package testutil;
import java.util.logging.*;
public class LoggingConfig {
public LoggingConfig() {
try {
// Load a properties file from class path that way can't be achieved with java.util.logging.config.file
/*
final LogManager logManager = LogManager.getLogManager();
try (final InputStream is = getClass().getResourceAsStream("/logging.properties")) {
logManager.readConfiguration(is);
}
*/
// Programmatic configuration
System.setProperty("java.util.logging.SimpleFormatter.format",
"%1$tY-%1$tm-%1$td %1$tH:%1$tM:%1$tS.%1$tL %4$-7s [%3$s] (%2$s) %5$s %6$s%n");
final ConsoleHandler consoleHandler = new ConsoleHandler();
consoleHandler.setLevel(Level.FINEST);
consoleHandler.setFormatter(new SimpleFormatter());
final Logger app = Logger.getLogger("app");
app.setLevel(Level.FINEST);
app.addHandler(consoleHandler);
} catch (Exception e) {
// The runtime won't show stack traces if the exception is thrown
e.printStackTrace();
}
}
}
java.util.logging: Programmatic configuration and logging with Java8 lambdas
TweetPosted on Monday Mar 30, 2015 at 06:24PM in Technology
Configuration
We can put configurations in following places (ordered by priority):
-
java.util.logging.config.classsystem property. specify FQCN of a class here -
java.util.logging.config.filesystem property. specify the path to a property file here -
$JAVA_HOME/lib/logging.propertiesfile. put JRE-wide configuration here
Use of java.util.logging.config.class is most flexible. in that way we can simply put a config class under src/test/java for unit tests. we need to put configuration procedures in the default constructor. an implementation would be something like following:
If you prefer configuration in a property file rather than a config class, following will work as the same to config class:
handlers=java.util.logging.ConsoleHandler java.util.logging.ConsoleHandler.formatter=java.util.logging.SimpleFormatter java.util.logging.SimpleFormatter.format=%1$tY-%1$tm-%1$td %1$tH:%1$tM:%1$tS.%1$tL %4$-7s [%3$s] (%2$s) %5$s %6$s%n java.util.logging.ConsoleHandler.level=FINEST app.level=FINEST
To set system property for every test execution, put following plugin definition to your pom.xml. note that IntelliJ IDEA respects this configuration in its test execution.
<plugin>
<artifactId>maven-surefire-plugin</artifactId>
<version>2.18.1</version>
<configuration>
<systemPropertyVariables>
<java.util.logging.config.class>
testutil.LoggingConfig
</java.util.logging.config.class>
<!-- If you prefer a file this will work too -->
<!--<java.util.logging.config.file>-->
<!--src/test/resources/logging.properties-->
<!--</java.util.logging.config.file>-->
</systemPropertyVariables>
</configuration>
</plugin>
Logging examples
Application class:
public class MyClass {
private static final Logger log = Logger.getLogger(MyClass.class.getName());
public String hello(String greetings, String name) {
// entering will be logged as FINER
log.entering(MyClass.class.getName(), "hello", new Object[]{greetings, name});
// lambdas
log.finest(() -> "finest: " + LocalDateTime.now());
log.finer(() -> "finer: " + LocalDateTime.now());
log.fine(() -> "fine: " + LocalDateTime.now());
log.info(() -> "info: " + LocalDateTime.now());
log.warning(() -> "warning: " + LocalDateTime.now());
log.severe(() -> "severe: " + LocalDateTime.now());
// exception logging
// throwing will be logged as FINER
log.throwing(MyClass.class.getName(), "hello", new Exception("test"));
// exception + message logging with lambda
log.log(Level.FINEST, new Exception("test"), () -> String.format("arg=%s", name));
// exception + parameter logging with LogRecord
final LogRecord record = new LogRecord(Level.FINEST, "arg={0}");
record.setThrown(new Exception("test"));
record.setLoggerName(log.getName()); // logger name will be null unless this
record.setParameters(new Object[]{name});
log.log(record);
final String rc = greetings + ", " + name;
// exiting will be logged as FINER
log.exiting(MyClass.class.getName(), "hello", rc);
return rc;
}
}
Test:
public class MyClassTest {
@org.junit.Test
public void testHello() throws Exception {
MyClass sut = new MyClass();
Assert.assertEquals("Hello, Kyle", sut.hello("Hello", "Kyle"));
}
}
Output:
2015-03-30 18:01:19.362 FINER [app.MyClass] (app.MyClass hello) ENTRY Hello Kyle 2015-03-30 18:01:19.425 FINEST [app.MyClass] (app.MyClass hello) finest: 2015-03-30T18:01:19.425 2015-03-30 18:01:19.427 FINER [app.MyClass] (app.MyClass hello) finer: 2015-03-30T18:01:19.427 2015-03-30 18:01:19.428 FINE [app.MyClass] (app.MyClass hello) fine: 2015-03-30T18:01:19.428 2015-03-30 18:01:19.429 INFO [app.MyClass] (app.MyClass hello) info: 2015-03-30T18:01:19.429 2015-03-30 18:01:19.431 WARNING [app.MyClass] (app.MyClass hello) warning: 2015-03-30T18:01:19.430 2015-03-30 18:01:19.433 SEVERE [app.MyClass] (app.MyClass hello) severe: 2015-03-30T18:01:19.433 2015-03-30 18:01:19.434 FINER [app.MyClass] (app.MyClass hello) THROW java.lang.Exception: test at app.MyClass.hello(MyClass.java:27) at app.MyClassTest.testHello(MyClassTest.java:10) ... 2015-03-30 18:01:19.439 FINEST [app.MyClass] (app.MyClass hello) arg=Kyle java.lang.Exception: test at app.MyClass.hello(MyClass.java:30) at app.MyClassTest.testHello(MyClassTest.java:10) ... 2015-03-30 18:01:19.442 FINEST [app.MyClass] (app.MyClass hello) arg=Kyle java.lang.Exception: test at app.MyClass.hello(MyClass.java:34) at app.MyClassTest.testHello(MyClassTest.java:10) ... 2015-03-30 18:01:19.447 FINER [app.MyClass] (app.MyClass hello) RETURN Hello, Kyle
Tags: logging
