package test;public class Test {public static void main(String[] args) {System.out.println("###############对象时比的都是地址################");TestObj t = new TestObj();TestObj t2 = new TestObj();System.out.println(t==t2);//falseSystem.out.println(t.equals(t2));//false
        System.out.println("############基本类型[==]比的是值###########");int a=1;float b=1f;System.out.println(a==b);//true//  System.out.println(a.equals(b)); 写法错误
        System.out.println("##########Integer特殊(equals重写成比较值，但new时==还是比较地址)##########");Integer i1=0;Integer i2=0;System.out.println(i1==i2);//trueSystem.out.println(i1.equals(i2));//trueInteger i3 = new Integer(0);Integer i4 = new Integer(0);System.out.println(i3==i4);//falseSystem.out.println(i3.equals(i4));//trueSystem.out.println(i1==i3);//falseSystem.out.println(i1.equals(i3));//trueSystem.out.println(i4.equals(i2));//trueint i5 = 0;System.out.println(i1.equals(i5));//true 和基本int类型比是比值System.out.println(i1==i5);//true 和基本int类型比也是比值System.out.println(i3.equals(i5));//true new的和基本int类型比是比值System.out.println(i3==i5);//true  new的和基本int类型比也是比值float f6 = 0f;//等同f6=0;System.out.println(i1.equals(f6));//false 注意结果不同说明equals的重写只是对int类型时是比值System.out.println(i1==f6);//trueSystem.out.println(i3.equals(f6));//false 注意结果不同说明equals的重写只是对int类型时是比值System.out.println(i3==f6);//true
        System.out.println("=======String特殊=======");String s1="a";String s2="a";System.out.println(s1==s2);System.out.println(s1.equals(s2));String s3 = new String("a");String s4 = new String("a");System.out.println(s3==s4);System.out.println(s3.equals(s4));System.out.println(s1==s3);System.out.println(s1.equals(s3));System.out.println(s4.equals(s2));}}

/*** Compares this object to the specified object.  The result is* {@code true} if and only if the argument is not* {@code null} and is an {@code Integer} object that* contains the same {@code int} value as this object.** @param   obj   the object to compare with.* @return  {@code true} if the objects are the same;*          {@code false} otherwise.*/public boolean equals(Object obj) {if (obj instanceof Integer) {return value == ((Integer)obj).intValue();}return false;}