In Arch Linux Wiki page, it mentioned that OpenJDK is nearly perfect which we need not to install Oracle proprietary Java. But sadly to know, there are some Java applet which needs Java Runtime Environment version 6 instead of 7. That means, neither OpenJDK nor Oracle proprietary Java 7 works.
However, in Arch Linux, if doing replacement, that means we need to remove the unwanted packages. Removing the packages, because of the dependencies, all the other packages depend on them will also need to be removed. Yet, this problem can be solved with some tricks in pacman,
sudo pacman -Rndd jdk7-openjdk jre7-openjdk jre7-openjdk-headless icedtea-web-java7 java-rhino #Use -dd to ignore dependencies check
As a result, only those packages will be removed. The other packages depend on them will not be removed, such as jedit. By this, we can install the jre6 and jdk6 after that.
Besides that, we can check whether missing dependencies with “testdb” command from pkgtools package. It will be helpful if we remove some of the packages without dependencies check.
Now, the Java applet is working.