javaweb 实现文件下载的方法及实例代码
javaweb实现文件下载
不要再说用<a>标签下载了,这个会把文件打开而不是下载
例如:
<ahref="E:\MyDesktop\37fecd65330184de67d419a8d02e7081.jpg">下载</a>
如果我这样写,浏览器就会把图片直接打开,除非是一个浏览器打不开的文件
所以我们还是要用到java本身的文件读写来进行文件的下载
<ahref="downloadFile?filename=<s:propertyvalue='document_filename'/>">下载</a>
packagecom.cpsec.tang.chemical.action; importjava.io.File; importjava.io.FileInputStream; importjava.io.FileNotFoundException; importjava.io.FileOutputStream; importjava.io.IOException; importjava.io.InputStream; importjava.io.OutputStream; importjava.text.SimpleDateFormat; importjava.util.Calendar; importjava.util.List; importjava.util.Random; importjavax.annotation.Resource; importjavax.servlet.http.HttpServletRequest; importjavax.servlet.http.HttpServletResponse; importorg.apache.struts2.ServletActionContext; importorg.springframework.stereotype.Controller; importcom.cpsec.tang.chemical.biz.DocumentBiz; importcom.cpsec.tang.chemical.entity.Document; importcom.cpsec.tang.chemical.util.Pager; importcom.opensymphony.xwork2.ActionSupport; @Controller("documentAction") publicclassDocumentActionextendsActionSupport{privateStringfilename; publicStringdownloadFile(){ System.out.println(filename); try{ HttpServletResponseresponse=ServletActionContext.getResponse(); //设置文件MIME类型 response.setContentType(ServletActionContext.getServletContext().getMimeType(filename)); //设置Content-Disposition response.setHeader("Content-Disposition","attachment;filename="+filename); //获取目标文件的绝对路径 StringfullFileName=ServletActionContext.getServletContext().getRealPath("/files/"+filename); //System.out.println(fullFileName); //读取文件 InputStreamin=newFileInputStream(fullFileName); //读取目标文件,通过response将目标文件写到客户端 OutputStreamout=response.getOutputStream(); //写文件 intb; while((b=in.read())!=-1) { out.write(b); } in.close(); out.close(); }catch(Exceptione){ e.printStackTrace(); } returnSUCCESS; } }
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