求解决困扰几天了：数据库连接超时： Connection timed out: connect

Question

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

 

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) ~[mysql-connector-java-8.0.23.jar:8.0.23]
	at com.mysql.cj.jdbc.exceptions.SQLError.createSQLException(SQLError.java:97) ~[mysql-connector-java-8.0.23.jar:8.0.23]
	at com.mysql.cj.jdbc.exceptions.SQLError.createSQLException(SQLError.java:89) ~[mysql-connector-java-8.0.23.jar:8.0.23]
	at com.mysql.cj.jdbc.exceptions.SQLError.createSQLException(SQLError.java:63) ~[mysql-connector-java-8.0.23.jar:8.0.23]
	at com.mysql.cj.jdbc.exceptions.SQLError.createSQLException(SQLError.java:73) ~[mysql-connector-java-8.0.23.jar:8.0.23]
	at com.mysql.cj.jdbc.ConnectionImpl.connectWithRetries(ConnectionImpl.java:903) ~[mysql-connector-java-8.0.23.jar:8.0.23]
	at com.mysql.cj.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:828) ~[mysql-connector-java-8.0.23.jar:8.0.23]
	at com.mysql.cj.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:453) ~[mysql-connector-java-8.0.23.jar:8.0.23]
	at com.mysql.cj.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:246) ~[mysql-connector-java-8.0.23.jar:8.0.23]
	at com.mysql.cj.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:198) ~[mysql-connector-java-8.0.23.jar:8.0.23]
	at com.alibaba.druid.filter.FilterChainImpl.connection_connect(FilterChainImpl.java:156) ~[druid-1.1.16.jar:1.1.16]
	at com.alibaba.druid.filter.stat.StatFilter.connection_connect(StatFilter.java:218) ~[druid-1.1.16.jar:1.1.16]
	at com.alibaba.druid.filter.FilterChainImpl.connection_connect(FilterChainImpl.java:150) ~[druid-1.1.16.jar:1.1.16]
	at com.alibaba.druid.pool.DruidAbstractDataSource.createPhysicalConnection(DruidAbstractDataSource.java:1598) ~[druid-1.1.16.jar:1.1.16]
	at com.alibaba.druid.pool.DruidAbstractDataSource.createPhysicalConnection(DruidAbstractDataSource.java:1662) ~[druid-1.1.16.jar:1.1.16]
	at com.alibaba.druid.pool.DruidDataSource$CreateConnectionThread.run(DruidDataSource.java:2601) ~[druid-1.1.16.jar:1.1.16]
Caused by: com.mysql.cj.exceptions.CJCommunicationsException: Communications link failure

已确定信息：服务器Mysql版本：8.0.23，项目mysql-connecter..版本：8.0.23

                     mysql过期时间已经已经设为最大：wait_timeout | 31536000；interactive_timeout | 31536000

                     navicat连接数据库正常，端口开放，防火墙关闭

 

 

求求怎么解决，困扰几天了

 

Answer 1

你写个简单的 demo，然后连一下这个数据库试试呢，就用 DriverManager.getConnection(url, username, password) 试试。先看看是环境还问题，还是其他问题