Sun Helper Functions

• Object *unhand(Handle *)

  Dereference a handle to an Object or Array. There is no equivalent macro for this operation. Objects are passed by reference in Toba, not by handles.
  
  

• int obj_length(Harray *)

  Return the length of an array. There is no equivalent macro for this operation. To achieve the same result an Object must be cast to one of the array structure types and the size field examined:

      struct carray *ca = (carray *)obj;
      int length;
  
      length = ca->length;
  

  
  
  
• Object *bodyof(Harray *)

  Return the data portion of an array. There is no equivalent macro for this operation. To achieve the same result an Object must be cast to the proper array structure and the data field accessed:

      struct carray *ca = (carray *)obj;
      Char *data;
  
      data = ca->data;
  

  
  
  
• ClassClass * FindClass(struct execenv *ee, char *name, bool_t resolve)

  Return the class with the given name. This class is provided by the Java API function Class.forName(). An upcall into Java from C should be done to call this method.
  
  

• HArrayOfChar *MakeString(char *str, int len)
• Hjava_lang_String *makejavaString(char *str, int len)

  Make an array of characters or Java string from a C string. The function struct in_java_lang_String *javastring(char *) performs a similar operation
  
  

• Handle *ArrayAlloc(int type, int len)

  Allocate an array of the given type and length. The function Object anewarray(Class c, int nelem) performs a similar operation. Class structures for primitives are provided for making arrays of primitive types:

      struct carray = anewarray(&cl_char, 3);
  

  
  
  
• long execute_method(struct execenv *current, void *obj, char *method, ...)
• long execute_static_method(struct execenv *current, ClassClass *cb, char *method, ...)

  Execute methods. There is no equivalent function in Toba. Java methods get translated into C functions and are directly callable (modulo the name-hashing) from C. In order to call a Java method its name should be looked up in the appropriate header file. A static invocation is a direct call to the desired method:

      struct in_java_lang_String *str = (struct in_java_lang_String *)arg2;
      Int hash = hashCode__mK6Su(str);
  

  Dynamic invocations are indirect calls through the classes method table:

      hash = str->class.M.hash_Code__mK6Su.f(str);
  

  
  
  
• Hobject *execute_java_constructor(struct execenv *current, char *method, ...)

  Create a new object. An object can be constructed using the default constructor by calling the construct() function. In order to call another constructor the object should be created explicitly with new and the appropriate constructor should be called directly (the name of the constructor can be found in the generated header file).
  
  

• SignalError(0, JAVAPKG, "Exception Name", "mesg")

  Throw an exception. The function athrow(Object o) raises an exception of type o. There are many wrapper functions for creating the object and setting its message type. See void throwMesg(Class etype, char *mesg) and the many other throw* functions.
  
  

• void javaStringPrint(Hjava_lang_String *s)

  Print a string object. There is no Toba function with an equivalent operation. An equivalent operation can be done by translating the string to a C string and printing it, or by calling a Java method that will print out the string.
  
  

• int javaStringLength(Hjava_lang_String *s)

  Return the length of a string. There is no Toba function with an equivalent operation. You can get the length of a string by accessing the instances count field:

      struct in_java_lang_String *s = (struct in_java_lang_String *)obj;
  
      length = s->count;
  

  
  
  
• char *makeCString(Hjava_lang_String *s)
• char *allocCString(Hjava_lang_String *s)

  Create a C string from a Java string. The function char *cstring(struct in_java_lang_String *s) performs the same operation. The returned C string will be garbage collected
  
  

• unicode *javaString2unicode(Hjava_lang_String *s, unicode *buf, int len)

  Create an array of unicode characters from a string. There is no Toba function implementing this function
  
  

• char *javaString2Cstring(Hjava_lang_String *s, char *buf, int len)

  Create a C string in the buffer provided. There is no Toba function implementing this function. The cstring function performs a similar operation.