java文件下载

方法1：

package tutorial;   

 import java.io.BufferedInputStream;   
 import java.io.File;   
 import java.io.FileInputStream;   
 import java.io.OutputStream;   


 import org.apache.struts2.ServletActionContext;   

 import com.opensymphony.xwork2.ActionSupport;   

 public class FileUploadAction extends ActionSupport  {  
    private String fileName;
    public String getFileName() {
		return fileName;
	}

	public void setFileName(String fileName) {
		this.fileName = fileName;
	}   
     private static void down(String filePath)  {  
try{ 
         if (file.exists()) {
				BufferedInputStream bis = new BufferedInputStream(
						new FileInputStream(file));

				byte[] buffer = new byte[1024];
				filePath=java.net.URLEncoder.encode(
						filePath, "UTF-8");// 处理中文文件名的问题
				filePath=new String(filePath
						.getBytes("UTF-8"), "GBK"));// 处理中文文件名的问题
				response.reset();
				getResponse().setCharacterEncoding("UTF-8");
				response.setContentType("application/x-rar-compressed");// 不同类型的文件对应不同的MIME类型
				response.setHeader("Content-Disposition",
						"attachment; filename=" + attachmentMO.getFileName());
				OutputStream os = response.getOutputStream();
				while (bis.read(buffer) > 0) {
					os.write(buffer);
				}
				bis.close();
				os.close();
			} else {
				System.out.println("文件不存在.");			}
    }    
   }catch(Exception e){
      e.printStackTrace();
   }


    @Override  
     public String execute()      {           

        down(fileName);   
        return SUCCESS;   
    }    

}   

方法2：
直接将页面中的链接指向所要下载资源的路径，如图
[img]http://dl.iteye.com/upload/attachment/166663/e6b1b4af-9839-3118-af9c-c459726ce6a9.jpg[/img]