In Oracle Metalink (Oracle's support site - Note ID 736273.1) I found that this is a bug in JDBC adapter (version 10.2.0.0.0 to 11.1.0.7.0) that when you call preparedStatement with more than 7 positional parameters then JDBC will throw this error.
Exception in thread "main" java.lang.ArrayIndexOutOfBoundsException: 12
at oracle.jdbc.driver.OracleSql.computeBasicInfo(OracleSql.java:950)
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