The Eclipse IDE

The Eclipse IDE
An Introduction

Prof. David Bernstein
James Madison University

Computer Science Department

bernstdh@jmu.edu

Integrated Development Environments (IDEs)

Defined:
- A tool that provides integrated capabilities for the development of software
Common Capabilities:
- Source code editor
- Debugger
- Build tools
- Document management
Categories:
- Student-oriented (e.g., jGRASP, Dr. Java)
- Professional (e.g., Eclipse, NetBeans, IntelliJ)

Integrated Development Environments (cont.)

Two Observations:
- Most professional IDEs have similar capabilities
- Most professional IDEs differ in "important" ways
An Implication:
- Most people have a favorite IDE and are staunch supporters of it

The IDE for this Course

Which One?
- Eclipse
Why?
- No particular reasons except that it is free and available on all major platforms

From Student-Oriented IDE to Professional IDE

Why Now?
- A professional IDE will make you more productive (and you'll be writing a lot of code)
Downsides:
- Professional IDEs have a "steeper learning curve"
- Professional IDEs assume a level of understanding of programming and the language that you may not have yet
Implications:
- Spend some time becoming familiar with Eclipse right away
- Think before you click (i.e., don't work for Eclipse, let Eclipse work for you)

From Student-Oriented IDE to Professional IDE (cont.)

Important Differences:
- Project-oriented
- Oriented towards large code bases
- Dynamic compilation
- "Intelligent" completion
Implications:
- You may need to change the way you think
- You may need to change the way you work

Project Orientation

What It Means:
- Code is organize based on the product or library it will be a part of
What It Means for You:
- You will need to create a project for each programming assignment and each lab
- You may need to have multiple copies of the same code if it is used for different programming assignments and/or labs
- You will need to backup entire projects (if you don't have a systematic way to backup your entire hard drive)
- It will be hard for you to move a project from one machine to another

Large Code Bases

What It Means:
- Eclipse uses a complicated scheme for organizing source code and byte code that is appropriate for large projects
What It Means for You:
- Until you understand packages you must manually put your code in the default package (and Eclipse will complain)
- It will be difficult for you to work from the command-line (i.e., you will have to work from within Eclipse almost exclusively)
- It will be much easier to change the names of variables and classes

Dynamic Compilation

What It Means:
- Eclipse will compile your code (to check for syntax errors) and analyze your code (to check for style errors) while you type
What It Means for You:
- You must think more carefully about different kinds of errors
- You must not rush to correct "mistakes" that are highlighted by Eclipse because they might just be things that you haven't gotten to yet

"Intelligent" Completion

What It Means:
- Eclipse will try to reduce the amount of typing that you need to do by completing things for you
What It Means for You:
- Because you make unsophisticated mistakes, the advice is often wrong and/or confusing
- The order in which type can have a dramatic impact on your productivity (e.g., if you type the signature of a method before you type the comments it will scaffold the comments for you)
- You may not need to use a browser to read the API documentation

A Warning

An Observation:
- "Techies" have a tendency to become obsessed with gadgets
A Consequence:
- Programmers have a tendency to become obsessed with tweaking their IDEs
What This Means for You:
- You can trick yourself into thinking that you're being productive when, in fact, you aren't

The Parts of an Eclipse Window

The Parts of an Eclipse Window (cont.)

The Parts of an Eclipse Window (cont.)

The Editor Area and Editors:
- The editor area can (and usually will) contain multiple tabbed editors
- Each editor is for a single source file
- Editors use color syntax highlighting and include the ability to "fold" the code in various ways
The Tool Bar:
- Contains buttons to save, run and debug the code (among other things)
- Does not contain a button to compile the code since it is compiled dynamically

Creating Projects and Classes

Creating a Project:
- File+New+Java Project
- Remember to un-check "Create module-info.java" (or, if you forget, click on Don't Create when asked for the name of the module)
Creating a Class:
- File+New+Class
- Until we discuss packaging, you must put the class in the default package (i.e., the "Package" field must be blank) even though Eclipse will warn you that "The use of the default package is discouraged"