Interface Definition Language In Java we cannot separate a class’s definition from its implementations as we can in C++ Header files Implementation files CORBA allows the separation of definition and implementation CORBA uses IDL for defining interfaces between clients and servers ORB Vendors provide specific IDL compilers for supported languages create target language stubs and skeletonsfor building CORBA clients and servers C, C++, Smalltalk, Java, COBOL …

IDL/Java type mapping due to differences in heritage IDL and Java types don’t have a 1 to 1 mapping: long Java int short Java short float Java float double Java double char Java char boolean Java boolean octet java byte string java.lang.String any Special type consisting of any of the above

an IDL interface ex. interface Cooler { int getHotWaterLevel(); int getWarnWaterLevel(); int getColdWaterLevel(); exception NoMoreWaterException { }; int getHotWater() throws NoMoreWaterException; int getWarmWater() throws NoMoreWaterException; int getColdWater() throws NoMoreWaterException; }

Compiling the IDL Compiling the IDL using the javatoidl compiler will produce six classes: CoolerRef CoolerHolder CoolerOperations CoolerStub CoolerServant CoolerSkeleton