java底层JDK Logging日志模块处理细节深入分析

package com.bes.logging;
import java.util.logging.Level;
import java.util.logging.Logger;
public class LoggerTest {
      private static Loggerlogger = Logger.getLogger("com.bes.logging");
      public static void main(String argv[]) {
               // Log a FINEtracing message
               logger.info("Main running.");
               logger.fine("doingstuff");
               try {
                         Thread.currentThread().sleep(1000);// do some work
               } catch(Exception ex) {
                         logger.log(Level.WARNING,"trouble sneezing", ex);
               }
               logger.fine("done");
      }
}

handlers= java.util.logging.FileHandler,java.util.logging.ConsoleHandler
.level= INFO
java.util.logging.FileHandler.pattern = %h/java%u.log
java.util.logging.FileHandler.limit = 50000
java.util.logging.FileHandler.count = 1
java.util.logging.FileHandler.formatter =java.util.logging.XMLFormatter
java.util.logging.ConsoleHandler.level = INFO
java.util.logging.ConsoleHandler.formatter =java.util.logging.SimpleFormatter
com.xyz.foo.level = SEVERE
sun.rmi.transport.tcp.logLevel = FINE 

    public static synchronized Logger getLogger(String name) {
           LogManager manager =LogManager.getLogManager();
        returnmanager.demandLogger(name);
    }

static {
   AccessController.doPrivileged(newPrivilegedAction<Object>() {
       public Object run() {
           String cname =null;
           try {
               cname =System.getProperty("java.util.logging.manager");
               if (cname !=null) {
                  try {
                       Class clz =ClassLoader.getSystemClassLoader().loadClass(cname);
                       manager= (LogManager) clz.newInstance();
                   } catch(ClassNotFoundException ex) {
               Class clz =Thread.currentThread().getContextClassLoader().loadClass(cname);
                      manager= (LogManager) clz.newInstance();
                   }
               }
           } catch (Exceptionex) {
              System.err.println("Could not load Logmanager \"" + cname+ "\"");
              ex.printStackTrace();
           }
           if (manager ==null) {
               manager = newLogManager();
           }
      
           manager.rootLogger= manager.new RootLogger();
          manager.addLogger(manager.rootLogger);
 
           Logger.global.setLogManager(manager);
          manager.addLogger(Logger.global);
 
           return null;
       }
   });
}

     Logger demandLogger(String name) {
       Logger result =getLogger(name);
       if (result == null) {
           result = newLogger(name, null);
           addLogger(result);
           result =getLogger(name);
       }
       return result;
     }

    public void log(Levellevel, String msg) {
          if (level.intValue() < levelValue ||levelValue == offValue) {
              return;
          }
          LogRecord lr = new LogRecord(level, msg);
          doLog(lr);
    }

    private void doLog(LogRecord lr) {
          lr.setLoggerName(name);
          String ebname =getEffectiveResourceBundleName();
          if (ebname != null) {
              lr.setResourceBundleName(ebname);
              lr.setResourceBundle(findResourceBundle(ebname));
          }
          log(lr);
    }

   public void log(LogRecord record) {
          if (record.getLevel().intValue() <levelValue || levelValue == offValue) {
              return;
          }
          synchronized (this) {
              if (filter != null &&!filter.isLoggable(record)) {
                  return;
              }
          }
          Logger logger = this;
          while (logger != null) {
              Handler targets[] = logger.getHandlers();
              if(targets != null) {
                  for (int i = 0; i < targets.length; i++){
                           targets[i].publish(record);
                       }
              }
              if(!logger.getUseParentHandlers()) {
                       break;
              }
              logger= logger.getParent();
          }
    }

public class ConsoleHandler extends StreamHandler {
    public ConsoleHandler() {
          sealed = false;
          configure();
          setOutputStream(System.err);
          sealed = true;
    }

 public synchronized void publish(LogRecord record) {
       if(!isLoggable(record)) {
           return;
       }
       String msg;
       try {
           msg =getFormatter().format(record);
       } catch (Exception ex){
           // We don't want tothrow an exception here, but we
           // report theexception to any registered ErrorManager.
           reportError(null,ex, ErrorManager.FORMAT_FAILURE);
           return;
       }
       try {
           if (!doneHeader) {
              writer.write(getFormatter().getHead(this));
               doneHeader =true;
           }
           writer.write(msg);
       } catch (Exception ex){
           // We don't want tothrow an exception here, but we
           // report theexception to any registered ErrorManager.
           reportError(null,ex, ErrorManager.WRITE_FAILURE);
       }
    }

    java.util.logging.ConsoleHandler.level= FINE//修改
    com.bes.logging.level=FINE//添加

public synchronized String format(LogRecord record) {
    StringBuffer sb = new StringBuffer();
    // Minimize memory allocations here.
    dat.setTime(record.getMillis());
    args[0] = dat;
    StringBuffer text = new StringBuffer();
    if (formatter == null) {
        formatter = new MessageFormat(format);
    }
    formatter.format(args, text, null);
    sb.append(text);
    sb.append(" ");
    if (record.getSourceClassName() != null) {     
        sb.append(record.getSourceClassName());
    } else {
        sb.append(record.getLoggerName());
    }
    if (record.getSourceMethodName() != null) {
        sb.append(" ");
       sb.append(record.getSourceMethodName());
    }
    sb.append(lineSeparator);
    String message = formatMessage(record);
   sb.append(record.getLevel().getLocalizedName());
    sb.append(": ");
    sb.append(message);
    sb.append(lineSeparator);
    if (record.getThrown() != null) {
        try {
            StringWriter sw = newStringWriter();
            PrintWriter pw = newPrintWriter(sw);
           record.getThrown().printStackTrace(pw);
            pw.close();
             sb.append(sw.toString());
        } catch (Exception ex) {
        }
    }
    return sb.toString();
}