Session Callbacks Structure

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Session Callbacks Structure

When you create an instantiation of the Java runtime environment using the JMOpenSession function, you must pass a data structure that supplies callback information for that instantiation. The session callbacks data structure is defined by the JMSessionCallbacks data type.



 
struct JMSessionCallbacks {

    UInt32                  fVersion;           /* set to kJMVersion */

    JMConsoleProcPtr        fStandardOutput;    /* standard output */

    JMConsoleProcPtr        fStandardError;     /* standard error */

    JMConsoleReadProcPtr    fStandardIn;        /* standard input */

    JMExitProcPtr           fExitProc;          /* handle System.exit */ 

    JMAuthenticateURLProcPtrfAuthenticateProc;  /* for authentication */

    JMLowMemoryProcPtr      fLowMemProc;        /* low memory warning */

};

Field descriptions

fVersion: The version of JManager. You should set this field to kJMVersion .
fStandardOutput: A pointer to a function that handles text sent to the standard output. JManager sends all console output to this function. This callback has the following type definition:



 
                    typedef void (*JMConsoleProcPtr) (

                        JMSessionRef session, const char* message, 

                        UInt32 messageLen);

For more information, see the description of the application-defined function MyStandardOutput.; Note that all text sent to this function will be encoded using the text encoding you specified when calling JMOpenSession .
fStandardError: A pointer to a function that handles standard error output. JManager sends any error messages to this function. This callback has the following type definition:



 
                    typedef void (*JMConsoleProcPtr) (

                        JMSessionRef session, const char* message,

                        UInt32 messageLen);

For more information, see the description of the application-defined function MyStandardError.; Note that all text sent to this function will be encoded using the text encoding you specified when calling JMOpenSession .
fStandardIn: A pointer to a function that handles console input. JManager accepts input from this routine. This value can be a null pointer, which indicates default behavior (no console input). This callback has the following type definition:



 
                    typedef SInt32 (*JMConsoleReadProcPtr) (

                        JMSessionRef session, char* buffer, 

                        SInt32 maxBufferLength);

For more information, see the description of the application-defined function MyStandardIn.
fExitProc: A pointer to a function that handles calls to java.lang.System.exit (that is, requests to quit). This callback has the following type definition:



 
                    typedef Boolean (*JMExitProcPtr) (

                        JMSessionRef session, int value);

For more information, see the description of the application-defined function MyExit.
fAuthenticateProc: A pointer to a function that handles user authentication requests (such as a request for a password) for a URL. This callback has the following type definition:



 
                    typedef Boolean (*JMAuthenticateURLProcPtr) (

                        JMSessionRef session, const char* url, 

                        const char* realm, char userName[255], 

                        char password[255]);

For more information, see the description of the application-defined function MyAuthenticate.
fLowMemProc: A pointer to a function that handles low-memory conditions. This callback has the following type definition:



 
                    typedef Boolean (*JMLowMemoryProcPtr) (

                        JMSessionRef session);

For more information, see the description of the application-defined function MyLowMem.