JSP 点击链接后下载文件(相当于右键另存)功能

/**
* 实现文件另存功能
*
* @param text
* 文件内容
* @param filename
* 文件名称
* @return
*/
protected string renderfile(string text, string filename)
throws ioexception
{
response.addheader("content-disposition", "attachment; filename="
+ filename);
response.setcontenttype("application/octet-stream");
response.setcharacterencoding("gb2312");
response.getwriter().write(text);
response.flushbuffer();
response.getwriter().close();
return null;
}

下载的action:

/** *//**
* 提供下载的方法
* @return
*/
public string down()
{
string dir = getfullpath() + "/upload/file/";
try
{
if (!fileutils.exists(dir))
{
new file(dir).mkdirs();
}
random r = new random(system.currenttimemillis());
integer randomint = r.nextint();
this.renderfile("test content:" + randomint,randomint + ".txt");
}
catch (ioexception e)
{
e.printstacktrace();
this.rendertext(e.getmessage());
}
return null;
}

页面链接调用:

<a href="${ctx}/va/va!down.do" >下载</a>