Java LogManager.getLogger方法代码示例

import java.util.logging.LogManager; //导入方法依赖的package包/类
public static @Nullable ClassLogger find(@Nullable Logger parent, Class<?> klass, @Nullable String instanceKey) {
    if(parent == null) {
        parent = Logger.getLogger("");
    }

    String name = getName(klass, instanceKey);
    if(parent instanceof ClassLogger && Objects.equals(parent.getName(), name)) {
        // If the given parent logger looks exactly like the logger
        // we are supposed to return, just use it. This makes it easy
        // to replace a parent logger with a child once only e.g.
        //
        //     logger = ClassLogger.get(logger, getClass(), "myInstance")
        return (ClassLogger) parent;
    }

    LogManager lm = LogManager.getLogManager();
    Logger logger = lm.getLogger(name);
    if(logger instanceof ClassLogger) {
        if(parent != logger.getParent()) {
            throw new IllegalStateException("Already registred logger " + name + " has a different parent than the one requested:\n  old = " + logger.getParent() + "\n  new = " + parent);
        }
        return (ClassLogger) logger;
    } else {
        return null;
    }
}
 

import java.util.logging.LogManager; //导入方法依赖的package包/类
public static void redirectInternalJavaLoggers() {
  // Do we need to this on re-connect?
  LogManager logManager = LogManager.getLogManager();

  try {
    Enumeration<String> loggerNames = logManager.getLoggerNames();

    while (loggerNames.hasMoreElements()) {
      String loggerName = loggerNames.nextElement();
      if (loggerName.startsWith("java.") || loggerName.startsWith("javax.")) {
        // System.out.println(loggerName);
        Logger javaLogger = logManager.getLogger(loggerName);
        /*
         * From Java Docs: It is also important to note that the Logger associated with the String
         * name may be garbage collected at any time if there is no strong reference to the
         * Logger. The caller of this method must check the return value for null in order to
         * properly handle the case where the Logger has been garbage collected.
         */
        if (javaLogger != null) {
          LogWrapper.getInstance().setParentFor(javaLogger);
        }
      }
    }
  } catch (SecurityException e) {
    // e.printStackTrace();
    LogWrapper.getInstance().warning(e.getMessage(), e);
  }
}
 

import java.util.logging.LogManager; //导入方法依赖的package包/类
public static @Nullable Logger findLogger(String search) throws CommandException {
    LogManager lm = LogManager.getLogManager();
    if("".equals(search)) return lm.getLogger("");
    String name = findLogger(search, Collections.list(lm.getLoggerNames()));
    return name == null ? null : lm.getLogger(name);
}
 

import java.util.logging.LogManager; //导入方法依赖的package包/类
/**
 * This test is designed to test the behavior of additional LogManager instances.
 * It must be noted that if the security manager is off, then calling
 * Bridge.changeContext() has actually no effect - which explains why we have
 * some differences between the cases security manager on & security manager
 * off.
 **/
public static void testSix() {
    for (int i=0; i<3 ; i++) {
        Bridge.desactivate();
        LogManager manager = new LogManager() {};
        Logger logger1 = manager.getLogger(Logger.GLOBAL_LOGGER_NAME);
        Logger logger1b = manager.getLogger(Logger.GLOBAL_LOGGER_NAME);
        assertNull(logger1);
        assertNull(logger1b);
        Logger global = new Bridge.CustomLogger(Logger.GLOBAL_LOGGER_NAME);
        manager.addLogger(global);
        Logger logger2 = manager.getLogger(Logger.GLOBAL_LOGGER_NAME);
        Logger logger2b = manager.getLogger(Logger.GLOBAL_LOGGER_NAME);
        assertNotNull(logger2);
        assertNotNull(logger2b);
        assertEquals(logger2, global);
        assertEquals(logger2b, global);
        assertNull(manager.getLogger(""));
        assertNull(manager.getLogger(""));

        for (int j = 0; j<3; j++) {
            Bridge.changeContext();

            // this is not a supported configuration:
            // We are in an applet context with several log managers.
            // We however need to check our assumptions...

            // Applet context => root logger and global logger should also be null.

            Logger expected = (System.getSecurityManager() == null ? global : null);
            Logger logger3 = manager.getLogger(Logger.GLOBAL_LOGGER_NAME);
            Logger logger3b = manager.getLogger(Logger.GLOBAL_LOGGER_NAME);
            assertEquals(expected, logger3);
            assertEquals(expected, logger3b);
            Logger global2 = new Bridge.CustomLogger(Logger.GLOBAL_LOGGER_NAME);
            manager.addLogger(global2);
            Logger logger4 = manager.getLogger(Logger.GLOBAL_LOGGER_NAME);
            Logger logger4b = manager.getLogger(Logger.GLOBAL_LOGGER_NAME);
            assertNotNull(logger4);
            assertNotNull(logger4b);
            expected = (System.getSecurityManager() == null ? global : global2);;
            assertEquals(logger4,  expected);
            assertEquals(logger4b, expected);

            Logger logger5 = manager.getLogger("");
            Logger logger5b = manager.getLogger("");
            Logger expectedRoot = null;
            assertEquals(logger5, expectedRoot);
            assertEquals(logger5b, expectedRoot);
        }

    }
}