How do I overwrite the hashcode method that returns a unique hashcode value with its unique object id in my specific Java object?

Question

, Java , . Object hashcode equals , , hashcode, - , hashcode Integer, , ID . , -, ?

.

+3

Brady Zhu 09 . '14 6:03

3

hashcode Long

:

(4).hashCode();

0

Ankit Gupta 09 . '14 6:06

The most common way the core Java libraries convert long

to int

for a method hashCode()

is with multiple bitwise operations:

@Override
public int hashCode() {
    return (int)(value ^ (value >>> 32));
}

There is often a Long.hashCode(long)

static method in Java 8 that does just that:

@Override
public int hashCode() {
    return Long.hashCode(value);
}

Note that this process is not reversible - there is no one-to-one value between the hash codes long

due to the different ranges.

0

thkala 09 Sep '14 at 6:11

Mureinik · Accepted Answer · 2014-09-09T06:07:06+0000

- java.lang.Long

hashCode()

:

@Override
public int hashCode() {
    return Long.valueOf(getId()).hashCode();
}

:
, java.lang.Long

, long

, :

@Override
public int hashCode() {
    return getId().hashCode();
}