What is the "jar" command to replace some class files in a JAR? I have recompiled classes in a folder ready to replace those same classes in a JAR file.

To replace existing class files in an existing JAR file, you can use the "jar -uvf jarname foldername" command.

For example, the following session updates an existing JAR file with all classes in the .\javax folder:

\fyicenter>"%java_home%\bin\jar" -xvf jms.jar

\fyicenter>"%java_home%\bin\jar" -cvf myNew.jar .\javax

(Recompile all classes under .\javax, if you the source code)

\fyicenter>"%java_home%\bin\jar" -uvf myNew.jar .\javax
adding: javax/(in = 0) (out= 0)(stored 0%)
adding: javax/jms/(in = 0) (out= 0)(stored 0%)
adding: javax/jms/BytesMessage.class(in = 1202) (out= 494)(deflated 58%)
adding: javax/jms/Connection.class(in = 945) (out= 373)(deflated 60%)
adding: javax/jms/ConnectionConsumer.class(in = 275) (out= 189)(deflated 31%
adding: javax/jms/ConnectionFactory.class(in = 311) (out= 179)(deflated 42%)
adding: javax/jms/ConnectionMetaData.class(in = 544) (out= 271)(deflated 50%
adding: javax/jms/DeliveryMode.class(in = 207) (out= 160)(deflated 22%)
adding: javax/jms/Destination.class(in = 113) (out= 95)(deflated 15%)
...

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