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com.flexstor.common.modules.registry
Class SharedAssetInstanceId  view SharedAssetInstanceId download SharedAssetInstanceId.java

java.lang.Object
  extended bycom.flexstor.common.modules.registry.SharedAssetInstanceId
All Implemented Interfaces:
java.lang.Comparable

public class SharedAssetInstanceId
extends java.lang.Object
implements java.lang.Comparable

A shared record id consists of:
an element id
an asset id

Please note that the main difference between SharedAssetInstanceId and AssetInstanceId is that SharedAssetInstanceId implements the Comparable interface and provides an hashCode() method optimized for the registries.

Version:
3.0

Field Summary
private  long nAssetId
           
private  long nElementId
           
 
Constructor Summary
SharedAssetInstanceId(com.flexstor.common.data.ejb.search.AssetInstanceId id)
           
SharedAssetInstanceId(long nElementId, long nAssetId)
           
 
Method Summary
 int compareTo(java.lang.Object o)
          Compares this object with another, and returns a numerical result based on the comparison.
 boolean equals(java.lang.Object o)
          Determine whether this Object is semantically equal to another Object.
 long getAssetId()
           
 long getElementId()
           
 int hashCode()
          Get a value that represents this Object, as uniquely as possible within the confines of an int.
 java.lang.String toString()
          Convert this Object to a human-readable String.
 
Methods inherited from class java.lang.Object
clone, finalize, getClass, notify, notifyAll, wait, wait, wait
 

Field Detail

nElementId

private long nElementId

nAssetId

private long nAssetId
Constructor Detail

SharedAssetInstanceId

public SharedAssetInstanceId(long nElementId,
                             long nAssetId)

SharedAssetInstanceId

public SharedAssetInstanceId(com.flexstor.common.data.ejb.search.AssetInstanceId id)
Method Detail

getElementId

public long getElementId()

getAssetId

public long getAssetId()

compareTo

public int compareTo(java.lang.Object o)
Description copied from interface: java.lang.Comparable
Compares this object with another, and returns a numerical result based on the comparison. If the result is negative, this object sorts less than the other; if 0, the two are equal, and if positive, this object sorts greater than the other. To translate this into boolean, simply perform o1.compareTo(o2) <op> 0, where op is one of <, <=, =, !=, >, or >=.

You must make sure that the comparison is mutual, ie. sgn(x.compareTo(y)) == -sgn(y.compareTo(x)) (where sgn() is defined as -1, 0, or 1 based on the sign). This includes throwing an exception in either direction if the two are not comparable; hence, compareTo(null) should always throw an Exception.

You should also ensure transitivity, in two forms: x.compareTo(y) > 0 && y.compareTo(z) > 0 implies x.compareTo(z) > 0; and x.compareTo(y) == 0 implies x.compareTo(z) == y.compareTo(z).

Specified by:
compareTo in interface java.lang.Comparable

hashCode

public int hashCode()
Description copied from class: java.lang.Object
Get a value that represents this Object, as uniquely as possible within the confines of an int.

There are some requirements on this method which subclasses must follow:

  • Semantic equality implies identical hashcodes. In other words, if a.equals(b) is true, then a.hashCode() == b.hashCode() must be as well. However, the reverse is not necessarily true, and two objects may have the same hashcode without being equal.
  • It must be consistent. Whichever value o.hashCode() returns on the first invocation must be the value returned on all later invocations as long as the object exists. Notice, however, that the result of hashCode may change between separate executions of a Virtual Machine, because it is not invoked on the same object.

Notice that since hashCode is used in java.util.Hashtable and other hashing classes, a poor implementation will degrade the performance of hashing (so don't blindly implement it as returning a constant!). Also, if calculating the hash is time-consuming, a class may consider caching the results.

The default implementation returns System.identityHashCode(this)


equals

public boolean equals(java.lang.Object o)
Description copied from class: java.lang.Object
Determine whether this Object is semantically equal to another Object.

There are some fairly strict requirements on this method which subclasses must follow:

  • It must be transitive. If a.equals(b) and b.equals(c), then a.equals(c) must be true as well.
  • It must be symmetric. a.equals(b) and b.equals(a) must have the same value.
  • It must be reflexive. a.equals(a) must always be true.
  • It must be consistent. Whichever value a.equals(b) returns on the first invocation must be the value returned on all later invocations.
  • a.equals(null) must be false.
  • It must be consistent with hashCode(). That is, a.equals(b) must imply a.hashCode() == b.hashCode(). The reverse is not true; two objects that are not equal may have the same hashcode, but that has the potential to harm hashing performance.

This is typically overridden to throw a java.lang.ClassCastException if the argument is not comparable to the class performing the comparison, but that is not a requirement. It is legal for a.equals(b) to be true even though a.getClass() != b.getClass(). Also, it is typical to never cause a java.lang.NullPointerException.

In general, the Collections API (java.util) use the equals method rather than the == operator to compare objects. However, java.util.IdentityHashMap is an exception to this rule, for its own good reasons.

The default implementation returns this == o.


toString

public java.lang.String toString()
Description copied from class: java.lang.Object
Convert this Object to a human-readable String. There are no limits placed on how long this String should be or what it should contain. We suggest you make it as intuitive as possible to be able to place it into System.out.println() 55 and such.

It is typical, but not required, to ensure that this method never completes abruptly with a java.lang.RuntimeException.

This method will be called when performing string concatenation with this object. If the result is null, string concatenation will instead use "null".

The default implementation returns getClass().getName() + "@" + Integer.toHexString(hashCode()).