Why am I getting package javax.crypto does not exist

问题

When I compile a class using javax.crypto.Mac I get this error message?

package javax.crypto does not exist

I can fix it by including jre/lib/jce.jar in my compile classpath.

Why is jce.jar not on the default jdk classpath? jre/lib/rt.jar is on the classpath, and includes other javax packages, but jce seems special?

回答1:

OK, this was a mistake on my part. The Ant file I was using to compile the code had this attribute on the javac task:

bootclasspath="${java.home}/lib/rt.jar" 

Doh. You can add the JCE jar like this:

bootclasspath="${java.home}/lib/rt.jar:${java.home}/lib/jce.jar"

回答2:

Beware! This class is only included in the jdk from oracle. That means your program won;t be portable among different jdk (eg openjdk) It is preferable to use this lib externally, it can be downloaded from here

回答3:

It worked for me, I downloaded the zip and paste these 3 files into C:\Program Files\Java\jdk1.7.0_11\jre\lib\ext as explained in jce-1_2_2/jce1.2.2/INSTALL.html in the zip file.

• jce1_2_2.jar
• US_export_policy.jar
• local_policy.jar

来源：https://stackoverflow.com/questions/14935447/why-am-i-getting-package-javax-crypto-does-not-exist