java项目一启动就报错

Question

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.GeneratedConstructorAccessor55.newInstance(Unknown Source)
	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.NativeSocketConnection.connect(NativeSocketConnection.java:91)
	at com.mysql.cj.NativeSession.connect(NativeSession.java:152)
	at com.mysql.cj.jdbc.ConnectionImpl.connectWithRetries(ConnectionImpl.java:849)
	... 10 common frames omitted
Caused by: java.net.ConnectException: Connection timed out: connect
	at java.net.DualStackPlainSocketImpl.connect0(Native Method)
	at java.net.DualStackPlainSocketImpl.socketConnect(DualStackPlainSocketImpl.java:75)
	at java.net.AbstractPlainSocketImpl.doConnect(AbstractPlainSocketImpl.java:476)
	at java.net.AbstractPlainSocketImpl.connectToAddress(AbstractPlainSocketImpl.java:218)
	at java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:200)
	at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:162)
	at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:394)
	at java.net.Socket.connect(Socket.java:606)
	at com.mysql.cj.protocol.StandardSocketFactory.connect(StandardSocketFactory.java:155)
	at com.mysql.cj.protocol.a.NativeSocketConnection.connect(NativeSocketConnection.java:65)
	... 12 common frames omitted
16:44:49.599 [NettyClientSelector_1] INFO  RocketmqRemoting - [info,95] - closeChannel: close the connection to remote address[] result: true
16:44:50.915 [NettyClientSelector_1] INFO  RocketmqRemoting - [info,95] - closeChannel: close the connection to remote address[] result: true
16:45:19.601 [NettyClientSelector_1] INFO  RocketmqRemoting - [info,95] - closeChannel: close the connection to remote address[] result: true
16:45:20.915 [NettyClientSelector_1] INFO  RocketmqRemoting - [info,95] - closeChannel: close the connection to remote address[] result: true
16:45:49.041 [Druid-ConnectionPool-Create-1303127336] ERROR c.a.d.p.DruidDataSource - [run,2781] - create connection SQLException, url: jdbc:mysql://rm-bp1941yb51xai5t3s.mysql.rds.aliyuncs.com:3306/trade_test?useUnicode=true&characterEncoding=UTF-8&autoReconnect=true&serverTimezone=GMT%2B8&failOverReadOnly=false, errorCode 0, state 08001
java.sql.SQLNonTransientConnectionException: Could not create connection to database server. Attempted reconnect 3 times. Giving up.
	at com.mysql.cj.jdbc.exceptions.SQLError.createSQLException(SQLError.java:110)
	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.ConnectionImpl.connectWithRetries(ConnectionImpl.java:905)
	at com.mysql.cj.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:830)
	at com.mysql.cj.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:455)
	at com.mysql.cj.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:240)
	at com.mysql.cj.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:207)
	at com.alibaba.druid.filter.FilterChainImpl.connection_connect(FilterChainImpl.java:156)
	at com.alibaba.druid.filter.stat.StatFilter.connection_connect(StatFilter.java:218)
	at com.alibaba.druid.filter.FilterChainImpl.connection_connect(FilterChainImpl.java:150)
	at com.alibaba.druid.pool.DruidAbstractDataSource.createPhysicalConnection(DruidAbstractDataSource.java:1646)
	at com.alibaba.druid.pool.DruidAbstractDataSource.createPhysicalConnection(DruidAbstractDataSource.java:1710)
	at com.alibaba.druid.pool.DruidDataSource$CreateConnectionThread.run(DruidDataSource.java:2779)
Caused by: com.mysql.cj.exceptions.CJCommunicationsException: Communications link failure

Answer 1

连接超时，找不到服务器哦。应该是网络慢的原因吧，如果是在服务器的话用内网IP吧。