Configure the JCE Development Environment

Although jdk1.4 includes the Java security package in the core library, if JCE is not configured, JCE cannot be used for development.

First, go to Sun.Download jce1.2.2(All I see on the Internet is downloading a package, and Sun's default package is useless ),Copy all the jar files in the decompressed lib to your_jdk \ JRE \ Lib \ Ext.(Your_jdk is your JDK installation directory ),Edit your_jdk \ JRE \ Lib \ SECURITY \ Java. Policy File, Add

Grant codebase " File: $ {java. Home}/lib/EXT/sunjce_provider.jar "   {
Permission java. Io. filepermission
" File: $ {java. Home}/lib/EXT/sunjce_provider.jar " , " Read " ;
Permission java. Lang. runtimepermission
" Getprotectiondomain " ;
Permission java. Security. securitypermission
" Putproviderproperty. sunjce " ;
} ;

Grant access permissions to sunjce_provider

The optional provider type is configured in your_jdk \ JRE \ Lib \ SECURITY \ Java. Security. The default configuration is used here. (Here, the provider can also be replaced by the package provided by another vendor. I am not sure how to do it ).
Because I am using JBuilder for development, the link to the relevant database must be added. Therefore, add references to jce1_2_2.jar and sunjce_provider.jar in the properties library settings under the project. After the configuration is complete, you can perform JCE-relatedProgramCompiled.

I used JCE to write a small DES encryption and decryption program. I don't know why, but it runs very slowly. It seems that it takes time to load the provider. Even n doesn't know why Sun uses provider to install components, which is troublesome and unnecessary. I have not completed the configuration in eclipse for half a day, so I am depressed.