Change Java defualt logging level

修改 java.util.logging default level

import java.io.IOException;
import java.util.logging.Handler;
import java.util.logging.Level;
import java.util.logging.Logger;

/* 
  Properties: ${JAVA_HOME}/jre/lib/logging.properties
  Log Level: ALL < FINEST < FINER < FINE < CONFIG < INFO < WARNING < SEVERE < OFF
*/
public class Main {
 // default logger
 private static Logger logger = Logger.getLogger("");
 
 private static void testLog(){
     logger.finest("Finest");
     logger.finer("Finer");
     logger.fine("Fine");
     logger.config("Config");
     logger.info("Info");
     logger.warning("Warning");
     logger.severe("Severe");       
 }

 public static void main(String[] args) throws SecurityException, IOException {   
  logger.setLevel(Level.FINEST);
  // get default handler
  Handler handler = logger.getHandlers()[0];
  
  handler.setLevel(Level.FINEST);
  testLog();
  
  handler.setLevel(Level.SEVERE);
  testLog(); 
 }
}

/* Stdout

2008/3/16 下午 11:24:25 java.util.logging.LogManager$RootLogger log
最細緻: Finest
2008/3/16 下午 11:24:25 java.util.logging.LogManager$RootLogger log
更細緻: Finer
2008/3/16 下午 11:24:25 java.util.logging.LogManager$RootLogger log
細緻: Fine
2008/3/16 下午 11:24:25 java.util.logging.LogManager$RootLogger log
配置: Config
2008/3/16 下午 11:24:25 java.util.logging.LogManager$RootLogger log
資訊: Info
2008/3/16 下午 11:24:25 java.util.logging.LogManager$RootLogger log
警告: Warning
2008/3/16 下午 11:24:25 java.util.logging.LogManager$RootLogger log
嚴重的: Severe
2008/3/16 下午 11:24:25 java.util.logging.LogManager$RootLogger log
嚴重的: Severe
*/