Understanding JRE

Posted on 2003-03-20
Medium Priority
Last Modified: 2013-11-23
Hi All,

Cud u please help me understand this pls. As I understand to run a HelloWorld application program  which prints HelloWorld on Console, I need  JRE (WHICH COMES WITH JAVA.EXE) and so I can do java HellWorld and it runs HelloWorld.

As in other question, I understand that JRE is actually JVM..

Now without JRE, I cannnot do java HelloWorld..

but without JRE on my machine, I can run Applet HelloWorld because IE comes with JRE 1.3 .. so IE as well as Netscape has JVM in built for them but older version..

If I download JRE 1.4 on my machine.. and install it, so I can do java HelloWorld

but now applets in browser also runs with more recent version of JRE 1.4 (which i downloaded).

So now browsers are using JVM on my machine instead of their own JVM's?
Could somebody explain me what happened here? I downloaded JVM on my machine (JRE 1.4). Why are browsers are not using their own JVM's (1.3).

Am i understanding it correctly.. or am i missing something here.

Thanks for help,
Question by:hunky_sh
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Expert Comment

ID: 8173927
They are using the installed JVM because in the process of installation on the host computer, the JRE will install the Java Plug-in for all installed browsers. Since the plugin is JRE version dependent, will overwrite the default one installed in your browsers.

Accepted Solution

Ovi earned 300 total points
ID: 8173941
The applets in the browsers are running under jre1.1.8 in IE and 1.1.x in netscape. This is the default JVM installed in the browsers. This old versions are incapable of running java swing applets. For that the JRE will install the plugin, to give the possibility to the user to run such applets.

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