✎ javacard:jcvm:6.8.2.3_class_info_items [wiki]

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=== 6.8.2.3 class_info Items ===

**super_class_ref** 

The **super_****class_ref****** item of the **class_info** structure is a ****class_ref**** structure representing the superclass of this class. The ****class_ref**** structure is defined as part of the **CONSTANT_Classref_info** structure ([[6.7.1_CONSTANT_Classref| Section 6.7.1, CONSTANT_Classref]]). 

The ****super_**class_ref****** item has the value of **0xFFFF** only if this class does not have a superclass. Otherwise the value of the ****super_**class_ref****** item is limited only by the constraints of the **class_ref** structure. 

**declared_instance_size** 

The **declared_instance_size** item of the **class_info** structure represents the number of 16-bit cells required to represent the instance fields declared by this class. It does not include instance fields declared by superclasses of this class. 

Instance fields of type int are represented in two 16-bit cells, while all other field types are represented in one 16-bit cell. 

**first_reference_token** 

The **first_reference_token** item of the **class_info** structure represents the instance field token ([[4.3.7.5_Instance Fields| Section 4.3.7.5, Instance Fields]]) value of the first reference type instance field defined by this class. It does not include instance fields defined by superclasses of this class. 

If this class does not define any reference type instance fields, the value of the ****first_reference_token**** is **0xFF**. Otherwise the value of the ****first_reference_token**** item must be within the range of the set of instance field tokens of this class. 

**reference_count** 

The **reference_count** item of the **class_info** structure represents the number of reference type instance field defined by this class. It does not include reference type instance fields defined by superclasses of this class. 

Valid values of the **reference_count** item are between 0 and the maximum number of instance fields defined by this class. 

**public_method_table_base** 

The ******public_method_table_base****** item of the ****class_info**** structure is equal to the virtual method token value ([[4.3.7.6_Virtual Methods| Section 4.3.7.6, Virtual Methods]]) of the first method in the ****public_virtual_method_table[]**** array. If the ****public_virtual_method_table[]**** array is empty, the value of the ******public_method_table_base****** item is equal to the ******public_method_table_base****** item of the ****class_info**** structure of this class' superclass plus the **public_method_table_count** item of the ****class_info**** structure of this class' superclass. If this class has no superclass and the ****public_virtual_method_table[]**** array is empty, the value of the ******public_method_table_base****** item is zero. 

**public_method_table_count** 

The **public_method_table_count** item of the class_info structure indicates the number of entries in the **public_virtual_method_table[]** array. 

If this class does not define any public or protected override methods, the minimum valid value of ****public_method_table_count**** item is the number of public and protected virtual methods declared by this class. If this class defines one or more public or protected override methods, the minimum valid value of ****public_method_table_count**** item is the value of the largest public or protected virtual method token, minus the value of the smallest public or protected virtual override method token, plus one. 

The maximum valid value of the **public_method_table_count** item is the value of the largest public or protected virtual method token, plus one. 

Any value for the **public_method_table_count** item between the minimum and maximum specified here is valid. However, the value must correspond to the number of entries in the **public_virtual_method_table[]** array. 

**package_method_table_base** 

The ********package_method_table_base******** item of the ****class_info**** structure is equal to the virtual method token value ([[4.3.7.6_Virtual Methods| Section 4.3.7.6, Virtual Methods]]) of the first entry in the ******package_virtual_method_table[]****** array. If the ******package_virtual_method_table[]****** array is empty, the value of the ********package_method_table_base******** item is equal to the ********package_method_table_base******** item of the ****class_info**** structure of this class' superclass, plus the **package_method_table_count** item of the ****class_info**** structure of this class' superclass. If this class has no superclass or inherits from a class defined in another package and the ******package_virtual_method_table[]****** array is empty, the value of the ********package_method_table_base******** item is zero. 

**package_method_table_count** 

The **package_method_table_count** item of the class_info structure indicates the number of entries in the **package_virtual_method_table[]** array. 

If this class does not define any override methods, the minimum valid value of ****package_method_table_count**** item is the number of package visible virtual methods declared by this class. If this class defines one or more package visible override methods, the minimum valid value of ****package_method_table_count**** item is the value of the largest package visible virtual method token, minus the value of the smallest package visible virtual override method token, plus one. 

The maximum valid value of the **package_method_table_count** item is the value of the largest package visible method token, plus one. 

Any value for the **package_method_table_count** item between the minimum and maximum specified here are valid. However, the value must correspond to the number of entries in the **package_virtual_method_table[]**. 

**public_virtual_method_table[]** 

The ****public_virtual_method_table[]**** item of the class_info structure represents an array of public and protected virtual methods. These methods can be invoked on an instance of this class. The ****public_virtual_method_table[]**** array includes methods declared or defined by this class. It may also include methods declared or defined by any or all of its superclasses. The value of an index into this table must be equal to the value of the virtual method token of the indicated method, minus the value of the **public_method_table_base** item. 

Entries in the **public_virtual_method_table[]** array that represent methods defined or declared in this package contain offsets into the info item of the Method Component ([[6.9_Method Component| Section 6.9, Method Component]]) to the **method_info** structure representing the method. Entries that represent methods defined or declared in an imported package contain the value **0xFFFF**. 

Entries for methods that are declared abstract are represented in the **public_virtual_method_table[]** array in the same way as non-abstract methods. 

**package_virtual_method_table[]** 

The ****package_virtual_method_table[]**** item of the class_info structure represents an array of package-visible virtual methods. These methods can be invoked on an instance of this class. The ****package_virtual_method_table[]**** array includes methods declared or defined by this class. It may also include methods declared or defined by any or all of its superclasses that are defined in this package. The value of an index into this table must be equal to the value of the virtual method token of the indicated method **&amp; 0x7F**, minus the value of the **package_method_table_base** item. 

All entries in the **package_virtual_method_table[]** array represent methods defined or declared in this package. They contain offsets into the info item of the Method Component ([[6.9_Method Component| Section 6.9, Method Component]]) to the **method_info** structure representing the method. 

Entries for methods that are declared abstract, not including those defined by interfaces, are represented in the **package_virtual_method_table[]** array in the same way as non-abstract methods. 

**interfaces[]** 

The **interfaces** item of the **class_info** structure represents a table of variable-length **implemented_interface_info** structures. The table must contain an entry for each of the directly implemented **interfaces** indicated in the declaration of this class and each of the **interfaces** in the hierarchies of those **interfaces**. Interfaces that occur more than once are represented by a single entry. 

Given the declarations below, the number of entries for class **c0** is 1 and the entry in the ****interfaces**** array is ****i0****. The number of entries for class ******c1****** is 3 and the entries in the ****interfaces**** array are **i1**, **i2**, and **i3**. The entries for class ******c1****** must not include interface ****i0****, which is implemented only by the superclass of ******c1******. 

**remote_interfaces** 

The ****remote_interfaces**** item represents information required if this class or any of its super classes implements a remote interface. This item must be omitted if the **ACC_REMOTE** flag has a value of zero. The ****remote_interfaces**** item is defined by a **remote_interface_info** structure.
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