struts2学习之文件的上传与下载

骑猪看日落 2022-08-07 17:58 91阅读 0赞

# 单文件上传 #

**SingleUploadAction.java**

public class SingleUploadAction extends ActionSupport implements Serializable {
    
        private static final long serialVersionUID = -1732593542292662802L;
        //对应表单输入域name="image"，Struts2框架会封装成File类型的
        private File image;
        //上传文件的名称,自定义的image和FileName的组合，由struts封装
        private String imageFileName;
        //上传文件的MIME类型，自定义的image和ContentType的组合，由struts封装
        private String imageContentType;    
    
        public String singleUpload() {
            try {
                //得到文件名
                String filename = this.imageFileName;
                //得到ServletContext对象的引用
                ServletContext context = ServletActionContext.getServletContext();
                //构建存储路径
                String savepath = context.getRealPath("/upload");                       
                //读写入数据，把上传文件拷贝到新建目录        
                FileUtils.copyFile(image, new File(savepath, filename));
    
                ActionContext.getContext().put("message", "上传成功！");
                return SUCCESS;
            } catch (Exception e) {
                e.printStackTrace();
                ActionContext.getContext().put("message", "上传失败！");
                return ERROR;
            }
        }
    
    
        public File getImage() {
            return image;
        }
    
    
        public void setImage(File image) {
            this.image = image;
        }
    
    
        public String getImageFileName() {
            return imageFileName;
        }
    
    
        public void setImageFileName(String imageFileName) {
            this.imageFileName = imageFileName;
        }
    
    
        public String getImageContentType() {
            return imageContentType;
        }
    
    
        public void setImageContentType(String imageContentType) {
            this.imageContentType = imageContentType;
        }
    }

**upload.jsp**

## 普通单文件上传表单 ##

<b>普通表单单文件上传</b><br/>
    <form action="${pageContext.request.contextPath }/upload/singleupload" method="post" enctype="multipart/form-data">
        文件：<input type="file" name="image"/><br/>   
        <input type="submit" value="上传">
    </form>

## struts2单文件上传表单 ##

<b>struts表单单文件上传</b>
    <s:form action="singleupload" namespace="/upload" enctype="multipart/form-data">
        <s:file name="image" label="文件"></s:file>
    
        <s:submit value="上传"/>
    </s:form>

> 两个表单都必须添加enctype=”multipart/form-data”属性，否则会出错，无法上传。最好在里也添加method=”post”，不易出问题。

**struts.xml**

省略DTD部分。

<constant name="struts.multipart.maxSize" value="5242880"></constant>
    
    <package name="upload" namespace="/upload" extends="struts-default">
        <action name="singleupload" class="com.struts2.action.example.SingleUploadAction" method="singleUpload">
            <result name="success">/WEB-INF/jsp/success.jsp</result>
        </action>               
    </package>

**回执页面uploadsuccess.jsp**

文件名：<s:property value="imageFileName"/><br>
    文件类型：<s:property value="imageContentType"/><br/>
    <br/>

# 多文件上传 #

**MoreUploadAction.java**

public class MoreUploadAction extends ActionSupport implements Serializable {
    
        private static final long serialVersionUID = 7962335953329769349L;
    
        private File images[];
        private String[] imagesFileName;
        private String[] imagesContentType;
    
        public File[] getImages() {
            return images;
        }
        public void setImages(File[] images) {
            this.images = images;
        }
        public String[] getImagesFileName() {
            return imagesFileName;
        }
        public void setImagesFileName(String[] imagesFileName) {
            this.imagesFileName = imagesFileName;
        }
        public String[] getImagesContentType() {
            return imagesContentType;
        }
        public void setImagesContentType(String[] imagesContentType) {
            this.imagesContentType = imagesContentType;
        }
    
        public String moreUpload() {
    
            try {           
                if(images!=null&&images.length>0){
                    //得到ServletContext对象的引用
                    ServletContext sc = ServletActionContext.getServletContext();
                    //构建存储路径
                    String storePath = sc.getRealPath("/files");
                    for(int i=0;i<images.length;i++)
                        FileUtils.copyFile(images[i], new File(storePath,imagesFileName[i]));
                }
    
                ActionContext.getContext().put("message", "上传成功！");
                return SUCCESS;
    
                } catch (Exception e) {
                    e.printStackTrace();
                    ActionContext.getContext().put("message", "上传失败！");
                    return ERROR;
                }
    
        }
    }

**即将属性改为数组即可。**

**upload.jsp**

## 普通多文件上传表单 ##

<b>普通表单多文件上传</b>
    <form action="${pageContext.request.contextPath }/upload/moreupload" method="post" enctype="multipart/form-data">
        文件：<input type="file" name="images"/><br/>
        文件：<input type="file" name="images"/><br/>  
        文件：<input type="file" name="images"/><br/>      
        <input type="submit" value="上传">
    </form>

## struts2多文件上传表单 ##

<b>struts表单多文件上传</b>
    <s:form action="moreupload"  namespace="/upload" method="post" enctype="multipart/form-data">
        <s:file name="images" label="文件"></s:file>
        <s:file name="images" label="文件"></s:file>
        <s:file name="images" label="文件"></s:file>
        <s:submit value="上传"/>
    </s:form>

**struts.xml**

<action name="moreupload" class="com.struts2.action.example.MoreUploadAction" method="moreUpload">
            <result name="success">/WEB-INF/jsp/success.jsp</result>
    </action>

# 文件下载 #

客户端用户右键选择“另存为…”来下载，在回执页面添加如下代码：

<p>文件下载</p>
    <s:a href="%{imageFileName}">普通下载[右键另存为]</s:a>

以上。。。