BS ISO IEC 9075-13-2015 pdf free download – Information technology — Database languages — SQL — Part 13: SQL Routines and Types Using the Java TM Programming Language (SQL/JRT).
4Concepts
This Clause modifies Clause 4, “Concepts “, in ISO/IEC 9075-2.
4.1 The Java programming language
The Java programming language is a class-based, object-oriented language.This part of ISO/IEC 9075 usesthe following Java concepts and terminology.
A class is the basic construct of Java programs, in that all executable Java code is contained in a Java classdefinition. A class is declared by a class declaration that specifies a possibly empty set consisting of zero ormore fields, zero or more methods,zero or more nested classes, zero or more interfaces, zero or more instanceinitializers, zero or more static initializers, and zero or more constructors.
The scope of a variable is a class, an instance of the class, or a method of the class. The scope of a variable thatis declared static is the class, and the variable is called a class variable. The scope of each other variable declaredin the class is instances of the class, and such a variable is called an instance variable.Class variables andinstance variables of a class are called fields of that class. The scope of a variable declared in a method is theblock or Java for statement in which it is declared in that method, and the variable is called a local variable.A class instance consists of an instance of each instance variable declared in the class and each instance variabledeclared in the superclasses of the class. Class instances are strongly typed by the class name.The operationsavailable on a class instance are those defined for its class.
With the exception of the class java.lang.object, each class is declared to extend (at most) one otherclass; a class not explicitly declared to extend another class implicitly extends java.lang.object.Thedeclared class is a direct subclass of the class that it extends; the class that it extends is the direct superclassof the declared class.
Class B is a subclass of class A if B is a direct subclass of A, or if there exists some class C such that B is adirect subclass of C and C is a subclass of A. Likewise, class B is a superclass of class A if Bis a direct superclassof A, or if there exists some class C such that B is a direct superclass of C and C is a superclass of A.A subclasshas all of the fields and methods of its superclasses and an instance of class B may be used wherever an instanceof a superclass of B is permitted.
A method is an executable routine.A method can be declared static, in which case it is called a class method;otherwise, it is called an instance method.A class method can be referenced by qualifying the method namewith either the class name or the name of an instance of the cl.ass.An instance method is referenced by qualifyingthe method name with a Java expression that results in an instance of the class or, in the case of a constructor,with “new”.The method body of an instance method can reference its class variables, instance variables, andlocal variables.
The Java method signature of a method consists of the method name and the number of parameters and theirdata types.BS ISO IEC 9075-13 pdf download.