Strumenti e framework per lo sviluppo di linguaggi di programmazione e linguaggi domain-specific in java

La tesi ha lo scopo di indagare le tecnologie disponibili per la realizzazione di linguaggi di programmazione e linguaggi domain specific in ambiente Java. In particolare, vengono proposti e analizzati tre strumenti presenti sul mercato: JavaCC, ANTLR e Xtext. Al termine dell’elaborato, il lettore dovrebbe avere un’idea generale dei principali meccanismi e sistemi utilizzati (come lexer, parser, AST, parse trees, etc.), oltre che del funzionamento dei tre tools presentati. Inoltre, si vogliono individuare vantaggi e svantaggi di ciascuno strumento attraverso un’analisi delle funzionalità offerte, così da fornire un giudizio critico per la scelta e la valutazione dei sistemi da utilizzare.

Backport di una applicazione da Java 8 a Java 7

In Java 8, ultimo aggiornamento ufficiale del linguaggio Java, sono state introdotte alcune nuove funzionalità che permettono l’integrazione di alcuni meccanismi legati ai linguaggi dinamici o funzionali, come le espressioni lambda, l’utilizzo degli stream e la dichiarazione di metodi statici all’interno di interfacce. Se si volesse installare un’applicazione scritta in Java 8 su Android, Dalvik VM, la JVM in esso presente, fallirà il processo di traduzione del bytecode. In questa tesi quindi esplorerò, sia ad alto livello che a basso livello, l’origine del problema e presenterò una soluzione di backporting per un’applicazione esistente.

Recovery and Analysis of Transaction Scope from Scattered Information in Java Enterprise Applications

Java Enterprise Applications (JEAs) are large systems that integrate multiple technologies and programming languages. Transactions in JEAs simplify the development of code that deals with failure recovery and multi-user coordination by guaranteeing atomicity of sets of operations. The heterogeneous nature of JEAs, however, can obfuscate conceptual errors in the application code, and in particular can hide incorrect declarations of transaction scope. In this paper we present a technique to expose and analyze the application transaction scope in JEAs by merging and analyzing information from multiple sources. We also present several novel visualizations that aid in the analysis of transaction scope by highlighting anomalies in the specification of transactions and violations of architectural constraints. We have validated our approach on two versions of a large commercial case study.

On the Integration of Smalltalk and Java

After decades of development in programming languages and programming environments, Smalltalk is still one of few environments that provide advanced features and is still widely used in the industry. However, as Java became prevalent, the ability to call Java code from Smalltalk and vice versa becomes important. Traditional approaches to integrate the Java and Smalltalk languages are through low-level communication between separate Java and Smalltalk virtual machines. We are not aware of any attempt to execute and integrate the Java language directly in the Smalltalk environment. A direct integration allows for very tight and almost seamless integration of the languages and their objects within a single environment. Yet integration and language interoperability impose challenging issues related to method naming conventions, method overloading, exception handling and thread-locking mechanisms. In this paper we describe ways to overcome these challenges and to integrate Java into the Smalltalk environment. Using techniques described in this paper, the programmer can call Java code from Smalltalk using standard Smalltalk idioms while the semantics of each language remains preserved. We present STX:LIBJAVA - an implementation of Java virtual machine within Smalltalk/X - as a validation of our approach

CONVERSION OF DOMAIN TYPE ENFORCEMENT LANGUAGE TO THE JAVA SECURITY MANAGER

With today's prevalence of Internet-connected systems storing sensitive data and the omnipresent threat of technically skilled malicious users, computer security remains a critically important field. Because of today's multitude of vulnerable systems and security threats, it is vital that computer science students be taught techniques for programming secure systems, especially since many of them will work on systems with sensitive data after graduation. Teaching computer science students proper design, implementation, and maintenance of secure systems is a challenging task that calls for the use of novel pedagogical tools. This report describes the implementation of a compiler that converts mandatory access control specification Domain-Type Enforcement Language to the Java Security Manager, primarily for pedagogical purposes. The implementation of the Java Security Manager was explored in depth, and various techniques to work around its inherent limitations were explored and partially implemented, although some of these workarounds do not appear in the current version of the compiler because they would have compromised cross-platform compatibility. The current version of the compiler and implementation details of the Java Security Manager are discussed in depth.

Driving the refactoring of Java Enterprise applications by evaluating the distance between application elements

Java Enterprise Applications (JEAs) are complex systems composed using various technologies that in turn rely on languages other than Java, such as XML or SQL. Given the complexity of these applications, the need to reverse engineer them in order to support further development becomes critical. In this paper we show how it is possible to split a system into layers and how is possible to interpret the distance between application elements in order to support the refactoring of JEAs. The purpose of this paper is to explore ways to provide suggestions about the refactoring operations to perform on the code by evaluating the distance between layers and elements belonging those layers. We split JEAs into layers by considering the kinds and the purposes of the elements composing the application. We measure distance between elements by using the notion of the shortest path in a graph. Also we present how to enrich the interpretation of the distance value with enterprise pattern detection in order to refine the suggestion about modifications to perform on the code.

Etwas über die Rosenkultur auf der Insel Java

W. Reuschenbach

Zur Ethnologie von West-Java : Mitteilungen aus Missionar S. Coolsmas "West Java"

von Dr. R. Teuscher

Accumulation rates of bulk sediment and total organic carbon for Ontong Java Plateau sediments

Organic geochemical investigations were performed on sediments of Leg 130 to reconstruct the depositional environment of the Ontong Java Plateau. The Miocene to Quaternary sediments collected during the drilling campaign are characterized by extremely low organic carbon contents. As indicated by C/N ratios and Rock-Eval data, most of the organic matter is probably of marine origin. Based on mass-accumulation rates of organic carbon, the paleoproductivity for the Miocene-Pliocene and the late Pliocene-Pleistocene time intervals as well as the modern surface-water production were estimated. The productivity values of the surface sediments (25-59 gC/m2/yr) reflect the various influences of the equatorial upwelling cell on the different sites. The accumulation rates of organic carbon are generally low; however, they show a distinct increase at 8 Ma and a decrease at 2 Ma.