create or replace and compile java source named zipblob as
 import  oracle.sql.BLOB;
 import  java.io.EOFException;
 import  java.io.InputStream;
 import  java.sql.Connection;
 import  java.sql.DriverManager;
 import  java.util.zip.ZipEntry;
 import  java.util.zip.ZipOutputStream;
 public   class  ZipBlob {
   public   static  BLOB compress(BLOB blob, String fileName)
     throws  Exception {
    Connection con = DriverManager.getConnection("jdbc:default:connection:");
    BLOB result = BLOB.createTemporary(con, true, BLOB.DURATION_SESSION);
    ZipOutputStream out =  new  ZipOutputStream(result.getBinaryOutputStream());
    InputStream in =  null ;
     try  {
      in = blob.getBinaryStream();
      out.putNextEntry( new  ZipEntry(fileName));
       byte [] b =  new   byte [blob.getChunkSize()];
       int  iCount;
       do  {
        iCount = in.read(b);
         if  (iCount != - 1 ) {
          out.write(b,  0 , iCount);
        }
      }  while  (iCount != - 1 );
    }  catch  (EOFException e) {
    }  finally  {
       if  (in !=  null ) {in.close();}
    }
    out.close();
     return  result;
  }
}

report.zip: Unexpected end of archive