1. 普通的飽漢式、餓漢式

package org.bighead.test2;

public class TestPrivate {
	private String str = "strPrivate";
	private static final TestPrivate TESTPRIVATE = new TestPrivate();
	// 飽漢式、餓漢式
	private TestPrivate() {
		super();
		System.out.println(str);
	}
	
	public TestPrivate getInstance(){
		return TESTPRIVATE;
	}
	
	public void toPrint(){
		System.out.println("私有構造-公開方法--單實例");
	}
}

反射創建實例、調用方法（實例可訪問的）

package org.bighead.test2;

import java.lang.reflect.Constructor;
import java.lang.reflect.InvocationTargetException;

public class TestDefaultSub  {
	
	public static void main(String[] args) {
		Class<TestPrivate> clazz = TestPrivate.class;
		try {
			Constructor<?> constructor = clazz.getDeclaredConstructor();
			constructor.setAccessible(true);
			TestPrivate tp = (TestPrivate) constructor.newInstance();
			tp.toPrint();
		} catch (NoSuchMethodException e) {
			e.printStackTrace();
		} catch (InstantiationException e1) {
			e1.printStackTrace();
		} catch (IllegalAccessException e1) {
			e1.printStackTrace();
		} catch (InvocationTargetException e1) {
			e1.printStackTrace();
		}
	}
}

2. 並發也會影響　　

java反射（java.lang.reflect) ---普通單例模式唯一性問題