com.mysql.cj.jdbc.exceptions.CommunicationsException: Communications link failure

The last packet successfully received from the server was 5,011 milliseconds ago. The last packet sent successfully to the server was 5,011 milliseconds ago.
	at com.mysql.cj.jdbc.exceptions.SQLError.createCommunicationsException(SQLError.java:174) ~[mysql-connector-java-8.0.19.jar:8.0.19]
	at com.mysql.cj.jdbc.exceptions.SQLExceptionsMapping.translateException(SQLExceptionsMapping.java:64) ~[mysql-connector-java-8.0.19.jar:8.0.19]
	at com.mysql.cj.jdbc.ConnectionImpl.isReadOnly(ConnectionImpl.java:1414) ~[mysql-connector-java-8.0.19.jar:8.0.19]
	at com.mysql.cj.jdbc.ConnectionImpl.isReadOnly(ConnectionImpl.java:1399) ~[mysql-connector-java-8.0.19.jar:8.0.19]
	at com.zaxxer.hikari.pool.PoolBase.setupConnection(PoolBase.java:398) ~[HikariCP-3.4.2.jar:na]
	at com.zaxxer.hikari.pool.PoolBase.newConnection(PoolBase.java:359) ~[HikariCP-3.4.2.jar:na]
	at com.zaxxer.hikari.pool.PoolBase.newPoolEntry(PoolBase.java:202) ~[HikariCP-3.4.2.jar:na]
	at com.zaxxer.hikari.pool.HikariPool.createPoolEntry(HikariPool.java:473) [HikariCP-3.4.2.jar:na]
	at com.zaxxer.hikari.pool.HikariPool.access$100(HikariPool.java:71) [HikariCP-3.4.2.jar:na]
	at com.zaxxer.hikari.pool.HikariPool$PoolEntryCreator.call(HikariPool.java:719) [HikariCP-3.4.2.jar:na]
	at com.zaxxer.hikari.pool.HikariPool$PoolEntryCreator.call(HikariPool.java:705) [HikariCP-3.4.2.jar:na]
	at java.util.concurrent.FutureTask.run(FutureTask.java:266) [na:1.8.0_131]
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142) [na:1.8.0_131]
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617) [na:1.8.0_131]
	at java.lang.Thread.run(Thread.java:748) [na:1.8.0_131]
Caused by: com.mysql.cj.exceptions.CJCommunicationsException: Communications link failure

The last packet successfully received from the server was 5,011 milliseconds ago. The last packet sent successfully to the server was 5,011 milliseconds ago.
	at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) ~[na:1.8.0_131]
	at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62) ~[na:1.8.0_131]
	at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45) ~[na:1.8.0_131]
	at java.lang.reflect.Constructor.newInstance(Constructor.java:423) ~[na:1.8.0_131]
	at com.mysql.cj.exceptions.ExceptionFactory.createException(ExceptionFactory.java:61) ~[mysql-connector-java-8.0.19.jar:8.0.19]
	at com.mysql.cj.exceptions.ExceptionFactory.createException(ExceptionFactory.java:105) ~[mysql-connector-java-8.0.19.jar:8.0.19]
	at com.mysql.cj.exceptions.ExceptionFactory.createException(ExceptionFactory.java:151) ~[mysql-connector-java-8.0.19.jar:8.0.19]
	at com.mysql.cj.exceptions.ExceptionFactory.createCommunicationsException(ExceptionFactory.java:167) ~[mysql-connector-java-8.0.19.jar:8.0.19]
	at com.mysql.cj.protocol.a.NativeProtocol.readMessage(NativeProtocol.java:539) ~[mysql-connector-java-8.0.19.jar:8.0.19]
	at com.mysql.cj.protocol.a.NativeProtocol.checkErrorMessage(NativeProtocol.java:703) ~[mysql-connector-java-8.0.19.jar:8.0.19]
	at com.mysql.cj.protocol.a.NativeProtocol.sendCommand(NativeProtocol.java:642) ~[mysql-connector-java-8.0.19.jar:8.0.19]
	at com.mysql.cj.protocol.a.NativeProtocol.sendCommand(NativeProtocol.java:128) ~[mysql-connector-java-8.0.19.jar:8.0.19]
	at com.mysql.cj.NativeSession.sendCommand(NativeSession.java:311) ~[mysql-connector-java-8.0.19.jar:8.0.19]
	at com.mysql.cj.NativeSession.queryServerVariable(NativeSession.java:1008) ~[mysql-connector-java-8.0.19.jar:8.0.19]
	at com.mysql.cj.jdbc.ConnectionImpl.isReadOnly(ConnectionImpl.java:1406) ~[mysql-connector-java-8.0.19.jar:8.0.19]
	... 12 common frames omitted
Caused by: java.net.SocketTimeoutException: Read timed out
	at java.net.SocketInputStream.socketRead0(Native Method) ~[na:1.8.0_131]
	at java.net.SocketInputStream.socketRead(SocketInputStream.java:116) ~[na:1.8.0_131]
	at java.net.SocketInputStream.read(SocketInputStream.java:171) ~[na:1.8.0_131]
	at java.net.SocketInputStream.read(SocketInputStream.java:141) ~[na:1.8.0_131]
	at com.mysql.cj.protocol.ReadAheadInputStream.fill(ReadAheadInputStream.java:107) ~[mysql-connector-java-8.0.19.jar:8.0.19]
	at com.mysql.cj.protocol.ReadAheadInputStream.readFromUnderlyingStreamIfNecessary(ReadAheadInputStream.java:150) ~[mysql-connector-java-8.0.19.jar:8.0.19]
	at com.mysql.cj.protocol.ReadAheadInputStream.read(ReadAheadInputStream.java:180) ~[mysql-connector-java-8.0.19.jar:8.0.19]
	at java.io.FilterInputStream.read(FilterInputStream.java:133) ~[na:1.8.0_131]
	at com.mysql.cj.protocol.FullReadInputStream.readFully(FullReadInputStream.java:64) ~[mysql-connector-java-8.0.19.jar:8.0.19]
	at com.mysql.cj.protocol.a.SimplePacketReader.readHeader(SimplePacketReader.java:63) ~[mysql-connector-java-8.0.19.jar:8.0.19]
	at com.mysql.cj.protocol.a.SimplePacketReader.readHeader(SimplePacketReader.java:45) ~[mysql-connector-java-8.0.19.jar:8.0.19]
	at com.mysql.cj.protocol.a.TimeTrackingPacketReader.readHeader(TimeTrackingPacketReader.java:52) ~[mysql-connector-java-8.0.19.jar:8.0.19]
	at com.mysql.cj.protocol.a.TimeTrackingPacketReader.readHeader(TimeTrackingPacketReader.java:41) ~[mysql-connector-java-8.0.19.jar:8.0.19]
	at com.mysql.cj.protocol.a.MultiPacketReader.readHeader(MultiPacketReader.java:54) ~[mysql-connector-java-8.0.19.jar:8.0.19]
	at com.mysql.cj.protocol.a.MultiPacketReader.readHeader(MultiPacketReader.java:44) ~[mysql-connector-java-8.0.19.jar:8.0.19]
	at com.mysql.cj.protocol.a.NativeProtocol.readMessage(NativeProtocol.java:533) ~[mysql-connector-java-8.0.19.jar:8.0.19]
	... 18 common frames omitted

解决方案:

修改url连接, 改为

jdbc:mysql://xxx:8082/platform_admin_server?useSSL=true&useUnicode=true&characterEncoding=utf8&serverTimezone=CTT&autoReconnect=true&failOverReadOnly=false