Java Resources

COMP 310 Java Resources Eclipse Resources

Having problems running Java, e.g. blocked by security settings? See the Java Tips and Traps page!

This page is a collection of general resources on the Java language.

Quick Links:

JDK installation instructions The Java JDK must be installed FIRST!
Java Language
UML Diagrams and OO Design Techniques
Design Patterns
GUI Programming
Performance Profiling
Geographic Information Systems (GIS)
Java Tips and Traps -- Problems? Look here first!
Java How-To's -- Solutions to various Java coding tasks.
Distributed Systems
- Server vs. Microservice Architectures
- Synchronization of Distributed Data
Misc. topics

The main site for Java is http://www.oracle.com/technetwork/java/index.html

The course always uses the latest version of Java, so be sure that you have updated your JDK!

Legacy Note for 64-bit System Users

Since applets and Java Web Start (JNLP files) are no longer supperted at all in the latest Java versions, the following is only for legacy situations and not applicable for most current Java installations.

Java Web Start (JNLP) applications for Java 11+ can be run using OpenWebStart.

Java support for applets (Java programs that run in web browsers) is problematic in 64-bit browsers, e.g. they will not run at all. Installing a 64-bit JDK does NOT install Java support in the 32-bit browser in 64-bit operating systems. Since the 32-bit browser is usually the default browser, this can cause problems in displaying the on-line demos for Comp310 and displaying applets in general.

In Windows Internet Explorer 8, you can tell if Java is installed in the browser correctly by going to Tools/Internet Options/Programs/Manage Add-ins and seeing if the "Java(tm) Plugin 2 SSV Helper" is installed.

To run applets in the usually, default, 32-bit browser, you must install the 32-bit JRE (you don't need the entire JDK), which you can obtain here: http://www.java.com/en/download/manual.jsp

If you are having trouble running applets in the the 64-bit browser, e.g. it fails the verification below, try reinstalling the 64-bit plugin from the link above.

Windows 10 users running the Microsoft Edge browser: Edge does NOT run Java applets, so you will have to switch to Internet Explorer to run the on-line demos in the class web pages: On any page in Edge, go to "More Actions" and select "Open with Internet Explorer".

Problems Running Java?

Java Language

Documentation -- Java SE Docs home
- Standard Edition 16 API documentation: https://docs.oracle.com/en/java/javase/16/docs/api/index.html -- May NOT be the latest version! If not, browse for the latest API docs through the docs home page link above.
- General Standard Edition documentation: http://www.oracle.com/technetwork/java/javase/documentation/index.html
- Java Language Primer (Connexions module): http://cnx.org/content/m11791/latest/
- Javadocs: Code commenting in Java
  - Sharing generated Javadocs
Language Issues
- What's new in Java 8
- Anonymous, Inner and Nested Classes
  - Inner and Nested Classes
  - Anonymous Inner Class Techniques
- Closures
- Lambda Functions
- Java Generics
- Threads -- including Producer-Consumer models and multi-thread synchronization
  - Cross-Thread Invocations onto the GUI Thread
  - Threading Issues
- Dynamic Class Loading
- Serialization
- No static Fields or Methods!
Remote Method Invocation (RMI)
- RMI connectivity issues
Java How-To's (Miscellaneous tips and techniques for common tasks)

Java Development Kit (JDK) Installation

Download and install the latest Java Standard Edition (SE) JDK: http://www.oracle.com/technetwork/java/javase/downloads/index.html
- Install the 64-bit version unless you have very special circumstances!
- If you have a 32-bit operating system, download the 32-bit version, referred to as "x86" or just plain "Windows".
- If you have a 64-bit operating system, you can install either the 32-bit or 64-bit (referred to as "x64") systems.
  - Whatever version you install, be sure to install the same version of Eclipse and any associated plug-ins!
  - Even on 64-bit operating systems, most browsers use a 32-bit JRE to run applets (on-line demos). This means that in addition to the 64-bit JDK, you must ALSO install a 32-bit JRE (not JDK!) for the browsers to use.

Notes for Mac users:

JDK 1.8 issues:

Java ver 1.8 may not be installed in the Mac OS, but JDK1.8, which will also install the JRE, is available as a download from the above Java download links.
JDK 1.8 requires at least "Mountain Lion" OS 10.8 -- If you do not have this....upgrade!
Instructions from Oracle: JDK 8 Installation for OS X
After installing, Eclipse may not automatically recognize that the 1.8 compiler and JRE are installed. Please see the instructions here.

Other potential issues:

The Java JDK is pre-installed on OS X, though perhaps not the latest version available directory from Sun/Oracle. See, for instance, Apple's FAQ's on Java: http://developer.apple.com/java/faq/
OS X, if 64-bit capable may have both 32-bit and 64-bit JDK's installed, but the default is to run the 32-bit version. See, for instance, http://developer.apple.com/java/javaleopard.html
Java updates are part of the OS X updating mechanism but are not automatically updated.
ApApple does not make Java download available to the general public. You have to be a registered Apple developer to get some Java downloads.

Notes for Linux users:

Instructions from Oracle: JDK 8 Installation for Linux Platforms

UML Diagrams and OO Design Techniques:

Class Diagrams, aka "UML Diagrams" -- static relationships between classes
- Connexions module on UML diagrams: http://cnx.org/content/m11658/latest/
Design Process:
- Design Process Overall Guidelines
  - API Design and Evaluation Considerations
Use Case Diagrams

Use Case Diagrams -- User-centric, implementation-independent view of the system in terms of what is being done.
- https://creately.com
  - Use Case Diagram Tutorial ( Guide with Examples )
System Block Diagrams -- Decomposition of a system in terms of decoupled modules.

Sequence Diagrams -- Time-dependent interactions between objects.
- https://creately.com
  - Sequence Diagram Tutorial: Complete Guide with Examples
  - The Basics & the Purpose of Sequence Diagrams (part 1) (part 2)
  - Beyond the Basics of Sequence Diagrams (part 1) (part 2) (part 3)
  - 10 common mistakes to avoid in sequence diagrams
- http://en.wikipedia.org/wiki/Sequence_diagram
- http://www.agilemodeling.com/artifacts/sequenceDiagram.htm
- http://www.ibm.com/developerworks/rational/library/3101.html
- http://www.tracemodeler.com/articles/a_quick_introduction_to_uml_sequence_diagrams/
- Quick diagram syntax reminders:
  - Message arrows, labeled with their semantic:
    - Synchronous message: solid line + solid arrowhead
      - Return response: dotted line + open arrowhead
    - Asynchronous message: solid line + open arrowhead
  - Optional or if-else operations: Surrounded by a labeled box which might be sub-divided to show multiple options.
  - Race conditions
    - Simple race condition example diagram
- Example diagrams:
  - IMPORTANT: The following diagrams do NOT use a pub-sub system for data synchronizations, the use of which would markedly change the protocols used for the protocols being described! These diagrams are strictly for illustrating sequence diagrams ONLY!!
    - team joining process
    - RemoteException Handling with Asynchronous Messaging and a Central Truth Server
Component-Framework Systems -- Decomposition of a system into an invariant framework controlling variant plug-in components.
Diagramming Tools: (for tools integrated with Eclipse, please see the Eclipse Resources)
- Creately.com -- Free on-line tool that makes most types of diagrams.
Industry Buzzwords -- Common busswords and acronyms that you may encounter in industry and what they mean.

Design Patterns:

OpenStax (Connexions) General Resources
- OOP/D-related modules by Dr. Wong
  - Design patterns-related modules by Dr. Wong
Quick links to some of the OpenStax (Connexions) modules:
- Abstraction
- Abstract Factory Pattern
- Adapter Pattern
- Command Pattern
- Composite Pattern
- Decorator Pattern
- Model-View-Controller
  - Easy MVC Creation using Anonymous Inner Classes
  - How To Make Mini-MVC's Inside a Main MVC
- Null Object Pattern
- Oberserver-Observable Pattern
- State Pattern
- Strategy Pattern
- Template Pattern
- Union Design Pattern (see also: http://cnx.org/content/m11796/latest/ )
- Visitor Pattern
  - A nice article written by a Rice almuni. (the broken "alma mater" link in the article is referencing the above Visitor Pattern link.)
Portland Design Pattern Repository -- descriptions of the standard patterns plus some new ones.

GUI Programming

Java GUI Programming Primer
Setting the behavior of closing a frame
Animations in Java
Tool tips: All JComponent's have a method called "setToolTipText(String text)" that will cause the component to display a pop-up text message when the mouse is held over that component. This is very useful for giving the user information on what that component is for.
Cross-Thread Invocations onto the GUI Thread
Dynamically Modifying GUIs

Performance Profiling

Sometime you need to investigate how well your program is running in terms of speed, threads and memory usage. A "profiler" is needed to do this and can be invaluable in both debugging difficult problems such as performance issues, memory leaks and excessive thread usage, as well as for focussed performance optimizations.