我有这个奇怪的问题连接JDBC到Oracle 11g。它本周一突然开始发生，没有我或团队意识到的任何设置更改。在Stackoverflow和Oracle论坛中阅读（参见底部的链接）我已经了解到在linux 64bit机器上生成随机字节存在问题。它导致我尝试了几件事，但遗憾的是没有用。以下是我所知道的所有信息的摘要。
奇怪的是我可以使用sqlplus通过终端连接，但不能使用JDBC。
感谢您的任何想法或帮助，
阿米特
OS: Ubuntu 12.04
Java: Both 7 and 6_45 (Issue is the same)
JDBC: Downloaded from the Oracle official site (see further description down)
Connection behind a Cisco VPN
JDBC-舱单：
odbc7.jar：
Manifest-Version: 1.0
Ant-Version: Apache Ant 1.7.1
Created-By: 20.12-b01 (Sun Microsystems Inc.)
Implementation-Vendor: Oracle Corporation
Implementation-Title: JDBC
Implementation-Version: 12.1.0.1.0
Repository-Id: JAVAVM_12.1.0.1.0_LINUX.X64_130403
Specification-Vendor: Sun Microsystems Inc.
Specification-Title: JDBC
Specification-Version: 4.0
Main-Class: oracle.jdbc.OracleDriver
sealed: true
Name: oracle/sql/converter/
Sealed: false
Name: oracle/sql/
Sealed: false
Name: oracle/sql/converter_xcharset/
Sealed: false
odbc6.jar：
Manifest-Version: 1.0
Ant-Version: Apache Ant 1.7.1
Created-By: 20.12-b01 (Sun Microsystems Inc.)
Implementation-Vendor: Oracle Corporation
Implementation-Title: JDBC
Implementation-Version: 12.1.0.1.0
Repository-Id: JAVAVM_12.1.0.1.0_LINUX.X64_130403
Specification-Vendor: Sun Microsystems Inc.
Specification-Title: JDBC
Specification-Version: 4.0
Main-Class: oracle.jdbc.OracleDriver
sealed: true
Name: oracle/sql/converter/
Sealed: false
Name: oracle/sql/
Sealed: false
Name: oracle/sql/converter_xcharset/
Sealed: false
amit @ mymachine：/ usr / lib / oracle $ sqlplus / @ DB_HOST_IP：1521 / DB_NAME
SQL * Plus：2014年4月22日星期二11:35:58发布12.1.0.1.0版本
版权所有（c）1982,2013，Oracle。保留所有权利。
连接到： Oracle Database 11g 11.2.0.3.0版 - 64位生产
SQL＆GT;
DriverManager.getConnection(
"jdbc:oracle:thin:@//DB_HOST_IP:1521/DB_NAME", username,
password);
挂起约20秒并抛出：
ava.sql.SQLRecoverableException: IO Error: Connection reset
at oracle.jdbc.driver.T4CConnection.logon(T4CConnection.java:682)
at oracle.jdbc.driver.PhysicalConnection.<init>(PhysicalConnection.java:711)
at oracle.jdbc.driver.T4CConnection.<init>(T4CConnection.java:385)
at oracle.jdbc.driver.T4CDriverExtension.getConnection(T4CDriverExtension.java:30)
at oracle.jdbc.driver.OracleDriver.connect(OracleDriver.java:558)
at java.sql.DriverManager.getConnection(DriverManager.java:582)
at java.sql.DriverManager.getConnection(DriverManager.java:185)
at OracleJDBC.main(OracleJDBC.java:32)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at com.intellij.rt.execution.application.AppMain.main(AppMain.java:120)
Caused by: java.net.SocketException: Connection reset
at java.net.SocketInputStream.read(SocketInputStream.java:168)
at oracle.net.ns.Packet.receive(Packet.java:311)
at oracle.net.ns.DataPacket.receive(DataPacket.java:105)
at oracle.net.ns.NetInputStream.getNextPacket(NetInputStream.java:305)
at oracle.net.ns.NetInputStream.read(NetInputStream.java:249)
at oracle.net.ns.NetInputStream.read(NetInputStream.java:171)
at oracle.net.ns.NetInputStream.read(NetInputStream.java:89)
at oracle.jdbc.driver.T4CSocketInputStreamWrapper.readNextPacket(T4CSocketInputStreamWrapper.java:123)
at oracle.jdbc.driver.T4CSocketInputStreamWrapper.read(T4CSocketInputStreamWrapper.java:79)
at oracle.jdbc.driver.T4CMAREngineStream.unmarshalUB1(T4CMAREngineStream.java:426)
at oracle.jdbc.driver.T4C8TTIdty.receive(T4C8TTIdty.java:688)
at oracle.jdbc.driver.T4C8TTIdty.doRPC(T4C8TTIdty.java:595)
at oracle.jdbc.driver.T4CConnection.connect(T4CConnection.java:1439)
at oracle.jdbc.driver.T4CConnection.logon(T4CConnection.java:486)
... 12 more
Fatal NI connect error 12170.
VERSION INFORMATION:
TNS for Linux: Version 11.2.0.3.0 - Production
Oracle Bequeath NT Protocol Adapter for Linux: Version
11.2.0.3.0 - Production
TCP/IP NT Protocol Adapter for Linux: Version 11.2.0.3.0 - Production
Time: 22-APR-2014 09:57:45
Tracing not turned on.
Tns error struct:
ns main err code: 12535
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=<my.ip.address>)(PORT=42738))
ORA-12535: TNS:operation timed out
Cause: The requested operation could not be completed within the time out period.
Action: Look at the documentation on the secondary errors for possible remedy. See SQLNET.LOG to find secondary error if not provided explicitly. Turn on tracing to gather more information.
ORA-12606: TNS: Application timeout occurred
Cause: A network session did not reach an application-defined stage within the allowed time interval.
Action: This is an error which does not normally appear at the high level. The action to take is application specific, and is detailed in the higher level error description.
-Djava.security.egd=file:///dev/urandom。设置rng-tools以帮助＆＃39; OS的熵发生器。 （见链接）
以下代码运行时没有产生随机字节数组的问题（无论参数-Djava.security.egd如何：
int a = 10000;
while (a-- > 0){
byte[] array = new byte[2048];
new SecureRandom().nextBytes(array);
System.out.println(a);
}
上述所有内容似乎都没有改变错误（超时）。
编辑：新尝试：
SQL> select secure_params from session_token where id=11065073;＆lt; - 查询被卡住了。
重启客户端
在这个特定的行中越来越多地更新这个字段我仍然可以读取该字段，如果它的大小是429个字符，但是当我将其增加到587个字符时它又被卡住了。
SQL> select length( secure_params) from session_token where id=11065073;
LENGTH(SECURE_PARAMS)
---------------------
587
SQL> select secure_params from session_token where id=11065073;＆lt; - 查询再次陷入困境。
第4次尝试让我想到这里可能还有一个问题，因为应用程序能够创建初始连接并从数据库中获取一些简短数据，但只有在结果集获得时才会失败有点胖。
END OF EDIT
Stackoverflow：Oracle JDBC intermittent Connection Issue
答案 0 :(得分：2)
ORA-12170表示与数据库侦听器的TCP连接失败。
如果这是一直发生的错误，请检查防火墙和网络ACL。可能是中间人改变了什么？
或者，它可能是影响TCP连接的其他工件，例如IP地址冲突。我自己最近遇到过这个问题，并在http://distracted-it.blogspot.co.nz/2014/04/ora-12170-tnsconnect-timeout-resolved.html
发表了博客文章希望它有所帮助。