基本类型与包装类

public class TestNoSync {

	public static void main(String[] args) throws IOException {
		Integer i1 = 100;
		Integer i2 = 100;
		Integer i3 = 130;
		Integer i4 = 130;
		Long l1 = 110L;
		Long l2 = 110L;
		Byte b1 = 110;
		Byte b2 = 110;
		Short s1 = 110;
		Short s2 = 110;
		Character c1 = 110;
		Character c2 = 110;
		System.out.println(i1 == i2);
		System.out.println(i3 == i4);
		System.out.println(l1 == l2);
		System.out.println(b1 == b2);
		System.out.println(s1 == s2);
		System.out.println(c1 == c2);
	}
}

　　console：

true
false
true
true
true
true

总结：

• 如果整型字面量的值在-128~127之间，那么不会new出新的Integer对象，而是直接使用常量池中的Integer对象
• Byte，Long，Short，Character也同样适用