Download JavaOne 2002

JavaOne 2002
http://servlet.java.sun.com/javaone/
Greg White,
March 24-29th 2002
Content
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J2SE
Interoperability with XML based protocols
Real-time java
Performance tuning
References to Best picks
Greg White, ESD
J2 Standard Edition (J2SE)
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The basic (default) Java package, freely distributed
Now in v1.4. Stability, scalability, compatibility
Includes V1.3 of Java2D ~ 100% faster than v1.2, X support 4-5 times faster
Includes CORBA
“New I/O”. Much faster IO, file/screen/socket, abstract data type buffer
manipulation
1 VM : many threads on many cpus.
64bit clean, now in Spark, soon on itanium.
Logging API included. Simple assertion.
Exception chaining
Core XML support bundled, include JAX*, SAX, DOM
Connectivity: IPv6 addressing, new URI class.
Security: JSSE Secure Socket Extension (ssl, HTTPS), kerberos
Greg White, ESD
J2SE continued
• JFC/Swing gives full drag and drop.
• Deployment: Web Start now in SDK
• v1.4.1 (autumn)
– >1 VM Sharing loaded libraries, so SHR, GBL
• v1.5 (late next year)
– Templates!
– Compiler conversion of primitive types
Greg White, ESD
Interoperability XML based Protocols
(“Web Services”)
• WSDL, defines a “service” in XML, CORBA like
– SOAP, MIME, http bindings. W3C Spec and Example
• UDDI (Universal Description Discovery Integration)
– A standard for Name and Directory services
• JAX-RPC, can be used to implement the service according to the
WSDL with SOAP implementation
• JAXP, Parses XML, both SAX and DOM. It’s a XML implementation
independent layer and API for XML document processing.
• JAXR, Access to XML based registries, like name or directory
services.
• JAXM, An API for XML based messaging.
• JAXB, Maps XML tags and types to Java language types
Greg White, ESD
Why Might Web Services be Important
to Us down the line?
• If we package application data in XML
• E.g. in SDDS like model
App
XML format data
X-bean
BPM data
Web
JAX-RPC
Servlet
Greg White, ESD
Why Might Web Services be Important
to Us down the line?
• If we package application data in XML
• JAXP for parsing, JAXM for messaging, JAXB for
mapping XML data to objects
App
Web
XML format data
SOAP/
WSDL
JAXM X-bean
Dir/Svc
BPM
UDDI
AIDA
EPICS
History
Servlet
Greg White, ESD
Real Time Java
• RTSJ - Real Time Specification for Java
– Predictable execution > fast execution: “Real Time != Real fast”
– No syntax extensions, but more APIs and Extensible Classes
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Scheduler class
Timer class
Asynch event handling
Asynch Transfer of Control (ACT) like setjmp/longjmp
High resolution time (~1ns)
– Objects not managed by regular Garbage Collection
• “Immortal Memory Area”
• Physical memory control
– Ref: http://www.rtsj.org
Greg White, ESD
RT Java con’t
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Tools for smaller class
– Jopt, JAX, DashO, javac -g:none
Implementations
– VxWorks implementation: Insignia Solutions impl of Personal Java
(PersonalJ) http://java.sun.com/products/personaljava/
– jStamp: HW aJile chip and PS. 1x2in, DIP40 pins
http://jstamp.systronix.com/
Talks:
J2ME in Lindholm Tech Keynote
RT Java in Deeply Embedded Sys: TS-3190
Greg White, ESD
Performance Tuning
• Do’s
– Architect to call-by-reference (ie use reference types)
– Avoid JNI if Java enabled database driver
– Threading
• Size thread pool appropriately
• In v1.4 1 JVM/cpu can manage >1 thread (because Java/JVM threads
!= kernel threads).
• Use thread monitoring tool (Hpview).
• Kill -QUIT on JVM will give you a thread dump
– Hotspot:
• Choose carefully between “-client” and “-server”
• Use -verbose:gc to see what its doing. Resize generations (“eden” and
“old”) wisely
• -Xincgo for better pauses
• -? For better throughput
• Try bigger heap (-Xmx), or bigger new generation
Greg White, ESD
Programming for Performance
• Array sizing: Size array in declaration (otherwise it does dbgetc-like
remalloc).
• Don’t use exception based flow-control (!)
• Use New I/O buffer classes for array manipulation
• Minimize object creation - do it at init. Pool objects. Design methods
to modify existing objects, not create new ones.
• Avoid synchronization
• Avoid serializing
• Understand how lib methods work.
• Use external caching support (eg HTTP Cache-control tags)
• Use long instead of java.util.Date
• Use arguments and locals in preference to member variables
• Use char array instead of StringBuffer
• Use db connection pooling
Greg White, ESD
Best Picks
• Graham Hamilton, Tech Keynote
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http://servlet.java.sun.com/javaone/sf2002/conf/keynotes/index.en.jsp
Optimizing for the Java(TM) Servlet API and Java DataBase Connectivity(TM)
(JDBCTM) Technology TS-1355. Speakers: Tim Kientzle
– Performance optimization tools, what to look for, practical actions for improvement
A Programmer Survivor's Guide for Java(TM) Technology, Using Mature Programming
Practices, Patterns and Principles TS-2758
Performance Tuning for 'Big Iron' TS-2008
The Java(TM) 2 Platform, Standard Edition (J2SETM) 1.4 Release and Beyond TS1756, Speakers: Graham Hamilton
Best Practices for CORBA TS-1663 Speakers: Ken Cavanaugh,Hemanth Puttaswamy
New I/O APIs for the Java(TM) Platform TS-3477, Speakers: Mark Reinhold
Performance Technologies for the Java(TM) Platform, for Deeply Embedded and RealTime Systems TS-3190
An Introduction to the Java(TM) Native Interface (JNI) TS-2253: Speakers: John
Chamberlain
The Java(TM) 2 Platform, Enterprise Edition (J2EETM) Tutorial TS-1715
Speakers: Stephanie Bodoff,Dale Green,Kathy Walrath
Greg White, ESD