How to generate log files that is received by my Java Server from android client?

Question

I have a working system here which communicates my android client to my Java Server. Basically it just send a message by my android client and my server receives it by System.out.println(message); . Now what I want to happen is to save all receives message to a single textfile that will serve as my logs and it will update as soon as my server receives a new message.

while ((message = bufferedReader.readLine()) != null) {
                    System.out.println("Message from " + message + " at " + dateFormat.format(cal.getTime()));
                    str.append(message+"\n");


                }

This one is a part of my Java Serve code. BTW I am using TCP port to communicate my server and my client thru the same network. I want to save to a textfile the text that is holded by the str string. How can I do that? Or is that possible? Thanks in advance!

Kindly check out my code:

PrintWriter out= new PrintWriter(new BufferedWriter(new FileWriter("C:/foo.txt")));
                while ((message = bufferedReader.readLine()) != null) {
                    System.out.println("Message from " + message + " at " + dateFormat.format(cal.getTime()));
                    str.append(message+"\n");
                    out.println(message);


                }

score 1 · Accepted Answer · answered Sep 25 '13 at 16:45

1

One easy way to achieve file output is to run the Server code with an output redirection

java -cp<Whatever classpath> ServerClassName >file &

If you need to write to a file from java, you can use following pseudo code

PrintWriter out= new PrintWriter(new BufferedWriter(new FileWriter("foo.out")));
while ( read message as you doing now)  {
    // do something 
    out.println(message);
    // do something
}

answered Sep 25 '13 at 16:45

Akhilesh Singh

2,548
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I can't understand this statement java -cp ServerClassName >file & What is Whatever classpath? And where should i declare this? – Kerv Sep 25 '13 at 16:47
Do you want to see the whole code of mine? Wait I'll update the post. – Kerv Sep 25 '13 at 16:49
I meant how are you executing the code? Is it from some kind of IDE or you running from command prompt? – Akhilesh Singh Sep 25 '13 at 16:50
Updated! @Akhilesh Singh – Kerv Sep 25 '13 at 16:51
JAVA ECLIPSE is where i run it. – Kerv Sep 25 '13 at 16:52
So you can forget about the first approach. It is relevant for only command prompt.You will need to use the PrintWriter method. – Akhilesh Singh Sep 25 '13 at 16:52
I'll give it a try. Does it will save a log.txt for example? because i need logging the messages that the server receives. – Kerv Sep 25 '13 at 16:55
"foo.out" is filename which you can change to suit your needs. – Akhilesh Singh Sep 25 '13 at 16:56
Yeah! Thanks for your help. Keep you updated if i succeed in this stuff. – Kerv Sep 25 '13 at 16:57
Hey there! @Akhilesh Singh Its not working. Is my syntax correct? Check out my post. I've posted the code. – Kerv Sep 25 '13 at 17:29
Refer here : http://stackoverflow.com/questions/4430143/why-is-bufferedwriter-not-writing-in-the-file. Essentially, you are using BufferedWriter and will need to call close/flush or wait till internal buffer of BufferedWriter is full. – Akhilesh Singh Sep 26 '13 at 06:11

How to generate log files that is received by my Java Server from android client?

1 Answers1