Project Jigsaw was launched with the primary objective to simplify development and maintenance of libraries and large application. In addition to modularizing the Java Development Kit (JDK), Project Jigsaw also aims to boost the maintainability and security of Java SE Platform Implementations. Initially, the project was intended for Java 7. But it was subsequently deferred to Java 8. Project Jigsaw finally modularized JDK in 2017 by implementing a standard module system for Java 9.
While using Java 9, programmers can leverage the standard module system implemented by Project Jigsaw by availing widely used design principle- modularity. They can now simplify development, testing, and maintenance of large and complex enterprise applications by dividing the program into a number of independent modules. They can even use a standardized interface to make the individual components communicate with each other seamlessly. Hence, Project Jigsaw contributed immensely towards making Java 9 different from its predecessors.
How Project Jigsaw Makes Java 9 Different from Its Predecessors?
Implements Modularity Design Principle
Project Jigsaw enables Java 9 to compete with modern programming languages by supporting widely used design principle like modularity. While writing applications in Java 9, programmers can divide the single program into multiple independent modules. They can further simplify large application development by deploying the modules as loosely coupled units, providing a unique ID to each module, hiding implementation details, and making the components interact with each other through an open interface.
Introduces a Variety of Modules
While writing applications in Java 9, programmers can work with a variety of modules – application modules, unnamed modules, automated modules, and platform modules. They can create application modules to achieve specific functionality and include the JAR files and classes on the class path in unnamed modules. Likewise, they can create automated modules to export the required packages and access other modules by including the JAR files in the module path. At the same time, Project Jigsaw also divides JDK into a number of platform modules like java.se and java.xml.ws.
Eliminates Need to Install JDK Fully
As noted earlier, Project Jigsaw was started with the aim to modularize JDK. It converts JDK into a modular structure. The programmers can now access and install the required components of JDK as individual platform modules. The modularity further improves JDK’s accessibility and performance across both small and large devices. The small devices can now run Java application smoothly by installing only the required JDK modules. Likewise, the large devices can eliminate memory and storage space constraints by not installing the unnecessary SDK modules.
Resolves JAR or Classpath Problems
Java was not originally designed as a modular programming language. While using earlier versions of Java, programmers have to implement modularity through packages and JAR achieves. The JAR format as effective in unifying Java class files, metadata and resources into a single file. But the programmers lack the option to use JAR for creating independent modules.
Also, the classes and interfaces included in a JAR file depend on classes included in other JAR files to function flawlessly. Hence, developers have to put extra time and effort to check compatibility between JAR files and upgrade dependent modules. Project Jigsaw solves the problems associated with JAR or Classpath by making Java 9 modular,
Removes Common Encapsulation Flaws
Like other object-oriented programming languages, Java also supports encapsulation. It allows programmers to wrap data and code as a single unit. But many programmers find Java encapsulation concepts to be ambiguous. They even explore ways to overcome some of the common Java encapsulation flaws. Project Jigsaw resolves common Java encapsulation flaws by implementing modularity. While writing applications in Java 9, developers can hide both implementation and Public. They can hide the implementation fully while exposing it through interfaces. Likewise, they can Public invisible till it is not exported to module-info.java.
Accelerates Development, Testing, Debugging, and Maintenance
Project Jigsaw will contribute towards keeping Java’s popularity intact over a longer period of time. The standard module system for Java 9 implemented by Project Jigsaw makes it easier for programmers to write large and complex applications by dividing the program into a number of unique modules. Likewise, they can maintain and upgrade the applications quickly by making changes only to the required modules. At the same time, the modular programs can also be debugged quickly due to their decoupled components. The modularity further helps developers to perform unit, functionality, and integration testing during the development process.
On the whole, Project Jigsaw differentiates Java 9 from its predecessors by implementing a standard module system. The Java developers can easily accelerate development, testing, maintenance, debugging, upgrading and deployment by dividing monolithic programs into a number of unique modules. At the same time, Project Jigsaw modularizes JDK and enables users to install only the required components of JDK as platform modules. It further makes Java 9 compete with other modern programming languages by resolving common problems related to JAR files and encapsulation.