执行JDBC程序时，连接到数据库时出现以下错误：

Exception in thread "main" 
com.mysql.jdbc.exceptions.MySQLNonTransientConnectionException: Client does 
not support authentication protocol requested by server; consider upgrading 
MySQL client
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:921)
at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:2985)
at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:885)
at com.mysql.jdbc.MysqlIO.secureAuth411(MysqlIO.java:3421)
at com.mysql.jdbc.MysqlIO.doHandshake(MysqlIO.java:1247)
at com.mysql.jdbc.Connection.createNewIO(Connection.java:2775)
at com.mysql.jdbc.Connection.<init>(Connection.java:1555)
at 
com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:285)
at java.sql.DriverManager.getConnection(DriverManager.java:664)
at java.sql.DriverManager.getConnection(DriverManager.java:270)
at main.java.MyFirstJdbcProgram.readDataBase(MyFirstJdbcProgram.java:23)
at main.java.Main.main(Main.java:6)

在研究此问题时，我知道以下错误是因为我需要向用户授予特权，所以请按照以下步骤操作

1. mysql -u root -p
2. 然后输入密码
3. 然后我跑了

   GRANT ALL PRIVILEGES ON *.* TO 'root'@'localhost' IDENTIFIED BY 'mypassword';
   

我也用过

    UPDATE user SET authentication_string=password('mypassword') WHERE user='root';

但是我正在错误以下

错误1064（42000）：您的SQL语法有错误；检查与您的MySQL服务器版本相对应的手册以获取正确的语法，以在第1行的’IDENTIFIED
BY’mypassword’附近使用