【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//DTDStruts 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