场景:使用Servlet实现文件下载服务端
1.创建spring的web项目,确保启动正常。
2.创建DownloadServlet类继承HttpServlet并实现doGet方法。
public class DownloadServlet extends HttpServlet{
private static final Logger logger =
LoggerFactory.getLogger(DownloadServlet.class);
private static final long serialVersionUID = 1033412753252391835L;
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
logger.info("下载开始......");
/**1.从请求中获取下载名称*/
String fileName = request.getParameter("filename");
fileName=new String(fileName.getBytes("ISO8859-1"),"UTF-8");
/**2.设置附件形式下载,浏览器根据此参数做判断*/
response.setHeader("Content-Disposition", "attachment;filename="+fileName);
/**3.本地存放给服务下载的压缩文件夹的路径*/
String dir = "D:/DownloadDir/";
String filePath = dir + fileName;
/**4.创建输入流*/
InputStream in=new FileInputStream(filePath);
/**5.从response获取输出流*/
ServletOutputStream out=response.getOutputStream();
/**6.把输入流写入到输出流,实际就是一个拷贝过程*/
int len=0;
byte [] buffer=new byte[1024 * 4];
while((len=in.read(buffer))>0) {
out.write(buffer, 0, len);
}
in.close();
out.close();
logger.info("下载结束......");
}
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
doGet(request,response);
}
}
3.在web.xml中配置Servlet的url映射关系
<!-- 下载服务start -->
<servlet>
<display-name>
</display-name>
<servlet-name>downloadServlet</servlet-name>
<servlet-class>com.zbz.servlet.DownloadServlet</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>downloadServlet</servlet-name>
<url-pattern>/download</url-pattern>
</servlet-mapping>
<!-- 下载服务end -->
4.启动服务在浏览器访问
本例是本地搭建服务,直接从D盘读取一个文件供下载,
D:\DownloadDir\8195B04F2E924C2E9596AC79488351EF.zip
下载url是:
http://127.0.0.1:8080/study/download?filename=8195B04F2E924C2E9596AC79488351EF.zip
其中: study是项目名称
以上,TKS.