Member Avatar for omar isaid

java.io.FilePermission
this exception always thrown when I am trying to run my code using tahiti server that i am developing java mobile agent

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  • Latest Post Latest Post by omar isaid

Dani AI

Generated

Good catch by and a solid prompt from to get a stack trace — permission errors are usually resolved by checking class/package layout first and then the security policy.

Checklist to avoid java.io.FilePermission with Tahiti/Aglets

  • Make sure the class is declared in a package (use the lowercase package keyword) and that the package name exactly matches the folder structure under the server’s public codebase.
  • The compiled .class (or JAR) must be placed under the public codebase in the same path as the package.
  • When instantiating an aglet, provide the aglet’s fully qualified class name (package + class). On Unix-like systems names are case-sensitive — match case exactly.
  • The aglet class should be public and its filename must match the public class name.

If the FilePermission still appears

  • Inspect the server-side stack trace to see which component attempted file I/O. That tells whether it was the classloader, the aglet code, or your own code being blocked.
  • If the SecurityManager is blocking legitimate reads from the public directory, grant read permission in the server’s policy file and restart Tahiti. Example (replace the path with your server public path):
grant {
  permission java.io.FilePermission "/path/to/tahiti/public/-", "read";
};

Quick debugging tips

  • Try a minimal public aglet in a simple package to verify the server can instantiate it, then move to your real package.
  • Avoid the default package for anything the server must load.
  • When reopening the issue, include the exact stack trace and server log lines so helpers can see whether the problem is classloading vs. security policy.

Recommended Answers

All 3 Replies

Member Avatar for peter_budo

There must be reason why that error is thrown.

Please post relevant code and do not forget include stack trace of error

Member Avatar for omar isaid

Thank you very much I found the error

AgletProxy p;  //line 1
p=getAgletContext().createAglet(getCodeBase(),"child",null); //line 2

line2 is the error and correction is

AgletProxy p;  //line 1
p=getAgletContext().createAglet(getCodeBase(),
"examples.folder1.child",null);          //line 2

where in windows OS
C:\aglets-2.0.2\public\examples\folder1

and "folder1" contains java files I am developing

Edited by peter_budo because: Keep It Organized - For easy readability, always wrap programming code within posts in [code] (code blocks)
Member Avatar for omar isaid

There must be reason why that error is thrown.

Please post relevant code and do not forget include stack trace of error

Thank you very much I found the error

AgletProxy p;  //line 1
p=getAgletContext().createAglet(getCodeBase(),"child",null); //line 2

line2 is the error and correction is

AgletProxy p;  //line 1
p=getAgletContext().createAglet(getCodeBase(),
"examples.folder1.child",null);          //line 2

where in windows OS
C:\aglets-2.0.2\public\examples\folder1

and "folder1" contains java files I am developing

Thank you very Much Peter you are so gentle
I have a problem in the package that the correct syntax is

Package examples.folder1;

examples is a folder appears after installation of Tahiti server
folder1 : the Folder I created to create java files inside it

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