Struts2实现文件上传和下载，多文件上传，限制文件大小，限制文件类型

文件上传使用的包：commons-upload-xx.jar

commons-io-xx.jar

一.实现文件上传：

1.在表单空间中添加enctype=”multipart/form-data”

2.创建Action:

①在action中添加属性

private File xnamex; //指定文件名，文件名必须与文件域的name属性名一样

private String xnamexUploadContentType; //文件类型

private String xnamexFileName; //文件名称

②重写execute或自定义方法：

获取远程站点真正路径,指定文件保存路径：

String savePath= ServletActionContext.getServletContext.get(“/upload”);

通过IO操作将文件写入保存文件夹

  1: package com.action;

  2: import java.io.File;

  3: import org.apache.commons.io.IOUtils;

  4: import org.apache.struts2.ServletActionContext;

  5: import com.opensymphony.xwork2.ActionSupport;

  6:

  7: public class UploadAction extends ActionSupport {

  8:   private File upload;//上传的文件

  9:   private String uploadContentType;//文件类型

 10:   private String uploadFileName;//文件名

 11:

 12:   public File getUpload() {

 13:     return upload;

 14:   }

 15:   public void setUpload(File upload) {

 16:     this.upload = upload;

 17:   }

 18:   public String getUploadContentType() {

 19:     return uploadContentType;

 20:   }

 21:   public void setUploadContentType(String uploadContentType) {

 22:     this.uploadContentType = uploadContentType;

 23:   }

 24:   public String getUploadFileName() {

 25:     return uploadFileName;

 26:   }

 27:   public void setUploadFileName(String uploadFileName) {

 28:     this.uploadFileName = uploadFileName;

 29:   }

 30:   @Override

 31:   public String execute() throws Exception {

 32:     String savaPath = ServletActionContext.getServletContext()

 33:         .getRealPath("/upload");

 34:     FileOutputStream fos=null;

 35:     FileInputStream fis=null;

 38:       fis=new FileInputStream(upload[i]);

 39:       fos=new FileOutputStream(savaPath+"\\"+uploadFileName[i]);

 44:       IOUtils.copy(fis, fos);

 45:       fis.close();

 46:       fos.flush();

 47:       fos.close();

 49:     return "success";

 50:   }

 52: }

3.在struts2.xml文件中配置：

<action name="upload" class="com.action.UploadAction">

      <result name="success">/uploadfile.jsp</result>

</action>

二.限制文件大小:

方法一：在struts2.xml文件中配置常量参数：

<constant name=”struts.multipart.maxSize” value=”50000” />

value值为 byte

方法二：在action中引用系统定义的fileUpload拦截器,

配置拦截器参数：<param name=”maximumSize”>50000</param>

三.限制文件类型:

在action中引用系统定义的fileUpload拦截器,

配置拦截器参数：

<param name=”allowedTypes”>application/msword,·····</param>

tomcat中，在conf/web.xml中查找type

四.实现多个文件同时上传

①，将Action中属性改为数组：

private File[] xnamex; //指定文件名

private String[] xnamexUploadContentType; //文件类型

private String[] xnamexFileName; //文件名称

②，在方法中添加数组遍历

五.在struts.xml中配置中配置保存路径

①.在action标签中添加参数配置

<param name=”path”>upload</param> //指定文件夹名

②.修改文件上传Action：

添加属性：private String path; //与配置文件中参数的name属性一致

更改保存路径：savaPath=ServletActionContext.getActionContext.get(“/”+path);

实现文件下载（点击）

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