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Java Backporting Tools
Java backporting tools are programs (usually written in Java) that convert Java classes bytecodes from one version of the Java Platform to an older one (for example Java 5.0 backported to 1.4). Java backporting tools comparison Main information The JVM has evolved a lot for the past years. However, most language features that were added are simply a syntactic sugar. They do not require new byte-code, hence can be compiled to the Java 8. But, since the Java language was always bound to the JVM development, new language features require the same target as the JVM because they get released all together. Features See also * Backporting Backporting is the action of taking parts from a newer version of a software system or software component and porting them to an older version of the same software. It forms part of the maintenance step in a software development process, and it is ... References External links How to use Java 5 language features in earlier JDKs Computing co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Java (programming Language)
Java is a high-level, class-based, object-oriented programming language that is designed to have as few implementation dependencies as possible. It is a general-purpose programming language intended to let programmers ''write once, run anywhere'' ( WORA), meaning that compiled Java code can run on all platforms that support Java without the need to recompile. Java applications are typically compiled to bytecode that can run on any Java virtual machine (JVM) regardless of the underlying computer architecture. The syntax of Java is similar to C and C++, but has fewer low-level facilities than either of them. The Java runtime provides dynamic capabilities (such as reflection and runtime code modification) that are typically not available in traditional compiled languages. , Java was one of the most popular programming languages in use according to GitHub, particularly for client–server web applications, with a reported 9 million developers. Java was originally developed ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anonymous Function
In computer programming, an anonymous function (function literal, lambda abstraction, lambda function, lambda expression or block) is a function definition that is not bound to an identifier. Anonymous functions are often arguments being passed to higher-order functions or used for constructing the result of a higher-order function that needs to return a function. If the function is only used once, or a limited number of times, an anonymous function may be syntactically lighter than using a named function. Anonymous functions are ubiquitous in functional programming languages and other languages with first-class functions, where they fulfil the same role for the function type as literals do for other data types. Anonymous functions originate in the work of Alonzo Church in his invention of the lambda calculus, in which all functions are anonymous, in 1936, before electronic computers. In several programming languages, anonymous functions are introduced using the keyword ''lambda' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Backporting
Backporting is the action of taking parts from a newer version of a software system or software component and porting them to an older version of the same software. It forms part of the maintenance step in a software development process, and it is commonly used for fixing security issues in older versions of the software and also for providing new features to older versions. Overview The simplest and probably most common situation of backporting is a fixed security hole in a newer version of a piece of software. Consider this simplified example: * Software v2.0 had a security vulnerability that is fixed by changing the text 'is_unsecured' to 'is_secured'. * The same security hole exists in Software v1.0, from which the codebase for the newer version is derived, but there the text may read 'is_notsecure'. By taking the modification that fixes Software v2.0 and changing it so that it applies to Software v1.0, one has effectively backported the fix. In real-life situations, the mod ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Covariant Return Type
In object-oriented programming, a covariant return type of a method is one that can be replaced by a "narrower" type when the method is overridden in a subclass. A notable language in which this is a fairly common paradigm is C++. C# supports return type covariance as of version 9.0. Covariant return types have been (partially) allowed in the Java language since the release of JDK5.0, were introduced to circumvent problems introduced by polymorphism and the new generic type erasure so the following example wouldn't compile on a previous release: [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reflection (computer Science)
In computer science, reflective programming or reflection is the ability of a process to examine, introspect, and modify its own structure and behavior. Historical background The earliest computers were programmed in their native assembly languages, which were inherently reflective, as these original architectures could be programmed by defining instructions as data and using self-modifying code. As the bulk of programming moved to higher-level compiled languages such as Algol, Cobol, Fortran, Pascal, and C, this reflective ability largely disappeared until new programming languages with reflection built into their type systems appeared. Brian Cantwell Smith's 1982 doctoral dissertation introduced the notion of computational reflection in procedural programming languages and the notion of the meta-circular interpreter as a component of 3-Lisp. Uses Reflection helps programmers make generic software libraries to display data, process different formats of data, perform seri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Enumeration (programming)
In computer programming, an enumerated type (also called enumeration, enum, or factor in the R programming language, and a categorical variable in statistics) is a data type consisting of a set of named values called ''elements'', ''members'', ''enumeral'', or ''enumerators'' of the type. The enumerator names are usually identifiers that behave as constants in the language. An enumerated type can be seen as a degenerate tagged union of unit type. A variable that has been declared as having an enumerated type can be assigned any of the enumerators as a value. In other words, an enumerated type has values that are different from each other, and that can be compared and assigned, but are not specified by the programmer as having any particular concrete representation in the computer's memory; compilers and interpreters can represent them arbitrarily. For example, the four suits in a deck of playing cards may be four enumerators named ''Club'', ''Diamond'', ''Heart'', and ''Spade'', ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Variadic Function
In mathematics and in computer programming, a variadic function is a function of indefinite arity, i.e., one which accepts a variable number of arguments. Support for variadic functions differs widely among programming languages. The term ''variadic'' is a neologism, dating back to 1936–1937. The term was not widely used until the 1970s. Overview There are many mathematical and logical operations that come across naturally as variadic functions. For instance, the summing of numbers or the concatenation of strings or other sequences are operations that can be thought of as applicable to any number of operands (even though formally in these cases the associative property is applied). Another operation that has been implemented as a variadic function in many languages is output formatting. The C function and the Common Lisp function are two such examples. Both take one argument that specifies the formatting of the output, and ''any number'' of arguments that provide the valu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Static Imports
Static import is a feature introduced in the Java programming language that allows members (fields and methods) which have been scoped within their container class as public static, to be used in Java code without specifying the class in which the field has been defined. This feature was introduced into the language in version 5.0. The feature provides a typesafe mechanism to include constants into code without having to reference the class that originally defined the field. It also helps to deprecate the practice of creating a constant interface (an interface Interface or interfacing may refer to: Academic journals * ''Interface'' (journal), by the Electrochemical Society * ''Interface, Journal of Applied Linguistics'', now merged with ''ITL International Journal of Applied Linguistics'' * '' Inte ... that only defines constants then writing a class implementing that interface, which is considered an inappropriate use of interfaces.) The mechanism can be used to reference ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Autoboxing
In computer science, boxing (a.k.a. wrapping) is the transformation of placing a primitive type within an object so that the value can be used as a reference. Unboxing is the reverse transformation of extracting the primitive value from its wrapper object. Autoboxing is the term for automatically applying boxing and/or unboxing transformations as needed. Boxing Boxing's most prominent use is in Java where there is a distinction between reference and value types for reasons such as runtime efficiency and syntax and semantic issues. In Java, a can only store values of type . One might desire to have a of , but this is not directly possible. Instead Java defines primitive wrapper classes corresponding to each primitive type: and , and , and , etc. One can then define a using the boxed type and insert values into the list by boxing them as objects. (Using generic parameterized types introduced in J2SE 5.0, this type is represented as .) On the other hand, C# has no pri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Java Annotation
In the Java computer programming language, an annotation is a form of syntactic metadata that can be added to Java source code. Classes, methods, variables, parameters and Java packages may be annotated. Like Javadoc tags, Java annotations can be read from source files. Unlike Javadoc tags, Java annotations can also be embedded in and read from Java class files generated by the Java compiler. This allows annotations to be retained by the Java virtual machine at run-time and read via reflection. It is possible to create meta-annotations out of the existing ones in Java. History The Java platform has various ''ad-hoc'' annotation mechanisms—for example, the ''transient'' modifier, or the ''@Deprecated'' javadoc tag. The Java Specification Request JSR-175 introduced the general-purpose annotation (also known as ''metadata'') facility to the Java Community Process in 2002; it gained approval in September 2004. Annotations became available in the language itself beginning w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
J2SE 5
J, or j, is the tenth letter in the Latin alphabet, used in the modern English alphabet, the alphabets of other western European languages and others worldwide. Its usual name in English is ''jay'' (pronounced ), with a now-uncommon variant ''jy'' ."J", ''Oxford English Dictionary,'' 2nd edition (1989) When used in the International Phonetic Alphabet for the ''y'' sound, it may be called ''yod'' or ''jod'' (pronounced or ). History The letter ''J'' used to be used as the swash letter ''I'', used for the letter I at the end of Roman numerals when following another I, as in XXIIJ or xxiij instead of XXIII or xxiii for the Roman numeral twenty-three. A distinctive usage emerged in Middle High German. Gian Giorgio Trissino (1478–1550) was the first to explicitly distinguish I and J as representing separate sounds, in his ''Ɛpistola del Trissino de le lettere nuωvamente aggiunte ne la lingua italiana'' ("Trissino's epistle about the letters recently added in the Ital ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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