<?xml version="1.0"?> <!DOCTYPE book PUBLIC "-//OASIS//DTD DocBook XML

V4.5//EN" "http://www.oasis-open.org/docbook/xml/4.5/docbookx.dtd">

<book id="index">

<!-- Meta info -->

<bookinfo> <date>2009-08-03</date> <title>A Quick Start Guide to

DrJava</title> </bookinfo> <toc></toc>

<!-- Chapter: Intro -->

<chapter id="intro"> <title>Introduction</title>

<para>DrJava is a programming environment for Java designed specifically

for beginners, but it is also suitable for advanced program

development.

This document is a quick introduction to DrJava that will help you set it up

properly on your computer and introduce you to some of its key features.</para>

<para>For more detailed and technical user documentation, see the User

Documentation available from our website: <ulink

url="http://www.drjava.org">http://www.drjava.org</ulink></para>

</chapter>

<!-- **** Chapter: Starts and Beginnings (Getting Ready to Use DrJava) ****

<chapter id="gettingready"> <title>Getting Ready to Use DrJava</title>

<para>This chapter describes how to start using DrJava, including where

to get the program and how to run it.</para>

<section id="downloadJDK"> <title>Downloading the JDK</title> <para> To

compile programs in DrJava, you must make sure you have a Java JDK

(Java Development Kit) installed on your machine. All Java

distributions available for downloading come in two forms: a JDK

and a JRE (Java Runtime Environment). A JDK distribution consists

of a JRE distribution (a Java Virtual Machine implementation) plus

a collection of development tools including

<command>javac</command>, a Java compiler, and

<command>javadoc</command>, Java documentation generator. DrJava

requires a JDK installation because it uses both

<command>javac</command> and <command>javadoc</command> as plugin

components. Without these components, DrJava can only edit Java

programs; it cannot execute them or generate documentation for

them. If you do not have a JDK installed already, you can download

one for Windows, Linux, or Solaris computers directly from the

Oracle webite. Apple Macintosh machines running Mac OS X already

have a JDK installed. To download a JDK from the Oracle website,

just follow these steps! </para>

<itemizedlist mark="number"> <listitem> <para> Go to <ulink

url="http://www.oracle.com/technetwork/java/javase/downloads/index.html">http://www.oracle.com/technetwork/java/javase/downloads/index.html</ulink>,

</para> </listitem> <listitem> <para> Do a search for "JDK" </para>

</listitem> <listitem> <para> Select the most recent build of

Java from the list of options you see. We recommend Java 8,

assuming that you are using a current release of DrJava.

Recent releases of DrJava are not compatible with versions of

the JDK prior to Java 5 (previously called Java 1.5.0). Older

versions of DrJava are compatible with Java 1.3 and Java 1.4.

</para> </listitem> <listitem> <para> Click on the link

to download the JDK. <mediaobject> <imageobject>

<imagedata fileref="JDKDownload.jpg"

format="jpg" width="80%"/> </imageobject>

</mediaobject> </para></listitem> <listitem><para> Now, install the

JDK, and you are ready to install and run DrJava! </para>

</listitem> </itemizedlist>

</section>

<section id="downloading"> <title>Downloading DrJava</title> <para>Follow

these easy step by step instructions to download DrJava:</para>

<itemizedlist mark="opencircle"> <listitem><para> Go to <ulink

url="http://www.drjava.org">http://www.drjava.org.</ulink>

</para></listitem> <listitem><para> Select which build of

DrJava is right for you, and click on the appropriate

button. We recommend using the most recent stable or beta

releases since they support all of the Java 8 language

extensions, which make Java programming simpler. We also

recommend that Windows users download the

<filename>.exe</filename> file, that Mac OS X users use the

<filename>osx.tar.gz</filename> version, and that other

users download the <filename>.jar</filename> version. If

you have problems with a beta release of DrJava, you can

roll back to the most recent stable version. Experienced

users may want to experiment with other versions of DrJava

including the most recent Development Build jar instead. To

do so, click on the "more download options" link.

<mediaobject> <imageobject> <imagedata

fileref="CurrentStableRelease.jpg" format="jpg"

width="80%" /> </imageobject> </mediaobject>

</para></listitem> <listitem><para> Click on one of the Download buttons to

go to the download server. Choose a site to download the file from, and

then click on the corresponding icon in the "Download" column on the far

right to start the download. <mediaobject> <imageobject> <imagedata

fileref="DownloadServer.jpg" format="jpg" width="80%" />

</imageobject> </mediaobject> </para></listitem> <listitem><para> The

download should begin automatically. When prompted, select where you wish

to save the file to disk, and it will be downloaded to your computer.

</para></listitem> <listitem><para> Congratulations! You have now

downloaded DrJava! Now let's get DrJava running on your machine.

</para></listitem> </itemizedlist> </section> </chapter>

<!-- **** Using DrJava: Basics **** -->

<chapter id="usingdj"> <title>Using DrJava, the Basics</title> <para> Okay,

you've downloaded DrJava. Now, how do you use it? You're about to

find out. This chapter will tell you how to run DrJava as well as

how to do basic file editing and compilation. You'll also learn how

to use the most powerful feature of DrJava: The Interactions

Pane</para>

<section id="running"> <title>Running DrJava</title> <para>If you are

running on Windows, all you need to do is double-click DrJava's

<filename>.exe</filename> file, and DrJava will launch. On Mac

OSX, unpack the <filename>osx.tar.gz</filename> (you can use

StuffIt, or run

<informalexample><literal>$ tar -xvzf

osx.tar.gz</literal></informalexample>

in a Terminal),

and drag the file to Applications. On all other platforms, run

DrJava from the command line by giving the command

<informalexample><literal>$ java -jar &lt;DrJava jar

file&gt;</literal></informalexample>

</para>

</section>

<section id="openingfiles"> <title>Opening and Creating Files</title>

<para>To create a new file, choose "File, New" from the File menu, or

click on the "New" button on the toolbar. A new file is created

for you, and you can begin typing in it. To open a file, choose

"File, Open" from the File menu, or click on the "Open" button on

the toolbar. A file chooser window will then be opened. The

current directory is displayed at the top of the pop-up window.

Navigate through this and select the file or files you wish to

open.</para>

<mediaobject> <imageobject> <imagedata fileref="OpenDialog.jpg"

format="jpg" width="80%" /> </imageobject> </mediaobject>

<para>Once you have opened an existing file or created a new file, you

will notice that the names of all open files are listed on the left

of the screen, and the text of one file is displayed on the right.

Select a file name on the left to have the file's text display on the

right. The right pane is called the Definitions Pane. It is where

you edit your files.</para> <mediaobject> <imageobject> <imagedata

fileref="PlainOldDrJavaDefault.jpg" format="jpg" width="80%"

/> </imageobject> </mediaobject> </section>

<section id="savingfiles"> <title>Saving Files</title> <para> To save a

file, either click on the "Save" button or choose "File, Save." If

your file has been saved in the past, this will just overwrite the

old version. If your file has never been saved, you will be

prompted for where you wish to save the file. The current directory

is displayed at the top of the pop-up window. You can also use

"File, Save As" to save the file with a different name, and "File,

Save All" to save all open files. </para>

<mediaobject> <imageobject> <imagedata fileref="SaveDialog.jpg"

format="jpg" width="80%" /> </imageobject> </mediaobject>

</section>

<section id="compilingfiles"> <title>Compiling Files</title> <para> To

compile all open files, click on the "Compile" button. If you want

to just compile a specific file, right click on its name on the

left listing of files, and select Compile Current Document. Once

the compile is completed, the results are displayed on the Compiler

Output tab at the bottom of the screen. If there are no errors, you

will see "Last compilation completed successfully". If there are

errors, they will be listed. If both errors and warnings are found,

the number of each is listed, and errors will be listed before

warnings. If you click on an error, it will highlight the place in

your source code where the error is. Use the up and down arrow

buttons to navigate between error messages.</para>

<mediaobject> <imageobject> <imagedata fileref="CompilerErrors.jpg"

format="jpg" width="80%" /> </imageobject> </mediaobject>

</section>

<section id="interactionspane"> <title>The Interactions Pane</title>

<mediaobject> <imageobject> <imagedata

fileref="InteractionsPaneFull.jpg" format="jpg" width="80%"

/> </imageobject> </mediaobject>

<para> The Interactions Pane is one of the best and most distinctive

features of DrJava. It offers both beginning students and more

experienced programmers the ability to quickly try out code without

having to write cumbersome main methods. </para> <para> 1. One way to

use the Interactions Pane is to input basic Java expressions like 1+1.

Those expressions will then be interpreted and evaluated, and the

result will be displayed. This example shows how to do basic

calculations in the Interactions Pane:</para>

<mediaobject> <imageobject> <imagedata

fileref="InteractionsPane1Plus1.jpg" format="jpg"

width="80%" /> </imageobject> </mediaobject>

<para>2. Another way to use the Interactions Pane is to instantiate classes

and then call their methods--this allows you to quickly and easily

verify the behavior of methods. This example shows how to instantiate a

class and call one of its methods:</para>

<mediaobject> <imageobject> <imagedata

fileref="InteractionsPaneTom.jpg" format="jpg" width="80%"

/> </imageobject> </mediaobject>

<para>3. In addition, you can define classes and interfaces in the

Interactions Pane, and then instantiate these classes and test them.

This example shows how to create a class and call one of its

methods:</para> <mediaobject> <imageobject> <imagedata

fileref="InteractionsPaneTryMe.jpg" format="jpg" width="80%" />

</imageobject> </mediaobject>

<para>4. It is important to remember that if you are working with classes

that are packaged in the Definitions Pane (where the file's text is),

it is important to make the same package declaration in the

Interactions Pane. Also, you need to import any other packages you

wish to use, like you would in a normal <filename>.java</filename>

file. In this example, you can see how the package is used, and also

that until the <filename>java.util</filename> package is imported,

<filename>Vector</filename> cannot be used:</para>

<mediaobject> <imageobject> <imagedata

fileref="InteractionsPanePackageImport.jpg" format="jpg"

width="80%" /> </imageobject> </mediaobject> </section>

<section id="systemim"> <title>System.in</title>

<para>Many beginner programs rely on keyboard input read through

<filename>System.in</filename>. DrJava provides full support for

this. There are two ways to use <filename>System.in</filename> in

DrJava. First, you can invoke a method in your code that relies on

<filename>System.in</filename> in the Interactions Pane. When you

do this, the System.in input box will appear. Type your input, and

press Return.</para>

<mediaobject> <imageobject> <imagedata fileref="SystemInInput.jpg"

format="jpg" width="80%" /> </imageobject> </mediaobject>

<para>Alternatively, you can use the <filename>System.in.read()</filename>

method in the Interactions Pane directly. When the input box appears,

type your text and then either press Return.</para>

<mediaobject> <imageobject> <imagedata

fileref="SystemInInputInteractionsPane.jpg" format="jpg"

width="80%" /> </imageobject> </mediaobject>

<para>When the the input box appears in the Interactions Pane, you can choose

to close the input stream by selecting the menu item "Tools, Interactions

&amp; Console, Close System.in", or by pressing the keyboard shortcut for

it, which is <filename> Ctrl-D </filename>. The shortcut is labeled

<filename>Close System.in</filename> in the Key Bindings section of the

preferences.</para>

<para>Here is an example of closing the input stream. The text in square

brackets was entered by the user.</para>

<programlisting> Welcome to DrJava. Working directory is

/Users/Shared/drjava > System.in.read() [1] 49 > System.in.read() 10 >

System.in.read() // press Ctrl-D now [] -1 > </programlisting>

<para>The user first types '1' and then presses Return. This lets DrJava read a

49, which is the ASCII code for the character '1', and then 10, which is

the ASCII code for the new line created by Return. In the second input box,

the user pressed Ctrl-D immediately to close the input stream. This lets

DrJava read -1, indicating of the end of the stream.</para>

</section>

<section id="findandreplace"> <title>Find and Replace</title>

<mediaobject> <imageobject> <imagedata fileref="FindReplace.jpg"

format="jpg" width="80%" /> </imageobject> </mediaobject>

<para> The Find and Replace menu is a useful way to search for specific

text in your files, and replace it, if you so choose. To launch the

Find/Replace tab, either use the keyboard shortcut Ctrl-F or choose

"Edit, Find and Replace" from the menu at the top of the DrJava

window. Once you do this, the Find/Replace tab will appear at the

bottom of the screen. Type the text you want to search for in the

"Find Next" box, and if you want to replace it with anything, type

that in the "Replace With" box. Then, chose which of the four

options to the right of those text boxes that you want to use, and

press one of the buttons at the bottom, or the Enter key. The

direction of the search executed by pressing the Enter key depends

on the direction of the last search. (The last direction is

indicated by the label of the Find box: "Find Next" or "Find

Prev").</para>

<itemizedlist mark="opencircle"> <listitem><formalpara> <title>Match

Case:</title> <para> Makes the search becomes case

sensitive.</para> </formalpara></listitem>

<listitem><formalpara> <title>Search All Documents:</title> <para> Causes

your search text to be looked for in all open files. </para>

</formalpara></listitem>

<listitem><formalpara> <title>Whole Word:</title> <para> Only finds

instances of your search text that are preceeded and followed

by either a space, a period, or an open or close parenthesis.

</para> </formalpara></listitem>

<listitem><formalpara> <title>No Comments/String:</title> <para> Ignores

any instances found within comments or strings. </para>

</formalpara></listitem>

<listitem><formalpara> <title>Search Selection Only:</title> <para>Only

used with Find/Replace All. Allows user to find/replace all

instances of a word or phrase within a highlighted portion of

the document. </para> </formalpara></listitem>

</itemizedlist>

<para>To go from instance to instance of your search text, use the four

buttons at the bottom. </para> <itemizedlist mark="opencircle">

<listitem><formalpara> <title>Find Next:</title> <para>Finds the next

instance. Switches the label of the Find box to "Find

Next", indicating the direction of the next search.</para>

</formalpara></listitem>

<listitem><formalpara> <title>Find Previous:</title> <para>Finds the

previous instance. Switches the label of the Find box to "Find

Prev", indicating the direction of the next search. </para>

</formalpara></listitem>

<listitem><formalpara> <title>Find All:</title> <para>Find all occurrences

of the search string. This opens a new "Find: word" pane, where

"word" is replaced with the search string. In this pane, view

all found instances and jump to their locations in the text.

You can have as many "Find All" panes as you like open

concurrently. The "Find All" tool also automatically underlines

the occurrences. In the screenshot below, the user searched for

the word "System": <mediaobject> <imageobject> <imagedata

fileref="FindAll.jpg" format="jpg" width="80%" />

</imageobject> </mediaobject></para> </formalpara></listitem>

<listitem><formalpara> <title>Replace/Find Next:</title> <para> Replaces

the current instance with your replace text and then finds the

next instance. Switches the label of the Find box to "Find

Next", indicating the direction of the next search </para>

</formalpara></listitem>

<listitem><formalpara> <title>Replace/Find Previous:</title> <para>

Replaces the current instance with your replace text and then

finds the previous instance. Switches the label of the Find box

to "Find Previous", indicating the direction of the next search

</para> </formalpara></listitem>

<listitem><formalpara> <title>Replace:</title> <para> Replaces the current

instance with your replace text. </para>

</formalpara></listitem>

<listitem><formalpara> <title>Replace All:</title> <para> Replaces all

instances of the search text with the replace text

automatically </para> </formalpara></listitem> </itemizedlist>

<para> A relatively new feature of Find and Replace is the ability to

search across more than one line of text. The Find and Replace text

boxes can accept more than one line of text. To use this feature you

have two options. First, you can copy/paste directly into the Find and

Replace boxes and search/replace as normal. Second, you can type text

directly into the boxes, and when you want to create a new line press

Ctrl-Enter (Note: Pressing only the Enter key when inside the Find box

executes a Find. It DOES NOT create a new line. Both Enter and

Ctrl-Enter create a new line inside the Replace box).</para>

<mediaobject> <imageobject> <imagedata fileref="FindReplaceTwoLines.jpg"

format="jpg" width="80%" /> </imageobject> </mediaobject>

</section>

</chapter>

<!-- Chapter: Advanced Features -->

<chapter id="advanced"> <title>Advanced Features</title> <para>DrJava

provides support for many advanced features.</para>

<section id="junittesting"> <title>JUnit Testing of Files</title> <para>

DrJava offers a JUnit test facility. For information about JUnit

and JUnit tests, check out <ulink

url="http://www.junit.org">http://www.junit.org.</ulink> Click

the "Test" button to test all open JUnit tests, or select the file

you want to test on the left menu, right click, and select "Test

Current Document". The tests will be run, and the output will be

displayed on the Test Output tab at the bottom of the screen. If

all your tests passed, you will see a green bar.</para>

<mediaobject> <imageobject> <imagedata fileref="TestsPassed.jpg" format="jpg"

width="80%" /> </imageobject> </mediaobject>

<para> If any tests failed, you will see a red bar. All failing tests

will be listed in the test pane. Click on one, and its location in the

source code will be highlighted.</para>

<mediaobject> <imageobject> <imagedata fileref="TestFails.jpg" format="jpg"

width="80%" /> </imageobject> </mediaobject>

</section>

<section id="codecoverage"> <title>Integrated Code Coverage</title> <para>

DrJava provides code coverage analysis with JaCoCo 0.7.7. For more

information, see <ulink

url="http://www.eclemma.org/jacoco/index.html">EclEmma's

documentation.</ulink> Click the "Code Coverage" button to open

a popup where you can tell DrJava to open your default browser with

the report upon completion, and specify a directory in which to put

the coverage report.</para>

<mediaobject> <imageobject> <imagedata

fileref="CodeCoverageWindow.png" format="png"

width="80%" /> </imageobject> </mediaobject>

<para> When the analysis finishes, you can view the report in your

browser of choice. If you didn't choose to have the report

automatically opened, you can direct your browser to the

<filename>index.html</filename> file in the directory

containing the report. Entries in the "Element" column are

links to more specific analysis of that item.</para>

<mediaobject> <imageobject> <imagedata

fileref="CodeCoverageReport.png" format="png"

width="80%" /> </imageobject> </mediaobject>

</section>

<section id="javadocgen"> <title>Generating JavaDoc Documentation</title>

<para>DrJava offers the ability to generate JavaDoc documentation for

the user's java files. For information about what JavaDoc is and

how to format your comments to take advantage of it, see <ulink

url="http://www.oracle.com/technetwork/java/javase/documentation/index-137868.html">http://www.oracle.com/technetwork/java/javase/documentation/index-137868.html</ulink>.</para>

<para>To generate JavaDoc for all files in the same directories as your

open files, click the "JavaDoc" button on the toolbar. You will then

be asked where you want to save the javadoc files. Select a location

and click OK. Your JavaDoc will be generated for you.</para>

<mediaobject> <imageobject> <imagedata fileref="JavaDocMenu.jpg" format="jpg"

width="80%" /> </imageobject> </mediaobject>

<para>To generate JavaDoc for one specific file, select it from the open

list of files and right click and select "Preview JavaDoc" for current

Document. You will be able to view the JavaDoc for that file in the

JavaDoc viewer.</para>

<mediaobject> <imageobject> <imagedata fileref="Javadoc.jpg" format="jpg"

width="80%" /> </imageobject> </mediaobject>

</section>

<section id="thedebuger"> <title>The Debugger</title> <para>The debugger

allows you to step through the execution of a program and stop at

any point you choose so that you can track down bugs in your code.

What makes our debugger an unusually powerful tool is that it

allows you to modify the values of fields and variables

<emphasis>while debugging</emphasis>! First, we will explain a

little bit about how the debugger works in general, and then we

will explain how you can use the Interactions Pane to modify field

and variable values during runtime and thus more quickly zero in on

problems in your code.</para>

<para>To enable the debugger, select "Debugger, Debug Mode". This will

launch the debug panel in the lower part of DrJava, right above the

Interactions Pane.</para>

<mediaobject> <imageobject> <imagedata fileref="EnableDebugger.jpg"

format="jpg" width="80%" /> </imageobject> </mediaobject>

<formalpara> <title>Debug Panel:</title> <para>The Debug Panel has three

tabs to help you track control flow in your program. These tabs

are labeled Watches, Stack, and Threads.</para> </formalpara>

<itemizedlist mark="opencircle"> <listitem><formalpara>

<title>Watches:</title> <para> This is a table that displays

the instantaneous values of specified fields and variables

given the current line that the debugger is on. To add a

watch, click in the leftmost column on the first empty row.

A cursor should appear and you can type in the name of the

field or variable. You can also put in expressions that

require evaluation such as x + 1 or array accesses.</para>

</formalpara> <mediaobject> <imageobject> <imagedata

fileref="VariableWatch2.jpg" format="jpg" width="80%" />

</imageobject> </mediaobject> </listitem>

<listitem><formalpara> <title>Stack:</title> <para>This a table that lists

the current stackframes. Use this to determine the trail of

methods that have been invoked to arrive at the current line in

the execution. You can double-click on a particular stack

frame to scroll to center it in the Definitions Pane.</para>

</formalpara>

<mediaobject> <imageobject> <imagedata fileref="StackStuff.jpg"

format="jpg" width="80%" /> </imageobject> </mediaobject>

</listitem>

<listitem> <formalpara> <title>Threads:</title> <para> This is list of the

threads that are running in the virtual machine. If there are

multiple threads that are suspended, you can set the active

thread (the thread whose execution you're examining) by

double-clicking on the desired thread. </para> </formalpara>

<mediaobject> <imageobject> <imagedata fileref="Threads.jpg"

format="jpg" width="80%" /> </imageobject> </mediaobject>

</listitem> </itemizedlist>

<formalpara><title>Breakpoints</title> <para>Another important part of the

debugger is the breakpoints panel. Even when the debugger is not

enabled, you can set breakpoints using the <keycode>Ctrl+B</keycode>

shortcut or by selecting the "Toggle Breakpoint" command from the

Debugger menu or the context menu. This will highlight the current line

in red, and the debugger will stop the running program when it reaches

this line. To remove a breakpoint again, place the cursor on the same

line and press <keycode>Ctrl+B</keycode> again.</para></formalpara>

<para>To view all the breakpoints you have set and to navigate between them,

you can open the Breakpoints Panel by pressing

<keycode>Ctrl+Shift+B</keycode> or selecting the "Breakpoints" command from

the Debugger menu. In this panel, all currently set breakpoints are listed,

sorted by document and line number. To move the cursor to the location of a

breakpoint, double-click on one of the entries in the Breakpoints panel, or

select it and press the "Go to" button.</para> <para>You can also select

one or more breakpoints and use the "Enable" or "Disable" button to

temporarily enable or disable the selected breakpoints. If a breakpoint is

disabled, it remains set, but the program will not stop there. This is

useful if you may need a breakpoint again later, but want it ignored right

now.</para> <para>With the "Remove" button, you can remove one or more

selected breakpoints. The "Remove All" button clears the entire list of

breakpoints.</para> <para>Breakpoints are considered part of a project and

are therefore saved to and restored from a project file.</para>

<mediaobject> <imageobject> <imagedata fileref="BreakpointsPanel.jpg"

format="jpg" width="80%" /> </imageobject> </mediaobject>

</section>

<section id="usingDebugger"> <title>Using the Debugger</title> <para>To use the

debugger, you must first set a <emphasis>breakpoint</emphasis> on the

line(s) of code on which you want execution to stop. To do this, right

click on the line of code that you want the breakpoint on and select

Toggle Breakpoint from the menu.</para>

<mediaobject> <imageobject> <imagedata fileref="ToggleBreakpoint.jpg"

format="jpg" width="80%" /> </imageobject> </mediaobject>

<para>Once a breakpoint is set, it is highlighted in red, like this:</para>

<mediaobject> <imageobject> <imagedata fileref="BreakpointSet.jpg" format="jpg"

width="80%" /> </imageobject> </mediaobject>

<para>Once you have set the breakpoint(s), enable the debugger by pressing

<keycode>Ctrl+D</keycode> or invoking the "Debug Mode" command of the

Debugger menu.</para>

<mediaobject> <imageobject> <imagedata fileref="EnableDebugMode.jpg"

format="jpg" width="80%" /> </imageobject> </mediaobject>

<para>Now enter a statement in the Interactions Pane that will run the method

containing the breakpoint(s). Once execution reaches a breakpoint, it will

halt, awaiting input from you. </para>

<mediaobject> <imageobject> <imagedata fileref="HitBreakpoint.jpg"

format="jpg" width="80%" /> </imageobject> </mediaobject>

<para>At this point, the line that is about to be executed is highlighted in a

special color (light blue by default), the "resume", "step into", "step

over", and "step out" buttons are enabled, and a special prompt appears in

the Interactions Pane.</para>

<itemizedlist> <listitem><formalpara> <title>The Resume Button:</title>

<para>runs the program until another breakpoint is reached, or

the interaction has ended.</para> </formalpara></listitem>

<listitem><formalpara> <title>The Step Into Button:</title> <para>steps

through the execution of the method invocations in the current

line.</para> </formalpara></listitem>

<listitem><formalpara> <title>The Step Over Button:</title> <para>executes

the current line and stops execution on the next line.</para>

</formalpara></listitem>

<listitem><formalpara> <title>The Step Out Button:</title> <para>executes

the rest of the current method and stops execution at the line

from which the current method was called.</para>

</formalpara></listitem> </itemizedlist>

<para>At the prompt, you can still type arbitrary Java expressions like

usual, but you have additional power--all the fields, variables,

methods, and classes than can be seen from the current point in the

execution can be viewed and modified. This gives you incredible

power--you can actually modify the values of your fields and variables

while debugging. All you have to do is type in an assignment

statement.</para> </section>

</chapter>

<!-- Chapter: Project Facility -->

<chapter id="projects"> <title>The Project Facility</title> <section

id="project-overview"> <title>Overview</title> <para>The project

facility is intended to provide a lightweight approach to

managing a large number of files spread between different

subfolders and packages.</para>

<para>The project facility makes it easy to work with larger projects, and

allows you to save open java files into a project file and then reopen

the project at a later time. This means that you don't have to waste

time reopening files in multiple folders. The project facility was

designed with two goals in mind:</para> <para>1. To allow sets of

related files to be opened together.</para> <para>2. To allow DrJava's

tools and options to manage a set of related files as a single

entity.</para>

<para>The fundamental difference between the DrJava project facility and

the project facilities of most professional development environments is

that DrJava does not distinguish between "Open" files and "Project"

files--if a file is open and in the project source directory, it is

part of the project.</para>

</section>

<section id="project-treeview"> <title>Tree View</title>

<para>This project facility introduces a new view in DrJava called

<emphasis>Tree View</emphasis>. When you are working with a project,

the left hand pane displays the files in a tree view rather than the

traditional list view. This means that you can see where your files

are in relationship to each other. If you select a folder in the tree

view, when you select "Open" or "Save", the default directory DrJava

looks in will correspond to that folder.</para>

<mediaobject> <imageobject> <imagedata fileref="FullTreeView.jpg"

format="jpg" width="80%" /> </imageobject> </mediaobject>

<para>There are three main categories of files in Tree View: Source,

External, and Auxilary files.</para>

<itemizedlist mark="opencircle"> <listitem><formalpara> <title>Source

Files:</title> <para>All files located in or below the

project file's directory(project directory). Thus, the

location of your project file determines what files are

part of your project. It is important to put the project

file in the root of your project hierarchy.</para>

</formalpara></listitem>

<listitem><formalpara> <title>External Files:</title> <para>Files that are

not in the project directory. They will never be compiled or

tested as part of your project. They are not saved in the

project file.</para> </formalpara></listitem>

<listitem><formalpara> <title>Included External Files:</title> <para>Files

that are located outside of the project directory but that are

still important to the project. They are compiled and tested

with the project and are opened whenever the project is

opened.</para> </formalpara></listitem>

</itemizedlist>

<para>To move a file from the External Files branch to the Included

External Files branch, right click on the file in the tree listing, and

select the appropriate option at the bottom of the menu.</para>

<para>The behavior of some of the buttons also changes in Tree View. The

"Compile All" button only compiles open project source and auxiliary

files, instead of all open files. "Test All" will only tess open

project source and auxiliary files. To compile or test the external

files, you can right click on the folder and select "Compile Folder" or

"Test Folder".</para>

<mediaobject> <imageobject> <imagedata

fileref="ProjectFolderOptions.jpg" format="jpg" width="80%"

/> </imageobject> </mediaobject>

</section>

<section id="project-new"> <title>Creating and Saving a Project</title>

<para>When you want to create a new project, you have two options. The

first is that you can chose "Project, New" from the top menu to create

a brand new project. Once you have done this, a Save dialog box pops

up. Specifiy where you want the project file to be saved, and you are

ready to go. It is important to note that all project files must be in

the directory or a subdirectory of where the project file is

saved.</para>

<mediaobject> <imageobject> <imagedata fileref="NewProjectSaveDialog.jpg"

format="jpg" width="80%" /> </imageobject> </mediaobject>

<para>The other way to create a project is to open up the java files you

want to include in the project, and then select "Project, Save As".

This will create a new project consisting of those files.</para>

<mediaobject> <imageobject> <imagedata

fileref="ProjectSaveDialogFromFiles.jpg" format="jpg"

width="80%" /> </imageobject> </mediaobject>

<para> To add new files to your project, just open them. They will

automatically be sorted into the correct folder. When you save the

project, they will be saved with it.</para> </section> <section

id="project-save"> <title>Saving Your Project</title> <para>If you make any

changes to the structure or state of your project (for instance,

collapsing a folder tree or opening or closing files), you will want to

save it so your preferences are maintained. To save a project, select

"Project, Save". Note that saving a project only saves the list of

what files are in the project; it does not save the files themselves.

Use "File, Save All" to save all the files in the project.</para>

<para>Saving a project will also save which document you are currently

viewing so that it will be re-displayed the next time you open the

project. It also saves the cursor location in each file as well as

whether a folder in the project tree is collapsed or expanded.</para>

</section>

<section id="project-open"> <title>Opening a Project</title>

<para>To open a project file, just select "Project, Open" and select the

project file you wish to open.</para>

<mediaobject> <imageobject> <imagedata fileref="ProjectOpen.jpg"

format="jpg" width="80%" /> </imageobject> </mediaobject>

</section>

<section id="project--compiling"> <title>Compiling Your Project</title>

<para> When compiling a project, you must decide whether you want to

compile only the open project files or all of the files in a

project. Compiling all open files will only compile those files

that are open in the project view (source files and auxiliary

files). To do this, sellect "Project, Compile Open Project Files"

or right click on the root of the project tree and select "Compile

Open Project Files". You can also click on the "Compile All"

button.</para>

<para>To compile all project files (source and auxiliary), even ones not

currently open in DrJava, select "Project, Compile Project", or right

click on the root of the project and click "Compile Project".</para>

<para>Note that all files in the External Files folder will not be compiled

as part of the project--you must do this separately.</para>

<para>You can compile from the Project Menu:</para>

<mediaobject> <imageobject> <imagedata

fileref="ProjectCompileFromTopMenu.jpg" format="jpg"

width="80%" /> </imageobject> </mediaobject>

<para>Or from the Navigator Pane:</para>

<mediaobject> <imageobject> <imagedata

fileref="ProjectCompileFromSideMenu.jpg" format="jpg"

width="80%" /> </imageobject> </mediaobject>

</section>

<section id="project-testing"> <title>Testing Your Project</title>

<para>There are also two options for testing a project: test just the

open project files or test the entire project. These have the same

meaning that they do for compiling. To test only the open project

files, select "Project, Test Open Project Files". This will test

all JUnit test files currently open in the source files and

auxiliary files branches.</para> <para>To test all project files,

even those not open in DrJava, select "Project, TestProject". This

will test all JUnit test files in the project directory and its

subfolders as well as all of the auxiliary files.</para>

<para>External files will never be tested.</para>

<mediaobject> <imageobject> <imagedata fileref="ProjectTest.jpg"

format="jpg" width="80%" /> </imageobject> </mediaobject>

</section>

<section id="project-running"> <title>Running a Project</title> <para>To

run the main method of a project, select "Project, Run Main Class."

This will load the class specified as the project's main class in

Project Properties, and run its main method. If you have not

specified the file to load in Project Properties, this option is

grayed out</para>

<mediaobject> <imageobject> <imagedata fileref="ProjectRunMainDocument.jpg"

format="jpg" width="80%" /> </imageobject> </mediaobject>

<para>If you have configured a main class, then DrJava will also show a

"Run Project" toolbar button. If you have not specified a class as

main class, a "Run" button is shown instead that runs the main

method of the currently shown document.</para>

</section>

<section id="project-cleanbuilddir"> <title>Clean Build Directory</title>

<para> This option is only enabled once you have specified a build

directory in the Project Properties dialog box. Once you have

specified a build directory, selecting this option will remove all

<filename>.class</filename> files and empty directories in the

build directory.</para>

<mediaobject> <imageobject> <imagedata

fileref="ProjectCleanBuildDirectory.jpg" format="jpg"

width="80%" /> </imageobject> </mediaobject> </section>

<section id="project-properties"> <title>Project Properties</title>

<para>The Project Properties dialog box allows you to set two optional

properties to better utilize the project facility. To access the

Project Properties dialog, select "Project, Project

Properties".</para>

<formalpara> <title>Project Root:</title> <para>This is the directory where

the source files are located. It corresponds to the default package

of your project. If no directory is entered, the directory

containing the project file is assumed.</para> </formalpara>

<formalpara> <title>Build Directory:</title> <para>Set this if you want

your compiled files to be compiled to a directory other than the

source directory. This is often useful if your project is large or

you want to be able to clean the build directory (see the option on

the Project menu).</para> </formalpara>

<formalpara> <title>Working Directory:</title> <para>DrJava will use this

directory as "current" directory for the Interactions pane and the

user program.</para> </formalpara>

<formalpara> <title>Main Class:</title> <para>This allows you to specify

the class that holds the main method for the project. When this is

set, you can use "Project, Run Main Class" to launch the

program.</para> </formalpara>

<formalpara> <title>Extra Classpath:</title> <para>In this section you

can list directories or JAR files that should be included on the

classpath while you are working with this project. The classes

added this way are available both in the Interactions pane and when

compiling.</para> </formalpara>

<mediaobject> <imageobject> <imagedata fileref="ProjectProperties.jpg"

format="jpg" width="80%" /> </imageobject> </mediaobject>

</section>

</chapter>

<!-- Chapter: Preferences Menu -->

<chapter id="preferences"> <title>The Preferences Menu</title> <para> The

Preferences menu in DrJava can be accessed by selecting "Edit,

Preferences" on the main toolbar, or by the keyboard shortcut

Ctrl-semi-colon. This menu gives you the ability to tweak your

configuration of DrJava so that it better serves your needs. To

switch between Preference Categories, click on the names in the left

part of the Preferences window.</para>

<section id="resourcelocations"> <title>Resource Locations</title>

<para>The Resource Locations menu allows you to specify the location of

many important resources. All of these fields are optional and can

be left blank if you want default values to take effect. </para>

<itemizedlist> <listitem><formalpara> <title>Web Browser and Web Browser

Command:</title> <para> Allow you to specify which web

browser you want to use for viewing Javadoc and Help files.

You can choose to specify the Web Browser program directly,

state the command you use to launch your browser, or leave

both blank if your system has a default browser.</para>

</formalpara></listitem>

<listitem><formalpara> <title>Tools.jar Location:</title> <para>The

directory of your tools.jar file which has the compiler and

debugger. This file is usually created during the installation

of the Java JDK.</para> </formalpara></listitem>

<listitem><formalpara> <title>Display All Compiler Versions:</title>

<para>By default, DrJava only displays one compiler per major

version, even if multiple updates are found (Example: You have

JDK 6 Updates 10 and 14 installed; DrJava will only display JDK

6 Update 14). To display all compiler versions, mark this

checkbox. Note: You have to restart DrJava when you change this

setting.</para> </formalpara></listitem>

<listitem><formalpara> <title>Extra Classpath:</title> <para> A way for you

to specify extra directories you want the compiler to look in

when it is trying to find class files. Use "Add" and "Remove"

to control which directories are on the classpath, and "Move

Up" and "Move Down" to order the directories in the order you

want them to be looked through. If no directories are

specified here, the compiler will look in the directories of

the files you are compiling.</para> </formalpara></listitem>

</itemizedlist>

<mediaobject> <imageobject> <imagedata fileref="ResourceLocation.jpg"

format="jpg" width="80%" /> </imageobject> </mediaobject>

<para>Older versions of DrJava also had the following options:</para>

<itemizedlist> <listitem><formalpara> <title>JSR-14 and JSR-14 Collections

Path:</title> <para>The JSR-14 jar is the location of the

JSR14 compiler, while the JSR-14 Collections path is a

collection of the generified collection classes, such as

Vector&lt;?&gt;. If you are not using the JSR14 compiler,

you can just leave these blank.</para>

</formalpara></listitem> </itemizedlist>

</section>

<section id="displayoptions"> <title>Display Options</title> <para>The

Display Options menu allows you to control how DrJava looks.

</para>

<itemizedlist> <listitem><formalpara> <title>Look and Feel:</title> <para>

Specify what theme DrJava uses</para>

</formalpara></listitem>

<listitem><formalpara> <title>Plastic Theme:</title> <para> If Plastic is

selected as Look and Feel, then the specific theme can be

selected here</para> </formalpara></listitem>

<listitem><formalpara> <title>Toolbar Buttons:</title> <para>Choose the

configuration of text and graphics that you want on your

toolbar.</para> </formalpara></listitem>

<listitem><formalpara> <title>Line Numbers:</title> <para>Choose whether

you want these shown on the left hand side of the definitions

pane.</para> </formalpara></listitem>

<listitem><formalpara> <title>Show sample of source code when fast

switching:</title> <para>Choose whether a sample of the source

code around the current caret position should be shown in the

Fast Switch window.</para> </formalpara></listitem>

<listitem><formalpara> <title>Show Code Preview Popups:</title>

<para>Whether a sample of the source code around the document

location should be shown in the Breakpoints, Bookmarks and Find

Results panes.</para> </formalpara></listitem>

<listitem><formalpara> <title>Size of Clipboard History:</title>

<para>DrJava puts all text that you copy or cut out of text in a

<keycode>Ctrl+Shift+V</keycode>, you can show the entries of

the history and paste one of its items. This setting determines

the size of the history.</para> </formalpara></listitem>

<listitem><formalpara> <title>Display Fully-Qualified Class Names in "Go to

File" Dialog:</title> <para>If this option is checked, the "Go

to File" dialog displays both the simple and the

fully-qualified class name (i.e. both MyClass and

foo.bar.MyClass). This sometimes makes navigation easier, but

it may increase the time it takes to display the "Go to File"

dialog.</para> </formalpara></listitem>

<listitem><formalpara> <title>Scan Class Files For Auto-Completion After

Each Compile:</title> <para>DrJava can auto-complete the names

of user classes. If this option is checked, DrJava will scan

all class files that were created after each compile to obtain

the names, even of inner classes. IF this option is not

checked, DrJava can only auto-complete the names of the

documents that are open. Selecting this option slows down

compiles.</para> </formalpara></listitem>

<listitem><formalpara> <title>Consider Java API Classes for Auto

Completion:</title> <para>When this option is enabled, DrJava

will include the names of the standard Java API classes in the

list of names used for auto-completion.</para>

</formalpara></listitem>

<listitem><formalpara> <title>Display Right Margin:</title> <para>Enable

this option to let DrJava display a vertical line representing

the right margin of the document.</para>

</formalpara></listitem>

<listitem><formalpara> <title>Right Margin Position:</title> <para>This

option controls the position of the right margin. By default,

the right margin line is displayed after 120 columns, provided

the "Display Right Margin" option above is enabled.</para>

</formalpara></listitem>

</itemizedlist>

<mediaobject> <imageobject> <imagedata fileref="DisplayOptions.jpg"

format="jpg" width="80%" /> </imageobject> </mediaobject>

<para>There are two submenus under Display Options, Fonts and

Colors.</para> </section>

<section id="fontdisplayoptions"> <title>Fonts Options</title> <para>The

Fonts Options allows you to specify how the font should look.

There are four font categories.</para> <itemizedlist> <listitem>

<formalpara> <title>Main Font:</title> <para>Specifies the font

for the text in the definitions pane and the

Interactions Pane.</para> </formalpara></listitem>

<listitem><formalpara> <title>Line Numbers Font:</title> <para>Specifies

the font for the line numbers in the definitions pane, if you

enabled them.</para> </formalpara></listitem>

<listitem><formalpara> <title>Document List Font:</title> <para>Specifies

the font for the file names in the navigator pane on the

left.</para> </formalpara></listitem>