jsp+servlet+jdbc实现表单提交

1.新建一个maven工程，选webapp模板

2.安装tomcat

https://tomcat.apache.org/download-80.cgi 下载解压到自定义目录上

ps:在全局变量加上JAVA_HOME变量指向JDK（例如:D:Javav1.8）,tomcat才能正常运行

3.eclipse配置server

Windows-->Preferences-->Server-->Runtime Environments

添加tomcat

4.增加tomcat的libary

工程右击--->Build Path --->Configure Build path

选择刚刚加到eclipse的tomcat

5.编写jsp

<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Insert title here</title>
</head>
<body>
    <form action="${pageContext.request.contextPath}/saveUserInfo" method="GET">
        username:<input type="text" name="username"></input><br/>
        adress:<input type="text" name="address"></input>
        <input type="submit" value="保存"/>
    </form>
</body>
</html>

6.编写映射到servlet接口类的配置文件，web.xml

<?xml version="1.0" encoding="UTF-8"?>
<web-app version="2.5" xmlns="http://java.sun.com/xml/ns/javaee"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://java.sun.com/xml/ns/javaee   
    http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd">
    <servlet>
        <servlet-name>hello</servlet-name>
        <servlet-class>amie.servlet.helloServlet</servlet-class>
    </servlet>
    <servlet-mapping>
        <servlet-name>hello</servlet-name>
        <url-pattern>/saveUserInfo</url-pattern>
    </servlet-mapping>
</web-app>

7.编写servlet类

从上面可以得到，tomcat服务器的路径“/saveUserInfo”已经映射到“amie.servlet.helloServlet”这个类上了

package amie.servlet;

import java.io.IOException;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import jdbc.jdbc;

public class helloServlet extends HttpServlet {
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        response.setCharacterEncoding("gbk");
        String username = new String(request.getParameter("username").getBytes("UTF8"));
        String address = new String(request.getParameter("address").getBytes("UTF8"));
        jdbc mj = new jdbc();
        try {
            mj.insert(username, address);
            response.getWriter().println("写入成功");
        } catch (Exception e) {
            response.getWriter().print(e);
        }
    }
}

doGet、doPost等方法会对应路径“/saveUserInfo”的GET、POST的方法

8.编写jdbc

我们上面用了一个jdbc.jdbc类的insert方法

package jdbc;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;

public class jdbc {
    public void insert(String name, String address) throws Exception{
        String url = "jdbc:mysql://localhost:3306/20171113";
        String userName = "root";
        String password = "";
        Connection conn = DriverManager.getConnection(url,userName,password);
        String sql = "INSERT INTO user(username,address) VALUES(?,?)";
        PreparedStatement ps = conn.prepareStatement(sql);
        ps.setString(1, name);
        ps.setString(2, address);
        ps.execute();
        conn.close();
    }
}

这里值得一提的是：jdbc的mysql驱动（mysql-connector-java-x.x.x-bin）一定要加在jrelibext下,因为此时已经运行在tomcat上脱离了eclipse，runtime的依赖包一定要到java的安装目录下获取。

9.运行

项目右击，run as --> run on server

保存后

数据库也成功存入数据