今天eclipse连接mysql遇到不少问题。
我用的环境如下（错误的情况下）：
eclipse 4.7；
jdk1.7（Java project）；
mysql5.6；
mysql-connector-java-8.0.12.jar(需要导入)；
部分连接语句（错误的部分）：
String driver = "com.mysql.jdbc.Driver";
String url = "jdbc:mysql://localhost:3306/test ";1 版本错误：Unsupported major.minor version 52.0
JDK版本在官方对应的版本号列表如下(引用https://blog.csdn.net/zixiao217/article/details/52818658)：
此错误将
JDK 8.0 = 52,
JDK 7.0 = 51,
JDK 6.0 = 50,
JDK 5.0 = 49,
JDK 1.4 = 48,
JDK 1.3 = 47,
JDK 1.2 = 46,
JDK 1.1 = 45将jdk 修改成1.8后这个错误消失
2 连接驱动driver错误
错误提示：
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.
加入‘cj.’修改为此错误消失：
String driver = "com.mysql.cj.jdbc.Driver";3 时区没有设置
错误提示：
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.
at com.mysql.cj.jdbc.exceptions.SQLError.createSQLException(SQLError.java:129)
at com.mysql.cj.jdbc.exceptions.SQLError.createSQLException(SQLError.java:97)
at com.mysql.cj.jdbc.exceptions.SQLError.createSQLException(SQLError.java:89)
at com.mysql.cj.jdbc.exceptions.SQLError.createSQLException(SQLError.java:63)
at com.mysql.cj.jdbc.exceptions.SQLError.createSQLException(SQLError.java:73)
at com.mysql.cj.jdbc.exceptions.SQLExceptionsMapping.translateException(SQLExceptionsMapping.java:76)
at com.mysql.cj.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:832)
at com.mysql.cj.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:456)
at com.mysql.cj.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:240)
at com.mysql.cj.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:207)
at java.sql.DriverManager.getConnection(DriverManager.java:664)
at java.sql.DriverManager.getConnection(DriverManager.java:247)
at mysqljdbc1217.main.main(main.java:29)
Caused by: com.mysql.cj.exceptions.InvalidConnectionAttributeException: 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.
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
at java.lang.reflect.Constructor.newInstance(Constructor.java:423)
at com.mysql.cj.exceptions.ExceptionFactory.createException(ExceptionFactory.java:61)
at com.mysql.cj.exceptions.ExceptionFactory.createException(ExceptionFactory.java:85)
at com.mysql.cj.util.TimeUtil.getCanonicalTimezone(TimeUtil.java:128)
at com.mysql.cj.protocol.a.NativeProtocol.configureTimezone(NativeProtocol.java:2236)
at com.mysql.cj.protocol.a.NativeProtocol.initServerSession(NativeProtocol.java:2260)
at com.mysql.cj.jdbc.ConnectionImpl.initializePropsFromServer(ConnectionImpl.java:1314)
at com.mysql.cj.jdbc.ConnectionImpl.connectOneTryOnly(ConnectionImpl.java:963)
at com.mysql.cj.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:822)
... 6 more修改 ：
String url = "jdbc:mysql://localhost:3306/test "+ "?serverTimezone=GMT%2B8";
错误全部消失。
全部代码如下：
package mysqljdbc1217;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
public class main {
public static void main(String[] args) {
//声明Connection对象
Connection con;
//驱动程序名
String driver = "com.mysql.cj.jdbc.Driver";
//URL指向要访问的数据库名mydata
String url = "jdbc:mysql://localhost:3306/test "+ "?serverTimezone=GMT%2B8";
//MySQL配置时的用户名
String user = "root";
//MySQL配置时的密码
String password = "11111";
//遍历查询结果集
try {
//加载驱动程序
System.out.println("执行结果如下所示:");
Class.forName(driver);
System.out.println("执行结果如下所示:");
//1.getConnection()方法，连接MySQL数据库！！
con = DriverManager.getConnection(url,user,password);
if(!con.isClosed())
System.out.println("Succeeded connecting to the Database!");
//2.创建statement类对象，用来执行SQL语句！！
Statement statement = con.createStatement();
//要执行的SQL语句
String sql = "select * from temporpary_data";
//3.ResultSet类，用来存放获取的结果集！！
ResultSet rs = statement.executeQuery(sql);
System.out.println("-----------------");
System.out.println("执行结果如下所示:");
System.out.println("-----------------");
System.out.println("姓名" + "\t" + "职称");
System.out.println("-----------------");
String job = null;
String id = null;
/* while(rs.next()){
//获取stuname这列数据
job = rs.getString("job");
//获取stuid这列数据
id = rs.getString("ename");
//输出结果
System.out.println(id + "\t" + job);
}
rs.close();
con.close();*/
} catch(ClassNotFoundException e) {
//数据库驱动类异常处理
System.out.println("Sorry,can`t find the Driver!");
e.printStackTrace();
} catch(SQLException e) {
//数据库连接失败异常处理
e.printStackTrace();
}catch (Exception e) {
// TODO: handle exception
e.printStackTrace();
}finally{
System.out.println("数据库数据成功获取！！");
}
}
}