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use of rt.jar

vikas malviya

Joined: Aug 06, 2009
Posts: 14
is it necessary to include any of the below jar files in the classpath

1.rt.jar ,tools.jar,dt.jar

2.what is the use of these jar files???

Vikas Malviya
Campbell Ritchie

Joined: Oct 13, 2005
Posts: 45286
No. Unless you use a very old JVM, it will automatically search those .jars.

The Sun Java API classes are (I think) inside rt.jar. On my machine dt.jat appears to contain all the Swing class files. You will have difficulty running anything without rt.jar!
Ulf Dittmer

Joined: Mar 22, 2005
Posts: 42959
No, it's not necessary. They contain code that's used by the various tools (java, javac, javadoc, jar, ...) and other stuff used internally by the JVM. But the JVM knows how and where to find these jar files, so you don't need to worry about them.
I agree. Here's the link:
subject: use of rt.jar
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