For an applet (or an application running under a securitymanager) to be allowed to perform secured actions (such as readingor writing a file), the applet (or application) must be grantedpermission for that particular action. In the Policy referenceimplementation, that permission must be granted by a grant entry ina policy configuration file. See below and the "Java Security ArchitectureSpecification" for more information. (The only exception isthat code always automatically has permission to read files fromits same (URL) location, and subdirectories of that location; itdoes not need explicit permission to do so.)