Loading Java code into OJVM for execution in an Oracle Database Session

Java Code in Oracle Database Session

-- see demo at https://hemantoracledba.blogspot.com/2021/04/ojvm-loading-java-code-and-running-it.html

-- grant Java Code permission to only READ only /home/oracle/tmp
-- this should have been provided by the DBA
begin
       dbms_java.grant_permission('HEMANT',
                                        'SYS:java.io.FilePermission',
                                        '/home/oracle/tmp',  'read');
  
       dbms_java.grant_permission( 'HEMANT',
                                        'SYS:java.io.FilePermission',
                                         '/home/oracle/tmp/*',
                                         'read' );
 
      dbms_java.grant_permission( 'HEMANT',
                                       'SYS:java.lang.RuntimePermission',
                                        'getFileSystemAttributes',
                                        '' );
end;
/



-- here is where I load the Java code into my schema
connect hemant/hemant@orclpdb1

-- load the java code into the database
create or replace and compile java source named "readOSDirectory"
        as
    /* using  java.io */
        import java.io.*;
  
    /* create the main class */
        public class readOSDirectory
        {
    /* create the class to be executed from a procedure */
        public static void getList(String directory)
        {
   /* use File class from java.io */
          File directoryPath = new File( directory );
          File filesList[] = directoryPath.listFiles();
 
   /* read till end of list */
          for (File file : filesList)
            {
              System.out.println("File Name: "+file.getName()
                                 + "  File Size:  "+file.length());
            }
         }
        }
/


/* create a PL/SQL procedure to call the getList class */
create or replace
       procedure Read_Directory( p_directory in varchar2 )
       as language java
       name 'readOSDirectory.getList( java.lang.String )';
/

/* enable output to screen-- serveroutput is for my sqlplus session */
SET SERVEROUTPUT ON SIZE 100000
CALL dbms_java.set_output (100000);

begin
    Read_Directory('/home/oracle/tmp');
 end;
/