org.mov.quote
Class Symbol

java.lang.Object
  org.mov.quote.Symbol

All Implemented Interfaces:

java.lang.Cloneable, java.lang.Comparable

public class Symbol
extends java.lang.Object
implements java.lang.Cloneable, java.lang.Comparable

An immutable representation of a stock symbol, e.g. CBA or WBC. Previously the stock symbol was stored as a String but this created the question of whether it should be stored in lower or upper case. Unfortunately, due to development drift, even though the stock symbols were always displayed in upper case, they were stored in lower case. Often a "missing" conversion meant the symbol was displayed in lower case or worse it was stored in upper case which could cause the stock symbol to become "invisible".

By creating a single class we reduce the amount of toUpperCase() and toLowerCase() calls required, and have a single place to store symbol parsing code.

To reduce memory, symbols are stored canonically. That is there is a single object for each symbol. For example the string symbol "CBA" would be represented by a single class, no matter where it was used. So instead of instantiating a new symbol class, you find the canonical object using the find(java.lang.String) method.

Author:

Andrew Leppard

Field Summary

static int	MAXIMUM_SYMBOL_LENGTH The maximum valid length for a symbol.
static int	MINIMUM_SYMBOL_LENGTH The minimum valid length for a symbol

Method Summary

char	charAt(int offset) Return the character at the given offset.
java.lang.Object	clone() Create a clone of this symbol.
int	compareTo(java.lang.Object object) Compare this symbol to the given symbol.
boolean	equals(java.lang.Object object) Compare this symbol to the given symbol.
static Symbol	find(java.lang.String string) Return the canonical symbol instance of the given symbol string.
java.lang.String	get() Return the symbol string.
int	hashCode() Calculate the hash code for this symbol.
int	length() Return the length of the symbol.
static java.util.SortedSet	toSortedSet(java.lang.String string, boolean checkExists) Convert a string containing a list of symbols separated by spaces or commas into a sorted set of symbols with duplicates removed.
java.lang.String	toString() Convert the symbol to a string.
static Symbol	toSymbol(java.lang.String string) Convert a string containing a single symbol into a quote symbol.

Methods inherited from class java.lang.Object

finalize, getClass, notify, notifyAll, wait, wait, wait

Field Detail

MINIMUM_SYMBOL_LENGTH

public static final int MINIMUM_SYMBOL_LENGTH

The minimum valid length for a symbol

See Also:

Constant Field Values

MAXIMUM_SYMBOL_LENGTH

public static final int MAXIMUM_SYMBOL_LENGTH

The maximum valid length for a symbol.

See Also:

Constant Field Values

Method Detail

find

public static Symbol find(java.lang.String string)
                   throws SymbolFormatException

Return the canonical symbol instance of the given symbol string.

Parameters:

string - a string containing a single symbol

Throws:

SymbolFormatException - if the string doesn't contain a valid quote

get

public java.lang.String get()

Return the symbol string.

Returns:

an upper case symbol string

length

public int length()

Return the length of the symbol. This is guaranteed to be within bounds.

Returns:

the symbol length.

charAt

public char charAt(int offset)

Return the character at the given offset. See the java.lang.String class for more details.

Parameters:

offset - the character offset

Returns:

the character at the given offset

toSortedSet

public static java.util.SortedSet toSortedSet(java.lang.String string,
                                              boolean checkExists)
                                       throws SymbolFormatException

Convert a string containing a list of symbols separated by spaces or commas into a sorted set of symbols with duplicates removed. This function Checks that all symbols appear in the quote source. e.g "CBA WBC TLS" -> [CBA, TLS, WBC].

Parameters:

string - a comma or space separated list of symbols

checkExists - set this flag to TRUE to make sure that the symbols are in the current quote source

Returns:

a sorted set of symbols

Throws:

SymbolFormatException - if the string doesn't contain a list of valid quotes

toSymbol

public static Symbol toSymbol(java.lang.String string)
                       throws SymbolFormatException

Convert a string containing a single symbol into a quote symbol. This differs from find(java.lang.String) as it performs better error checking and checks that the symbol exists.

Parameters:

string - a string containing a single symbol

Throws:

SymbolFormatException - if the string doesn't contain a valid quote

clone

public java.lang.Object clone()

Create a clone of this symbol.

Overrides:

clone in class java.lang.Object

Returns:

clone of this symbol

compareTo

public int compareTo(java.lang.Object object)

Compare this symbol to the given symbol.

Specified by:

compareTo in interface java.lang.Comparable

Parameters:

object - symbol to compare

Returns:

the value 0 if the symbols are equal; 1 if this symbol is after the specified symbol or -1 if this symbol is before the specified symbol.

equals

public boolean equals(java.lang.Object object)

Compare this symbol to the given symbol.

Overrides:

equals in class java.lang.Object

Parameters:

object - the symbol to compare

Returns:

true if they are equal

hashCode

public int hashCode()

Calculate the hash code for this symbol.

Overrides:

hashCode in class java.lang.Object

Returns:

the hash code

toString

public java.lang.String toString()

Convert the symbol to a string. This is identical to the get() method.

Overrides:

toString in class java.lang.Object

Returns:

the symbol string