droolsscriptevaluator.java

rule engine drools-2.0-beta-18

                            Map appData  )
    {
        Set keys = appData.keySet( );
        Iterator it = keys.iterator( );
        String key;
        Class clazz;
        String type;
        int nestedClassPosition;

        while ( it.hasNext( ) )
        {
            key = ( String ) it.next( );
            clazz = (Class) appData.get( key );

            type = clazz.getName( );
            nestedClassPosition = type.indexOf( '$' );

            if ( nestedClassPosition != -1 )
            {
                type = type.substring( 0, nestedClassPosition );
            }

            imports.add( type );

            Scanner.Location loc = scanner.peek( ).getLocation( );

            Java.VariableDeclarator[] variables = new Java.VariableDeclarator[]{ // variableDeclarators
            new Java.VariableDeclarator(
                                         loc, // location
                                         key, // name
                                         0, // brackets
                                         new Java.Cast(
                                                        // optionalInitializer
                                                        loc, // location
                                                        this.classToType( loc,
                                                                          clazz ), // targetType
                                                        new Java.MethodInvocation(
                                                                                   // value
                                                                                   loc, // location
                                                                                   block, // enclosingScope
                                                                                   new Java.AmbiguousName(
                                                                                                           // optionalTarget
                                                                                                           loc,
                                                                                                           block,
                                                                                                           new String[]{"applicationData"} ),
                                                                                   "get", // methodName
                                                                                   new Java.Rvalue[]{ // arguments
                                                                                   new Java.Literal(
                                                                                                     scanner.new StringLiteralToken(
                                                                                                                                     key ) )} ) ) )};

            block
                 .addStatement( new Java.LocalVariableDeclarationStatement(
                                                                            loc, // location
                                                                            block, // declaringBock
                                                                            Mod.FINAL, // modifiers
                                                                            this.classToType( loc,
                                                                                              clazz ), // type
                                                                            variables ) );
        }
    }

    private void addDeclarations(Scanner scanner,
                                 Java.Block block,
                                 Declaration[] declarations,
                                 Set imports)
    {
        ObjectType objectType;
        Class clazz;
        String identifier;
        Declaration declaration;

        String type;
        int nestedClassPosition;

        for ( int i = 0; i < declarations.length; i++ )
        {
            declaration = declarations[i];
            identifier = declaration.getIdentifier( );
            objectType = declaration.getObjectType( );

            clazz = ( ( ClassObjectType ) objectType ).getType( );

            type = clazz.getName( );
            nestedClassPosition = type.indexOf( '$' );

            if ( nestedClassPosition != -1 )
            {
                type = type.substring( 0, nestedClassPosition );
            }

            imports.add( type );

            Scanner.Location loc = scanner.peek( ).getLocation( );

            Java.VariableDeclarator[] variables = new Java.VariableDeclarator[]{ // variableDeclarators
            new Java.VariableDeclarator(
                                         loc, // location
                                         identifier, // name
                                         0, // brackets
                                         new Java.Cast(
                                                        // optionalInitializer
                                                        loc, // location
                                                        this
                                                            .classToType( loc,
                                                                          clazz ), // targetType
                                                        new Java.MethodInvocation(
                                                                                   // value
                                                                                   loc, // location
                                                                                   block, // enclosingScope
                                                                                   new Java.AmbiguousName(
                                                                                                           // optionalTarget
                                                                                                           loc,
                                                                                                           block,
                                                                                                           new String[]{"tuple"} ),
                                                                                   "get", // methodName
                                                                                   new Java.Rvalue[]{new Java.ArrayAccessExpression(
                                                                                                                                     loc,
                                                                                                                                     new Java.AmbiguousName(
                                                                                                                                                             loc,
                                                                                                                                                             block,
                                                                                                                                                             new String[]{"decls"} ),
                                                                                                                                     new Java.ConstantValue(
                                                                                                                                                             loc,
                                                                                                                                                             PrimitiveWrapper
                                                                                                                                                                             .wrap( i ) ) )} ) ) )};

            block
                 .addStatement( new Java.LocalVariableDeclarationStatement(
                                                                            loc, // location
                                                                            block, // declaringBock
                                                                            Mod.FINAL, // modifiers
                                                                            this
                                                                                .classToType(
                                                                                              loc,
                                                                                              clazz ), // type
                                                                            variables ) );
        }
    }

    public static Object compile(String block,
                                 Class interfaceToImplement,
                                 String[] parameterNames,
                                 Declaration[] declarations,
                                 Set imports,
                                 Map applicationData) throws Java.CompileException,
                                                     Parser.ParseException,
                                                     Scanner.ScanException,
                                                     IOException
    {
        DroolsScriptEvaluator scriptEvaluator = new DroolsScriptEvaluator( block,
                                                                           interfaceToImplement,
                                                                           parameterNames,
                                                                           declarations,
                                                                           imports, 
                                                                           applicationData );

        try
        {
            return scriptEvaluator.getMethod().getDeclaringClass().newInstance();
        }
        catch ( InstantiationException e )
        {
            // SNO - Declared class is always non-abstract.
            throw new RuntimeException( e.toString( ) );
        }
        catch ( IllegalAccessException e )
        {
            // SNO - interface methods are always PUBLIC.
            throw new RuntimeException( e.toString( ) );
        }
    }
}