struts2 文件下载

package com.cioside.web;

import java.io.FileInputStream;
import java.io.InputStream;
import java.io.UnsupportedEncodingException;

import javax.servlet.http.HttpServletResponse;

import org.apache.struts2.convention.annotation.Namespace;
import org.apache.struts2.convention.annotation.Result;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springside.modules.utils.web.struts2.Struts2Utils;

import com.cioside.entity.Attachment;
import com.cioside.service.UploadManager;
import com.opensymphony.xwork2.ActionSupport;

@Controller
@Namespace("/service")
@Result(type = "stream", params = { "contentType",
??"application/octet-stream;charset=ISO8859-1", "inputName",
??"downloadFile", "contentDisposition",
??"attachment;filename=${downloadChineseFileName}", "bufferSize", "4096" })
public class DownloadAction extends ActionSupport {

?private static final long serialVersionUID = -7815222637330155732L;

?@Autowired
?private UploadManager uploadManager;
?private String fileName;
?private Long workId;
?private Long id;
?private String msg;

?public InputStream getDownloadFile() {
??InputStream in = null;
??try {

???Attachment attachment = new Attachment();
???if (id != null) {
????attachment = uploadManager.getAttachment(id);
???}
???HttpServletResponse response = Struts2Utils.getResponse();
???response.setContentType("application/x-download");
???response.setHeader("Content-Disposition", "attachment; fileName="
?????+ java.net.URLEncoder.encode(fileName, "ISO8859-1"));
???in = new FileInputStream(attachment.getLocation());

???if (in == null) {
????System.out
??????.println("Can not find a java.io.InputStream with the name [inputStream] in the invocation stack. Check the <param name=\"inputName\"> tag specified for this action.检查action中文件下载路径是否正确.");
???}
???response.reset();
??} catch (Exception e) {
???msg = "文件不存在！";
??}

??return in;
?}

?// 如果下载文件名为中文，进行字符编码转换
?public String getDownloadChineseFileName() {
??String downloadChineseFileName = fileName;

??try {
???downloadChineseFileName = new String(downloadChineseFileName
?????.getBytes(), "ISO8859-1");
??} catch (UnsupportedEncodingException e) {
???e.printStackTrace();
??}

??return downloadChineseFileName;
?}

?@Override
?public String execute() throws Exception {

??return "success";
?}

?public String getFileName() {

??return fileName;
?}

?public void setFileName(String fileName) {

??this.fileName = fileName;
?}

?public Long getWorkId() {
??return workId;
?}

?public void setWorkId(Long workId) {
??this.workId = workId;
?}

?public Long getId() {
??return id;
?}

?public void setId(Long id) {
??this.id = id;
?}

}