向JSP添加注释 [英] add annotation to JSP

问题描述

因此，在我的课堂上，我被责令将图像上传到数据库，并将其发布并显示在网站上，使用servlet或php时非常简单，但是我被要求仅使用JSP文件来完成.为此，我必须从用户那里获取图像并将其作为参数传递，并获得参数的一部分，这不是问题.

so in my class i was ordered to upload images to database and get them out and show them on a website, pretty simple when using servlet or php, but i was asked to do it using only JSP files. to do so i had to get an image from the user and pass it as a parameter and get a part of the parameter, not a problem.

当我尝试运行它并且服务器要求@multipartconfig注释时，问题就开始了.我找不到将其添加到jsp代码中的方法.

the problem started when i tried to run it and the server asked for @multipartconfig annotation. i cant find a way to add it to the jsp code.

    <%@page import="javax.servlet.annotation.MultipartConfig"%>
<%@page import="java.sql.*"%>
<%@page import="java.io.InputStream"%>
<%@page contentType="text/html" pageEncoding="UTF-8"%>


<%
    request.setCharacterEncoding("UTF-8");
    Part p = request.getPart("image");
    InputStream inputStream = null;
    if (p != null) {
        inputStream = p.getInputStream();
    }

    String driver = "com.mysql.jdbc.Driver";
    String url = "jdbc:mysql://localhost:3306/test42";
    Class.forName(driver);
    Connection con = DriverManager.getConnection(url, "root", "1234");

    String sqlString = "INSERT INTO test42.images items(idimages) values(" + inputStream + ");";

    String msg = p.toString();

%>

这是上传表单:

  <form method="post" action="mainPage.jsp" enctype="multipart/form-data">
                choose file :
                <input type="file" name="image" />

                <input type="submit" value="submit">
            </form>

这是来自服务器的消息:

and this is the messege from the server:

java.lang.IllegalStateException: Request.getPart is called without multipart configuration. Either add a @MultipartConfig to the servlet, or a multipart-config element to web.xml

我尝试将其添加到web.xml中，但没有成功.... 该应用程序因构建错误而崩溃； 我从这里得到了这个解决方案: http://docs.oracle.com/javaee/6/tutorial/doc /gmhal.html

i tried adding it to the web.xml but it didnt work.... the app just crash with a build error; i got this solution from here: http://docs.oracle.com/javaee/6/tutorial/doc/gmhal.html

<?xml version="1.0" encoding="UTF-8"?>
<web-app version="3.1" xmlns="http://xmlns.jcp.org/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd">

    <session-config>
        <session-timeout>
            30
        </session-timeout>
   </session-config>

   <multipart-config>
    <location>/tmp</location>
    <max-file-size>20848820</max-file-size>
    <max-request-size>418018841</max-request-size>
    <file-size-threshold>1048576</file-size-threshold>
</multipart-config>

</web-app>

推荐答案

您需要具有一个servlet和一个servlet-mapping标签.

You need to have a servlet and a servlet-mapping tag.

<?xml version="1.0" encoding="UTF-8"?>
<web-app version="3.1" xmlns="http://xmlns.jcp.org/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd">

<session-config>
    <session-timeout>
        30
    </session-timeout>
</session-config>
<servlet>   
           <servlet-name>uploadfile</servlet-name>
           <jsp-file>/mainPage.jsp</jsp-file>
           <multipart-config>
               <location>/temp</location>
               <max-file-size>20848820</max-file-size>
               <max-request-size>418018841</max-request-size>
               <file-size-threshold>1048576</file-size-threshold>
           </multipart-config>
</servlet>
<servlet-mapping>
            <servlet-name>uploadfile</servlet-name>
            <url-pattern>/mainPage.jsp</url-pattern>
</servlet-mapping


</web-app>

这篇关于向JSP添加注释的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！