Caused by: java.sql.SQLException: Io 异常: The Network Adapter could not establish the connection
at oracle.jdbc.driver.DatabaseError.throwSqlException(DatabaseError.java:112) ~[oracle-jdbc-driver-1.0.0.jar:Oracle JDBC Driver version - "10.2.0.1.0"]
at oracle.jdbc.driver.DatabaseError.throwSqlException(DatabaseError.java:146) ~[oracle-jdbc-driver-1.0.0.jar:Oracle JDBC Driver version - "10.2.0.1.0"]
at oracle.jdbc.driver.DatabaseError.throwSqlException(DatabaseError.java:255) ~[oracle-jdbc-driver-1.0.0.jar:Oracle JDBC Driver version - "10.2.0.1.0"]
at oracle.jdbc.driver.T4CConnection.logon(T4CConnection.java:387) ~[oracle-jdbc-driver-1.0.0.jar:Oracle JDBC Driver version - "10.2.0.1.0"]
at oracle.jdbc.driver.PhysicalConnection.<init>(PhysicalConnection.java:414) ~[oracle-jdbc-driver-1.0.0.jar:Oracle JDBC Driver version - "10.2.0.1.0"]
at oracle.jdbc.driver.T4CConnection.<init>(T4CConnection.java:165) ~[oracle-jdbc-driver-1.0.0.jar:Oracle JDBC Driver version - "10.2.0.1.0"]
at oracle.jdbc.driver.T4CDriverExtension.getConnection(T4CDriverExtension.java:35) ~[oracle-jdbc-driver-1.0.0.jar:Oracle JDBC Driver version - "10.2.0.1.0"]
at oracle.jdbc.driver.OracleDriver.connect(OracleDriver.java:801) ~[oracle-jdbc-driver-1.0.0.jar:Oracle JDBC Driver version - "10.2.0.1.0"]
at org.apache.commons.dbcp.DriverConnectionFactory.createConnection(DriverConnectionFactory.java:38) ~[commons-dbcp-1.4.jar:1.4]
at org.apache.commons.dbcp.PoolableConnectionFactory.makeObject(PoolableConnectionFactory.java:582) ~[commons-dbcp-1.4.jar:1.4]
at org.apache.commons.dbcp.BasicDataSource.validateConnectionFactory(BasicDataSource.java:1556) ~[commons-dbcp-1.4.jar:1.4]
at org.apache.commons.dbcp.BasicDataSource.createPoolableConnectionFactory(BasicDataSource.java:1545) ~[commons-dbcp-1.4.jar:1.4]
at org.apache.commons.dbcp.BasicDataSource.createDataSource(BasicDataSource.java:1388) ~[commons-dbcp-1.4.jar:1.4]
at org.apache.commons.dbcp.BasicDataSource.getConnection(BasicDataSource.java:1044) ~[commons-dbcp-1.4.jar:1.4]
at org.springframework.jdbc.datasource.DataSourceUtils.doGetConnection(DataSourceUtils.java:111) ~[spring-jdbc-3.0.7.RELEASE.jar:3.0.7.RELEASE]
at org.springframework.jdbc.datasource.DataSourceUtils.getConnection(DataSourceUtils.java:77) ~[spring-jdbc-3.0.7.RELEASE.jar:3.0.7.RELEASE]
... 19 more
原因：未插网线(lll￢ω￢)
公司的项目启动的时候报错，这个异常出现的很奇怪。因为之前一直好好的，启动的时候从来没有出过错，总不可能是因为今天不是黄道吉日，所以工程罢工了。
看错误信息：The Network Adapter could not establish the connection，无法建立连接。我寻思着可能是数据库配置文件出了问题，然后在DBeaver中重新连接了一下，然后发现数据库也连不上了。那应该就不是我本机项目的问题了，可能是数据库真的出了问题。然后我又去问同事，发现他们的都正常。这就很奇怪了。然后我突然想起来我今天把网线转换头落在家里了，来公司之后一直用的是WIFI，猜测是WIFI环境连不上公司的库。去找人借了个转换头，连上网线，重启项目，成功。
来源：oschina
链接：https://my.oschina.net/u/4391321/blog/3644506