Oracle JDBC and Oracle CHAR data type -

I have a difficult issue with the Oracle jdbc driver's code CHAR handling data types. Take simple table:

  make table x (c char (4)); Insert in X (C) values ​​('A'); - Inserted 'A'   
 So when I put something in  CHAR (4) , the string always gets filled with white space. Is when I execute a query like this:  
 select  from x where c = 'a'; - 1 selection of records * from x where c = 'a'; - 1 selection of records * from x where c = 'a'; - 1 selects the record   
 Here, the constant  'a'  is also full of whitespace, which is why the record always comes back. This is true when these questions are executed simultaneously with a JDBC  created location  Now the hard thing is that when I want to use a bind variable:  < Pre class = "lang-java prettyprint-override">  created statement stmt = conn.prepareStatement ("x * from * select c =?"); Stmt.setString (1, "A"); // It will not return any record stmt.setString (1, "A"); // This will return a record stmt.executeQuery ();   
 This is a workaround:  
  created condition stmt = conn.prepareStatement ("From X Choose * where trim (c) = trim (?) "); Stmt.setString (1, "A"); // This will return a record stmt.setString (1, "A"); // This will return a record stmt.executeQuery ();  Edit : These barriers are now:  
 
 The above solution is not required because it modifies the content of both  C  and ? , and it's hard to use indexed on  c .  
 Columns  CHAR <  
  edit : The reason for these obstacles is that it is not possible   
  Edit  Because I ask about the developer's approach to this question, a database intangible library So my needs are to provide a very common solution that does not break anything in Juke's client code, this is the reason why I am not really a big fan of the solution. And that's why I do not have access to that  CHAR  column announcement. But still, I want to be able to handle this issue.  
 What would you do instead?    
   
 
 If you want  
  stmt.setString (1, "a"); // This will not return a record   
, please try  
  conn.prepareStatement ("Select * from x * c = cast (? Four (four)) ")