tailieunhanh - ColdFusion Developer’s Guide phần 9

Báo cáo Builder cho phép bạn chuyển đổi giữa chúng bằng cách bấm vào các tab ở phía trên cùng của cửa sổ. Để lại một cửa sổ bến tàu công cụ hoặc bảng điều khiển, kéo nó sang bên hoặc góc cho đến khi một hình chữ nhật xuất hiện, và sau đó thả nút chuột. | ADOBE COLDFUSION 8 941 ColdFusion Developer s Guide I Under most situations when the method names are not ambiguous ColdFusion can determine the data types that are required by a Java object and often it can convert ColdFusion data to the required types. For example ColdFusion text strings are implicitly converted to the Java String type. Similarly if a Java object contains a doIt method that expects a parameter of type int and CFML is issuing a doIt call with a CFML variable x that contains an integer value ColdFusion converts the variable x to Java int type. However ambiguous situations can result from Java method overloading where a class has multiple implementations of the same method that differ only in their parameter types. The following sections describe how ColdFusion handles the unambiguous situations and how it provides you with the tools to handle ambiguous ones. Default data type conversion Whenever possible ColdFusion automatically matches Java types to ColdFusion types. The following table lists how ColdFusion converts ColdFusion data values to Java data types when passing arguments. The left column represents the underlying ColdFusion representation of its data. The right column indicates the Java data types into which ColdFusion can automatically convert the data CFML Java Integer short int long short and int might result in a loss of precision . Real number float double float might result in a loss of precision. Boolean boolean Date-time String including lists String short int long float double when a CFML string represents a number or date. boolean for strings with the value Yes No True and False case-insensitive . Array ColdFusion Arrays are internally represented using an instance of a object. ColdFusion can also map a CFML array to any of the following when the CFML array contains consistent data of a type that can be converted to the Java array s data type byteũ charũ booleanũ .