org.assistments.util

Class IdConversions

java.lang.Object

org.assistments.util.IdConversions

public class IdConversions
extends java.lang.Object

IdConversions provides methods for encoding database IDs to shorter alpha-numeric strings and to decode those strings back to database IDs.

Encoded database IDs are of the form:
<type code> <version identifier> <encoded ID part>

Where:

• <type code> is the String representation of an enum value IdConversions.SupportedDataTypes
• <version identifier> is the String representation of an enum value IdConversions.EncodingVersions
• <encoded ID part> is an encoded database ID

Background information:

• https://tracker.assistments.org:8443/browse/AS-241
• http://stackoverflow.com/questions/742013/how-to-code-a-url-shortener

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	IdConversions.EncodingVersions The list of supported encoding format versions.
static class	IdConversions.SupportedDataTypes The list of data types supported for encoding/decoding.

Field Summary

Fields

Modifier and Type	Field and Description
(package private) static java.lang.String	VER_A_CHARSET
(package private) static java.lang.String	VER_A_INVALID_CHARSET

Constructor Summary

Constructors

Constructor and Description
IdConversions()

Method Summary

Modifier and Type	Method and Description
static boolean	containsAnyChars(java.lang.String str, java.lang.String chars) Returns whether a string contains one or more characters.
static Pair<IdConversions.SupportedDataTypes,java.lang.Integer>	decodeConentId(java.lang.String encodedId) Decodes a previously encoded database ID.
static java.lang.String	encodeContentId(IdConversions.SupportedDataTypes idType, java.lang.String encodingVersion, int dbId) Encodes a datatbase ID

Methods inherited from class java.lang.Object

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

Field Detail

VER_A_CHARSET

static final java.lang.String VER_A_CHARSET

See Also:

Constant Field Values

VER_A_INVALID_CHARSET

static final java.lang.String VER_A_INVALID_CHARSET

See Also:

Constant Field Values

Constructor Detail

IdConversions

public IdConversions()

Method Detail

containsAnyChars

public static boolean containsAnyChars(java.lang.String str,
                                       java.lang.String chars)

Returns whether a string contains one or more characters.

Parameters:

str - String to check

chars - Characters to look for in str

Returns:

true if str contains any of the characters contained in chars; otherwisre false

decodeConentId

public static Pair<IdConversions.SupportedDataTypes,java.lang.Integer> decodeConentId(java.lang.String encodedId)
                                                                               throws java.lang.IllegalStateException

Decodes a previously encoded database ID.

Parameters:

encodedId - Encoded database ID.

Returns:

A Pair where the first member specifies the type of object and the second member contains the decoded database ID.

Throws:

java.lang.IllegalStateException - If there is something invalid about encodedId

encodeContentId

public static java.lang.String encodeContentId(IdConversions.SupportedDataTypes idType,
                                               java.lang.String encodingVersion,
                                               int dbId)

Encodes a datatbase ID

Parameters:

idType - The type of ID to encode

encodingVersion - The encoding version to use

dbId - The database ID to encode

Returns:

The encoded form of the ID