使用jdbc连接mysql为什么报错？

当我用JDBC连接MySql数据库时，编译报了如下错误：

错误1：

Loading class `com.mysql.jdbc.Driver'. This is deprecated. The new driver class is `com.mysql.cj.jdbc.Driver'. The driver is automatically registered via the SPI and manual loading of the driver class is generally unnecessary.

这要求我们注册驱动时，把Class.forName("com.mysql.jdbc.Driver")改成 Class.forName("com.mysql.cj.jdbc.Driver")

当我信息满满的修改之后重新编译时，再次出现了错误：

错误2：

Fri Feb 22 08:55:38 CST 2019 WARN: Establishing SSL connection without server's identity verification is not recommended. According to MySQL 5.5.45+, 5.6.26+ and 5.7.6+ requirements SSL connection must be established by default if explicit option isn't set. For compliance with existing applications not using SSL the verifyServerCertificate property is set to 'false'. You need either to explicitly disable SSL by setting useSSL=false, or set useSSL=true and provide truststore for server certificate verification.

这要求我们在设置url参数时，将useSSL=false，修改后 jdbc:mysql://localhost:3306/ds3?useSSL=false

当我修改后，本以为这下应该没问题了，没想到，再一次出现了问题

错误3：

Exception in thread "main" java.sql.SQLException: The server time zone value 'Öйú±ê׼ʱ¼ä' is unrecognized or represents more than one time zone. You must configure either the server or JDBC driver (via the serverTimezone configuration property) to use a more specifc time zone value if you want to utilize time zone support.

这要求我们修改时区，修改成jdbc:mysql://localhost:3306/ds3?useSSL=false&serverTimezone=UTC

终于，不在报错误了。

错误4：当我们配置xml文件时，要把&转为其本身的转义字符

配置properties文件的urlurl=jdbc:mysql:///ds3?useSSL=false&serverTimezone=UTC配置xml文件的url<property name="url">jdbc:mysql://localhost:3306/ds3?useSSL=false&serverTimezone=UTC</property>

LZ 实际做项目的时候 都要直连 从网上找找 那三个直连包吧

代码如下：

package com.bl.db

import java.sql.DriverManager

import java.sql.SQLException

import com.blog.port.*

import java.sql.*

public class DBTool implements IDBTool {

Connection conn

public Connection getConn(){

try {

DriverManager.registerDriver(new com.microsoft.jdbc.sqlserver.SQLServerDriver())

conn = DriverManager.getConnection("jdbc:microsoft:sqlserver://127.0.0.1:1433databasename=Data","sa","")

} catch (SQLException e) {

// TODO 自动生成 catch 块

e.printStackTrace()

}

return conn

}

public void Close(ResultSet rs,PreparedStatement pst,Connection conn){

try {

if(rs!=null){

rs.close()

}

if(pst!=null){

pst.close()

}

if(conn!=null){

conn.close()

}

} catch (SQLException e) {

e.printStackTrace()

}

}

}

我采用的是 分层模式

1，驱动配置有误：driver=com.mysql.jdbc.Driver

2，数据库连接地址有误：url=jdbc:mysql://localhost:3306/test?3useUnicode=true&characterEncoding=utf8

3，密码或帐号有误：username=root

password=root

4，数据库未启动或无权访问

5，项目未引入对应的驱动jar包mysql-connector-java-5.1.6-bin.jar

6,mysql root没有远程访问的权限，需要增加权限，增加权限的步骤如下：

进入mysql数据库：

grant all privileges on *.* to 'root'@'%' identified by 'root' with grant option

flush privileges

7.jdbc驱动要放到jre里面。

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