springboot-oracle工程win下正常，centos下不能访问数据库

工程在win下正常运行，部署到centos下出现下述异常：

### Error querying database.  Cause: org.springframework.jdbc.CannotGetJdbcConnectionException: Failed to obtain JDBC Connection; nested exception is java.sql.SQLRecoverableException: IO Error: Connection reset
### The error occurred while executing a query
### Cause: org.springframework.jdbc.CannotGetJdbcConnectionException: Failed to obtain JDBC Connection; nested exception is java.sql.SQLRecoverableException: IO Error: Connection reset
        at org.apache.ibatis.exceptions.ExceptionFactory.wrapException(ExceptionFactory.java:30)
        at org.apache.ibatis.session.defaults.DefaultSqlSession.selectList(DefaultSqlSession.java:149)
        at org.apache.ibatis.session.defaults.DefaultSqlSession.selectList(DefaultSqlSession.java:140)
        at org.apache.ibatis.session.defaults.DefaultSqlSession.selectOne(DefaultSqlSession.java:76)
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
        at java.lang.reflect.Method.invoke(Method.java:498)
        at org.mybatis.spring.SqlSessionTemplate$SqlSessionInterceptor.invoke(SqlSessionTemplate.java:426)
        ... 78 common frames omitted
Caused by: org.springframework.jdbc.CannotGetJdbcConnectionException: Failed to obtain JDBC Connection; nested exception is java.sql.SQLRecoverableException: IO Error: Connection reset
        at org.springframework.jdbc.datasource.DataSourceUtils.getConnection(DataSourceUtils.java:81)
        at org.mybatis.spring.transaction.SpringManagedTransaction.openConnection(SpringManagedTransaction.java:80)
        at org.mybatis.spring.transaction.SpringManagedTransaction.getConnection(SpringManagedTransaction.java:67)
        at org.apache.ibatis.executor.BaseExecutor.getConnection(BaseExecutor.java:336)
        at com.baomidou.mybatisplus.core.executor.MybatisSimpleExecutor.prepareStatement(MybatisSimpleExecutor.java:93)
        at com.baomidou.mybatisplus.core.executor.MybatisSimpleExecutor.doQuery(MybatisSimpleExecutor.java:66)
        at org.apache.ibatis.executor.BaseExecutor.queryFromDatabase(BaseExecutor.java:324)
        at org.apache.ibatis.executor.BaseExecutor.query(BaseExecutor.java:156)
        at org.apache.ibatis.executor.CachingExecutor.query(CachingExecutor.java:109)
        at com.github.pagehelper.PageInterceptor.intercept(PageInterceptor.java:108)
        at org.apache.ibatis.plugin.Plugin.invoke(Plugin.java:61)
        at com.sun.proxy.$Proxy151.query(Unknown Source)
        at org.apache.ibatis.session.defaults.DefaultSqlSession.selectList(DefaultSqlSession.java:147)
        ... 85 common frames omitted
Caused by: java.sql.SQLRecoverableException: IO Error: Connection reset
        at oracle.jdbc.driver.T4CConnection.logon(T4CConnection.java:498)
        at oracle.jdbc.driver.PhysicalConnection.<init>(PhysicalConnection.java:553)
        at oracle.jdbc.driver.T4CConnection.<init>(T4CConnection.java:254)
        at oracle.jdbc.driver.T4CDriverExtension.getConnection(T4CDriverExtension.java:32)
        at oracle.jdbc.driver.OracleDriver.connect(OracleDriver.java:528)
        at com.zaxxer.hikari.util.DriverDataSource.getConnection(DriverDataSource.java:136)
        at com.zaxxer.hikari.pool.PoolBase.newConnection(PoolBase.java:369)
        at com.zaxxer.hikari.pool.PoolBase.newPoolEntry(PoolBase.java:198)
        at com.zaxxer.hikari.pool.HikariPool.createPoolEntry(HikariPool.java:467)
        at com.zaxxer.hikari.pool.HikariPool.checkFailFast(HikariPool.java:541)
        at com.zaxxer.hikari.pool.HikariPool.<init>(HikariPool.java:115)
        at com.zaxxer.hikari.HikariDataSource.getConnection(HikariDataSource.java:112)
        at org.springframework.jdbc.datasource.DataSourceUtils.fetchConnection(DataSourceUtils.java:157)
        at org.springframework.jdbc.datasource.DataSourceUtils.doGetConnection(DataSourceUtils.java:115)
        at org.springframework.jdbc.datasource.DataSourceUtils.getConnection(DataSourceUtils.java:78)
        ... 97 common frames omitted
Caused by: java.net.SocketException: Connection reset
        at java.net.SocketOutputStream.socketWrite(SocketOutputStream.java:115)
        at java.net.SocketOutputStream.write(SocketOutputStream.java:155)
        at oracle.net.ns.DataPacket.send(DataPacket.java:210)
        at oracle.net.ns.NetOutputStream.flush(NetOutputStream.java:230)
        at oracle.net.ns.NetInputStream.getNextPacket(NetInputStream.java:321)
        at oracle.net.ns.NetInputStream.read(NetInputStream.java:268)
        at oracle.net.ns.NetInputStream.read(NetInputStream.java:190)
        at oracle.net.ns.NetInputStream.read(NetInputStream.java:107)
        at oracle.jdbc.driver.T4CSocketInputStreamWrapper.readNextPacket(T4CSocketInputStreamWrapper.java:124)
        at oracle.jdbc.driver.T4CSocketInputStreamWrapper.read(T4CSocketInputStreamWrapper.java:80)
        at oracle.jdbc.driver.T4CMAREngine.unmarshalUB1(T4CMAREngine.java:1137)
        at oracle.jdbc.driver.T4CTTIfun.receive(T4CTTIfun.java:350)
        at oracle.jdbc.driver.T4CTTIfun.doRPC(T4CTTIfun.java:227)
        at oracle.jdbc.driver.T4CTTIoauthenticate.doOSESSKEY(T4CTTIoauthenticate.java:407)
        at oracle.jdbc.driver.T4CConnection.logon(T4CConnection.java:416)
        ... 111 common frames omitted

原因：连接ORACLE服务器，客户端要生成随机密钥用于客户端认证，JDK默认使用/dev/random，random采用阻塞方式生成随机数，生成的速度很慢，ORACLE服务器会主动reset,并在alert.log中报错：

TNS-12535: TNS:operation timed out

ns secondary err code: 12606

nt main err code: 0

nt secondary err code: 0

nt OS err code: 0

Client address: (ADDRESS=(PROTOCOL=tcp)(HOST=192.168.6.21)(PORT=33460))

WARNING: inbound connection timed out (ORA-3136)

解决方法：

    方法1：编辑$JAVA_HOME/jre/lib/security/java.security
将securerandom.source=file:/dev/random 改为file:/dev/urandom（urandom采用非阴塞式生成随机数，性能很好，不会产生超时）
     方法2：加启动参数：-Djava.security.egd=file:/dev/urandom 

以上解决方案摘自：http://blog.sina.com.cn/s/blog_76c4136a0102yggp.html

我用的是方法1解决的。