Review of Previous Lesson 31/05/2019 Review of Previous Lesson State as many Vocabulary words and Learning Objectives that you remember from the last lesson as you can. Remember to grade yourself from 0 - 3.

31/05/2019 Introduction to Java

Vocabulary 31/05/2019 Content: Start End state describe common terms software hardware high level language machine code source code compiler

31/05/2019 Vocabulary Content: Start End object code Javac JVM JDK

Learning Objectives 31/05/2019 Content: Start End State and describe common java terms. State what needs to be installed to write, compile and run a Java program.

Software Software Hardware Computer instructions or data. 31/05/2019 Software Computer instructions or data. Makes a computer do something and are written to run on the hardware. Hardware Software

e.g. Visual Basic, Java, C, Fortran 31/05/2019 Software Software is usually written in a high level language which is fairly similar to our own spoken languages. This makes it easier for us humans to use. However, computers only understand machine code which is in binary form (1s and 0s). Hardware High Level Languages e.g. Visual Basic, Java, C, Fortran Machine Code

31/05/2019 Compilers Translate high level languages (the translator’s source code) into machine code (the translator’s object code) which can be executed by a computer. Compiler High Level Languages Machine Code Source Code Object Code written in a high level language. Code in executable form.

Java Compiler Javac Compiler Java Program Bytecode .java file 31/05/2019 Java Compiler Javac Compiler Java Program Bytecode .java file .class file

Java Virtual Machine (JVM) 31/05/2019 Java Virtual Machine (JVM) Executes the Java Bytecode (.class file) produced by Javac Compiler. Each Operating System (OS) e.g. Windows, Mac, Linux etc… has a different JVM to tell the OS what to do in its own machine code language. This is why we call Java a platform (OS) independent language. As any OS can execute a Java program as long as it has a Javac Compiler or it has previously been compiled into Java Bytecode and it has a JVM to execute this Java Bytecode.

Java Runtime Environment (JRE) 31/05/2019 Java Runtime Environment (JRE) Includes: JVM Browser plugins Programs written to add extra features to a browser. Applets support Java programs written to run on web pages. When you have JRE installed on your system, you can run a Java program however you wouldn’t be able to compile a Java program. Needed when you only need to run Java programs on your computer (not compile your own programs).

Java Development Kit (JDK) 31/05/2019 Java Development Kit (JDK) Includes: JRE Compilers Various other tools like JavaDoc, Java debugger etc. JavaDoc: software documentation generator for Java programmers in HTML format (from Java source code). Debugger: A program that assists in the detection and correction of errors in computer programs. In order to create, compile and run Java programs you will need JDK installed on your computer.

Install Java You can get the java from here. 31/05/2019 Remember you need to install the JDK. Recommended: install only the latest version of “8u…”. Later versions (11, 12, ..) are not needed and overcomplicate things for AP CS. Also although it is possible to install multiple versions of JDK/JRE concurrently, it is messy. If you have previous installations of older version(s) of JDK/JRE, un-install ALL of them. Search Windows for "Control Panel" ⇒ "Programs" ⇒ "Programs and Features" ⇒ Un- install ALL programs begin with "Java", such as "Java SE Development Kit ...", "Java SE Runtime ...", "Java X Update ...", and etc. I suggest that you click the back and forward arrows each time you uninstall to make sure you update the installed programs list. If necessary, read "JDK Installation Common Errors". For how to proceed on a Mac please see: https://www3.ntu.edu.sg/home/ehchua/programming/howto/JDK_Howto.html

31/05/2019 Permanent Java path setup guide - 1st time use only, this only needs to be done once It is possible to use an IDE like Eclipse to run java programs but I intend to only use a text editor and command prompt. The Java compiler javac.exe and Java runtime java.exe reside in the "bin" folder of the JDK folder. So to run JDK programs from the command prompt, it needs to be told to also search this folder for executable programs. This is done by adding this “bin” folder to what is known as the “Path”. Please follow the instructions on the next 5 slides to do this. For how to proceed on a Mac please see: https://www3.ntu.edu.sg/home/ehchua/programming/howto/JDK_Howto.html

31/05/2019 Permanent Java path setup guide - 1st time use only, this only needs to be done once Navigate to the folder which contains the JDK's programs. Click the yellow folder icon in the address bar. Copy the address for pasting later.

31/05/2019 Permanent Java path setup guide - 1st time use only, this only needs to be done once Click Windows for: environment variables Click Edit the system environment variables. 2 1 If you are using an older version of Windows or for whatever reason cannot do this, please see the next slide.

31/05/2019 Permanent Java path setup guide - 1st time use only, this only needs to be done once If you are using an older version of Windows or for whatever reason cannot do the instructions on the previous slide, use the Control Panel (Start Menu - Windows System). 2 3 1

31/05/2019 Permanent Java path setup guide - 1st time use only, this only needs to be done once If you cannot do slide 16 only.

31/05/2019 Permanent Java path setup guide - 1st time use only, this only needs to be done once If you cannot do slide 16 only.

31/05/2019 Permanent Java path setup guide - 1st time use only, this only needs to be done once If you cannot do slide 16 only.

31/05/2019 Permanent Java path setup guide - 1st time use only, this only needs to be done once If you cannot do slide 16 only.

31/05/2019 Permanent Java path setup guide - 1st time use only, this only needs to be done once Click Path and Edit.

Permanent Java path setup guide - 1st time use only, this only needs to be done once 31/05/2019 Read the following 3* before actually completing as there is no undo! Do NOT delete "Variable value" field. Otherwise, some existing applications may not run. To be SAFE, copy the content of the "Variable value" and paste to somewhere before changing it!!! Click at the beginning of the existing contents to get a cursor and paste the address that you copied earlier (Ctrl + v), of the “bin” folder, followed by a ; Click OK * 2 (this & the previous “Environment Variables” windows). If you don’t see the above, try the next slide.

31/05/2019 Permanent Java path setup guide - 1st time use only, this only needs to be done once If you didn’t see the screenshot on the previous slide, you should see this one. 1 2 Paste the address that you copied earlier (Ctrl + v), of the “bin” folder. Click OK * 2 (this & the previous “Environment Variables” windows).

5/31/2019 Grade yourself Grade yourself on the vocabulary and learning objectives of the presentation.