org.oreodata
Class AbstractRecord

java.lang.Object
  |
  +--org.oreodata.AbstractRecord

All Implemented Interfaces:

java.lang.Cloneable, java.io.Externalizable, OreoConstants, Record, java.io.Serializable

Direct Known Subclasses:

CompactRecord, DefaultRecord

public abstract class AbstractRecord

extends java.lang.Object

implements Record, java.io.Externalizable, java.lang.Cloneable, OreoConstants

An abstract base implementation of the Record interface In this implementation, the records can be written out as a human-readable string. This is the scheme used for serialization. DefaultRecord implements the java.io.Externalizable interface in order to avoid the general-purpose serialization scheme. The goal was that the resulting storage format should be human-readable and modifiable in a text editor in a pinch.

Author:

Serialized Form

Field Summary

Fields inherited from interface org.oreodata.OreoConstants

RECORD_STATUS_KEY, RECORD_TYPE_KEY

Constructor Summary

AbstractRecord()

Method Summary

void	checkValidity() Check if the record's data is valid.
void	clearFields() set the fields to their default values.
boolean	equals(java.lang.Object o)
void	freeze() make this record immutable.
java.lang.Object	get(FieldDescriptor field) Low-level method to query the value of a field in a Record.
protected abstract java.lang.Object	get(int i)
java.lang.Object	get(java.lang.Object o)
java.lang.Object	get(java.lang.String fieldname) Method to get the value of a field by name.
java.util.List	getChildren() In this base implementation, this always returns an empty list.
RecordDescriptor	getMetadata()
Record	getMutableCopy() create a clone.
Record	getParent() In this base implementation, this always returns null.
java.lang.Object	getPrimaryKey() Retrieve the value of the record's primary key.
java.lang.String	getType()
boolean	hasChildren() In this base implementation, this always returns false.
boolean	isRootElement() In this base implementation, this always returns true.
boolean	isStale() Has this record been deleted or superseded in the associated DataSource?
protected void	postCheck() Called after checking the fields.
protected void	preCheck() Called before checking the fields.
void	readExternal(java.io.ObjectInput in)
void	set(FieldDescriptor field, java.lang.Object value) Low-level method to set an individual field value
protected abstract void	set(int i, java.lang.Object value)
void	set(java.lang.String fieldname, java.lang.Object value) Method to set the value of a field by name.
void	setMetadata(RecordDescriptor descriptor) Method only used internally.
void	setPrimaryKey(java.lang.Object o) set the value of this record's primary key.
java.lang.String	setValuesFromTable(java.util.Map table) Set the values of the record's fields from a key-value mapping of the fields (or field names) to values.
java.lang.String	toString() Provides a default string representation of the record for a human-readable flat-file persistence scheme.
void	writeExternal(java.io.ObjectOutput out)

Methods inherited from class java.lang.Object

clone, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Methods inherited from interface org.oreodata.Record

isImmutable

Constructor Detail

AbstractRecord

public AbstractRecord()

Method Detail

checkValidity

public final void checkValidity()
                         throws DataException

Check if the record's data is valid.

Throws:

DataException - if any of the fields are not valid. The appropriate error message is encoded in the exception.

isStale

public boolean isStale()

Description copied from interface: Record

Has this record been deleted or superseded in the associated DataSource?

Specified by:

isStale in interface Record

getPrimaryKey

public java.lang.Object getPrimaryKey()

Description copied from interface: Record

Retrieve the value of the record's primary key.

Specified by:

getPrimaryKey in interface Record

Returns:

the value of this record's primary key, or null if it has not been set.

setPrimaryKey

public void setPrimaryKey(java.lang.Object o)

Description copied from interface: Record

set the value of this record's primary key. The record must be in a mutable state AND the primary key must be unset.

Specified by:

setPrimaryKey in interface Record

toString

public java.lang.String toString()

Provides a default string representation of the record for a human-readable flat-file persistence scheme.

Overrides:

toString in class java.lang.Object

Returns:

string of form field=value \n field=value \n\n

preCheck

protected void preCheck()
                 throws DataException

Called before checking the fields. Does nothing in the base implementation. Overriding this method allows you to apply certain (possibly ad hoc) fixups before doing any validity checks. Basically, this gives a class a chance to massage data that wouldn't pass the validity check.

DataException

postCheck

protected void postCheck()
                  throws DataException

Called after checking the fields. Does nothing in the base implementaiton. If you want more, possibly cross-field or cross-record validity checks, override this method and put the checks here. If the data flunks, throw the appropriate data-related exception.

DataException

freeze

public void freeze()
            throws DataException

Description copied from interface: Record

make this record immutable. This will typically only be called by an OreoDataSource object.

Specified by:

freeze in interface Record

DataException

setValuesFromTable

public java.lang.String setValuesFromTable(java.util.Map table)
                                    throws DataException

Set the values of the record's fields from a key-value mapping of the fields (or field names) to values.

Parameters:

table - key-value string pairs to set values of fields.

Returns:

a string representing the status info contained in the table if any, possibly null.

DataException

get

public final java.lang.Object get(java.lang.String fieldname)

Description copied from interface: Record

Method to get the value of a field by name. Subclasses may wrap this with a higher-level get/set API.

Specified by:

get in interface Record

Parameters:

fieldname -

get

public final java.lang.Object get(FieldDescriptor field)

Description copied from interface: Record

Low-level method to query the value of a field in a Record.

Specified by:

get in interface Record

Parameters:

field - to query.

Returns:

an Object wrapper around field value.

set

public final void set(java.lang.String fieldname,
                      java.lang.Object value)

Description copied from interface: Record

Method to set the value of a field by name. Concrete implementations may wrap this with a higher-level get/set API.

Specified by:

set in interface Record

Parameters:

fieldname - the name of the field to set.

set

public final void set(FieldDescriptor field,
                      java.lang.Object value)

Description copied from interface: Record

Low-level method to set an individual field value

Specified by:

set in interface Record

Parameters:

field - to set.

value - Object wrapping the value

getMetadata

public final RecordDescriptor getMetadata()

Specified by:

getMetadata in interface Record

Returns:

an object that describes the data held in this record.

See Also:

RecordDescriptor

readExternal

public void readExternal(java.io.ObjectInput in)
                  throws java.io.IOException,
                         java.lang.ClassNotFoundException

Specified by:

readExternal in interface java.io.Externalizable

java.io.IOException

java.lang.ClassNotFoundException

getParent

public Record getParent()
                 throws MissingContextException

In this base implementation, this always returns null.

Specified by:

getParent in interface Record

Returns:

the parent element or null if there is none.

MissingContextException

getChildren

public java.util.List getChildren()
                           throws MissingContextException

In this base implementation, this always returns an empty list.

Specified by:

getChildren in interface Record

Returns:

a List of children.

MissingContextException

isRootElement

public boolean isRootElement()

In this base implementation, this always returns true.

Specified by:

isRootElement in interface Record

hasChildren

public boolean hasChildren()

In this base implementation, this always returns false.

Specified by:

hasChildren in interface Record

writeExternal

public void writeExternal(java.io.ObjectOutput out)
                   throws java.io.IOException

Specified by:

writeExternal in interface java.io.Externalizable

java.io.IOException

getMutableCopy

public Record getMutableCopy()

create a clone. A shallow copy of the values array should be enough for immutable records Note that a newly cloned object has its immutable flag set to false, so that it is in a modifiable state.

Specified by:

getMutableCopy in interface Record

get

public java.lang.Object get(java.lang.Object o)

clearFields

public void clearFields()

set the fields to their default values.

Specified by:

clearFields in interface Record

equals

public boolean equals(java.lang.Object o)

Overrides:

equals in class java.lang.Object

setMetadata

public void setMetadata(RecordDescriptor descriptor)

Description copied from interface: Record

Method only used internally.

Specified by:

setMetadata in interface Record

getType

public final java.lang.String getType()

Specified by:

getType in interface Record

Returns:

the name of this record type subclasses must implement this. e.g. "reminder"

get

protected abstract java.lang.Object get(int i)

set

protected abstract void set(int i,
                            java.lang.Object value)