经典单例模式及测试

public class ClassicSingleton {
  private static ClassicSingleton instance=new ClassicSingleton();
  
  private ClassicSingleton() {
    
  }
  public static ClassicSingleton getInstance() {
    return instance;
  }
}

import java.util.logging.Logger;

import junit.framework.Assert;
import junit.framework.TestCase;


public class SingletonTest extends TestCase {
  private ClassicSingleton sone=null;
  private ClassicSingleton stwo=null;
  private static Logger logger=Logger.getAnonymousLogger();
  
  public SingletonTest(String name) {
    super(name);
  }
  
  public void setUp() {
    logger.info("getting singleton...");
    sone=ClassicSingleton.getInstance();
    logger.info("...got singleton: "+sone);
    
    logger.info("getting singleton...");
    stwo=ClassicSingleton.getInstance();
    logger.info("...got singleton: "+stwo);
  }
  public void testUnique() {
    logger.info("checking singleton for equality");
    Assert.assertEquals(true, sone==stwo);
  }
}