jsp點擊鏈接后下載文件功能

    /** *//**
    * 實現(xiàn)文件另存功能
    *
    * @param text
    * 文件內(nèi)容
    * @param filename
    * 文件名稱
    * @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;
    }
    下載的action:
    /** *//**
    * 提供下載的方法
    * @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;
    }