gen_java.ml

   1 (* Java code generation *)
   2
   3 open ExtList
   4 open ExtString
   5 open Operators
   6 open Printf
   7
   8 open Stmt
   9 open Gen
  10 open Sql
  11
  12 module G = Gen_cxx
  13
  14 let comment = G.comment
  15 let empty_line = G.empty_line
  16
  17 let start_ cls =
  18    let f1 name =
  19    output "%s %s" cls name;
  20    G.open_curly ()
  21    in
  22    let f2 name =
  23    G.close_curly " // %s %s" cls name;
  24    empty_line ()
  25    in
  26    f1,f2
  27
  28 let (start_class,end_class) = start_ "public class"
  29 let (start_intf,end_intf) = start_ "public interface"
  30
  31 let as_java_type = function
  32   | Type.Int -> "int"
  33   | Type.Text -> "String"
  34   | Type.Float -> "float"
  35   | Type.Blob -> "Blob"
  36   | Type.Bool -> "boolean"
  37   | Type.Datetime -> "Timestamp"
  38
  39 let get_column attr index =
  40   sprintf "res.get%s(%u)"
  41     (attr.RA.domain >> as_java_type >> String.capitalize)
  42     (index + 1)
  43
  44 let param_type_to_string t = t >> Option.default Type.Text >> as_java_type
  45
  46 let set_param index param =
  47   let (id,t) = param in
  48   output "pstmt.set%s(%u, %s);"
  49     (t >> param_type_to_string >> String.capitalize)
  50     (index+1)
  51     (param_name_to_string id index)
  52
  53 let schema_to_values = List.mapi (fun i attr -> name_of attr i, attr.RA.domain >> as_java_type)
  54
  55 let output_schema_binder index schema =
  56   let name = "output" in
  57   start_intf name;
  58   output "public void callback(%s);" (G.Values.to_string (schema_to_values schema));
  59   end_intf name;
  60   name
  61
  62 let output_schema_binder index schema =
  63   match schema with
  64   | [] -> None
  65   | _ -> Some (output_schema_binder index schema)
  66
  67 let params_to_values = List.mapi (fun i (n,t) -> param_name_to_string n i, t >> param_type_to_string)
  68 let params_to_values = List.unique & params_to_values
  69
  70 let output_value_defs vals =
  71   vals >> List.iter (fun (name,t) -> output "%s %s;" t name)
  72
  73 let output_schema_data index schema =
  74   let name = default_name "data" index in
  75   start_class name;
  76   schema >> schema_to_values >> output_value_defs;
  77   end_class name
  78
  79 let output_params_binder index params = List.iteri set_param params
  80
  81 type t = unit
  82
  83 let start () = ()
  84
  85 let generate_code () index schema params kind props =
  86    let values = params_to_values params in
  87    let name = choose_name props kind index in
  88    let sql = G.quote (get_sql props kind params) in
  89    start_class name;
  90     output "PreparedStatement pstmt;";
  91     empty_line ();
  92     G.func "public" name ["db","Connection"] (fun () ->
  93       output "pstmt = db.prepareStatement(%s);" sql;
  94     );
  95     empty_line ();
  96     let schema_binder_name = output_schema_binder index schema in
  97     let result = match schema_binder_name with None -> [] | Some name -> ["result",name] in
  98     let all_params = values @ result in
  99     G.func "public int" "execute" all_params ~tail:"throws SQLException" (fun () ->
 100       output_params_binder index params;
 101       begin match schema_binder_name with
 102       | None -> output "return pstmt.executeUpdate();"
 103       | Some name ->
 104          output "ResultSet res = pstmt.executeQuery();";
 105          let args = List.mapi (fun index attr -> get_column attr index) schema in
 106          let args = String.concat "," args in
 107          output "int count = 0;";
 108          output "while (res.next())";
 109          G.open_curly ();
 110          output "result.callback(%s);" args;
 111          output "count++;";
 112          G.close_curly "";
 113          output "return count;"
 114       end);
 115    end_class name
 116
 117 let start_output () name =
 118   output "import java.sql.*;";
 119   empty_line ();
 120   start_class name
 121
 122 let finish_output () name = end_class name
 123