按照wso2官网（https://docs.wso2.com/display/ADMIN44x/Changing+to+MySQL）配置AM的数据库，想从H2换成Mysql5.7，费了将近一天的时间，老是报错，提示AuthorizationUtils Could not set authorizations for the root，报错如下：

Caused by: com.mysql.cj.exceptions.CJCommunicationsException: Communications link failure

The last packet sent successfully to the server was 0 milliseconds ago. The driver has not received any packets from the 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.cj.exceptions.ExceptionFactory.createException(ExceptionFactory.java:61)
        at com.mysql.cj.exceptions.ExceptionFactory.createException(ExceptionFactory.java:105)
        at com.mysql.cj.exceptions.ExceptionFactory.createException(ExceptionFactory.java:151)
        at com.mysql.cj.exceptions.ExceptionFactory.createCommunicationsException(ExceptionFactory.java:167)
        at com.mysql.cj.protocol.a.NativeProtocol.negotiateSSLConnection(NativeProtocol.java:361)
        at com.mysql.cj.protocol.a.NativeAuthenticationProvider.negotiateSSLConnection(NativeAuthenticationProvider.java:777)
        at com.mysql.cj.protocol.a.NativeAuthenticationProvider.proceedHandshakeWithPluggableAuthentication(NativeAuthenticationProvider.java:486)
        at com.mysql.cj.protocol.a.NativeAuthenticationProvider.connect(NativeAuthenticationProvider.java:202)
        at com.mysql.cj.protocol.a.NativeProtocol.connect(NativeProtocol.java:1449)
        at com.mysql.cj.NativeSession.connect(NativeSession.java:165)
        at com.mysql.cj.jdbc.ConnectionImpl.connectWithRetries(ConnectionImpl.java:849)
        ... 76 more
Caused by: java.net.SocketException: Broken pipe (Write failed)
        at java.net.SocketOutputStream.socketWrite0(Native Method)
        at java.net.SocketOutputStream.socketWrite(SocketOutputStream.java:111)
        at java.net.SocketOutputStream.write(SocketOutputStream.java:155)
        at sun.security.ssl.OutputRecord.writeBuffer(OutputRecord.java:431)
        at sun.security.ssl.OutputRecord.write(OutputRecord.java:417)