ACDK基于C++的模型（基本類型、接口、對(duì)象類，數(shù)組，異常，枚舉和命名空間）組織了自己的類型模型。
1、基本模型
基本類型 Object對(duì)象封裝 位數(shù)(bit)
bool Boolean 8
char Character 8
uc2char UnicodeCharacter 16
uc4char UnicodeCharacter 23
byte Byte 8
short Short 16
int Integer 32
jlong Long 64
float Float 32
double Double 64
2、Enum類型
使用C++的enum，假如需要考慮ACDK的元編譯，需要使用宏：ACDK_DECL_ENUM，用來(lái)提供元信息。動(dòng)態(tài)庫(kù)需要導(dǎo)出類型的時(shí)候，使用ACDK_DEF_LIB_ENUM。不牽扯到元信息的Enum類型可以在定義的時(shí)候使用foreign關(guān)鍵字。
3、對(duì)象類型
必須直接或者間接從Object派生
// declare the R-type RLegalAcdkClass
// and the Array type LegalAcdkClassArray and RLegalAcdkClassArray
ACDK_DECL_CLASS(LegalAcdkClass);
// The class itself:
class LegalAcdkClass : extends acdk::lang::Object // extend the Object class
{
ACDK_WITH_METAINFO(LegalAcdkClass); // optional, for class information see Metainfo
private:
RString message;
public:
// constructor
LegalAcdkClass() : Object() , message("")
{
}
// a method
RString getMessage()
{
return message;
}
}; 不能多繼承類，但是可以提供一種更好的辦法就是多繼承接口。
// declare the R-type RLegalAcdkClass
// and the Array type LegalAcdkClassArray and RLegalAcdkClassArray
ACDK_DECL_CLASS(LegalAcdkClass);
// The class itself:
class LegalAcdkClass : extends acdk::lang::Object // extend the Object class
, implements acdk::lang::Comparable // implements the interface
{
ACDK_WITH_METAINFO(LegalAcdkClass) // optional, for class information see Metainfo
private:
RString message;
public:
// implement the Comparable interface method
int compareTo(IN(RObject) other)
{
return getMessage()->compareTo(RLegalAcdkClass(other)->getMessage());
}
RString getMessage() { return message; }
};
Class信息
RStringBuffer sb1 = new StringBuffer("ACDK");
RStringBuffer sb2 = new StringBuffer("JAVA");
RClass cls1 = sb1->getClass();
RClass cls2 = sb2->getClass();
assert(cls1 == cls2); // always true
你可以定義不符合acdk規(guī)范的類型已經(jīng)結(jié)構(gòu)等，但是會(huì)失去acdk提供的一些特性。
ACDK的異常捕獲需要注意：
void foo()
{
try {
} catch (acdk::io::RIOException ex) {
// handle here type of IOException.
} catch (RThrowable ex) {
// handle all other ACDK exceptions
}
/**//* DONT DO THAT
otherwise Nullpointer exception will not handled properly
} catch () {
// this are not ACDK exception
// for example std::exception, if you use STL
}
*/
}
方法參數(shù)缺省傳遞方式是：
a、基本類型(int,float,char,etc)按值傳遞
b、enum按值
c、類和接口按引用傳遞
d、數(shù)組按引用傳遞
參數(shù)的in,out,inout
void foo(IN(RStringBuffer) buffer, int len)
{
//buffer = new StringBuffer(); // caller not be effected, RStringBuffer isn't changed
buffer->append("asdf"); // caller be effected.
len = 42; // caller not be effected
}
// is equivalent to
//void foo(RStringBuffer buffer, int len);
void use_foo()
{
RStringBuffer sb = new StringBuffer("");
RStringBuffer sbs = sb;
int value = 1000;
foo(sb, value);
//value == 1000 && sb == sbs
// sb->toString() == "ACDK"
}
in參數(shù)確保對(duì)象引用不會(huì)變化；可以傳遞棧對(duì)象
void foo(OUT(RStringBuffer) buffer, OUT(int) len)
{
// buffer is unitialized here
buffer = new StringBuffer(1024);
// buffer is now initialed;
buffer->append("ACDK");
len = buffer->length();
}
RString use_foo()
{
RStringBuffer sb;
int len;
foo(sb, len);
System::out->println("Buffer is [" + sb->toString() + "] len = " + len);
return sb->toString();
}
使用out參數(shù)，按照引用傳參，可以修改傳入?yún)?shù)，但是對(duì)于進(jìn)程間不可以傳遞棧對(duì)象。
posted on 2007-12-25 12:24
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