Here's a short tutorial on Java.
Testing Java at the command line:
Step 1: Here's a test program for a command-line java program:
Code:
class myfirstjavaprog
{
public static void main(String args[])
{
System.out.println("Hello World!");
}
}
One thing that annoys me about Java is that the name of file HAS TO MATCH the class name inside the file. So, name this file "myfirstjavaprog.java".
Step 2: Compile the test program:
Code:
javac myfirstjavaprog.java
This will create "myfirstjavaprog.class", if all is ok. If javac is not found at /usr/bin/javac, Java is not installed right. /usr/bin/javac is a symbolic link to /etc/alternatives/javac, which (in my case) is a symlink to /usr/lib/jvm/java-1.6.0-sun/bin/javac, which came out of an rpm file named jdk-1.6.0-fcs.i586.rpm, from Sun.
Step 3: Run the test program:
Code:
java myfirstjavaprog
Voila, a program that says "Hello world!".
Getting applets running in Firefox
Step 1: Get java running.
Step 2: Make the following symlink:
Code:
cd /usr/lib/mozilla/plugins
ln -s /usr/lib/jvm/java-1.6.0-sun-1.6.0/jre/plugin/i386/ns7/libjavaplugin_oji.so .
Step 3: Restart Firefox
Step 4: Test with
http://www.java.com/en/download/help/testvm.xml
If you have the dancing "Duke", congratulations. If you have a blank square, you have what I had yesterday. My accidental solution was to download the non-rpm version of java and install that. I think that was what fixed it, but I was trying a lot of stuff, so I can't be sure.
Getting JNLP pages (aka Java Web Start) to work
Step 1: In firefox, click on a JNLP file. When it asks what to do with it, tell it to run javaws. You'll have to browse for it. Mine is at /usr/java/jdk1.6.0/bin/javaws.
Step 2: There is no step 2. It should just work at this point.
Hope that helps!
Running Java, outside and inside a browser
