Editing ESC/Java (section)

{{More footnotes|date=March 2010}}
'''ESC/Java''' (and more recently '''ESC/Java2'''), the "Extended Static Checker for Java," is a [[programming tool]] that attempts to find common [[run-time error]]s in [[Java (programming language)|Java]] programs at [[compile time]].<ref>{{cite conference |last1=Flanagan |first1=C. |last2=Leino |first2=K.R.M. |last3=Lillibridge |first3=M. |last4=Nelson |first4=G. |author4-link=Greg Nelson (computer scientist)|last5=Saxe |first5=J. B. |author5-link=James B. Saxe|last6=Stata |first6=R. |author6-link=Raymie Stata|title=Extended static checking for Java |work=Proceedings of the Conference on Programming Language Design and Implementation |pages=234–245 |year=2002 |isbn=1-58113-463-0 |doi=10.1145/512529.512558}}</ref>  The underlying approach used in ESC/Java is referred to as [[extended static checking]], which is a collective name referring to a range of techniques for [[static code analysis|statically checking]] the correctness of various program constraints.  For example, that an integer variable is greater-than-zero, or lies between the [[bounds checking|bounds of an array]].  This technique was pioneered in ESC/Java (and its predecessor, ESC/[[Modula-3]]) and can be thought of as an extended form of [[type checking]].  Extended static checking usually involves the use of an [[automated theorem proving|automated theorem prover]] and, in ESC/Java, the Simplify theorem prover was used.

ESC/Java is neither [[soundness|sound]] nor [[completeness (logic)|complete]].  This was intentional and aims to reduce the number of errors and/or warnings reported to the programmer, in order to make the tool more useful in practice.  However, it does mean that: firstly, there are programs that ESC/Java will erroneously consider to be incorrect (known as ''false-positives''); secondly, there are incorrect programs it will consider to be correct (known as ''false-negatives'').  Examples in the latter category include errors arising from [[modular arithmetic]] and/or [[Thread (computer science)|multithreading]].

ESC/Java was originally developed at the [[DEC Systems Research Center|Compaq Systems Research Center]] (SRC).  SRC launched the project in 1997, after work on their original extended static checker, ESC/Modula-3, ended in 1996.  In 2002, SRC released the [[source code]] for ESC/Java and related tools.  Recent versions of ESC/Java are based around the [[Java Modeling Language]] (JML). Users can control the amount and kinds of checking by annotating their programs with specially formatted comments or ''[[Directive (programming)|pragmas]]''.

The [[Radboud University Nijmegen|University of Nijmegen]]'s ''Security of Systems'' group released alpha versions of ESC/Java2, an extended version of ESC/Java that processes the [[Java Modeling Language|JML]] specification language through 2004.  From 2004 to 2009, ESC/Java2 development was managed by the KindSoftware Research Group at [[University College Dublin]], which in 2009 moved to the [[IT University of Copenhagen]], and in 2012 to the [[Technical University of Denmark]].  Over the years, ESC/Java2 has gained many new features including the ability to reason with multiple [[Automated theorem prover|theorem prover]]s and integration with [[Eclipse (software)|Eclipse]].

[http://www.openjml.org/ OpenJML], the successor of ESC/Java2, is available for Java 1.8.<ref>{{cite web |url=http://jmlspecs.sourceforge.net/ |title = OpenJML download site on sourceforge}}</ref> The source is available at https://github.com/OpenJML

<ref>{{Cite web|url=https://sourceforge.net/p/jmlspecs/code/HEAD/tree/OpenJML/trunk/OpenJML/|title=Java Modeling Language (JML) / Code / &#91;r9606&#93; /OpenJML/Trunk/OpenJML}}</ref>