Servlet中的文件下载

public void doGet(HttpServletRequest request, HttpServletResponse response)
                    throws ServletException, IOException {
    response.setContentType("application/jar");

    ServletContext ctx = getServletContext();
    InputStream is = ctx.getResourceAsStream("/bookCode.jar");

    int read = 0;
    byte[] bytes = new byte[1024];

    OutputStream os = response.getOutputStream();
    while ((read = is.read(bytes)) != -1) {
        os.write(bytes, 0, read);
    }
    os.flush();
    os.close();
}

response.setContentType("application/jar")指定响应的是一个JAR文件，而不是HTML。

getResourceAsStream()方法要求以一个斜线（“/”）开头，这表示Web应用的根。

摘自《Head First Servlet & JSP（中文版）》129页