Java中equals和==的区别

public class equals_compareTo {
public static void main(String[] args) {
String a = "abcd";
String b = "abcd";

String c = new String("abcd");
String d = new String("abcd");

String e = c;
String f = "absd";

System.out.println("a.equals(b): " + a.equals(b));
System.out.println("b.equals(c): " + b.equals(c));

System.out.println("a == b: " + (a == b));

System.out.println("a == c: " + (a == c));
System.out.println("c == d: " + (c == d));

System.out.println("c == e: " + (c == e));

System.out.println("f.compareTo(c): " + f.compareTo(c));
System.out.println("a.compareTo(c): " + a.compareTo(c));
}
}
/*
a.equals(b): true
b.equals(c): true
a == b: true
a == c: false
c == d: false
c == e: true
f.compareTo(c): 16
a.compareTo(c): 0

*/