tomcat启动报错：ORA-04031: unable to allocate?报错

异常信息：

十一月 04, 2014 11:15:13 上午 org.logicalcobwebs.proxool.Prototyper sweep
SEVERE: Prototype
java.sql.SQLException: ORA-04031: unable to allocate 20596 bytes of shared memory ("shared pool","unknown object","sga heap(1,0)","session param values")


at oracle.jdbc.driver.DatabaseError.throwSqlException(DatabaseError.java:112)
at oracle.jdbc.driver.T4CTTIoer.processError(T4CTTIoer.java:331)
at oracle.jdbc.driver.T4CTTIoer.processError(T4CTTIoer.java:283)
at oracle.jdbc.driver.T4CTTIoer.processError(T4CTTIoer.java:278)
at oracle.jdbc.driver.T4CTTIoauthenticate.receiveOsesskey(T4CTTIoauthenticate.java:294)
at oracle.jdbc.driver.T4CConnection.logon(T4CConnection.java:357)
at oracle.jdbc.driver.PhysicalConnection.<init>(PhysicalConnection.java:439)
at oracle.jdbc.driver.T4CConnection.<init>(T4CConnection.java:165)
at oracle.jdbc.driver.T4CDriverExtension.getConnection(T4CDriverExtension.java:35)
at oracle.jdbc.driver.OracleDriver.connect(OracleDriver.java:801)
at java.sql.DriverManager.getConnection(DriverManager.java:579)
at java.sql.DriverManager.getConnection(DriverManager.java:190)
at org.logicalcobwebs.proxool.DefaultConnectionBuilder.buildConnection(DefaultConnectionBuilder.java:39)
at org.logicalcobwebs.proxool.Prototyper.buildConnection(Prototyper.java:159)
at org.logicalcobwebs.proxool.Prototyper.sweep(Prototyper.java:102)
at org.logicalcobwebs.proxool.PrototyperThread.run(PrototyperThread.java:44)

别人都说我是没有释放数据库连接，我用的是oracle+proxool连接池，我可以肯定我每次增删改查后我都关闭了连接。

//关闭连接
public static void closeConnection() {
try {
if (rs!=null) {
rs.close();
}
if (stmt!=null) {
stmt.close();
}
if(conn!=null&&!conn.isClosed())  
            {  
                conn.close();  
            }
} catch (Exception e) {
e.printStackTrace();
}
}
真心不知道为嘛这样，大家给我讲一下了。