io.netty.util

Interface HashingStrategy<T>

public interface HashingStrategy<T>

Abstraction for hash code generation and equality comparison.

Field Summary

Fields

Modifier and Type	Field and Description
static HashingStrategy	JAVA_HASHER A HashingStrategy which delegates to java's Object.hashCode() and Object.equals(Object).

Method Summary

Modifier and Type	Method and Description
boolean	equals(T a, T b) Returns true if the arguments are equal to each other and false otherwise.
int	hashCode(T obj) Generate a hash code for obj.

Field Detail

JAVA_HASHER

static final HashingStrategy JAVA_HASHER

A HashingStrategy which delegates to java's Object.hashCode() and Object.equals(Object).

Method Detail

hashCode

int hashCode(T obj)

Generate a hash code for obj.

This method must obey the same relationship that Object.hashCode() has with Object.equals(Object):

• Calling this method multiple times with the same obj should return the same result
• If equals(Object, Object) with parameters a and b returns true then the return value for this method for parameters a and b must return the same result
• If equals(Object, Object) with parameters a and b returns false then the return value for this method for parameters a and b does not have to return different results results. However this property is desirable.
• if obj is null then this method return 0

equals

boolean equals(T a,
               T b)

Returns true if the arguments are equal to each other and false otherwise. This method has the following restrictions:

• reflexive - equals(a, a) should return true
• symmetric - equals(a, b) returns true if equals(b, a) returns true
• transitive - if equals(a, b) returns true and equals(a, c) returns true then equals(b, c) should also return true
• consistent - equals(a, b) should return the same result when called multiple times assuming a and b remain unchanged relative to the comparison criteria
• if a and b are both null then this method returns true
• if a is null and b is non-null, or a is non-null and b is null then this method returns false