解决：Mysql8.0 ConnectionImpl.getServerCharset NullPointerException（亲测有效）

迷南。 2023-01-03 05:59 162阅读 0赞

1.  报错问题：在使用Java程序连接mysql的时候，会出现这样的一个报错

com.mysql.jdbc.exceptions.jdbc4.MySQLNonTransientConnectionException: Could not create connection to database server.
    	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.jdbc.Util.handleNewInstance(Util.java:425)
    	at com.mysql.jdbc.Util.getInstance(Util.java:408)
    	at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:918)
    	at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:897)
    	at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:886)
    	at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:860)
    	at com.mysql.jdbc.ConnectionImpl.connectOneTryOnly(ConnectionImpl.java:2330)
    	at com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2083)
    	at com.mysql.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:806)
    	at com.mysql.jdbc.JDBC4Connection.<init>(JDBC4Connection.java:47)
    	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.jdbc.Util.handleNewInstance(Util.java:425)
    	at com.mysql.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:410)
    	at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:328)
    	at java.sql.DriverManager.getConnection(DriverManager.java:664)
    	at java.sql.DriverManager.getConnection(DriverManager.java:247)
    	at JDBC.Demo.main(Demo.java:15)
    Caused by: java.lang.NullPointerException
    	at com.mysql.jdbc.ConnectionImpl.getServerCharset(ConnectionImpl.java:2997)
    	at com.mysql.jdbc.MysqlIO.sendConnectionAttributes(MysqlIO.java:1934)
    	at com.mysql.jdbc.MysqlIO.proceedHandshakeWithPluggableAuthentication(MysqlIO.java:1863)
    	at com.mysql.jdbc.MysqlIO.doHandshake(MysqlIO.java:1226)
    	at com.mysql.jdbc.ConnectionImpl.coreConnect(ConnectionImpl.java:2253)
    	at com.mysql.jdbc.ConnectionImpl.connectOneTryOnly(ConnectionImpl.java:2284)
    	... 13 more

1.  报错原因： mysql-connector-java mysql的Java驱动需要更新到8.0+  
    在Pom中换到8.0+即可解决问题

<dependency>
          <groupId>mysql</groupId>
          <artifactId>mysql-connector-java</artifactId>
          <version>8.0.21</version>
        </dependency>