How to estimate zip file size in java before creating it

Question

I am having a requirement wherein i have to create a zip file from a list of available files. The files are of different types like txt,pdf,xml etc.I am using java util clas

Answer 1

just wanted to share how we implemented manual way

            int maxSizeForAllFiles = 70000; // Read from property
        int sizePerFile = 22000; // Red from property
        /**
         * Iterate all attachment list to verify if ZIP is required
         */
        for (String attachFile : inputAttachmentList) {
            File file = new File(attachFile);
            totalFileSize += file.length();
            /**
             * if ZIP required ??? based on the size
             */
            if (file.length() >= sizePerFile) {
                toBeZipped = true;
                logger.info("File: "
                            + attachFile
                                + " Size: "
                                + file.length()
                                + " File required to be zipped, MAX allowed per file: "
                                + sizePerFile);
                break;
            }
        }
        /**
         * Check if all attachments put together cross MAX_SIZE_FOR_ALL_FILES
         */
        if (totalFileSize >= maxSizeForAllFiles) {
            toBeZipped = true;
        }
        if (toBeZipped) {
            // Zip Here iterating all attachments
        }