Programming Tools

Eclipse

JUnit Testing

make and ant

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Development Environments• Command line

– gvim/emacs– javac– java

• Integrated Development Environment– provides access to all the tools from a

single interface– Eclipse (3.3.2)

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Eclipse• "universal tool platform"• Developed by IBM

– Now an open source project• http://www.eclipse.org/downloads

• Primarily a development environment for Java– written in Java– Extendible

• Plug-ins can be added to support new functionality and other languages

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Eclipse Workbench• Provides the basic graphical interface• Divided up into views

– Navigator shows all projects– Editor has panes for all open files

• Views are organized into perspectives– a perspective contains a set of views that

are needed for a particular task• Java perspective• debug perspective

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Command Line Arguments in Eclipse

• To use command-line arguments, you need to create a Run Configuration for the project.

• From the Run menu (or the Run drop-down), select Open Run Dialog

• Create a new Run Configuration (or modify an existing on for the project)– Click the Arguments tab– Type the desired command-line arguments into

the Program Arguments text box– Click Apply and then Run

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IO Redirection in Eclipse

• Append the redirection operators to the command-line arguments

• Create a script to use as an external tool

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JUnit Testing

• JUnit is an open-source testing framework for Java– facilitates the writing of test cases

• You can create test cases and test suites by extending the appropriate class from the JUnit package

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JUnit Testing

• JUnit has been integrated into Eclipse

• Make sure junit.jar is on the build path– use the Properties menu– or let Eclipse find it when you create the

test case

• Create a test case– File -> New -> JUnit Test Case

• Run your application as a JUnit Test

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In the TestCase class

• Write methods that test each of the methods of your class– use the assertion methods on next slide for

testing results of methods

• You can override setup() and teardown() to create a set of objects to be shared by several tests

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Assertion methods

• assertEquals( expected, actual) for primitives

• assertFalse( condition), assertTrue(condition)

• assertNull( object), assertNotNull( object)

• assertSame( ecpected, actual), assertNotSame(expected, actual)

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Sources of Information

• The home page for JUnit is at http://www.junit.org/

• The documentation is at http://junit.sourceforge.net/javadoc/

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Debugging

• Compile time– Compiler forces your code to have correct

syntax

• Run time– How do you figure out what is wrong with a

program that isn't running correctly?– What information do you need?

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Debuggers• A debugger is a tool that is designed to help

you figure out what is going wrong in a program.

• Useful functionality– Start the program and have it stop just before

where you think the error occurs– Look at (and modify) variable values– Look at the call stack– Step through parts of the program one line at a

time

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Debugging in Eclipse• The debug perspective provides the

views needed for debugging.– Debug view – Variable View– Breakpoints view– Expressions view– Editor view– Outline and Console views are the same

as in the java perspective

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Debug View• Shows stack frames for any programs

currently being debugged• Buttons allow you to

– Resume - start from current instruction and continue to next breakpoint or end of program

– Suspend (e.g. for infinite loop) – Terminate stops the program– Remove all terminated launches

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Editor View• Essentially the same as in the Java

perspective• Breakpoints are marked at the edge of

the frame– Left click and select toggle breakpoint

• An arrow marks the next statement to execute

• Hovering mouse over a variable name will show its value

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Breakpoints

• A breakpoint is used to mark lines of code where you want the program to stop.– Once the program stops, you can examine

all the variables

• Breakpoint view shows all breakpoints and allows you to manage them– Disable, enable, remove, remove all

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Other kinds of Breakpoints• Watchpoints - suspend when the program is

going to change an instance variable– Run-> Add/Remove Watchpoint

• Method breakpoints - suspend on entry to or exit from a method– Run-> Add/Remove Method Breakpoint

• Exception breakpoints - suspend on a particular Exception– Run-> Add/Remove Exception Breakpoint

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More on Breakpoints• You can set breakpoints with hit counts

– program stops when the breakpoint has been reached the specified number of times

– Right-click on the breakpoint in the breakpoint view

• You can also set a breakpoint to trigger– when a variable changes– when a Boolean expression is true

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Stepping through code

• Step into goes into the code of a method that is being called

• Step over executes the entire method call

• Step return completes the current method call – Stops at breakpoints or at the point from

which the method was called

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Values and Expressions

• Double clicking on a variable in the Variable view allows you to change its value– new value is used when the program

resumes

• Type an expression into the Expression view to find out what its value is

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UML Diagrams

• Class diagrams

• Object diagrams

• Tools– dia– umbrello– violet

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UML Class Diagrams

• Used to illustrate relationships between classes

• Used to show the details of a particular class

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UML Symbols

Symbol Visibility

+ public

- private

# protected

~ package

Relationship Connector

inheritance (is-a)

open arrow

association (uses)

solid line

aggregation/

composition

(has-a)

open/

solid

diamond

inner class circle with cross

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Inheritance

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Class Hierarchy

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UML Class Diagram

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UML Object Diagram• Used to represent the state of the program at

some particular time

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Tools for UML Diagrams

• dia

• umbrello

• violet

• Eclipse plug-in

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Building Big Projects• For very large projects, the process of recompiling all

the modules that make up the project can take a long time.

• One way to reduce the amount of time needed to build a project is to only recompile the modules that have not changed and don't use modules that have changed.

• Two tools that determine what needs to be recompiled.– make– ant (for Java)

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The make Utility• make is a command generator designed to

help you manage large projects– make allows you to specify dependencies between

modules• if a class depends on another class, it should be

recompiled when that class changes

– make allows you to specify how to compile a particular class

– make uses these specifications to determine the minimum amount of work needed to recompile a program

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How does make Work?• make uses a file called Makefile (or makefile

or GNUMakefile) to determine what needs to be recompiled.

• The makefile contains a set of rules for executing the jobs it can be asked to do.

• When you run make, it uses the rules in the makefile to determine what needs to be done.

• make does the minimum amount of work needed to get the job done.

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The Makefile• A make file consists of a set of rules• Each rule has the form

target: dependencies commands

• target is (usually) the name of a file to be created• dependencies are the names of files that are needed

to create the target• commands is one or more commands that need to be

executed to create the target. • Each command is indented with a tab

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Example

• TestPriorityQueue uses KWPriorityQueue. PrintDocument and ComparePrintDocuments objects

• ComparePrintDocuments uses PrintDocument objects

• KWPriorityQueue implements Queue

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makefileTestPriorityQueue.class: TestPriorityQueue.java \

KWPriorityQueue.class PrintDocument.class \

ComparePrintDocuments.class

javac TestPriorityQueue.java

KWPriorityQueue.class: KWPriorityQueue.java Queue.class

javac KWPriorityQueue.java

Queue.class: Queue.java

javac Queue.java

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makefile (cont.)ComparePrintDocuments.class: \ ComparePrintDocuments.java PrintDocument.class javac ComparePrintDocuments.java

PrintDocument.class: PrintDocument.java javac PrintDocument.java

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Dummy targets

• The makefile can also have targets that don’t create files

• A target to run a java programTestPriorityQueue: TestPriorityQueue.class

java TestPriorityQueue

• A target to remove class filesclean:

rm -f *.class

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Sources of Information

• Managing Projects with make by Andrew Oram and Steve Talbot

• http://www.delorie.com/gnu/docs/make/make_toc.html

• Look at the man pageman make

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Ant

• make can be used with Java files

• ant was designed for building large Java projects– acronym for "Another Neat Tool"

• Ant uses XML format for build files

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build files• A build file is an xml file that contains

exactly one project element<?xml version="1.0" ?><project default="main">

</project>• main is target to build if none is given• name and basedir are optional

attributes for project

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Targets• A project element contains one or more

targets• Each target corresponds to a task

– the main target is required<target name="main>

</target>

• depends attribute contains list of targets that this target needs

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Tasks• Each target contains one or more tasks• There are a number of built-in tasks

– java • needs the classname attribute to be set to the main class

– javac

– jar - to create a java archive– javadoc - to create the documentation

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Sources of Information

• Ant The Definitive Guide by Steve Holzner

• Ant is an open source Apache project– http://ant.apache.org/