com.martiansoftware.trivialpersist
Class Record

java.lang.Object
  com.martiansoftware.trivialpersist.Record

All Implemented Interfaces:

Cloneable, Comparable

public class Record

extends Object

implements Comparable, Cloneable

A trivially persistent object. Records contain any number of fields of the following data types:

• String
• long
• Date
• boolean
• double

Floats or doubles may be added in the future.

The names and types of fields are defined in a <tablename>.schema file in the Store's base directory. The .schema file contains one line for each field, in the form fieldname=fieldtype. A silly example:

File order.schema
product_code=string
quantity=long
ordertime=date
rushdelivery=boolean


Author:

Marty Lamb TODO: remove some repetitive code

Method Summary

Record	asWriteable() Returns a copy of this Record that may be modified and saved.
int	compareTo(Object o) Compares this Record's key with that of the specified object.
void	delete() Deletes this record from the store (and disk).
boolean	getBoolean(String fieldName) Retrieves a boolean value from this record
Date	getDate(String fieldName) Retrieves a date field from this record
String	getDate(String fieldName, DateFormat format) Retrieves a date field from this record as a String.
double	getDouble(String fieldName) Retrieves a double value from this record
Key	getKey() Returns this record's key
long	getLong(String fieldName) Retrieves a long value from this record
Object	getObject(String fieldName) Returns the Object backing the specified field.
String	getString(String fieldName) Retrieves a string field from this record
String	getString(String fieldName, String defaultValue) Retrieves a string field from this record
Table	getTable() Returns the Table to which this Record belongs
boolean	hasValue(String fieldName) Returns true iff this record has any value set for the specified field
boolean	isDirty() Returns true iff this Record has unsaved changes
boolean	isNew() Returns true iff this Record has never been saved
boolean	isReadOnly() Returns true iff this Record is read-only
Record	save() Saves this record to disk.
Record	setBoolean(String fieldName, boolean value) Sets a boolean value for this record
Record	setDate(String fieldName, Date value) Sets a date field for this record.
Record	setDate(String fieldName, String value, DateFormat format) Sets a date field for this record
Record	setDouble(String fieldName, double value) Sets a double value for this record
Record	setLong(String fieldName, long value) Sets a long value for this record
Record	setString(String fieldName, String value) Sets a string field in this record
Record	unset(String fieldName) Removes any value set for the specified field (if any).

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Detail

hasValue

public boolean hasValue(String fieldName)

Returns true iff this record has any value set for the specified field

Parameters:

fieldName - the name of the field to check for a value

Returns:

true iff this record has any value set for the specified field

setString

public Record setString(String fieldName,
                        String value)

Sets a string field in this record

Parameters:

fieldName - the name of the field to set

value - the string value to set

Returns:

a reference to this Record (allows chaining of set methods)

getString

public String getString(String fieldName)

Retrieves a string field from this record

Parameters:

fieldName - the name of the field to retrieve

Returns:

the requested string value, or null if no value is associated with the requested field

getString

public String getString(String fieldName,
                        String defaultValue)

Retrieves a string field from this record

Parameters:

fieldName - the name of the field to retrieve

defaultValue - the default value to return if the specified field has a null value

Returns:

the value of the specified string field, or the specified default value if the string field contains a null value

setDate

public Record setDate(String fieldName,
                      Date value)

Sets a date field for this record.

Parameters:

fieldName - the name of the field to set

value - the Date value to set

Returns:

a reference to this Record (allows chaining of set methods)

setDate

public Record setDate(String fieldName,
                      String value,
                      DateFormat format)

Sets a date field for this record

Parameters:

fieldName - the name of the field to set

value - the date value to set, encoded as a string

format - the date format to use for converting the specified string to a java.util.Date. If a conversion error occurs, an IllegalArgumentException is thrown.

Returns:

a reference to this Record (allows chaining of set methods)

getDate

public Date getDate(String fieldName)

Retrieves a date field from this record

Parameters:

fieldName - the name of the date field to retrieve

Returns:

the requested date field, or null if no date value is set for the specified field name

getDate

public String getDate(String fieldName,
                      DateFormat format)

Retrieves a date field from this record as a String.

Parameters:

fieldName - the name of the date field to retrieve

format - the date format to use in converting the date value to a string

Returns:

the converted date, or an empty string if no date value is set for the specified field name

setBoolean

public Record setBoolean(String fieldName,
                         boolean value)

Sets a boolean value for this record

Parameters:

fieldName - the name of the field to set

value - the boolean value to set

Returns:

a reference to this Record (allows chaining of set methods)

getBoolean

public boolean getBoolean(String fieldName)

Retrieves a boolean value from this record

Parameters:

fieldName - the name of the boolean field to retrieve

Returns:

the requested boolean value, or false if no boolean value is set for the specified field.

See Also:

hasValue(String)

setLong

public Record setLong(String fieldName,
                      long value)

Sets a long value for this record

Parameters:

fieldName - the name of the field to set

value - the long value to set

Returns:

a reference to this Record (allows chaining of set methods)

setDouble

public Record setDouble(String fieldName,
                        double value)

Sets a double value for this record

Parameters:

fieldName - the name of the field to set

value - the double value to set

Returns:

a reference to this Record (allows chaining of set methods)

getLong

public long getLong(String fieldName)

Retrieves a long value from this record

Parameters:

fieldName - the name of the long value field to retrieve

Returns:

the requested long value, or zero of no long value is set for the specified field name

See Also:

hasValue(String)

getDouble

public double getDouble(String fieldName)

Retrieves a double value from this record

Parameters:

fieldName - the name of the double value field to retrieve

Returns:

the requested double value, or zero of no double value is set for the specified field name

See Also:

hasValue(String)

getObject

public Object getObject(String fieldName)

Returns the Object backing the specified field. No type checks or schema checks are performed, and no case conversion is performed on the field name. This is used only to support the FieldComparator class.

Parameters:

fieldName - the name of the field Object to retrieve

Returns:

the specified Object, or null if no such Object exists

unset

public Record unset(String fieldName)

Removes any value set for the specified field (if any). If no value is set for the specified field, or even if the field name is not valid for this table's schema, this method has no effect.

Parameters:

fieldName - the name of the field to unset.

Returns:

a reference to this Record (allows chaining of set methods)

save

public Record save()
            throws TrivialPersistException

Saves this record to disk. TODO: handle status changes reflected in the filename's :info section

Throws:

TrivialPersistException - if an error of any kind occurs while saving.

delete

public void delete()
            throws TrivialPersistException

Deletes this record from the store (and disk).

Throws:

TrivialPersistException - if an error of any kind occurs while deleting this record

compareTo

public int compareTo(Object o)

Compares this Record's key with that of the specified object.

Specified by:

compareTo in interface Comparable

Parameters:

o - the other Record to check

getKey

public Key getKey()

Returns this record's key

Returns:

this record's key

isNew

public boolean isNew()

Returns true iff this Record has never been saved

Returns:

true iff this Record has never been saved

getTable

public Table getTable()

Returns the Table to which this Record belongs

Returns:

the Table to which this Record belongs

isDirty

public boolean isDirty()

Returns true iff this Record has unsaved changes

Returns:

true iff this Record has unsaved changes

isReadOnly

public boolean isReadOnly()

Returns true iff this Record is read-only

Returns:

true iff this Record is read-only

asWriteable

public Record asWriteable()

Returns a copy of this Record that may be modified and saved.

Returns:

a copy of this Record that may be modified and saved.