A list of new features for the J2SE 1.5 version

By the end of the 2003 J2SE, j2se1.5 's beta version will be released. The release and two updates to the j2se1.4 that have now been released are 1.4.1 and 1.4.2, as expected by the 2003-year JavaOne conference. If you don't attend the conference, or if you want to revisit it, here's a brief summary of the Conference.


J2SE 1.4.1 and 1.4.2 releases

When 1.4.1 (development code "Hopper") was released in September 2002 and its subsequent version 1.4.2 (development code "Mantis") was released as scheduled in January 2003, more than 4,000 bugs were repaired and are still in the process of being repaired.

In the new features of j2se1.5, you will add some of the long-awaited features, such as full support for the Itenium CPU; swing users will see two new built-in look & feels, one Windows XP style, one GTK style At the same time, there are also improvements in start-up time.

Enhancements on the server side consist primarily of two additional GC, a parallel tagging algorithm (concurrent mark and sweep algorithm) and a similar young spatial collection (parallel younger space collector). These two new GC can be invoked through the compiled parameters:-XX:+USECONCMARKSWEEPGC and-XX:+USEPARALLELGC.

Next, how to use these parameters to adjust the best performance of the system is what we need to learn and understand in the j2se1.5.

J2SE 1.5 Release

J2SE 1.5 (Development code "Tiger") is a major change in the Java Platform and language, and currently includes 15 JSR requests and other similar updates. The release focuses on a few key themes: quality, monitoring and management, performance and scalability, easy development, and desktop clients.

Ease of Development (easy development)

You may have heard changes in the Java language that have been made to ease development difficulties. This time the J2SE is based on the requirements of the JSR to implement the following several JSR:JSR 201 contains 4 changes, JSR 175 is the core of supporting metadata (metadata), and JSR 14 is canonical generics.

The metadata feature provides declarative development and replaces the code generation and maintenance capabilities of some tools. Generics promote code reuse without manual transformation (manual casting), and often manual casting can pose some problems with type security.

The other four modifications were:

Use a For loop to traverse the container (Collection type) without requiring an explicit declaration of the container's iterator (iterator);
Enumeration types provide enhanced type security beyond the final static int;
Provides automatic boxing (autoboxing) functionality when using basic data types (primitive Types) in generics (primitive types are not available in the original generics);
The static constants class is introduced to improve the explicit sharing of a static data;
In order to achieve easy development, in addition to language changes, there are some additional things, such as some memory of the printf function will find it back again, a new concurrency tool (mentioned in JSR 166) will make multithreaded programming more simple and easy.


Scalability and performance (scalability and performance))


The J2SE 1.5 will promise improved scalability and performance, especially on boot time and memory footprint (memory footprint), allowing users to publish an application as quickly as possible. Built-in performance Engineering (performance ergonomics) and a powerful API profile tool will be implemented from JSR 163.


Monitoring and manageability (monitoring and management))


Monitoring and management is a major feature of Tiger. Developers who use JMX on the Java EE platform will be happy to see that this feature is implemented in J2SE. Monitoring of the JVM will allow full inspection of the health of published applications, including detection of underlying memory leaks, error handling, and even the monitoring of API stack traces (stack trace).


Core XML Support (kernel XML support))


The introduction of J2SE 1.5 was modified to the core platform of XML, which means that the core API of Java will include Xml1.1,sax 2.0 and Dom Level3. Web service Api,jax-rpc, and JAXB will continue to appear in the Web service package, which will be added to the core API in future releases.


Desktop Client (desktop clients))


The new feature of the final focus is the desktop client. This will bring a few built-in new look & feels support and enhanced support for skin (skins). In addition to the boot speed and memory footprint enhancements, desktop developers have several new features to look forward to.


Unicode 3.1 Support (support for Unicode 3.1))


The 32-bit proxy character (surrogate character) support will be carefully added to the new version, so the 1.5 version will still use the 16-bit char type.


New IO Support (newer IO support))


The new version will provide support for asynchronous IO and support the development of more in-depth use of these APIs in the appropriate place on the platform.


Developers with J2SE 1.4.2 and J2se1.5,java will have an exciting year.