cop 3330 notes 1/12. today's topics downloading java and eclipse hello world basic control...
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COP 3330
Notes 1/12
Today's topics
• Downloading Java and Eclipse
• Hello World
• Basic control structures
• Basic I/O
• Strings
Downloading Java
Downloading Java
Downloading Java
Downloading Eclipse
Downloading Eclipse
Creating a Java Program With Eclipse
Creating a Java Program With Eclipse
Creating a Java Program With Eclipse
Creating a Java Program With Eclipse
Creating a Java Program With Eclipse
Running a Java Program With Eclipse
Running a Java Program With Eclipse
• Double-click Java Application
Running a Java Program With Eclipse
Running a Java Program Using Command Line
Running a Java Program Using Command Line
Running a Java Program Using Command Line
Running a Java Program Using Command Line
• Add the path of the bin directory of your JDK install to your path environment variable
• In my case:– C:\Program Files\Java\jdk1.5.0_04\bin
Running a Java Program Using Command Line
Running a Java Program Using Command Line
Running a Java Program Using Command Line
• If you get the error: – Exception in thread "main"
java.lang.NoClassDefFoundError: HelloWorldApp
• Make sure you’re in the same directory as your .java file and that you typed everything correctly
• If you still get the error, type at the command line: set CLASSPATH=
Java Virtual Machine
• Java is compiled to Java bytecode, not machine language
• Java bytecode is similar to machine code except that it is meant for the Java Virtual Machine (JVM)
• The JVM is an interpreter of Java bytecode (i.e. it runs Java programs)
Java Virtual Machine
• Machine language must be specific to a processor, so programs written in most languages must be recompiled to run on different processors
• The same compiled Java program can run on any computer that can run the correct version of the JVM