Managing Policy Files
The Java Runtime provides default policy files to be used. See 

 http://java.sun.com/products/jdk/1.2/docs
               /guide/security/PolicyFiles.html
 
for more information. The location of these file is specified in the file java.home/lib/security/java.security. By default, this file specifies two locations: 
 file:/java.home
            /lib/security/java.policy
 file:/user.home
            /lib/security/.java.policy
 
The runtime's policy is the union of entries in these files. To specify an additional policy file, you can add entries to the java.security file: 
 > java -Djava.security.manager 
            -Djava.security.policy=someURL MyApp
 
or specify the addition at runtime: 
 > appletviewer 
        -J-Djava.security.policy=someURL HTMLfile
 
To ignore the policies in the java.security file, and only use the specified policy, use == instead of =: 
 >java -Djava.security.manager 
         -Djava.security.policy==someURL MyApp