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org.apache.derby.impl.db
Class DatabaseContextImpl  

java.lang.Object
  org.apache.derby.iapi.services.context.ContextImpl
      org.apache.derby.impl.db.DatabaseContextImpl

All Implemented Interfaces:

org.apache.derby.iapi.services.context.Context, org.apache.derby.iapi.db.DatabaseContext

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class DatabaseContextImpl

extends org.apache.derby.iapi.services.context.ContextImpl

implements org.apache.derby.iapi.db.DatabaseContext

A context that shutdowns down the database on a databsae exception.

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Field Summary
private  org.apache.derby.iapi.db.Database	db

 

Fields inherited from class org.apache.derby.iapi.services.context.ContextImpl

 

Fields inherited from interface org.apache.derby.iapi.db.DatabaseContext

CONTEXT_ID

 

Constructor Summary
(package private)	DatabaseContextImpl(org.apache.derby.iapi.services.context.ContextManager cm, org.apache.derby.iapi.db.Database db)

 

Method Summary
void	cleanupOnError(java.lang.Throwable t)           Contexts will be passed errors that are caught by the outer system when they are serious enough to require corrective action.
boolean	equals(java.lang.Object other)           Determine whether this Object is semantically equal to another Object.
org.apache.derby.iapi.db.Database	getDatabase()
int	hashCode()           Get a value that represents this Object, as uniquely as possible within the confines of an int.

 

Methods inherited from class org.apache.derby.iapi.services.context.ContextImpl

appendErrorInfo, getContextManager, getIdName, isLastHandler, popMe, pushMe

 

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, toString, wait, wait, wait

 

Methods inherited from interface org.apache.derby.iapi.services.context.Context

getContextManager, getIdName, isLastHandler, popMe, pushMe

 

Field Detail

db

private final org.apache.derby.iapi.db.Database db

Constructor Detail

DatabaseContextImpl

DatabaseContextImpl(org.apache.derby.iapi.services.context.ContextManager cm,
                    org.apache.derby.iapi.db.Database db)

Method Detail

cleanupOnError

public void cleanupOnError(java.lang.Throwable t)

Description copied from interface: org.apache.derby.iapi.services.context.Context

Contexts will be passed errors that are caught by the outer system when they are serious enough to require corrective action. They will be told what the error is, so that they can react appropriately. Most of the time, the contexts will react by either doing nothing or by removing themselves from the context manager. If there are no other references to the context, removing itself from the manager equates to freeing it.

Contexts must release all their resources before removing themselves from their context manager.

The context manager will "unwind" the contexts during cleanup in the reverse order they were placed on its global stack.

If error is an instance of StandardException then an implementation of this method may throw a new exception if and only if the new exception is an instance of StandardException that is more severe than the original error or the new exception is a not an instance of StandardException (e.g java.lang.NullPointerException).

Specified by:

cleanupOnError in interface org.apache.derby.iapi.services.context.Context

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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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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)

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getDatabase

public org.apache.derby.iapi.db.Database getDatabase()

Specified by:

getDatabase in interface org.apache.derby.iapi.db.DatabaseContext

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Overview  Package   Class  Use  Deprecated  Index
Home >> All >> org >> apache >> derby >> impl >> [ db overview ]	PREV CLASS  NEXT CLASS
SUMMARY:  JAVADOC |  SOURCE |  DOWNLOAD | NESTED | FIELD | CONSTR | METHOD	DETAIL: FIELD | CONSTR | METHOD

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