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<TITLE>Catching all Errors and Exceptions (Java Developers Almanac Example)
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<h1>The Java Developers Almanac 1.4</h1>
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<h3>e1084. Catching all Errors and Exceptions</h3>
All errors and exceptions extend from <code>Throwable</code>. By catching
<code>Throwable</code>, it is possible to handle all unexpected conditions.
<P> There are several scenarios where it is good practice to catch
<code>Throwable</code>. For example, in a server application, the threads that
handle requests should catch <code>Throwable</code> and relay any errors or
exceptions to the client. Another scenario is a long-running thread
that performs some background activity. Such threads should catch
<code>Throwable</code>, log any errors or exceptions, and then continue
functioning.
<P> It is rarely good practice for a method in a library to catch
<code>Throwable</code>. In general, errors and exceptions should not be masked
from the caller.
<P> This example demonstrates a long-running thread that catches
<code>Throwable</code> and logs the exception.
<pre> class BgThread extends Thread {
// Create a logger. For more information on the logging api's,
// see <a href="../java.util.logging/BasicLogging.html" class="eglink"><b>e385</b> The Quintessential Logging Program</a>
Logger logger = Logger.getLogger(<font color="#0066ff"><i>"com.mycompany.mypackage"</i></font>);
BgThread() {
// As a daemon thread, this thread won't prevent the application from exiting
setDaemon(true);
}
// Set to true to shut down this thread
boolean stop = false;
public void run() {
while (!stop) {
try {
// Perform work here
} catch (Throwable t) {
// Log the exception and continue
logger.log(Level.SEVERE, "Unexception exception", t);
}
}
}
}
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e1085. <a class="eglink" href="Operator.html?l=rel">
Operator Precedence
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