addLocalIMG() throws Exception{

    if(allowTypes.indexOf(uploadContentType)!=-1)

    {

        if(upload.length()<200000){

         String realFileName=generateFileName(uploadFileName);

         //以服务器的文件保存地址和原文件名建立上传文件输出流

         FileOutputStream fos = new FileOutputStream(getSavePath() + "//" + realFileName);

         //以上传文件建立一个文件上传流

         FileInputStream fis = new FileInputStream(upload);

         //将上传文件的内容写入服务器

         byte[] buffer = new byte[1024];

         int len = 0;

         while ((len = fis.read(buffer)) > 0)

         {

          fos.write(buffer , 0 , len);

         }

            fos.close();

            fis.close();

            //url=ServletActionContext.getRequest().getContextPath()+"/uploadFiles/"+realFileName;    //读取图片网络地址   

            return SUCCESS;            

        }

        else

        return "sizeError";

    }

    else

       return "typeError";     

      

   }

}

3.注意，最好在struts配置文件中修改最大上传文件大小，然后，在程序中再对文件大小做限制，并且这个限制的值不能大于struts配置文件中已经设置的最大值,单位为字节

<!DOCTYPE struts PUBLIC "-//Apache Software Foundation//DTD
Struts Configuration 2.0//EN"
"http://struts.apache.org/dtds/struts-2.0.dtd" >

<struts>

    <include file="struts-default.xml"/>

    <include file="struts-forward.xml"/>

    <include file="struts-back.xml"/>

    <constant name="struts.i18n.encoding" value="GBK"/>

    <constant name="struts.objectFactory" value="spring" />

    <constant name="struts.configuration.xml.reload" value="true" />
    <constant name="struts.multipart.maxSize" value="4000000" />

</struts>

注意，struts.multipart.maxSize默认为2M大小限制