diff --git a/tiddlers/content/_Coursework.tid b/tiddlers/content/_Coursework.tid
index ed48289..45c9175 100644
--- a/tiddlers/content/_Coursework.tid
+++ b/tiddlers/content/_Coursework.tid
@@ -16,6 +16,16 @@
 </$list>
 </div>
 
+! Review Exercises
+<div class="tc-table-of-contents">
+<$list filter="[tag[review]tag[toc]!tag[hidden]sort[title]]">
+<$set name="strippedTitle" filter="[all[current]split[/]last[]]">
+<$link><<strippedTitle>></$link><br>
+</$set>
+</$list>
+</div>
+
+
 <!--
 ! Reference
 <div class="tc-table-of-contents">
diff --git a/tiddlers/content/review/java_exercises/_Review_Application.md b/tiddlers/content/review/java_exercises/_Review_Application.md
new file mode 100644
index 0000000..ee3a4d7
--- /dev/null
+++ b/tiddlers/content/review/java_exercises/_Review_Application.md
@@ -0,0 +1,5 @@
+Create a new class that represents the application.  This class will contain the `main` method for the system.
+
+1.  Add a `main` method to the class that creates 5 instances of your contact domain class (initialise the objects using dummy data), and adds them to an array.
+
+1.   Add code to the `main`  method that iterates through the array, printing each of the contacts in the console.
\ No newline at end of file
diff --git a/tiddlers/content/review/java_exercises/_Review_Application.md.meta b/tiddlers/content/review/java_exercises/_Review_Application.md.meta
new file mode 100644
index 0000000..8309eec
--- /dev/null
+++ b/tiddlers/content/review/java_exercises/_Review_Application.md.meta
@@ -0,0 +1,4 @@
+section: 5.2
+tags: review
+title: /Review/Java Exercises/Application
+type: text/x-markdown
\ No newline at end of file
diff --git a/tiddlers/content/review/java_exercises/_Review_Console Menu.md b/tiddlers/content/review/java_exercises/_Review_Console Menu.md
new file mode 100644
index 0000000..6d42c93
--- /dev/null
+++ b/tiddlers/content/review/java_exercises/_Review_Console Menu.md
@@ -0,0 +1,22 @@
+Write a Java console program that displays a simple text-based menu in the
+console.
+
+The menu should:
+
+1. Display a text menu with three options.
+
+1. Prompt the user to select one of the menu options.
+
+1. Use multiple `if-else` statements to display a message that relates to the selected option.
+
+The following code can be used to read input from the console:
+
+``` java
+Scanner scanner = new Scanner(System.in);
+
+// this will read an integer
+int i = scanner.nextInt();
+
+// this will read a string
+String s = scanner.nextLine();
+```
diff --git a/tiddlers/content/review/java_exercises/_Review_Console Menu.md.meta b/tiddlers/content/review/java_exercises/_Review_Console Menu.md.meta
new file mode 100644
index 0000000..2e6a586
--- /dev/null
+++ b/tiddlers/content/review/java_exercises/_Review_Console Menu.md.meta
@@ -0,0 +1,4 @@
+section: 2
+tags: review
+title: /Review/Java Exercises/Console Menu
+type: text/x-markdown
\ No newline at end of file
diff --git a/tiddlers/content/review/java_exercises/_Review_Contact List.md b/tiddlers/content/review/java_exercises/_Review_Contact List.md
new file mode 100644
index 0000000..abd7120
--- /dev/null
+++ b/tiddlers/content/review/java_exercises/_Review_Contact List.md
@@ -0,0 +1,2 @@
+In the next few sections we will incrementally build up a contact list management system that lets the user manage a list of contacts.
+
diff --git a/tiddlers/content/review/java_exercises/_Review_Contact List.md.meta b/tiddlers/content/review/java_exercises/_Review_Contact List.md.meta
new file mode 100644
index 0000000..f939b34
--- /dev/null
+++ b/tiddlers/content/review/java_exercises/_Review_Contact List.md.meta
@@ -0,0 +1,4 @@
+section: 5
+tags: review
+title: /Review/Java Exercises/Contact List
+type: text/x-markdown
\ No newline at end of file
diff --git a/tiddlers/content/review/java_exercises/_Review_Create a Sequence Diagram.md b/tiddlers/content/review/java_exercises/_Review_Create a Sequence Diagram.md
new file mode 100644
index 0000000..cf4c1ae
--- /dev/null
+++ b/tiddlers/content/review/java_exercises/_Review_Create a Sequence Diagram.md
@@ -0,0 +1,7 @@
+Whenever you have a system that contains more than a couple of classes it can be easy to lose track of what is happening.  Drawing a sequence diagram using the code as a guide is a good way of helping you to understand what is going on.
+
+Draw a sequence diagram of the 'search' feature of your system.  Start with the user selecting the 'Search' option from the menu.
+
+Refer to the [sequence diagrams review exercise](#/Review/Diagrams/Sequence%20Diagrams) if you have not taken INFO201, or you need a quick refresher.
+
+
diff --git a/tiddlers/content/review/java_exercises/_Review_Create a Sequence Diagram.md.meta b/tiddlers/content/review/java_exercises/_Review_Create a Sequence Diagram.md.meta
new file mode 100644
index 0000000..aadf1c2
--- /dev/null
+++ b/tiddlers/content/review/java_exercises/_Review_Create a Sequence Diagram.md.meta
@@ -0,0 +1,4 @@
+section: 5.7
+tags: review
+title: /Review/Java Exercises/Create a Sequence Diagram
+type: text/x-markdown
\ No newline at end of file
diff --git a/tiddlers/content/review/java_exercises/_Review_Data Access Class.md b/tiddlers/content/review/java_exercises/_Review_Data Access Class.md
new file mode 100644
index 0000000..19a938b
--- /dev/null
+++ b/tiddlers/content/review/java_exercises/_Review_Data Access Class.md
@@ -0,0 +1,9 @@
+Create a new class that represents a contact list, and extend your program to use the new class.  The class is effectively a data access class for managing the contacts.
+
+1.   The class should contain a `private` field that is a collection (use `ArrayList`) of contact objects.
+
+1.   Add a method that takes a contact object as a parameter and add it to the list.
+
+1.   Add a method that displays the list of contacts in the console.
+
+1.   Modify your program so that it uses an instance of your new contact list class instead of using an array.
diff --git a/tiddlers/content/review/java_exercises/_Review_Data Access Class.md.meta b/tiddlers/content/review/java_exercises/_Review_Data Access Class.md.meta
new file mode 100644
index 0000000..e725a4c
--- /dev/null
+++ b/tiddlers/content/review/java_exercises/_Review_Data Access Class.md.meta
@@ -0,0 +1,4 @@
+section: 5.3
+tags: review
+title: /Review/Java Exercises/Data Access Class
+type: text/x-markdown
\ No newline at end of file
diff --git a/tiddlers/content/review/java_exercises/_Review_Delete Feature.md b/tiddlers/content/review/java_exercises/_Review_Delete Feature.md
new file mode 100644
index 0000000..9166b55
--- /dev/null
+++ b/tiddlers/content/review/java_exercises/_Review_Delete Feature.md
@@ -0,0 +1,8 @@
+Add some functionality to your system that allows you to delete unwanted contacts from your list.
+
+Add another menu option to the application class that allows the user to delete a contact.  Add another `static` method for this feature to the application class.
+
+Add a 'delete' method to your contact list class.
+
+The 'delete' method should search for a particular name (you could reuse the code in the 'search' method here), and when a match is found, it should delete that item using the relevant method in the `ArrayList` object.
+
diff --git a/tiddlers/content/review/java_exercises/_Review_Delete Feature.md.meta b/tiddlers/content/review/java_exercises/_Review_Delete Feature.md.meta
new file mode 100644
index 0000000..bed17fc
--- /dev/null
+++ b/tiddlers/content/review/java_exercises/_Review_Delete Feature.md.meta
@@ -0,0 +1,4 @@
+section: 5.6
+tags: review
+title: /Review/Java Exercises/Delete Feature
+type: text/x-markdown
\ No newline at end of file
diff --git a/tiddlers/content/review/java_exercises/_Review_Domain Class.md b/tiddlers/content/review/java_exercises/_Review_Domain Class.md
new file mode 100644
index 0000000..c4cccda
--- /dev/null
+++ b/tiddlers/content/review/java_exercises/_Review_Domain Class.md
@@ -0,0 +1,9 @@
+Create a domain class that represents a contact.  
+
+1. Add `private` fields for name, address, and phone number to the class.
+
+1. Add getters and setters for these fields.
+
+1. Add a constructor that will initialise the three fields.
+
+1. Override the `toString` method so that it will return the values of the three fields.
\ No newline at end of file
diff --git a/tiddlers/content/review/java_exercises/_Review_Domain Class.md.meta b/tiddlers/content/review/java_exercises/_Review_Domain Class.md.meta
new file mode 100644
index 0000000..fa59430
--- /dev/null
+++ b/tiddlers/content/review/java_exercises/_Review_Domain Class.md.meta
@@ -0,0 +1,4 @@
+section: 5.1
+tags: review
+title: /Review/Java Exercises/Domain Class
+type: text/x-markdown
\ No newline at end of file
diff --git a/tiddlers/content/review/java_exercises/_Review_Gradle.md b/tiddlers/content/review/java_exercises/_Review_Gradle.md
new file mode 100644
index 0000000..1d9de85
--- /dev/null
+++ b/tiddlers/content/review/java_exercises/_Review_Gradle.md
@@ -0,0 +1,13 @@
+Create a new project for these exercises.
+
+You will need to modify the `build.gradle` for the project to instruct Gradle to pass console input through to your programs.  The following is the complete `build.gradle` that you will need:
+
+```gradle
+plugins {
+	id "application"
+}
+
+run {
+	standardInput = System.in
+}
+```
\ No newline at end of file
diff --git a/tiddlers/content/review/java_exercises/_Review_Gradle.md.meta b/tiddlers/content/review/java_exercises/_Review_Gradle.md.meta
new file mode 100644
index 0000000..54435d1
--- /dev/null
+++ b/tiddlers/content/review/java_exercises/_Review_Gradle.md.meta
@@ -0,0 +1,4 @@
+section: 1
+tags: review
+title: /Review/Java Exercises/Gradle
+type: text/x-markdown
\ No newline at end of file
diff --git a/tiddlers/content/review/java_exercises/_Review_Java Exercises.md b/tiddlers/content/review/java_exercises/_Review_Java Exercises.md
new file mode 100644
index 0000000..bfc4fb5
--- /dev/null
+++ b/tiddlers/content/review/java_exercises/_Review_Java Exercises.md
@@ -0,0 +1,8 @@
+These exercises will help you to (re)familiarise yourself with the Java programming language.  Once you complete these exercises your Java skills should be up to where you
+will need them to be to take on INFO202.
+
+!! Contents
+<$set name="path" value="/Review/">
+<$macrocall $name="contents-tree" path=<<path>> />
+<div class="no-print"><$macrocall $name="openByPath" path=<<path>> /></div>
+</$set>
\ No newline at end of file
diff --git a/tiddlers/content/review/java_exercises/_Review_Java Exercises.md.meta b/tiddlers/content/review/java_exercises/_Review_Java Exercises.md.meta
new file mode 100644
index 0000000..535b0fb
--- /dev/null
+++ b/tiddlers/content/review/java_exercises/_Review_Java Exercises.md.meta
@@ -0,0 +1,3 @@
+tags: review toc
+title: /Review/Java Exercises/Java Exercises
+type: text/vnd.tiddlywiki
\ No newline at end of file
diff --git a/tiddlers/content/review/java_exercises/_Review_Loops.md b/tiddlers/content/review/java_exercises/_Review_Loops.md
new file mode 100644
index 0000000..8905e8c
--- /dev/null
+++ b/tiddlers/content/review/java_exercises/_Review_Loops.md
@@ -0,0 +1,6 @@
+Write a Java console program that sums all of the numbers from 1 to 100 (inclusive), and prints the result to the console.
+
+First use a `for` loop.  Repeat the sum using a `while` loop, and again using a `do-while` loop.
+
+**FYI**: the sum of all numbers from 1 to 100 is 5050.
+
diff --git a/tiddlers/content/review/java_exercises/_Review_Loops.md.meta b/tiddlers/content/review/java_exercises/_Review_Loops.md.meta
new file mode 100644
index 0000000..77bc14e
--- /dev/null
+++ b/tiddlers/content/review/java_exercises/_Review_Loops.md.meta
@@ -0,0 +1,4 @@
+section: 3
+tags: review
+title: /Review/Java Exercises/Loops
+type: text/x-markdown
\ No newline at end of file
diff --git a/tiddlers/content/review/java_exercises/_Review_Menu.md b/tiddlers/content/review/java_exercises/_Review_Menu.md
new file mode 100644
index 0000000..5caf5a8
--- /dev/null
+++ b/tiddlers/content/review/java_exercises/_Review_Menu.md
@@ -0,0 +1,16 @@
+Extend the system so that a user can create, add contacts, and view the list:
+
+The following should be added to the application class that you created in section [5.2](#/Review/Application).
+
+1.   Write a text-based menu that gives the user the options to 'Create', 'Add', and 'View' the list.
+
+1.   Add three `public static void` methods that will be called in response to the user's menu input.
+
+1.   The 'Create' method should create a new instance of the contact list.
+
+1.   The 'Add' method should prompt the user for the data for a single contact, and use this data to construct an instance of the contact class, and add it to the list.
+
+1.   The 'View' method should call the method that displays the contact list.
+
+
+
diff --git a/tiddlers/content/review/java_exercises/_Review_Menu.md.meta b/tiddlers/content/review/java_exercises/_Review_Menu.md.meta
new file mode 100644
index 0000000..4caecaf
--- /dev/null
+++ b/tiddlers/content/review/java_exercises/_Review_Menu.md.meta
@@ -0,0 +1,4 @@
+section: 5.4
+tags: review
+title: /Review/Java Exercises/Menu
+type: text/x-markdown
\ No newline at end of file
diff --git a/tiddlers/content/review/java_exercises/_Review_Search Feature.md b/tiddlers/content/review/java_exercises/_Review_Search Feature.md
new file mode 100644
index 0000000..ce89614
--- /dev/null
+++ b/tiddlers/content/review/java_exercises/_Review_Search Feature.md
@@ -0,0 +1,9 @@
+Add a 'Search' feature to the system that allows the user to search the contact list for a particular contact's name:
+
+1.   Add a method to the contact list class for searching the list.  This method should take a name as a parameter and use that name to search through the `ArrayList`, comparing it to the names for each contact.  When a match is found, the matching item should be returned.
+
+     If there is no match then the method should return `null`.
+
+1.   Extend the menu in the application class to add a 'Search' option.
+
+     Add another `static` method that will prompt the user for a name.  The name that the user enters should then be passed to the 'search' method of the contact list object, and if 'search' method does not return `null` then the returned object should be printed to the console.
diff --git a/tiddlers/content/review/java_exercises/_Review_Search Feature.md.meta b/tiddlers/content/review/java_exercises/_Review_Search Feature.md.meta
new file mode 100644
index 0000000..581ef52
--- /dev/null
+++ b/tiddlers/content/review/java_exercises/_Review_Search Feature.md.meta
@@ -0,0 +1,4 @@
+section: 5.5
+tags: review
+title: /Review/Java Exercises/Search Feature
+type: text/x-markdown
\ No newline at end of file
diff --git a/tiddlers/content/review/java_exercises/_Review_Temperature Converter.md b/tiddlers/content/review/java_exercises/_Review_Temperature Converter.md
new file mode 100644
index 0000000..f07ab3b
--- /dev/null
+++ b/tiddlers/content/review/java_exercises/_Review_Temperature Converter.md
@@ -0,0 +1,15 @@
+Write a Java class that has two `public static` methods:
+
+* The first method should convert a decimal number argument from Celsius to Fahrenheit.
+
+* The second method should covert a decimal number argument from Fahrenheit to Celsius.
+
+Test the methods by copying and adapting the code for the [console menu](#/Review/Console%20Menu) that you created earlier to allow the user to choose which conversion they wish to perform and then enter the value that they want to convert.
+
+The following are the equations for the conversions:
+
+<$latex text="^{\circ}F=\left(\frac{9}{5}\ ^{\circ}C\right) + 32" />
+
+<$latex text="^{\circ}C=\frac{5}{9}\left(^{\circ}F - 32\right)" />
+
+**FYI**: <$latex text="32^{\circ}C = 89.6^{\circ}F" /> and <$latex text="68^{\circ}F=20^{\circ}C"/>
\ No newline at end of file
diff --git a/tiddlers/content/review/java_exercises/_Review_Temperature Converter.md.meta b/tiddlers/content/review/java_exercises/_Review_Temperature Converter.md.meta
new file mode 100644
index 0000000..c362dfb
--- /dev/null
+++ b/tiddlers/content/review/java_exercises/_Review_Temperature Converter.md.meta
@@ -0,0 +1,4 @@
+section: 4
+tags: review
+title: /Review/Java Exercises/Temperature Converter
+type: text/x-markdown
\ No newline at end of file
diff --git a/tiddlers/content/review/sequence-diagrams/_Review_Sequence Diagrams.tid b/tiddlers/content/review/sequence-diagrams/_Review_Sequence Diagrams.tid
new file mode 100644
index 0000000..e51982f
--- /dev/null
+++ b/tiddlers/content/review/sequence-diagrams/_Review_Sequence Diagrams.tid
@@ -0,0 +1,609 @@
+tags: review diagrams toc
+title: /Review/Diagrams/Sequence Diagrams
+type: text/vnd.tiddlywiki
+
+\rules except dash
+
+This is the sequence diagram tutorial from INFO201.
+
+You can use VS Code in the Linux lab to create a new file with the extension `.pu`, or one of the various online PlantUML editors.
+
+!PlantUML Sequence Diagram Documentation
+http://plantuml.com/sequence-diagram
+
+!Conventions in this Tutorial
+
+<mark style="background:lime">Green highlighting shows that code has been added since the last example.</mark>
+
+<mark style="background:aqua">Blue highlighting is code that has changed since the last example.</mark>
+
+<mark style="background:fuchsia">Pink highlighting shows that code has been removed (or moved elsewhere) since the last example.</mark>
+
+You should incrementally change the code as shown so that you can see the effect of each modification.
+
+If you get totally lost you can click the diagram to open it in PlantText.
+
+!Simple Example
+The simplest example looks like:
+
+```
+@startuml
+A -> B : do stuff
+@enduml
+```
+
+[[plantuml[
+@startuml
+A -> B : do stuff
+@enduml
+]]]
+
+`A` and `B`  are both //participants// (which would usually represent Java classes) and //do stuff// is a message (usually a method call) from `A` to `B`.
+
+The footer boxes are just clutter, and the default arrows make it hard to see the difference between the different forms of messages, so we will usually put PlantUML into Strict UML mode:
+
+<pre>@startuml
+<mark style="background:lime">' use strict UML mode
+skinparam style strictuml</mark>
+
+A -> B : do stuff
+@enduml
+</pre>
+
+[[plantuml[
+@startuml
+' use strict UML mode
+skinparam style strictuml
+
+A -> B : do stuff
+@enduml
+]]]
+
+!Method Call with Return
+<pre>@startuml
+' use strict UML mode
+skinparam style strictuml
+
+A -> B : <mark style="background:aqua">getName()</mark>
+<mark style="background:lime">return name</mark>
+@enduml
+</pre>
+
+
+[[plantuml[
+@startuml
+' use strict UML mode
+skinparam style strictuml
+
+A -> B : getName()
+return name
+@enduml
+]]]
+
+This represents `A` calling the `getName()` method on `B`, and `B` returning a `name` to `A`.
+
+Solid lines represent method calls, and dashed lines represent the response to calling those methods.
+
+!Participants
+Our participants are a bit boring.  Let's beef them up a bit:
+
+<pre>@startuml
+' use strict UML mode
+skinparam style strictuml
+
+<mark style="background:lime">participant "BookEditor" as editor &lt;&lt;form&gt;&gt;
+participant "Book" as book &lt;&lt;domain&gt;&gt;</mark>
+
+<mark style="background:aqua">editor -> book</mark> : getName()
+<mark style="background:aqua">return name</mark>
+@enduml
+</pre>
+
+[[plantuml[
+@startuml
+' use strict UML mode
+skinparam style strictuml
+
+participant "BookEditor" as editor <<form>>
+participant "Book" as book <<domain>>
+
+editor -> book : getName()
+return name
+@enduml
+]]]
+
+The names in the speech marks are independent of the alias (the bits defined by the `as`).  This is handy for large diagrams because it means that we can change the displayed name of a participant without needing to change all references in the source code.  We can also use much shorter names for the aliases which makes referring to the participants much easier.
+
+The stereotypes (the bits in the `<< >>`) are additional information that describe the type or role of a class.  They are a handy way of adding additional information about a class particularly if it is not that obvious what role the class plays from the class name alone.  Note that stereotypes are optional, but handy, so we will use them for most classes.
+
+! Self Calls
+We can show an object performing internal processing, or making calls on itself using a self-call:
+<pre>@startuml
+' use strict UML mode
+skinparam style strictuml
+
+participant "BookEditor" as editor &lt;&lt;form&gt;&gt;
+participant "Book" as book &lt;&lt;domain&gt;&gt;
+
+<mark style="background:aqua">' self call
+editor -> editor : getText() </mark>
+@enduml
+</pre>
+[[plantuml[
+@startuml
+' use strict UML mode
+skinparam style strictuml
+
+participant "BookEditor" as editor <<form>>
+participant "Book" as book <<domain>>
+
+' self-call
+editor -> editor : getText()
+
+@enduml
+]]]
+
+!Variables and Parameters
+Here is how to show variables and parameters:
+
+<pre>@startuml
+' use strict UML mode
+skinparam style strictuml
+
+participant "BookEditor" as editor &lt;&lt;form&gt;&gt;
+participant "Book" as book &lt;&lt;domain&gt;&gt;
+
+' get the author from the text component
+editor -> editor : getText() <mark style="background:aqua">: author</mark>
+
+<mark style="background:lime">' set the author field in the book
+editor -> book : setAuthor(author)</mark>
+
+@enduml
+</pre>
+
+[[plantuml[
+@startuml
+' use strict UML mode
+skinparam style strictuml
+
+participant "BookEditor" as editor <<form>>
+participant "Book" as book <<domain>>
+
+' get the author from the relevant text component
+editor -> editor : getText() <color red>: author</color>
+
+' set the author field in the book
+editor -> book : setAuthor(<color red>author</color>)
+
+@enduml
+]]]
+The `getText` call introduces a variable (`author`) that is then passed to the book as a parameter in the `setAuthor` call.
+
+Note that we will sometimes used a dashed line for these self-calls that return values since the call and response are combined &mdash; using the dashed line makes it more obvious that the call is returning something important:
+
+<pre>@startuml
+' use strict UML mode
+skinparam style strictuml
+
+participant "BookEditor" as editor &lt;&lt;form&gt;&gt;
+participant "Book" as book &lt;&lt;domain&gt;&gt;
+
+' get the author from the text component
+editor <mark style="background:cyan">--></mark> editor : getText(): author
+
+' set the author field in the book
+editor -> book : setAuthor(author)
+
+@enduml
+</pre>
+
+[[plantuml[
+@startuml
+' use strict UML mode
+skinparam style strictuml
+
+participant "BookEditor" as editor <<form>>
+participant "Book" as book <<domain>>
+
+' get the author from the relevant text component
+editor --> editor : getText() : author
+
+' set the author field in the book
+editor -> book : setAuthor(author)
+
+@enduml
+]]]
+
+!Actors
+We can show users interacting with the system using an `actor`:
+
+<pre>@startuml
+' use strict UML mode
+skinparam style strictuml
+
+<mark style="background:lime">actor "User" as user</mark>
+participant "BookEditor" as editor &lt;&lt;form&gt;&gt;
+participant "Book" as book &lt;&lt;domain&gt;&gt;
+
+<mark style="background:lime">' user enters book details and clicks the save button
+user -> editor: enters book details
+user -> editor : clicks save button</mark>
+
+' get the author from the relevant text component
+editor --> editor : getText() : author
+
+' set the author field in the book
+editor -> book : setAuthor(author)
+
+@enduml
+</pre>
+
+
+[[plantuml[
+@startuml
+' use strict UML mode
+skinparam style strictuml
+
+actor "User" as user
+participant "BookEditor" as editor <<form>>
+participant "Book" as book <<domain>>
+
+' user enters book details and clicks the save book button
+user -> editor: enters book details
+user -> editor : clicks save button
+
+' get the author from the relevant text component
+editor --> editor : getText() : author
+
+' set the author field in the book
+editor -> book : setAuthor(author)
+
+@enduml
+]]]
+
+!Activation Bars
+Activation bars show when an object is active.  This will often be as a result of a method call on the object.  Activation bars can be helpful to show where a method call finishes and ends, and generally make the diagram easier to understand:
+
+<pre>@startuml
+' use strict UML mode
+skinparam style strictuml
+
+actor "User" as user
+participant "BookEditor" as editor &lt;&lt;form&gt;&gt;
+participant "Book" as book &lt;&lt;domain&gt;&gt;
+
+' user enters book details and clicks the save button
+user -> editor<mark style="background:aqua">++</mark> : enters book details
+<mark style="background:lime">editor--</mark>
+
+user -> editor<mark style="background:aqua">++</mark> : clicks save button
+
+' get the author from the relevant text component
+editor --> editor : getText() : author
+
+' set the author field in the book
+editor -> book<mark style="background:aqua">++</mark> : setText(author)
+<mark style="background:lime">book--
+
+editor--</mark>
+@enduml
+</pre>
+
+[[plantuml[
+@startuml
+' use strict UML mode
+skinparam style strictuml
+
+actor "User" as user
+participant "BookEditor" as editor <<form>>
+participant "Book" as book <<domain>>
+
+' user enters book details and clicks the save book button
+user -> editor++ : enters book details
+editor--
+
+user -> editor++ : clicks save button
+
+' get the author from the relevant text component
+editor --> editor : getText() : author
+
+' set the author field in the book
+editor -> book++ : setAuthor(author)
+book--
+editor--
+
+@enduml
+]]]
+
+You use `++` and `--` to control the activation bars on an object.
+
+A `return` will also deactivate an object.
+
+!Object Construction
+We can show an object being created as follows:
+
+<pre>@startuml
+' use strict UML mode
+skinparam style strictuml
+
+actor "User" as user
+participant "BookEditor" as editor &lt;&lt;form&gt;&gt;
+participant "Book" as book &lt;&lt;domain&gt;&gt;
+
+' user enters book details and clicks the save book button
+user -> editor++ : enters book details
+editor--
+
+user -> editor++ : clicks save button
+
+' get the author from the relevant text component
+editor --> editor : getText() : author
+
+<mark style="background:lime">' construct the book object
+create book
+editor -> book : &lt;&lt;construct&gt;&gt;</mark>
+
+' set the author field in the book
+editor -> book++ : setAuthor(author)
+editor--
+@enduml
+</pre>
+
+[[plantuml[
+@startuml
+' use strict UML mode
+skinparam style strictuml
+
+actor "User" as user
+participant "BookEditor" as editor <<form>>
+participant "Book" as book <<domain>>
+
+' user enters book details and clicks the save book button
+user -> editor++ : enters book details
+editor--
+
+user -> editor++ : clicks save button
+
+' get the author from the relevant text component
+editor --> editor : getText() : author
+
+create book
+editor -> book : <<construct>>
+
+' set the author field in the book
+editor -> book++ : setAuthor(author)
+book--
+editor--
+
+@enduml
+]]]
+
+If we wanted to pass the details into the Book constructor instead of using the set method:
+
+<pre>@startuml
+' use strict UML mode
+skinparam style strictuml
+
+actor "User" as user
+participant "BookEditor" as editor &lt;&lt;form&gt;&gt;
+participant "Book" as book &lt;&lt;domain&gt;&gt;
+
+' user enters book details and clicks the save book button
+user -> editor++ : enters book details
+editor--
+
+user -> editor++ : clicks save button
+
+' get the author from the relevant text component
+editor --> editor : getText() : author
+
+create book
+editor -> book : <mark style="background:aqua">&lt;&lt;construct(author)&gt;&gt;</mark>
+
+<mark style="background:fuchsia">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
+&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
+&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</mark>
+
+@enduml
+</pre>
+
+[[plantuml[
+@startuml
+' use strict UML mode
+skinparam style strictuml
+
+actor "User" as user
+participant "BookEditor" as editor <<form>>
+
+
+' user enters book details and clicks the save book button
+user -> editor++ : enters book details
+editor--
+
+user -> editor++ : clicks save button
+
+' get the author from the relevant text component
+editor --> editor : getText() : author
+
+create "Book" as book <<domain>>
+editor -> book : <<construct<color red>(author)</color>>>
+@enduml
+]]]
+
+! Variables and Construction
+We will usually do something with an object when we create it, so we need a variable name for representing the constructed object:
+
+<pre>@startuml
+' use strict UML mode
+skinparam style strictuml
+
+actor "User" as user
+participant "BookEditor" as editor &lt;&lt;form&gt;&gt;
+participant "<mark style="background:aqua">book: </mark>Book" as book &lt;&lt;domain&gt;&gt;
+
+' user enters book details and clicks the save book button
+user -> editor++ : enters book details
+editor--
+
+user -> editor++ : clicks save button
+
+create book
+<mark style="background:aqua">editor -> book : &lt;&lt;construct&gt;&gt;</mark>
+
+<mark style="background:lime">' get the author from the relevant text component
+editor --> editor : getText() : author
+
+' set the author field in the book
+editor -> book++ : setAuthor(author)
+book--
+
+' create a DAO
+create "BookListDAO" as dao &lt;&lt;DAO&gt;&gt;
+editor -> dao : &lt;&lt;construct&gt;&gt;
+
+' save book
+editor -> dao++ : save(book)
+dao--
+editor--</mark>
+@enduml
+</pre>
+
+
+[[plantuml[
+@startuml
+' use strict UML mode
+skinparam style strictuml
+
+actor "User" as user
+participant "BookEditor" as editor <<form>>
+participant "<color:red>book : </color>Book" as book <<domain>>
+participant "BookListDAO" as dao <<DAO>>
+
+' user enters book details and clicks the save book button
+user -> editor++ : enters book details
+editor--
+
+user -> editor++ : clicks save button
+
+create book
+editor -> book : <<construct>>
+
+' get the author from the relevant text component
+editor --> editor : getText() : author
+
+' set the author field in the book
+editor -> book++ : setAuthor(author)
+book--
+
+' create a DAO
+create dao
+editor -> dao : <<construct>>
+
+' save book
+editor -> dao++ : save(<color red>book</color>)
+dao--
+editor--
+@enduml
+]]]
+
+!Object Destruction
+We sometimes want to show when an object is destroyed, or at least no longer active.  This is useful for showing when a form is no longer being displayed on the screen.  If you have a main menu that creates other forms in response to the user clicking buttons, then destroying one of those other forms would imply that the user is back at the main menu again, and can longer interact with the destroyed form.
+
+<pre>@startuml
+' use strict UML mode
+skinparam style strictuml
+
+actor "User" as user
+<mark style="background:lime">participant "MainMenu" as menu <<form>></mark>
+participant "BookEditor" as editor &lt;&lt;form&gt;&gt;
+participant "book : Book" as book &lt;&lt;domain&gt;&gt;
+
+<mark style="background:lime">'user clicks add new book button
+user -> menu++: click 'Add New Book'
+create editor
+menu -> editor : &lt;&lt;construct&gt;&gt;</mark>
+
+' user enters book details and clicks the save book button
+user -> editor++ : enters book details
+editor--
+
+user -> editor++ : clicks save button
+
+create book
+editor -> book : &lt;&lt;construct&gt;&gt;
+
+' get the author from the relevant text component
+editor --> editor : getText() : author
+
+' set the author field in the book
+editor -> book++ : setAuthor(author)
+book--
+
+' create a DAO
+create "BookListDAO" as dao &lt;&lt;DAO&gt;&gt;
+editor -> dao : &lt;&lt;construct&gt;&gt;
+
+' save book
+editor -> dao++ : save(book)
+dao--
+editor--
+
+<mark style="background:lime">destroy editor</mark>
+
+@enduml
+</pre>
+
+
+[[plantuml[
+@startuml
+' use strict UML mode
+skinparam style strictuml
+
+actor "User" as user
+participant "MainMenu" as menu <<form>>
+participant "BookEditor" as editor <<form>>
+participant "book : Book" as book <<domain>>
+participant "BookListDAO" as dao <<DAO>>
+
+'user clicks add new book button
+user -> menu++: click 'Add New Book'
+create editor
+menu -> editor : <<construct>>
+
+' user enters book details and clicks the save book button
+user -> editor++ : enters book details
+editor--
+
+user -> editor++ : clicks save button
+
+create book
+editor -> book : <<construct>>
+
+' get the author from the relevant text component
+editor --> editor : getText() : author
+
+' set the author field in the book
+editor -> book++ : setAuthor(author)
+book--
+
+' create a DAO
+create dao
+editor -> dao : <<construct>>
+
+' save book
+editor -> dao++ : save(book)
+dao--
+editor--
+
+destroy editor
+
+@enduml
+]]]
+
+!Level of Detail
+We don't want a one-to-one mapping between diagram elements and source code.  That would produce a messy diagram that doesn't help us much.  What we are aiming for is to see the most important bits of the system, particularly the interaction between the objects.  It is a bit of a balancing act &mdash; too much detail results in a diagram that is effectively unreadable, and too little results in a diagram that is not a useful representation of the system.
+
+We want to show how the classes and methods that appear in the class diagrams are used to complete a particular use case.  It is the interactions between the classes and the method calls that we want to see in a sequence diagram.  If a programmer is given accurate domain and system model class diagrams, and a sequence diagram for a use case, then there should be just enough detail in the diagram to show the programmer how to use the classes in the class diagrams to implement the use case, and no more detail than that.
+
+Note:  Normally we wouldn't bother showing getter and setter calls like we have in this tutorial.  We wanted to keep it simple, and use something that you might have seen before if you have done some basic java programming.