Java.sql.SQLException: Byte array not long enough

Question

using thin jdbc returned this exception seems to be connected to the length of the statment:
////////create a prepared statement////////
preUpdateStatement = dbConnection.prepareStatement(updateStatement.toString());
// build data output stream on byte array output stream
ByteArrayOutputStream byte_os = new ByteArrayOutputStream();
DataOutputStream data_os = new DataOutputStream(byte_os);
// write chars to data output stream
data_os.writeChars(((Element)m_values_vector.elementAt(i)).m_value);
// create input stream and pass it to prepared statement
ByteArrayInputStream byte_is = new ByteArrayInputStream(byte_os.toByteArray());
preStatement.setUnicodeStream(i+1, byte_is, byte_os.toByteArray().length);
// execute
preUpdateStatement.executeUpdate();
preUpdateStatement.close();
null

Answer 1

stack is:
java.sql.SQLException: Io exception: Char array not long enough: javaCharsToUtf8Bytes
at java.lang.Throwable.<init>(Compiled Code)
at java.lang.Exception.<init>(Compiled Code)
at java.sql.SQLException.<init>(Compiled Code)
at oracle.jdbc.dbaccess.DBError.throwSqlException(Compiled Code)
at oracle.jdbc.dbaccess.DBError.throwSqlException(Compiled Code)
at oracle.jdbc.dbaccess.DBError.throwSqlException(Compiled Code)
at oracle.jdbc.driver.OracleStatement.executeNonQuery(Compiled Code)
at oracle.jdbc.driver.OracleStatement.doExecuteOther(Compiled Code)
at oracle.jdbc.driver.OracleStatement.doExecuteWithBatch(Compiled Code)
at oracle.jdbc.driver.OracleStatement.doExecute(Compiled Code)
at oracle.jdbc.driver.OracleStatement.doExecuteWithTimeout(Compiled Code)
at oracle.jdbc.driver.OraclePreparedStatement.executeUpdate(Compiled Code)