首先Java下根据JDBC规范连接数据库，有几种形式，参考

http://djdnmq.iteye.com/blog/356468 oracle 驱动oci thin 区别

Oracle客户端准备

10201_client_linux32.zip

安装完成后，需要确保在终端中可以正确的执行sqlplus命令

Oracle环境变量

如果Tomcat是服务，需要把Oracle的安装环境变量写到TOMCAT中，类似如下

Tomcat加入/home/**/apache-tomcat-6.0.35/bin/catalina.sh开头，当前的用户加入：.bash_profile的末尾，具体的内容如下：

export ORACLE_HOME=/home/ ** /oracle/product/10.2.0/client_1

export ORACLE_BASE=/home/ ** /oracle/product/10.2.0

export PATH=$ORACLE_HOME/bin:$PATH

export LD_LIBRARY_PATH=$ORACLE_HOME:$ORACLE_HOME/lib:$ORACLE_HOME/jdbc/lib:${LD_LIBRARY_PATH}

建立到目标数据库的TNS连接

类似在/home/**/oracle/product/10.2.0/client_1/bin执行./netmgr

建立到目标数据库的TNS名字，此时就可以使用JDBC的OCI形式访问Oracle数据库了

Web容器访问Oracle出现如下错误的一些参考资料 

no ocijdbc10 in java.library.path

https://forums.oracle.com/forums/thread.jspa?threadID=290097

https://forums.oracle.com/forums/thread.jspa?threadID=615281

- JDBC Thin Driver 
100% Java client-side JDBC driver for use in client applications, middle-tier servers and applets.

- JDBC OCI Driver 
Client-side JDBC driver for use on a machine where OCI is installed.

- JDBC Thin Server-side Driver 
JDBC driver for use in Java program in the database to access remote Oracle databases.

- JDBC Server-side Internal Driver Server-side JDBC driver for use by Java Stored procedures. This driver used to be called the "JDBC Kprb Driver".

http://www.oracle.com/technetwork/database/enterprise-edition/jdbc101040-094982.html

https://forums.oracle.com/forums/thread.jspa?threadID=290097