Java Classes

class advancedrelay.laygo.Laygo

All of the LayGO API related classes are contained in the advancedrelay.laygo package. The only class your application must use in this package is class advancedrelay.laygo.Laygo. This class provides the interface for dynamically loading a LayGO API shared object and calling the exported LayGO API functions from Java. This is the only way to access the LayGO API from Java using LayGO for Java.

class advancedrelay.laygo.Laygo throws an UnsatisfiedLinkError during class initialization if laygojni.dll (or cannot be loaded. The application must then call one of the following Laygo class methods to load the actual version of the LayGO API that will be used:

Each of these functions also throws an UnsatisfiedLinkError if it cannot load the requested shared object. This error can be caught, but the application must not call any other Laygo class method unless one of these methods completes successfully.

Each LayGO API function has a corresponding Laygo class method with the same name (including capitalization) but without the lgo_prefix. (The class name becomes the prefix.) For instance, the C language prototype:

extern LAYGOAPI LResult lgo_ConnectRequest(LCid, LCtlBuffer, LBufferSize);

becomes the class method:

public static native int ConnectRequest(int cid, byte [] ctlBuffer, int bufferSize);

So the C language function call:

LResult result = lgo_ConnectRequest(cid, ctlBuffer, bufferSize);

becomes the class method invocation:

int result = Laygo.ConnectRequest(cid, ctlBuffer, bufferSize);

Notice that the method returns an integer, not a laygo.Result object. The Java class laygo.Result is defined specifically for those cases in which a value is returned through a method parameter, for instance:

public static native int Poll(int cid, Result result);

The Laygo class also exports defined constants corresponding to the C language definitions in laygodef.h. As Java lacks enumerated types, these take the form of public static final integers.

The Laygo class is documented in Java Class Documentation. The semantics of each class method is exactly the same as that stated for the corresponding API function in the LayGO API Manual, which remains the primary source for this information.

Other advancedrelay.laygo Classes

Your application may call Laygo class methods directly. However, each of the other classes in the laygo package encapsulates an element of the LayGO API so that it can be more naturally incorporated into Java programs. These classes make all the Laygo class method calls required.

Class Encapsulates
Laygo LayGO API functions.
ProtocolStack Supervisory access to the LayGO protocol stack.
ProtocolStackException Error condition detected while initializing a ProtocolStack object.
ProtocolStackServer Access to the LayGO RPC server.
ProtocolService LayGO Connection Identifiers (CIDs).
ProtocolEvent State changing events.
DataEvent Data events received on a CID.
ProtocolEventException State changing events encountered while reading data.
StatusReport LStatusReport structure.
StatisticsTable LStatisticsTable structure.

These classes are documented in Java Class Documentation and their use demonstrated in the Jtdrv and Stdrv test programs.

Finally, the laygo package contains a class which exports the defined constants of each protocol layer:

These classes are also documented in Java Class Documentation, and class X21bis is used in the test programs.