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org.apache.derby.iapi.store.access
Class GlobalXact  

java.lang.Object
  org.apache.derby.iapi.store.access.GlobalXact

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public abstract class GlobalXact

extends java.lang.Object

This abstract class represents a global transaction id which can be tested for equality against other transaction ids, which can be hashed into a hash table, and which can be output as a string.

This class has 2 direct subclasses.

• org.apache.derby.iapi.store.access.xa.XAXactId : this class is a specific implementation of the JTA Xid interface
• org.apache.derby.impl.store.access.GlobalXactId : this class represents internal cloudscape transaction ids

The main reason for this class is to ensure that equality etc. works in a consistent way across both subclasses.

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Field Summary
protected  byte[]	branch_id
protected  int	format_id           Protected Fields of the class
protected  byte[]	global_id

 

Constructor Summary

GlobalXact()

 

Method Summary
boolean	equals(java.lang.Object other)           Determine whether this Object is semantically equal to another Object.
int	hashCode()           Provide a hashCode which is compatable with the equals() method.
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

format_id

protected int format_id

Protected Fields of the class

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global_id

protected byte[] global_id

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branch_id

protected byte[] branch_id

Constructor Detail

GlobalXact

public GlobalXact()

Method Detail

equals

public boolean equals(java.lang.Object other)

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.

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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()).

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hashCode

public int hashCode()

Provide a hashCode which is compatable with the equals() method.

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Home >> All >> org >> apache >> derby >> iapi >> store >> [ access overview ]	PREV CLASS  NEXT CLASS
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