Java Programming For Mac



  1. Java Programming Environment Mac
  2. Java Jdk For Mac
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Hello, World in Java on Mac OS X


This documents instructs you on how to setup a Java programmingenvironment for your Mac OS X computer and provides a step-by-stepguide to creating, compiling, and executing a Java program.We assume you are running at least OS X 10.2.3.All of the software is freely available on the Web.

Java

The Apple Java Extensions contains a very complete development guide with information on the deployment of Java applications on Mac OS X and the production of application bundles. It also introduces other aspects of the Apple Java Extensions, like the. Java works on different platforms (Windows, Mac, Linux, Raspberry Pi, etc.) It is one of the most popular programming language in the world It is easy to learn and simple to use It is open-source and free. The JDK is a development environment for building applications, applets, and components using the Java programming language. The JDK includes tools useful for developing and testing programs written in the Java programming language and running on the Java platform. Important Oracle JDK License Update. Creating 'Native' Java Applications on Mac OS X If you develop on Mac OS X you can use the Jar Bundler application to turn jar files into Mac OS X applications. Jar Bundler is distributed with the other developer tools and is located in Developer/Applications/. Start it, select the 'Classpath and Files' tab and add the file JavaSoundDemo.jar. The installer installs and configures a Java programming environment, including OpenJDK 11 and IntelliJ IDEA, Community Edition 2020.1. Log in to the user account in which you will be programming. Your account must have Administrator privileges. Download the Mac OS X installer lift-java.pkg.

You will use the Java compiler javac to compile your Java programs andthe Java interpreter java to run them.Mac OS X includes implementation of Java 2 Standard Edition (J2SE) 1.4.1,so there is nothing to do in this step.

Command line interface

You will type commands in an application called the Terminal.You might enjoy reading Neal Stephenson's light-heartedessay In the Beginningwas the Command Line.

For
  • Open a terminal window. You can find this underGo -> Applications -> Utilities. Drag the Terminal to your dock sinceyou will be using it frequently.
  • You should now have a Terminal window somewhere on the screen.It will have a command prompt that looks something like:
  • To check that you have the right version of Java installed, typethe text in boldface below.
    If Java is installed, you should see something like:
    Now, check that the Java compiler is accessible.
    If it is installed, you should see something like
    If not, install the Developers Tools CD that came with your Mac anduse Software Update to make sure you have the latest version.
  • Now, create a directory to store your Java programs.In the window containing the Command Prompt, type the bold commandsbelow:
    The mkdir command creates a new directory;the cd command changes the current working directory.After executing these commands, your working directoryis the newly created ~username/introcs/hello/. All of yourfiles for Assignment 0 will go here.Don't be scared by the Terminal - you will only need to use afew basic commands. Keep this window open since you will need it laterin the assignment.
  • Since you will be using the Terminal frequently, we recommend customizingWe recommend customizing the default settings....

Text Editor

You will type and edit your programs in a text editor called JEdit.JEdit is similar to conventional word processors like MS Word,but it features many specialized programming tools includingsyntax highlighting, bracket matching, auto indenting, indentshifting, line numbering, and commenting out code. It's even written in Java.

  • Downloadthe latest stable version of JEdit using the MacOSX package link.
  • We recommend the following JEdit customizations.
    • Enable Mac OS style menubar inUtilities -> Global Options -> Plugins -> Mac OS Settings
    • Change the default indentation to four spaces viaUtilities -> Global Options -> Editing -> Indent Width andUtilities -> Global Options -> Editing -> Tab Width. Global Options -> Editing -> Soft tabs.-->
    • Change the default tab width when printing to four spaces viaUtilities -> Global Options -> Printing -> Tab width when printing
    • Add line numbers by checking Utilities -> Global Options -> Gutter -> Line Numbering
    • Allow at most 80 characters per line byUtilities -> Global Options -> Editing -> Word wrap -> hard andUtilities -> Global Options -> Editing -> Wrap margin -> 80.
    • Change the default line separator to Unix viaUtilities -> Global Options -> Loading & Saving -> Default Line Separator
    • Remove the annoying . that marks the end of a line by uncheckingUtilities -> Global Options -> Text Area -> End of Line Markers
  • To associate .java files with JEdit so that when you double-click a .java file,it opens it in JEdit:
    • Right click a .java file (or click then shift-right click it if using Windows NT)
    • Choose Open With...
    • Select JEdit from the list of programs or locate JEdit by selecting Otherif necessary.
    • Check the Always use this program to open this file type box
Apple purists may prefer Project Builder which can be found in the Findervia Computer -> OS X Partition -> Developer -> Applications -> Project Builder.
Create the program

Now you are ready to write your first Java program.

  • Launch JEdit Start -> jEdit.
  • In the JEdit window, type the Java program exactly as it appears below.If you omit even a semicolon, the program won't work.
  • When you're done, save the program usingFile -> Save As, chose the directory C:introcshelloand type in the file name HelloWorld.java.The file name is case sensitive and must exactly match the name of the classin the Java program. Don't forget to include the .java extension in thefile name.
Compile the program

It is now time to convert your Java program into a form more amenable for executingon a computer.

  • From the Command Prompt, type
    If javac complains in some way, you mistyped something, and you should check your program carefully. Ask for help if you can't see the mistake.
  • If everything went well, you should see the followingin the Command Prompt:
    Silence is golden in computer science.
Execute the program

Now it is time to run your program. This is the fun part.

  • At the Command Prompt, type
  • If all goes well, you should see
  • You may need to repeat this edit-compile-execute cycle a few times before it all goes smoothly.Use the up and down arrow keys to repeat previous commands and avoid extra typing.
Congratulations, you are now a Java programmer!
Troubleshooting

Java Programming Environment Mac

When I try to run java I get: Exception in thread 'main'java.lang.NoClassDefFoundErrorYour CLASSPATH may have been set by some other program so that it no longer includes the current working directory in the search path. Try running your program with the command line


In this section, our plan is to lead you into the world of Java programming by taking you through the three basic steps required to get a simple program running. As with any application, you need to be sure that Java is properly installed on your computer.You also need an editor and a terminal application. Here aresystem specific instructions for three popular home operating systems.[Mac OS X ·Windows ·Linux]

Programming in Java.

We break the process of programming in Java into three steps:
  1. Create the program by typing it into a text editor andsaving it to a file named, say, MyProgram.java.
  2. Compile it by typing 'javac MyProgram.java' in theterminal window.
  3. Execute (or run) it by typing'java MyProgram' in the terminal window.

The first step creates the program; the second translates it into a languagemore suitable for machine execution (and puts the result in a file namedMyProgram.class); the third actually runs the program.

  • Creating a Java program.A program is nothing more than a sequence of characters, like a sentence, aparagraph, or a poem. To create one, we need only define that sequence charactersusing a text editor in the same way as we do for email.HelloWorld.java is an example program.Type these character into your text editor and save it into a filenamed HelloWorld.java.
  • Compiling a Java program.A compiler is an application that translates programs from theJava language to a language more suitable for executing on the computer.It takes a text file with the .java extension as input (yourprogram) and produces a file with a .class extension (the computer-language version). To compile HelloWorld.java typethe boldfaced text below at the terminal. (We use the % symbolto denote the command prompt, but it may appear different dependingon your system.)If you typed in the program correctly, you should see no error messages.Otherwise, go back and make sure you typed in the program exactly asit appears above.
  • Executing (or running) a Java program.Once you compile your program, you can execute it.This is the exciting part, where the computer follows your instructions.To run the HelloWorld program, type the following in the terminal window:

    If all goes well, you should see the following response

  • Understanding a Java program.The key line with System.out.println() prints the text 'Hello, World'in the terminal window.When we begin to write more complicated programs, we will discuss themeaning of public,class, main,String[],args,System.out, and so on.
  • Creating your own Java program.For the time being, all of our programs will be just likeHelloWorld.java, except with a different sequence of statementsin main(). The easiest way to write such a program is to:
    • Copy HelloWorld.java into a new file whose name is theprogram name followed by .java.
    • Replace HelloWorld with the program name everywhere.
    • Replace the print statement by a sequence of statements.

Errors.

Most errors are easily fixed by carefully examining the program as wecreate it, in just the same way as we fix spelling and grammatical errors when we type an e-mail message.
  • Compile-time errors.These errors are caught by the system when we compile the program, because they prevent the compiler from doing the translation (so it issues an error message that tries to explain why).
  • Run-time errors.These errors are caught by the system when we execute the program, because the program triesto perform an invalid operation (e.g., division by zero).
  • Logical errors.These errors are (hopefully) caught by the programmer when we execute the programand it produces the wrong answer.Bugs are the bane of a programmer's existence.They can be subtle and very hard to find.
One of the very first skills that you will learn is to identify errors;one of the next will be to be sufficiently careful when coding to avoid many of them.

Input and output.

Typically, we want to provide input to our programs:data that they can process to produce a result. The simplest way to provide input data is illustrated in UseArgument.java.Whenever this program is executed, it reads the command-line argument that you type after the program name and prints it back out to the terminal as part of the message.

Exercises

Mac
  1. Write a program TenHelloWorlds.javathat prints 'Hello, World' ten times.
  2. Modify UseArgument.java to make a programUseThree.java that takes three namesand prints out a proper sentence with the names in the reverse of the order given, so that for example,'java UseThree Alice Bob Carol'gives 'Hi Carol, Bob, and Alice.'.

Web Exercises

Java Jdk For Mac

  1. Write a program Initials.java thatprints your initials using nine rows of asterisks like the one below.
  2. Describe what happens if, in HelloWorld.java, you omit
    1. main
    2. String
    3. HelloWorld
    4. System.out
    5. println
  3. Describe what happens if, in HelloWorld.java, you omit
    1. the ;
    2. the first '
    3. the second '
    4. the first {
    5. the second {
    6. the first }
    7. the second }
  4. Describe what happens if, in HelloWorld.java,you misspell (by, say, omitting the second letter)
    1. main
    2. String
    3. HelloWorld
    4. System.out
    5. println
  5. I typed in the following program. It compiles fine, but when I executeit, I get the error java.lang.NoSuchMethodError: main.What am I doing wrong?Answer: you forgot the String[] args. It isrequired.
Java Programming For Mac

Java Development For Mac


Java Programming Download For Mac

Last modified on August 02, 2016.
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