Performance DW at JavaOne: Next Wave--Java 1.4
Original English
content:JSR's deletion in version 1.4 The XML API is developing too fast. User has a parameter selection assertion training record New World "N" represents "new" database library arrives kernel into required authentication path using WebStart's quick Start "Tiger" eyes beyond the JSR consider turning to 1.4 reference Data on the author's evaluation of this article
Related content:A three-way solution for identifying users use the generic to find more errors at compile time Merlin's Magic: Swing's new Spinner component upcoming release performance and new features at a glance
John Zukowski (jaz@zukowski.net)
President, JZ Ventures, Inc.
June 2001
The
javaone 2001 meeting has several agendas to describe the new features of the recently released Java beta version 1.4. In this article, we focus on some of the agendas in the meeting and the performance of the new version.
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Graham Hamilton, who is the leader of the J2SE Merlin release specification, provides an overview of the new performance of the recently released Java 1.4 beta. In the details of his agenda and other agendas, developers can confidently start moving their development work to the world of Merlin, which is expected to complete this release at the end of the year.
Deletion of Eenie, Meenie, Minee, MO:JSR in version 1.4
Quality first, number two, version 1.4 will bring some long-awaited performance to the Java platform. Java Specification requirements for Merlin (JSR-059) Integrate some of the other JSR through the Java Community Process (JCP). If the debugging is stable, the JSR will step into the published version. The JSR includes:
- JSR-005 XML Syntax Analysis
- JSR-010 parameter Selection API
- JSR-031 XML Data Binding
- JSR-041 A simple assertion tool
- JSR-047 Logging API
- JSR-051 New IO API
- JSR-054 JDBC 3.0
- JSR-055 Authentication Path API
- JSR-056 Network boot API
- Long-term sustainability of JSR-057 JavaBeans
- JSR-063 XML Processing
IBM Reference
To give you more background on the meeting, take advantage of these rich references-papers, case studies, tools and DeveloperWorks, Alphaworks, and all IBM tutorials-grouped by a group of similar meeting agendas.
Some features have not been released, either because they are not ready, or because the JCP community feels that the JSR is not suitable for a broad Java development community. The JSR that is not included is:
- JSR-014 adding generic types to the Java programming language
- JSR-031 XML Data Binding specification
- JSR-051 printf/scanf Performance
- RMI Security of JSR-076 J2SE
- JSR-078 RMI Custom Remote Reference
The XML API is developing too fast.
XML support for Merlin is actually going backwards. Because XML technology is still evolving, we use the current stable JAXP API in version 1.4. Future XML APIs are provided as standard extensions like the JAXP API now.
This means that Merlin can provide SAX 1.0/2.0, DOM 1.0/2.0, and XSLT support, but does not provide support for XML messaging (JAXM), XML Registry (JAXR), or other Jax mentioned in many meetings. Xmlencoder/xmldecoder can be used for long-term JavaBeans sustainability.
User has a parameter selection
The new parameter selection API adds the ability to easily store and recover User Configuration data and application configuration data. To replace the Properties class with lightweight and thread-safe mechanisms, Sun Engineer Josh Bloch provides a preview of a new library that provides backup storage similar to the specific execution of the Windows registry.
Language-Level assertion training
At the meeting, Bloch was also busy describing the only language-level feature implanted in version 1.4, which asserts that the tool has a new assert keyword.
Assertions can add Boolean checks to the code, which can be started once it is required to ensure that the program is correct. For example, you have a
If-elseprogram block, where integers can only be "1", "2" or "3", and the last
ElseThe program block may not check "3". You can add an assertion to ensure that it is "3", as shown in Listing 1.
By default, assertions are disabled, but the assertion can be initiated with a dedicated command-line switch to ensure that the environment is correct when the user is creating a problem.
Listing 1. Using the Assert keyword
if (foo = = 1) {}
else if (foo = = 2) {}
else {assert (foo = = 3);}
Record a New World
The new recording tool in version 1.4 is presented by Graham Hamilton on a separate agenda in the morning of Thursday. Tools provide different record-level processing with a custom formatter using a single system-wide record manager. This useful small API can be stored, for example, up to 500 information in Foobar.xml files formatted with XML (see Listing 2).
Listing 2. The logging tool processes the custom record level
Logger Logger = Logger.getlogger ("Com.ibm.utils");
Logger.log (level.warning, "message", exception);
This new tool does make the future of the widely acclaimed open source log4j package uncertain. Of course, it is still used by version 1.4 of the previous Java language version.
"N" stands for "new"
In Merlin, the simplest name package is the new I/O library, which is in the Java.nio package. Yes
NRepresents a "new". ）
Sun Engineer Mark Reinhold describes the functionality of the new library on the June 4 agenda. You get a simple buffer that is set for the original type, character set encoder and decoder, and the regular expression and pattern matching tool for Perl. But the most interesting feature of the new library is memory-mapped files and non-modular I/O.
Database libraries reach the kernel
When using the Kestrel release (version 1.3), there are some libraries on the standard Java platform and several extension APIs. In Merlin, all of the extended database APIs are considered kernel APIs.
Finally, compared with other, CachedRowSet is standard. The Wednesday meeting elaborated on these new features, and the people who chaired the meeting were called John the Jonathan Bruce and Jon Ellis of Sun, and John Goodson of Merant.
Note: To support JDBC 3.0, a small portion of the Java transaction API (JTA) needs to be added to the kernel library.
Enter the required authentication path
The new authentication path API is part of a series of security changes that are added to Merlin. As a result of new and looser U.S. export restrictions, security APIs that were previously selectable and not available in most countries are now standard on the Java platform.
In the standard Merlin kernel, you get the Java Cryptographic Extensions (JCE), the Java Secure Sockets extension (JSSE), and the Java Authentication and authorization Services (JAAS) APIs. You will also get Kerberos V5 support under the Java Common Security Services Application interface (GSS-API).
Using WebStart's Quick start
Merlin adds a network-initiated Java WebStart product to the standard collection of deliverables. While you can tag small applications to get rid of Java sandbox (if you want to keep small applications in your browser), WebStart allows you to start a mature application that allows users to cache programs on the client side without having to download them every time you run the program.
Several agendas introduce the most important parts of the product. Sun Senior Engineer Rene Schmidt describes the most technical overview of product performance, and other agendas compare this technology with other client options like JavaServer Pages and Java plug-ins.
"Tiger" eyes.
Java 1.4 Adds some new performance on the Java platform. Next comes the Java 1.5 platform code-named "Tiger". Assuming the release cycle is 18 months, we look forward to seeing similar generic features in the new version sometime in 2003.
Gilad Bracha briefly introduces the implementation of the prototype currently available, essentially by adding a type-safe collection and canceling the need to perform styling when retrieving elements (from the collection). (See Resources for a recent article on DeveloperWorks.) ）
It is a good thing that the type checking of generic genera is moved to compile time and no longer in real time. As shown in Listing 3, they make the code much simpler.
Listing 3. The generic code becomes concise .
public static void Main (String args[]) {
... list<string> list = arrays.aslist (args);
String head = list.get (0);
.}
Another expectation for "Tiger" is the scanf/printf format tool, which is not included in the Merlin I/o change.
Beyond the JSR
All 1.4 library changes are not generated by a separate JSR. As Hamilton concludes, many of the new changes are only addressed on individual agendas or occasionally mentioned on other agendas.
For example, Java 1.4 will support IPV6, but it needs to support its operating system (such as Windows XP or Solaris 8). At the same time, Bloch hosted a BOF on the collections Framework, which describes the functions of the new library: 3 new execution methods in the collections class, a markup interface, and 6 new branches Holding method.
Consider turning to 1.4
If it is a cutting-edge and cutting-edge project and is expected to be released within 6-9 months, please consider turning to the Java 1.4 platform. This upcoming release contains several features that developers are looking forward to. For more information on how to use these new features, read the new I will soon open in the DeveloperWorks Java technology Zone
Merlin's magic.Column.
By the way, if you're looking for a slide show for the meeting, Sun seems to be trying to make some money from 2.5 million Java developers who didn't attend the meeting. You may have to wait until June 17, 2001 to browse http://java.sun.com/learning to get information.
Of course you have to pay about 30 dollars for each agenda, or you can spend 1,500 dollars to get information about the whole meeting. Students enjoy a 40% discount.
Resources
- For more information on the changes to the Merlin version, see the new features and enhanced overview documentation that comes with the developer suite.
- For more information about security and the Java platform, see the article in Joseph Sinclair: "A three-way solution to identify users" (developerworks,2001 June).
- LOG4J provides fast and efficient recording services.
- For more information about open source APIs, check out the log4j home page, which is part of the Apache Jakarta project.
- In this March 2001 DeveloperWorks article, Keith Turner studied the use of the generic to find more errors at compile time.
- IBM Education provides your classroom and satellite guidance on the cutting-edge implementation of the Java language.
About the author
John Zukowski for JZ Ventures, Inc. for strategic Java Consulting. His latest book is Apress.
Java CollectionsAnd
definitive Guide to Swing for Java 2(2nd edition). You can contact John via jaz@zukowski.net.
