struts2下载文件功能（边下载边打包）

多个文件，目录不同，通过条件查询如何进行打包下载呢？

1.利用ZipEntry进i行文件的压缩

2.前台jsp传入需要打包下载的一系列的文件的路径（数组类型）。因为是在checkBox中，表单提交会自动将其定义成数组。只需要将name名称命名成后台需要得到的路径数组名称

比如前台

downLoadZip.jsp

--------checkBox处代码-------------------------------

利用iterator迭代出来的filePath

<input type="checkbox" name="downLoadPaths"
value='<s:property value="filePath"/>'/>

后台Action

private String[] downLoadPaths;

对downLoadPaths进行遍历，打包。。。。

代码：

 /**
  * 批量下载（压缩成zip，然后下载）。不创建临时文件
  *
  * @author Cloudy
  *
  */
 @Namespace("xxxxxx")
 public class DownZipAction {
     /**
      *
      */
     private static final long serialVersionUID = 1L;
     // 传递一个List<String>()对象传值路径合集
     private String[] downLoadPaths;
     private OutputStream res;
     private ZipOutputStream zos;
     private String outPath;

     // Action主方法
     @Action(value="DownLoadZip",results={@Result(name="nodata",location="/error.jsp"),
             @Result(name="success",location="xxxx.jsp")})
     public String downLoadZip() throws Exception {
         // 有数据可以下载
         if (downLoadPaths.length != 0) {
             // 进行预处理
             preProcess();
         } else {
             // 没有文件可以下载，返回nodata
             return "nodata";
         }
         // 处理
         writeZip(downLoadPaths);
         // 后处理关闭流
         afterProcess();
         return SUCCESS;
     }

     // 压缩处理
     public void writeZip(String[] downLoadPaths) throws IOException {
         byte[] buf = new byte[8192];
         int len;

         for (String filename : downLoadPaths) {
             File file = new File(filename);
             if (!file.isFile())
                 continue;
             ZipEntry ze = new ZipEntry(file.getName()); //apache jar的ZipEntry
             zos.putNextEntry(ze);
             BufferedInputStream bis = new BufferedInputStream(new FileInputStream(file));
             while ((len = bis.read(buf)) > 0) {
                 zos.write(buf, 0, len);
             }
             bis.close();
             zos.closeEntry();
         }
     }

     // 预处理
     public void preProcess() throws Exception {
         HttpServletResponse response = ServletActionContext.getResponse();
         res = response.getOutputStream();
         // 清空输出流(在迅雷下载不会出现一长窜)
         response.reset();
         // 设定输出文件头
         response.setHeader("Content-Disposition", "attachment;filename=document.zip");
         response.setContentType("application/zip");
         zos = new ZipOutputStream(res);
     }

     // 后处理
     public void afterProcess() throws IOException {

         zos.close();
         res.close();
     }

     public OutputStream getRes() {
         return res;
     }

     public void setRes(OutputStream res) {
         this.res = res;
     }

     public ZipOutputStream getZos() {
         return zos;
     }

     public void setZos(ZipOutputStream zos) {
         this.zos = zos;
     }

     public String[] getDownLoadPaths() {
         return downLoadPaths;
     }

     public void setDownLoadPaths(String[] downLoadPaths) {
         this.downLoadPaths = downLoadPaths;
     }

     public String getOutPath() {
         return outPath;
     }

     public void setOutPath(String outPath) {
         this.outPath = outPath;
     }

 }