Package org.commonmark.ext.heading.anchor

Class IdGenerator

java.lang.Object

org.commonmark.ext.heading.anchor.IdGenerator

public class IdGenerator
extends Object

Generates strings to be used as identifiers.

Use builder() to create an instance.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	IdGenerator.Builder

Field Summary

Fields

Modifier and Type	Field	Description
private final Pattern	allowedCharacters
private String	defaultIdentifier
private final Map<String,Integer>	identityMap
private final String	prefix
private final String	suffix

Constructor Summary

Constructors

Modifier	Constructor	Description
private	IdGenerator(IdGenerator.Builder builder)

Method Summary

Modifier and Type	Method	Description
static IdGenerator.Builder	builder()
private static Pattern	compileAllowedCharactersPattern()
String	generateId(String text)	Generate an ID based on the provided text and previously generated IDs.
private String	normalizeText(String text)	Assume we've been given a space separated text.

Methods inherited from class java.lang.Object

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

Field Details

allowedCharacters

private final Pattern allowedCharacters

identityMap

private final Map<String,Integer> identityMap

prefix

private final String prefix

suffix

private final String suffix

defaultIdentifier

private String defaultIdentifier

Constructor Details

IdGenerator

private IdGenerator(IdGenerator.Builder builder)

Method Details

builder

public static IdGenerator.Builder builder()

Returns:

a new builder with default arguments

generateId

public String generateId(String text)

Generate an ID based on the provided text and previously generated IDs.

This method is not thread safe, concurrent calls can end up with non-unique identifiers.

Note that collision can occur in the case that

• Method called with 'X'
• Method called with 'X' again
• Method called with 'X-1'

In that case, the three generated IDs will be:

• X
• X-1
• X-1

Therefore if collisions are unacceptable you should ensure that numbers are stripped from end of text.

Parameters:

text - Text that the identifier should be based on. Will be normalised, then used to generate the identifier.

Returns:

text if this is the first instance that the text has been passed to the method. Otherwise, text + "-" + X will be returned, where X is the number of times that text has previously been passed in. If text is empty, the default identifier given in the constructor will be used.

compileAllowedCharactersPattern

private static Pattern compileAllowedCharactersPattern()

normalizeText

private String normalizeText(String text)

Assume we've been given a space separated text.

Parameters:

text - Text to normalize to an ID