Projects

Groovy

An agile dynamic language for the Java Platform with many features that are inspired by languages like Python, Ruby and Smalltalk, making them available to Java developers using a Java-like syntax. Developing web applications , writing shell scripts easily, writing concise, meaningful, test cases ... [More] using Groovy's JUnit integration, or prototyping and producing real industrial strength applications have never been so concise and groovy. [Less]

Apache Velocity

claimed by Apache Software Foundation

Velocity is a Java-based template engine. It permits anyone to use a simple yet powerful template language to reference objects defined in Java code.

ASM

ASM is a Java bytecode manipulation framework. It can be used to dynamically generate stub classes or other proxy classes, directly in binary form, or to dynamically modify classes at load time, i.e., just before they are loaded into the Java Virtual Machine. ASM offers similar functionalities as ... [More] BCEL or SERP, but is much smaller (33KB instead of 350KB for BCEL and 150KB for SERP) and faster than these tools (the overhead of a load time class transformation is of the order of 60% with ASM, 700% or more with BCEL, and 1100% or more with SERP). Indeed ASM was designed to be used in a dynamic way* and was therefore designed and implemented to be as small and as fast as possible. [Less]

cglib

Byte Code Generation Library is high level API to generate and transform JAVA byte code. It is used by AOP, testing, data access frameworks to generate dynamic proxy objects and intercept field access.

Jakarta BCEL

claimed by Apache Software Foundation

The Byte Code Engineering Library is intended to give users a convenient possibility to analyze, create, and manipulate (binary) Java class files (those ending with .class). Classes are represented by objects which contain all the symbolic information of the given class: methods, fields and byte ... [More] code instructions, in particular. Such objects can be read from an existing file, be transformed by a program (e.g. a class loader at run-time) and dumped to a file again. An even more interesting application is the creation of classes from scratch at run-time. The Byte Code Engineering Library (BCEL) may be also useful if you want to learn about the Java Virtual Machine (JVM) and the format of Java .class files. BCEL contains a byte code verifier named JustIce, which usually gives you much bette [Less]

Kawa Language Framework

Kawa is a framework written in Java for implementing high-level and dynamic languages, compiling them into Java bytecodes. It includes and implementation of the Scheme programming language with extensions to provide useful integration with the JDK and other Java classes. The included ... [More] gnu.bytecode package can be used as a standalone library for generating Java bytecode. [Less]

Javassist

Javassist (Java Programming Assistant) makes Java bytecode manipulation simple. It is a class library for editing bytecodes in Java; it enables Java programs to define a new class at runtime and to modify a class file when the JVM loads it. Unlike other similar bytecode editors, Javassist provides ... [More] two levels of API: source level and bytecode level. If the users use the source-level API, they can edit a class file without knowledge of the specifications of the Java bytecode. The whole API is designed with only the vocabulary of the Java language. You can even specify inserted bytecode in the form of source text; Javassist compiles it on the fly. On the other hand, the bytecode-level API allows the users to directly edit a class file as other editors. [Less]

Gauche

Gauche is an R5RS Scheme implementation developed to be a handy script interpreter, which allows programmers and system administrators to write small to large scripts for their daily chores. Quick startup, built-in system interface, native multilingual support are some of my goals. Gauche runs on several Unix-like platforms.

testability-explorer

Quick LinksGetting Started | How Testability is determined | How to Contribute | Scores for Open-Source projects Sample ReportsSource-annotated Report Testability-explorer is a tool which analyzes Java bytecode and computes how difficult it will be to write unit tests for the code. It attempts ... [More] to help you quantitatively determine how hard your code is to test, and where to focus to make it more testable. Testability Explorer can be used: As a learning tool which flags causes of hard to test code with detailed breakdown of reasons. To identify hard to test hair-balls in legacy code. As part of your code analysis-toolset. As a tool which can be added into continuous integration that can enforce testable code. Currently the tool computes: Non-Mockable Total Recursive Cyclomatic Complexity. Cyclomatic Complexity is a measure of how many different paths of execution are there in the code. It is computed, by counting the if, while, and case as branching primitives. It is recursive because cost of the method as well as any methods it calls are counted. It is total because cost of object construction as well as any static initializations are counted. And finally, it is non-mockable because any code which can be mocked out in test is not counted as part of the cost. This means that the score is based on the amount of complex code that cannot be mocked out in a unit test. Global Mutable State. Counts the number of fields which are globally reachable by the class under test and which are mutable. Mutable global state makes testing difficult as tests are not isolatable, the global state needs to be set up and cleared between tests. Law of Demeter. This is the principle that calling methods on objects you get from other collaborators is trouble, instead, the collaborator should call that method itself. It makes testing harder because your mocks must expose some internal state through these methods. Check out the Readme, or post a message to the mailing list. For a demo of testability-explorer in action see http://testabilityexplorer.org/report [Less]

objenesis

Okay, it's pretty easy to instantiate objects in Java through standard reflection. However there are many cases where you need to go beyond what reflection provides. For example, if there's no public constructor, you want to bypass the constructor code, or set final fields. There are ... [More] numerous clever (but fiddly) approaches to getting around this and this library provides a simple way to get at them. You will find the official site here. [Less]