Re: How to implement this?

From:

xz <zhang.xi.cn@gmail.com>

Newsgroups:

comp.lang.java.programmer

Date:

Mon, 06 Aug 2007 21:39:34 -0000

Message-ID:

<1186436374.139578.23810@19g2000hsx.googlegroups.com>

On Aug 6, 3:50 pm, Chris <spam_me_...@goaway.com> wrote:

xz wrote:

I want all the classes write the runtime information into one common
file, let's say, log.
So I define a BufferedWriter log in one of the classes and make it
public static, as follows,

import java.io.BufferedWriter;
import java.io.FileWriter;

public class Tester {

                static String path = "/home/xi/Desktop/D2V/
validation/";
                static FileWriter fwlog = new FileWriter(path +
"log");
                public static BufferedWriter log = new
BufferedWriter(fwlog);
                //the rest code
}

However, the constructor of FileWriter throws exception so it does not
compile:
--------------------
Tester.java:11: unreported exception java.io.IOException; must be
caught or declared to be thrown
                static FileWriter fwlog = new FileWriter(path +
"log");
                                          ^
1 error
--------------------

What can I do to handle this exception?

looks like I cannot either catch it here or put the "throws
IOException...." sentence after "public class Tester".

Try this:

public class Tester {
     private static BufferedWriter logger;

     public static BufferedWriter getLogger() throws IOException {
         if (logger==null) {
             logger = new BufferedWriter(whatever...);
         }
         return logger;
     }

}

In your code, call:

Tester.getLogger().write("some message");

Of if you want to avoid the call to if (logger==null) on every log
statement, create a static init() method and call that before the first
call to getLogger().

Thanks. That works.