Java – Overrides only the equals() method of Java objects

I’m working on a ScanResult that uses Android application purpose. The object has the form:

[SSID: __mynetwork__, BSSID: 00:0e:2e:ae:4e:85, capabilities: [WPA-PSK-TKIP][ESS], level: -69, frequency: 2457, timestamp: 117455824743]

How do I override only the equals() method without creating a client class that extends it so that only SSID, BSSID, capabilties, level, and frequency properties are compared? In other words, in the equals method, I want to eliminate the timestamp property so that when I compare the two objects, the equals() method will return a true value:

[SSID: __mynetwork__, BSSID: 00:0e:2e:ae:4e:85, capabilities: [WPA-PSK-TKIP][ESS], level: -69, frequency: 2457, timestamp: 117455824743]
[SSID: __mynetwork__, BSSID: 00:0e:2e:ae:4e:85, capabilities: [WPA-PSK-TKIP][ESS], level: -69, frequency: 2457, timestamp: 117460312231]

Note: When I derive a client class that extends ScanResult, I get the following error when I try to implement the constructor: The constructor ScanResult() is not visible

You just need to implement it without checking the fields you want to ignore. Don’t forget to override hasode() as well.

@Override
public int hashCode() {
    final int prime = 31;
    int result = 1;
    result = prime * result
            + ((field1 == null) ? 0 : field1.hashCode());
    result = prime * result + ((field2 == null) ? 0 : field2.hashCode());
            ... etc
    return result;
}

@Override
public boolean equals(Object obj) {
    if (this == obj)
        return true;
    if (obj == null)
        return false;
    if (getClass() != obj.getClass())
        return false;
    ScanResult other = (ScanResult ) obj;
    if (field1 == null) {
        if (other.field1 != null)
            return false;
    } else if (!field1.equals(other.field1))
        return false;
    if (field2 == null) {
        if (other.field2 != null)
            return false;
    } else if (!field2 .equals(other.field2 ))
        return false;
        }
... etc
}