struts2文件上传下载

1.上传页面
*<form action="对应上传的Action" enctype="multipart/form-data" method="post">
*文件上传框：<input type="file" id="upload_file" name="file"/> 此file必须和Action中的File file同名，并且文件名必须是fileFileName（struts2会自动填充文件名）
*form提交的按钮（可以直接用submit按钮，也可以写在js里）

<form action="${pageContext.request.contextPath}/pfl/attachment/saveAttachmentAction.action" enctype="multipart/form-data" method="post" id="uploadAttachmentForm" >
    <div class="row">
        <div class="row_table_top">
            <div class="row_table_top_left"><img src="${pageContext.request.contextPath}/system/assets/images/point_down.gif" width="7" height="8" /><fmt:message key="pfl.system.attachment.upload"/></div>
        </div>

        <div class="row_table_middle">
            

            <table width='100%' align=center height='200' cellspacing="0" cellpadding="0" border="0">
                <tr class="trform"><td colspan="2">

                </td></tr>

                <tr class="trform"><th valign="top">
                    <div align="right"><fmt:message key="pfl.system.attachment.select_file" /><fmt:message key="global.maohao"/></div>
                </th>
                    <td valign="top" style="">
                        <div align="left"><input type="file" id="upload_file" name="file"/></div>
                    </td>
                </tr>

                <tr class="trform">
                    <th valign="top"><div align="right">&nbsp;</div></th>
                    <td align="left">
                        <div align="left">
                            <input type="button" class="button2" id="go_ul" onclick="uploadAttachment();" value="<fmt:message key="pfl.system.attachment.submit"/>" />
                            &nbsp;&nbsp;&nbsp;
                            <input type="button" name="back" id="back" class="button2"  onclick="win_close();"  value="<fmt:message key="pfl.system.attachment.close" />"/>
                        </div>
                    </td>
                </tr>
            </table>

        </div>

    </div>
</form>

2.下载页面
*访问下载的Action（通过id获得不同文件）

<div id="docs" style="">
                                                    <c:forEach items="${contractAttachmentList}" var="contractAttachment">
                                                                     <span id="${contractAttachment.id}">
                                                                         <input type="hidden" name="contractAttachment.id" value="${contractAttachment.id}"/>
                                                                         <a href="${pageContext.request.contextPath}/pfl/attachment/downloadAttachmentAction.action?id=${contractAttachment.id}">${contractAttachment.name}</a>
                                                                     </span>
                                                    </c:forEach>
                                                </div>

3.Action

public class ContractAttachmentAction extends ActionSupport {

    private ContractAttachment contractAttachment;

    private IContractAttachmentService contractAttachmentService;

    private File file;
    private String fileFileName;
    private String fileContentType;
    private String savePath;

    private String path;

    private String downloadFile;
    private String downloadFileName;

    public String showupload(){
        HttpServletRequest request = ServletActionContext.getRequest();
        String id = request.getParameter("id");
        request.setAttribute("id",id);
        return "showupload";
    }

    public String save(){
        Date currentDate = UtilTools.getCurrentDate();
        HttpServletRequest request = ServletActionContext.getRequest();
        try{
            String contractID = request.getParameter("contractID");
            upload();
            if(contractID!=null&&!contractID.equals("")){
                contractAttachment.setCid(Integer.parseInt(contractID));
            }
            contractAttachment.setName(fileFileName);
            contractAttachment.setPath(path);
            contractAttachment.setCreateTime(currentDate);

            contractAttachmentService.saveOrUpdate(contractAttachment);
            request.setAttribute("success","success");
            request.setAttribute("contractAttachment",contractAttachment);
            return "showupload";
        }catch (Exception e){
            e.printStackTrace();
        }
        return "failure";
    }

    public String update(){

        try{
            contractAttachmentService.update(contractAttachment);
            return "update";
        }catch (Exception e){
            e.printStackTrace();
        }
        return "failure";
    }

    public String delete(){
//        HttpServletResponse response=  ServletActionContext.getResponse();
//        PrintWriter writer=null;
//        response.setContentType("text/text;charset=UTF-8");

        HttpServletRequest request = ServletActionContext.getRequest();
        savePath=ServletActionContext.getServletContext().getRealPath("/")+"uploads";
        File f=null;

        String id = request.getParameter("id");
        if(id==null&&id.trim().equals("")){return "failure";}
        try{
//            writer=response.getWriter();
            contractAttachment = contractAttachmentService.get(Integer.parseInt(id));

            f = new File(savePath,contractAttachment.getPath());

            if(f!=null){
                f.delete();
                //返回1代表删除成功
//                writer.write("1");
            }
//            else{
//                writer.write("0");
//            }
        }catch (Exception e){
            e.printStackTrace();
        }
        contractAttachmentService.delete(contractAttachment);
        return null;
    }

    public String download(){


        return "download";
    }

    public void upload() throws Exception {
        savePath=ServletActionContext.getServletContext().getRealPath("/")+"uploads";//获得上传文件放置的目录，可以自己定义，绝对路径
        System.out.println(savePath);

        String formatDate = UtilTools.getBussinessNoByDate();//获得当前时间
        int position = fileFileName.lastIndexOf(".");//文件后缀名
        String extension = fileFileName.substring(position);
        int random = new Random().nextInt(1000);//获得的是随机数字，用于构造文件名
        path = formatDate + random + extension;//已经构造号的文件名

        System.out.println(path);

        InputStream is = new FileInputStream(file);//读取上传页面过来的文件流
        System.out.println(fileFileName);
        System.out.println(fileContentType);
        File destFile = new File(savePath,path);//创建需写入的文件

        if(!destFile.exists()){
            destFile.createNewFile();
        }
        OutputStream os = new FileOutputStream(destFile);
        byte[] buffer = new byte[1024];
        int length = 0 ;
        while((length = is.read(buffer)) > 0){
            os.write(buffer, 0, length);//写入
        }

        is.close();
        os.close();

    }

    public ContractAttachment getContractAttachment() {
        return contractAttachment;
    }

    public void setContractAttachment(ContractAttachment contractAttachment) {
        this.contractAttachment = contractAttachment;
    }

    public IContractAttachmentService getContractAttachmentService() {
        return contractAttachmentService;
    }

    public void setContractAttachmentService(IContractAttachmentService contractAttachmentService) {
        this.contractAttachmentService = contractAttachmentService;
    }

    public File getFile() {
        return file;
    }

    public void setFile(File file) {
        this.file = file;
    }

    public String getFileFileName() {
        return fileFileName;
    }

    public void setFileFileName(String fileFileName) {
        this.fileFileName = fileFileName;
    }

    public String getFileContentType() {
        return fileContentType;
    }

    public void setFileContentType(String fileContentType) {
        this.fileContentType = fileContentType;
    }

    public String getSavePath() {
        return savePath;
    }

    public void setSavePath(String savePath) {
        this.savePath = savePath;
    }
    //从下载文件原始存放路径读取得到文件输出流
    public InputStream getDownloadFile(){
        HttpServletRequest request = ServletActionContext.getRequest();
        savePath=ServletActionContext.getServletContext().getRealPath("/")+"uploads\\";
        String id = request.getParameter("id");

        InputStream fileInputStream = null;
        try {
            if(id!=null&&!id.trim().equals("")){
                contractAttachment = contractAttachmentService.get(Integer.parseInt(id));
                downloadFile = savePath+contractAttachment.getPath();//下载文件绝对地址
                downloadFileName = new String(contractAttachment.getName().getBytes(),"ISO-8859-1");//避免中文乱码
            }
            fileInputStream = new FileInputStream(downloadFile);//手动new一个InputStream获得下载文件流
        } catch (Exception e) {
            e.printStackTrace();  //To change body of catch statement use File | Settings | File Templates.
        }

        return fileInputStream;

    }

    public void setDownloadFile(String downloadFile) {
        this.downloadFile = downloadFile;
    }

    public String getDownloadFileName() {
        return downloadFileName;
    }
}

4.配置

<package name="pfl-attachment" namespace="/pfl/attachment" extends="struts-default">
        <action name="*AttachmentAction" method="{1}" class="contractAttachmentAction">
            <result name="showupload">/pfl/system/contract/uploadAttachment.jsp</result>
            <result name="download" type="stream">
                <!-- 下载文件类型定义（通用类型） -->
                <param name="contentType">application/octet-stream;charset=ISO8859-1</param>
                <!-- 下载文件输出流定义,会找Action中的InputStream getDownloadFile() -->
                <param name="inputName">downloadFile</param>
                <!-- 下载文件处理方法,获得下载的文件名（Action中的getDownloadFileName() ） -->
                <param name="contentDisposition">attachment;filename="${downloadFileName}"</param>
                <param name="bufferSize">4096</param>                
            </result>
            <result name="failure">/error.jsp</result>
            <result name="input">/error.jsp</result>
            <interceptor-ref name="defaultStack">
                <param name="fileUpload.maximumSize">10240000</param>
                <!--<param name="fileUpload.allowedTypes">image/bmp,image/png,image/gif,image/jpeg,image/jpg ,image/x-png, image/pjpeg</param>-->
            </interceptor-ref>
        </action>
    </package>