1. Download Sun Java JDK or JRE
Download Sun Java JDK or JRE from here (current version is JDK 6 Update 20)http://java.sun.com/javase/downloads/index.jsp.
Note: you can Skip login step.
Download rpm.bin package (example jdk-6u20-linux-i586-rpm.bin).
2. Change to root.
su - ## OR ## sudo -i
3. Change right directory (example /tmp) and Make JDK or JRE binary executable
cd /tmp chmod +x jdk-6u20-linux-i586-rpm.bin
4. Run binary
./jdk-6u20-linux-i586-rpm.bin
5. Install new Sun java, javac, javaws and libjavaplugin.so (for Firefox/Mozilla) with alternatives command
alternatives --install /usr/bin/java java /usr/java/jdk1.6.0_20/jre/bin/java 20000 alternatives --install /usr/bin/javaws javaws /usr/java/jdk1.6.0_20/jre/bin/javaws 20000 alternatives --install /usr/lib/mozilla/plugins/libjavaplugin.so libjavaplugin.so /usr/java/jdk1.6.0_20/jre/lib/i386/libnpjp2.so 20000 ## Install javac only if you installed JDK alternatives --install /usr/bin/javac javac /usr/java/jdk1.6.0_20/bin/javac 20000
6. Check current java, javac, javaws and libjavaplugin.so versions
java -version java version "1.6.0_20" Java(TM) SE Runtime Environment (build 1.6.0_20-b02) Java HotSpot(TM) Server VM (build 16.3-b01, mixed mode) javac -version javac 1.6.0_20 javaws Java(TM) Web Start 1.6.0_20 [...]
Note: Check libjavaplugin.so with restarting Mozilla Firefox and writing about:config on address bar.
6. Swap between OpenJDK and Sun JDK
alternatives --config java # or javac or javaws or libjavaplugin.so There are 3 programs which provide 'java'. Selection Command ----------------------------------------------- 1 /usr/lib/jvm/jre-1.6.0-openjdk/bin/java 2 /usr/lib/jvm/jre-1.5.0-gcj/bin/java *+ 3 /usr/java/jdk1.6.0_20/bin/java
Some Post-Installation Setup
Set JAVA_HOME environment variable, add following to /etc/profile file or .bashrc file
export JAVA_HOME="/usr/java/jdk1.6.0_20"
原文：http://www.if-not-true-then-false.com/2010/howto-install-sun-java-jdk-jre-on-fedora-centos-red-hat/