Servlet——form表单提交数据

朴灿烈づ我的快乐病毒、 2023-02-26 04:27 3阅读 0赞

### form表单提交数据 ###

*  创建类
 *  表单页面代码
 *  Java代码
 *  配置web.xml
 *  代码编辑完成后，打包
 *  打包好的war放到webapps目录下
 *  启动Tomcat
 *  浏览器访问
 *  输入数据
 *  流程
 *  优化

# 创建类 #

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2NoYXJfbQ_size_16_color_FFFFFF_t_70]

# 表单页面代码 #

<!DOCTYPE html>
    <html lang="en">
    <head>
        <meta charset="UTF-8">
        <title>表单页面</title>
    </head>
    <body>
    <form method="get" action="ServletDemo2">
        <input type="text" name="firstName" placeholder="请输入名 ">
        <input type="text" name="secondName" placeholder="请输入姓 ">
        <input type="submit" value="提交" >
    </form>
    
    </body>
    </ht

# Java代码 #

import javax.servlet.ServletException;
    import javax.servlet.http.HttpServlet;
    import javax.servlet.http.HttpServletRequest;
    import javax.servlet.http.HttpServletResponse;
    import java.io.IOException;
    import java.io.Writer;
    
    public class ServletDemo2 extends HttpServlet {
        
        @Override
        protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        
            //处理表单数据
            String firstName = req.getParameter("firstName");
            String secondName = req.getParameter("secondName");
            //构造一个响应页面
            resp.setContentType("text/html; charset=utf-8");
            //一旦调用getWriter方法，此时header的内容就不能更改
            Writer writer = resp.getWriter();
            writer.write("<html>");
            writer.write("firstName: "+firstName);
            writer.write("<br/>");
            writer.write("secondMame: "+secondName);
            writer.write("</html>");
        }
    }

# 配置web.xml #

<?xml version="1.0" encoding="UTF-8"?>
    <web-app 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"
             version="3.1"
             metadata-complete="true">
    
      <servlet>
        <servlet-name>ServletDemo2</servlet-name>
        <servlet-class>ServletDemo.ServletDemo2</servlet-class>
        //因为包名为Servlet，所以在类名前要加上包名，这样才能找到类
      </servlet>
      <servlet-mapping>
        <servlet-name>ServletDemo2</servlet-name>
        <url-pattern>/ServletDemo2</url-pattern>
      </servlet-mapping>
    </web-app>

# 代码编辑完成后，打包 #

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2NoYXJfbQ_size_16_color_FFFFFF_t_70 1]

# 打包好的war放到webapps目录下 #

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2NoYXJfbQ_size_16_color_FFFFFF_t_70 2]

# 启动Tomcat #

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2NoYXJfbQ_size_16_color_FFFFFF_t_70 3]

# 浏览器访问 #

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2NoYXJfbQ_size_16_color_FFFFFF_t_70 4]

# 输入数据 #

![\*\*在这里插入图片描述\*\*][20200714112346737.png]

# 流程 #

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2NoYXJfbQ_size_16_color_FFFFFF_t_70 5]

# 优化 #

如果将get方法改为post方法  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2NoYXJfbQ_size_16_color_FFFFFF_t_70 6]  
没有实现post方法  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2NoYXJfbQ_size_16_color_FFFFFF_t_70 7]  
加上doPost方法，在里面调用doGet方法  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2NoYXJfbQ_size_16_color_FFFFFF_t_70 8]  
打包运行  
![在这里插入图片描述][2020071413094823.png]

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[20200714112346737.png]: https://img-blog.csdnimg.cn/20200714112346737.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2NoYXJfbQ_size_16_color_FFFFFF_t_70 5]: https://img-blog.csdnimg.cn/20200714113219726.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2NoYXJfbQ==,size_16,color_FFFFFF,t_70
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[2020071413094823.png]: https://img-blog.csdnimg.cn/2020071413094823.png