DownAction.java

package com.rlovep.file;

import java.io.File;
import java.io.InputStream;
import java.io.UnsupportedEncodingException;
import java.net.URLEncoder;
import java.util.Map;

import org.apache.struts2.ServletActionContext;

import com.opensymphony.xwork2.ActionContext;
import com.opensymphony.xwork2.ActionSupport;

public class DownAction extends ActionSupport{
	// 1. 获取要下载的文件的文件名
		private String fileName;
		public void setFileName(String fileName){
			//处理传入的参数中的编码问题
			try {
				fileName=new String(fileName.getBytes("ISO8859-1"), "utf-8");
			} catch (UnsupportedEncodingException e) {
				throw new RuntimeException(e);
			}
			this.fileName=fileName;
		}
	/***1.显示所有要下载的列表****/
	public String list() throws Exception{
		//得到upload目录路径
		String path = ServletActionContext.getServletContext().getRealPath("/upload");
		// 目录对象
		File file  = new File(path);
		// 得到所有要下载的文件的文件名
		String[] fileNames =  file.list();
		// 保存
		Map<String, Object> request = ActionContext.getContext().getContextMap();
		request.put("fileNames", fileNames);
		return "list";
	}
	/*************2. 文件下载*********************/
	//2. 下载提交的业务方法 (在struts.xml中配置返回stream)
		public String down() throws Exception {
			return "download";
		}
	//返回文件流的方法	
     public InputStream getAttrInputStream(){
    	 return ServletActionContext.getServletContext().getResourceAsStream("/upload/"+fileName);
     }
     //下载显示的文件名
     public String getDownFileName(){
    	// 需要进行中文编码
 		try {
 			fileName = URLEncoder.encode(fileName, "UTF-8");
 		} catch (UnsupportedEncodingException e) {
 			throw new RuntimeException(e);
 		}
 		return fileName;
 	}
     
}