Custom logging for Android Application
I want to create a custom logger for android application. The logging should be done in a separate thread as the application generates lots of information. I don't want to use the Android logs since i need to write the logs in a specific format. Multiple threads will be writing to the log file at the same time, so i have used a queue to keep the log messages
Here is the code that i have
Queue<LogEntry> logQueue = new LinkedBloc开发者_如何学GokingQueue<LogEntry>();
LogWritterThread logWritterThread = new LogWritterThread();
// to queue the log messages
public void QueueLogEntry(String message)
{
LogEntry le = new LogEntry(message);
{
logQueue.add(le);
logQueue.notifyAll();
}
logWritterThread.start();
}
class LogWritterThread extends Thread
{
public void run()
{
try
{
while(true)
{
//thread waits until there are any logs to write in the queue
if(logQueue.peek() == null)
synchronized(logQueue){
logQueue.wait();
}
if(logQueue.peek() != null)
{
LogEntry logEntry;
synchronized(logQueue){
logEntry = logQueue.poll();
}
// write the message to file
}
if(Thread.interrupted())
break;
}
}
catch (InterruptedException e)
{
}
}
}
Is there any thing wrong with this code? or a better way to create a logging queue
Thanks, Anuj
Java BlockingQueue implementations already have synchronization concerns built in. Your use of wait, notify, and synchronized is redundant and not needed.
Try mimicking the Producer/Consumer example giving in the BlockingQueue javadoc
class LogEntry {
private final String message;
LogEntry(String msg) {
message = msg;
}
}
class LogProducer {
private final BlockingQueue<LogEntry> queue;
LogProducer(BlockingQueue<LogEntry> q) {
queue = q;
}
public void log(String msg) {
queue.put(new LogEntry(msg));
}
}
class LogConsumer implements Runnable {
private final BlockingQueue<LogEntry> queue;
LogConsumer(BlockingQueue<LogEntry> q) {
queue = q;
}
public void run() {
try {
while(true) {
LogEntry entry = queue.take();
// do something with entry
}
} catch(InterruptedException ex) {
// handle
}
}
}
class Setup {
public static void main(String[] args) {
BlockingQueue<LogEntry> queue = new LinkedBlockingQueue<LogEntry>();
LogConsumer c = new LogConsumer(queue);
new Thread(c).start();
LogProducer p = new LogProducer(queue);
p.log("asynch");
p.log("logging");
}
}
I would use a Handler - I love handler's because they implement a queue and a message thread all of which is thread safe. That means you can create a class that extends a Handler and use that class all over your project. With a couple of lines of code with a handler, you can shrink your existing code dramatically.
Google's documentation: http://developer.android.com/reference/android/os/Handler.html
This is a very simple example: http://saigeethamn.blogspot.com/2010/04/threads-and-handlers-android-developer.html
this is a better example because they use "msg.what" to decide what to do (which you'll need for different levels of logging): https://idlesun.wordpress.com/2010/12/12/android-handler-and-message-tutorial/
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