The Eclipse IDE

1
The Eclipse IDE

• Section 10.4 (ALBINGs)
• http//help.eclipse.org/help32/index.jsp

2
Generating Getters and Setters

• Generating Code
• Getters and Setters
• Right click in the editor
• Select Source ? Generate Getters and Setters
• Constructor
• Right click in the editor
• Select Source ? Generate Constructor

3
Other Nice Features

• F3
• Navigating between related classes
• Position the cursor within the referenced type in
  the java editor
• Ctrlo
• Opens a lookup dialog containing a list of
  members in the current java editor
• F2
• gives more details on the selected item
• Ctrl1
• Activates Quick Fix for a warning or error at the
  current cursor position
• Ctrlspace
• Opens a Content Assist list using the enclosed or
  previous word as a ref for finding appropriate
  content suggestions

4
Import a Project to Eclipse

• Remove all .class files from your project folder
• Create a new project
• Type project name
• Select Create project from existing source
• Browse and select your project folder
• Under Default output folder
• Browse
• Click on the Project Name
• Create a new Folder called bin
• Now your project works as if it has been created
  within Eclipse but it may not be under your
  workspace

5
Eclipse Debugger
6
Start a Debugging Session

• Place a breakpoint at any line in the code by
  double clicking on the left hand-side ruler next
  to the desired line
• Right-click the file to debug in Package Explorer
• Debug gt Java Application
• Debug gt Debug in case you want to specify
  command line arguments
• Switch to Debug Perspective
• Window gt Open Perspective gt Debug
• Or click on Switch Button
• Should see the following views
• Debug
• Variables
• Expressions
• Code
• Console
• Window gt Show View to add a missing view

7
Creating Breakpoints

• Can create breakpoints to source at any time
• If you run program in debug mode prior to adding
  the breakpoints
• Program proceeds as if it is running normally
• Debugger has no effect
• Unless the program is waiting for input
• Need to add to breakpoints in Java Perspective
• Breakpoints can be added by double-clicking in
  the left ruler beside a line where you want a
  breakpoint
• Breakpoints can be removed by double-clicking them

8
Debug View

• Shows one or more stack frames for the given
  thread
• A stack frame shows the execution context
• containing local variables and arguments
• for the method call on that position of the call
  stack
• Note the Current Instruction Pointer in the code
  view which highlights the statement that will be
  executed next
• The Debug Call Stack
• Marks the line where the selected stack frame was
  suspended

9
Stepping Through Execution

• Look above the Debug View
• Resume (cont in jdb)
• Resumes execution until it either ends or
  encounters a breakpoint
• Suspend
• Inactive if the your program is already suspended
• Terminate
• Stop the Java VM
• Other step commands which are relative to the
  selected stack frame in Debug View

10
Stepping Through Execution

• For all following commands, the current line of
  execution in the selected frame is highlighted in
  the code editor
• Step Into(step in jdb)
• For method invocations
• Creates a new stack frame
• Invokes the method in the statement
• Suspends execution on the first statement in the
  method
• For other statements
• Like assignments and conditions
• Works like a Step Over
• Step Over (next in jdb)
• Executes current statement and suspends execution
  on the statement after that
• Step Return(step up in jdb)
• Resumes execution to the end of the current
  method
• Suspends execution on the statement after the
  method invocation or until a breakpoint is
  encountered

11
Variable View

• The Variable View shows fields, local variables
  and method parameters for the selected stack
  frame
• Selecting any of those variables displays its
  value
• At the bottom of the Variable View
• If the variable is an object as opposed to a
  primitive
• Can also be expanded to view member variables
• which in turn can also be expanded if appropriate

12
Expressions View

• Accumulates references to several expressions
  that one needs to watch while debugging
• A watch expression displays the result of a java
  expression that is reevaluated each time a thread
  is suspended
• Right-click in the Expressions View and choose
  Add Watch Expression to create a new entry
• catalogue.getItems.size()

13
Breakpoints View

• Provides a list of all breakpoints set in your
  workspace
• Allows you to enable, disable, remove one or all,
  and set conditions on the breakpoints
• Can Add Java Exception Breakpoint by clicking on
  J! icon in the Breakpoints View toolbar
• When you dont know what code is causing an
  exception to be thrown
• Debugger suspends at the point before the
  exception is encountered
• E.g. when debugging other code and you get an
  ExceptionX, dont bother looking for it, just
  enable the ExceptionX breakpoint

14
Breakpoints View

• Right click on any breakpoint to see options
• Select properties
• Hit Count
• Enable Condition
• Enter a Java expression that will be evaluated at
  runtime using fields or variables available at
  this breakpoints position in code
• Condition is true
• E.g. if (catalogue.getItems().size()6) return
  true

15
Hot Code Replacement

• Ability to change code in the midst of a debug
  session without stopping or restarting the Java
  VM
• Replacements work only when the signature of
  existing classes dont change
• Add a new class
• Change the body of a method
• Dont add or remove fields to existing classes or
  change their types after those classes are loaded
  in the VM
• Dont add or remove methods to existing classes
  or change their signatures after those classes
  are loaded in the VM
• Dont add or remove inner classes