Question

Hi I have a webapp – and in one method I need to encrypt part of data from request and store them on disk and return response.

Response is in no way related to encryption.

The encryption is quite time demanding however. How to make threads or so properly in this problem?

I tried something like

Thread thread …

thread.start();

or

JobDetail job = encryptionScheduler.getJobDetail(jobDetail.getName(), jobDetail.getGroup());

encryptionScheduler.scheduleJob(jobDetail,TriggerUtils.makeImmediateTrigger(“encryptionTrigger”,1,1)

I tried servlet where before encryption I close the outpuStream.

or: Executors.newFixedThreadPool(1);

But whatever I tried a client has to wait longer.

btw: why is that so? Can it be faster?

I haven’t tried to start thread after context initalization and wait somehow for method needing encryption.

how to speed up this?

thank you

————–EDIT:
//I use axis 1.4, where I have Handler, which in invoke method encrypt a value:

try {
    LogFile logFile = new LogFile(strategy,nodeValue,path, new Date());
    LogQueue.queue.add(logFile);
    }
    catch (Exception e) {
        log.error(e.getMessage(),e);
    }

EExecutor.executorService.execute(new Runnable() {
            public void run() {
                try {
                LogFile poll = LogQueue.queue.poll();
                String strategy = poll.getStrategy();
                    String value = poll.getNodeValue();
                    value = encrypt(strategy,value);
                    PrintWriter writer = new PrintWriter(new OutputStreamWriter(new BufferedOutputStream(new FileOutputStream(poll.getPath(), true )),"UTF-8"));
                    writer.print(value);
                    writer.close();
                }catch (IOException e  ) {
                    log.error(e.getMessage(),e);
                } 
            }

        });
        } catch (Throwable e ) {
            log.error(e.getMessage(),e);
        }

//besides I have executor service

public class EExecutor { public static ExecutorService executorService = Executors.newCachedThreadPool();}

//and what’s really interesting.. when I move encryption from this handler away into another handler which is called
last when I send response! It’s faster. But when I leave it in one of the first handlers when I receive request. It’s even slower without using threads/servlet etc.

Answer 1

The proper way to do something like this is to have a message queue, such as the standard J2EE JMS.

In a message queue, you have one software component whose job it is to receive messages (such as requests to encrypt some resource, as in your case), and make the request “durable” in a transactional way. Then some independent process polls the message queue for new messages, takes action on them, and transactionally marks the messages as received.