java.util.logging.StreamHandler#flush ( )源码实例Demo

private String testLog(String name, Runnable runnable) {
  ByteArrayOutputStream buffer = new ByteArrayOutputStream();
  StreamHandler handler = new StreamHandler(buffer, new java.util.logging.SimpleFormatter());
  Logger logger = Logger.getLogger(name);
  logger.addHandler(handler);
  try {
    runnable.run();
    handler.flush();
    return buffer.toString();
  } finally {
    logger.removeHandler(handler);
  }
}
 

public void testLogger( ) throws Exception
{
	Logger engineLogger = Logger.getAnonymousLogger( );
	ByteArrayOutputStream engineOut = new ByteArrayOutputStream( );
	StreamHandler engineHandler = new StreamHandler( engineOut,
			new SimpleFormatter( ) );
	engineHandler.setLevel( Level.ALL );
	engineLogger.addHandler( engineHandler );
	engineLogger.setLevel( Level.ALL );

	Logger taskLogger = Logger.getAnonymousLogger();
	ByteArrayOutputStream taskOut = new ByteArrayOutputStream( );
	StreamHandler taskHandler = new StreamHandler( taskOut,
			new SimpleFormatter( ) );
	taskHandler.setLevel( Level.ALL );
	taskLogger.addHandler( taskHandler );
	taskLogger.setLevel( Level.ALL );

	engine.setLogger( engineLogger );
	engine.changeLogLevel( Level.ALL );

	engineHandler.flush( );
	taskHandler.flush( );

	new File( "./utest/" ).mkdirs( );
	copyResource(
			"org/eclipse/birt/report/engine/api/engine-task-logger-test.rptdesign",
			"./utest/reportdesign.rptdesign" );
	IReportRunnable runnable = engine
			.openReportDesign( "./utest/reportdesign.rptdesign" );

	IRunTask task = engine.createRunTask( runnable );
	task.setParameter( "sample", "==golden values==", "displayText" );
	task.run( "./utest/report.rptdocument" );
	task.close( );

	// the logger is output to engine out.
	engineHandler.flush( );
	assertTrue( engineOut.toString( ).indexOf( "==golden values==" ) != -1 );
	engineOut.reset( );

	task = engine.createRunTask( runnable );
	task.setLogger( taskLogger );
	task.setParameter( "sample", "==golden values==", "displayText" );
	task.run( "./utest/report.rptdocument" );
	task.close( );

	engineHandler.flush( );
	taskHandler.flush( );
	assertTrue( engineOut.toString( ).indexOf( "==golden values==" ) == -1 );
	assertTrue( taskOut.toString( ).indexOf( "==golden values==" ) != -1 );
}