1. COP 3330 Notes 1/12

2. Today's topics Downloading Java and Eclipse Hello World Basic control structures Basic I/O Strings

3. Downloading Java

6. Downloading Eclipse

8. Creating a Java Program With Eclipse

13. Running a Java Program With Eclipse

14. Double-click Java Application

15. Running a Java Program With Eclipse

16. Running a Java Program Using Command Line

19. 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

20. Running a Java Program Using Command Line

22. 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=

23. 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)

24. 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