How to avoid OCIError in rails application?

OCIError (ORA-12541: TNS:no listener):
    oci8.c:270:in oci8lib.so
    /usr/local/ruby-1.8.7-p248/lib/ruby/gems/1.8/gems/activerecord-oracle_enhanced-adapter-1.2.4/lib/active_record/connection_adapters/oracle_enhanced_oci_connection.rb:223:in `new'
    /usr/local/ruby-1.8.7-p248/lib/ruby/gems/1.8/gems/activerecord-oracle_enhanced-adapter-1.2.4/lib/active_record/connection_adapters/oracle_enhanced_oci_connection.rb:223:in `new_connection'
    /usr/local/ruby-1.8.7-p248/lib/ruby/gems/1.8/gems/activerecord-oracle_enhanced-adapter-1.2.4/lib/active_record/connection_adapters/oracle_enhanced_oci_connection.rb:328:in `initialize'
    /usr/local/ruby-1.8.7-p248/lib/ruby/gems/1.8/gems/activerecord-oracle_enhanced-adapter-1.2.4/lib/active_record/connection_adapters/oracle_enhanced_oci_connection.rb:24:in `new'
    /usr/local/ruby-1.8.7-p248/lib/ruby/gems/1.8/gems/activerecord-oracle_enhanced-adapter-1.2.4/lib/active_record/connection_adapters/oracle_enhanced_oci_connection.rb:24:in `initialize'
    /usr/local/ruby-1.8.7-p248/lib/ruby/gems/1.8/gems/activerecord-oracle_enhanced-adapter-1.2.4/lib/active_record/connection_adapters/oracle_enhanced_connection.rb:9:in `new'
    /usr/local/ruby-1.8.7-p248/lib/ruby/gems/1.8/gems/activerecord-oracle_enhanced-adapter-1.2.4/lib/active_record/connection_adapters/oracle_enhanced_connect开发者_开发百科ion.rb:9:in `create'
    /usr/local/ruby-1.8.7-p248/lib/ruby/gems/1.8/gems/activerecord-oracle_enhanced-adapter-1.2.4/lib/active_record/connection_adapters/oracle_enhanced_adapter.rb:50:in `oracle_enhanced_connection'
    /usr/local/ruby-1.8.7-p248/lib/ruby/gems/1.8/gems/activerecord-2.0.2/lib/active_record/connection_adapters/abstract/connection_specification.rb:291:in `send'
    /usr/local/ruby-1.8.7-p248/lib/ruby/gems/1.8/gems/activerecord-2.0.2/lib/active_record/connection_adapters/abstract/connection_specification.rb:291:in `connection='
    /usr/local/ruby-1.8.7-p248/lib/ruby/gems/1.8/gems/activerecord-2.0.2/lib/active_record/connection_adapters/abstract/connection_specification.rb:259:in `retrieve_connection'
    /usr/local/ruby-1.8.7-p248/lib/ruby/gems/1.8/gems/activerecord-2.0.2/lib/active_record/connection_adapters/abstract/connection_specification.rb:78:in `connection'
    /usr/local/ruby-1.8.7-p248/lib/ruby/gems/1.8/gems/activerecord-2.0.2/lib/active_record/base.rb:1063:in `table_exists?'
    /usr/local/ruby-1.8.7-p248/lib/ruby/gems/1.8/gems/activerecord-2.0.2/lib/active_record/base.rb:1153:in `inspect'
    /usr/local/ruby-1.8.7-p248/lib/ruby/gems/1.8/gems/activesupport-2.0.2/lib/active_support/core_ext/class/inheritable_attributes.rb:131:in `to_proc'
    /usr/local/ruby-1.8.7-p248/lib/ruby/gems/1.8/gems/activesupport-2.0.2/lib/active_support/dependencies.rb:426:in `collect'

It seems that rails app lost oracle connection,how to avoid this in application controller:

  def rescue_action_in_public(exception)

I use

def rescue_action_in_public(exception)
case exception.class.to_s
when "OCIError"
  # my solution
end

It still throw me 500.html

If the OCIError is inside a module, it will not match, because exception.class may be returning something like Some::Module::OCIError.

You can compare class directly:

case exception
  when OCIError
    # my solution
  end
end

or, if you want to use the class name (not recommended):

case exception.class.to_s
  when /OCIError/
    # my solution
  end
end