解决在eclipse2021中，用mysql-connector-java-8.0.18.jar不兼容，导致无法访问数据库问题
（1）一个jsp Model1模式简单的商品查询为例，
（jsp+javabean+mysql）
- eclipse2021
- mysql1.5.6
- Tomcat9.0
- jdk 16.0.1
- mysql-connector-java-8.0.18.jar、mysql-connector-java-5.1.6-bin.jar
- jar下载
链接：https://pan.baidu.com/s/1HEc-0yJthDu0H6b9x-1mYQ
提取码：21bo
问题
如果用mysql-connector-java-8.0.18.jar，设置配置都没问题的情况下，则出现不兼容，报错：
换成mysql-connector-java-5.1.6-bin.jar，则可正常运行且写入：
如图：
由于未去修改字符编码，所以导致中文乱码
（2）代码块：
- model1index.jsp (位置：Testbean\webapp\model1index.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="model1prosess.jsp" method="post" onsubmit="return save(this);">
<table border="1" align="center" width="300" bordercolor="#000000">
<tr>
<td align="center" colspan="2">
<br><h1>录入物品信息</h1>
</td>
</tr>
<tr><td>物品名称</td><td><input type="text" name="name" id="name"></td></tr>
<tr><td>价格：</td><td><input type="text" name="price" id="price"></td></tr>
<tr><td>物品描述：</td><td><input type="text" name="description" id="description"></td></tr>
<tr><td align="center" colspan="2"><input type="submit" value="提交"> <input type="reset" value="重置"></td></tr>
</table>
</form>
</body>
</html>
- model1prosess.jsp (位置：Testbean\webapp\model1prosess.jsp)
<%@page import="javabean.model1.GoodsDao"%>
<%@ 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>
<% request.setCharacterEncoding("UTF-8"); %>
<jsp:useBean id="goods" class="javabean.model1.Goods"></jsp:useBean>
<jsp:setProperty name="goods" property="*" />
<jsp:useBean id="goodsDao" class="javabean.model1.GoodsDao"></jsp:useBean>
<% goodsDao.saveGoods(goods); %>
</body>
</html>
- Goods.java (位置：Testbean\src\javabean\model1\Goods.java)
package javabean.model1;
public class Goods {
private String name;
private double price;
private String description;
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public double getPrice() {
return price;
}
public void setPrice(double price) {
this.price = price;
}
public String getDescription() {
return description;
}
public void setDescription(String description) {
this.description = description;
}
}
- GoodsDao.java (Testbean\src\javabean\model1\GoodsDao.java)
package javabean.model1;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
public class GoodsDao {
public void saveGoods(Goods goods){
try {
Class.forName("com.mysql.cj.jdbc.Driver");//加载驱动程序
String url="jdbc:mysql://localhost:3306/javabean";//数据库链接地址
Connection conn=DriverManager.getConnection(url,"root","root");//获取数据库链接
//定义sql语句
String sql="insert into goods(name,price,description) values(?,?,?)";
//创建PreparedStatement对象
PreparedStatement ps=conn.prepareStatement(sql);
//sql参数赋值
ps.setString(1,goods.getName());
ps.setDouble(2, goods.getPrice());
ps.setString(3, goods.getDescription());
ps.executeUpdate();//更新操作
ps.close();
conn.close();
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
- 数据库 javabean 表：goods