Java technology, IBM style: Introduction to IBM Developer Kit

The IBM Developer Kit for the Java platform version 5.0 marks significant progress, with significant improvements in language features and low-level execution techniques. This article is the first in a 5-part article series that outlines some of the major changes and improvements IBM has made to its virtual machine technology, including traditional garbage collection, shared class data, and improvements in monitoring and debugging tools and APIs. However, before we discuss improvements to the IBM implementation, let's look at the improvements in Java 5.0 itself.

Improvements in Java 5.0

Since the introduction of the Java 2 platform, the Java 2 Standard Edition (J2SE 5.0) has introduced Xu in the Java Class Library (JCL) API and Java Virtual machine (Java dummy MACHINE,JVM) specification Multi-feature improvement. These features are available in all 5.0 implementations of the Java technology implementation vendors. They cover two areas: simplification of development and monitoring and management.

Features of simplified development

The simplified development features in version 5.0 are designed to help developers identify problems earlier in the development cycle by enabling developers to build simple constructs with fewer code and by providing more compile-time checks. The following is a brief introduction to these features:

Provide compile-time type security with generics: Generics are similar to C + + templates. Generic (that is, generics (generic)) classes are independent of specific types and provide type security by using parameterized types (parameterized type) when instantiated. The use of parameterized types and generic classes enables compile-time type security checking, which is used by collection classes in the Java 5.0 platform.

Extended for Loop: This new language construct is similar to the For Each loop in other languages, simplifying the process of looping through collections and arrays because you no longer need to use explicitly defined iterators and index variables.

Automatic boxing of native types: This feature simplifies the process of inserting a native type into a collection object because the Java native type (such as int) is no longer required to be boxed into the corresponding wrapper class (such as Java.lang.Integer), and it is not necessary to remove them (unbox).

Type-Safe enumeration: This feature introduces the Java language's support for enumerated types, providing a more powerful and type-safe solution than using static final declarations.

Support for import constants: This feature enables static methods and fields to be imported so that you do not have to use the fully qualified class name when accessing static members.

Java Language Metadata (callout): This feature allows developers to add annotations (annotation) to the code. Annotations, as modifiers, can be added to a package, class, interface, method, or field declaration. This information is stored in source code files and class files, and tools and Java applications can be obtained through the Java Reflection API. This additional information can be used by tools for document preparation, compiler checking, and code analysis.

Concurrency tools: This feature provides a basic building block for developing concurrent classes, including a collection of thread pools and threads security, and introduces low-level locking primitives, including semaphores and atomicity variables.

Monitoring and managing features

J2SE the new monitoring and management features are designed to simplify monitoring of the state of the Java runtime. You can use the monitoring and management APIs to invoke these features from Java code, or use JVM Tools Interface (JVMTI) to invoke from C code:

Monitoring and Management APIs: This feature enables a Java program or remote agent to monitor the "health state" of a virtual machine and observe other system-level activities and events. These features can be used to develop autonomous and adaptive systems.

JVM Tools Interface:jvmti is a lighter, flexible JVM Profiling Interface (JVMPI) Alternative, a C-based interface for writing development-time and run-time monitoring tools.

Value-added improvements from IBM: overview

The specification and API enhancements added through the Java compiler, JCL API, and JVM specification in 5.0 affect all new implementations of the Java platform, and allow Java vendors to develop and deliver their own value-added improvements in their Java implementations. IBM offers its own improvements in two ways: the Java language extensions developed by IBM and the improvements in the IBM implementation of the Java Runtime environment.