Module com.erudika.para.core

Package com.erudika.para.core.utils

Class Utils

java.lang.Object

com.erudika.para.core.utils.Utils

public final class Utils
extends Object

Miscellaneous Para utilities.

Author:

Alex Bogdanovski [[email protected]]

Method Summary

Modifier and Type	Method	Description
static String	abbreviate(String str, int max)	Abbreviates a string.
static String	abbreviateInt(Number number, int decPlaces)	Abbreviates an integer by adding a letter suffix at the end.
static String	arrayJoin(List<String> arr, String separator)	Joins a list of strings to String using a separator.
static String	base64dec(String str)	Decodes a string from Base64.
static String	base64enc(byte[] str)	Encodes a byte array to Base64.
static String	base64encURL(byte[] str)	Encodes a byte array to Base64.
static String	bcrypt(String s)	bcrypt hash function implemented by Spring Security.
static boolean	bcryptMatches(String plain, String storedHash)	Checks if a hash matches a string.
static String	compileMustache(Map<String,Object> context, String template)
static String	compileMustache(Map<String,Object> context, String template, boolean escapeHtml)	Compiles a mustache template with a given scope (map of fields and values).
static String	formatDate(Long timestamp, String format, Locale loc)	Formats a date in a specific format.
static String	formatDate(String format, Locale loc)	Formats the date for today, in a specific format.
static String	formatMessage(String msg, Object... params)	Formats a messages containing {0}, {1}...
static String	formatPrice(double price)	Returns the price with two fractional digits at the end.
static String	generateSecurityToken()	Generates an authentication token - a random 32 byte string encoded in Base64.
static String	generateSecurityToken(int length)	Generates an authentication token - a random string encoded in Base64.
static String	generateSecurityToken(int length, boolean urlSafe)	Generates an authentication token - a random string encoded in Base64.
static List<Field>	getAllDeclaredFields(Class<? extends ParaObject> clazz)	Returns a list of all declared fields in a class.
static String	getBaseURL(String url)	The basic URL without any parameters: >scheme<:>authority<.
static int	getCurrentYear()	Returns the current year.
static String	getHostFromURL(String url)	Returns the host part of the URL.
static HumanTime	getHumanTime()	HumanTime - a relative time formatter.
static Utils	getInstance()	Returns an instance of this class.
static Locale	getLocale(String localeStr)
static String[]	getMonths(Locale locale)	Returns an array of the months in the Gregorian calendar.
static String	getNewId()	Distributed id generator.
static String	getObjectURI(ParaObject obj, boolean includeName, boolean includeId)	Returns the default URL for a given domain object.
static String	getSystemProperty(String name)	Same as System.getProperty(java.lang.String).
static String	hmacSHA256(String message, String secret)	Computes the HmacSHA256 hash of a message.
static boolean	isBasicType(Class<?> clazz)	Checks if a class is primitive, String or a primitive wrapper.
static boolean	isJsonType(String contentType)	Checks if a response is of type JSON.
static boolean	isValidEmail(String email)	Email validation.
static boolean	isValidURL(String url)	URL validation.
static String	markdownToHtml(String markdownString)	Converts Markdown to HTML.
static String	markdownToHtml(String markdownString, boolean htmlTagsRenderingEnabled)	Converts Markdown to HTML.
static String	md5(String s)	md5 hash function.
static String	noSpaces(String str, String replaceWith)	Converts spaces to dashes.
static int	round(float d)	Rounds a float to an int.
static double	roundHalfUp(double d)	Round up a double using the "half up" method.
static double	roundHalfUp(double d, int scale)	Round up a double using the "half up" method.
static String	singularToPlural(String singul)	Quick and dirty singular to plural conversion.
static String	stripAndTrim(String str)	Strips all symbols, punctuation, whitespace and control chars from a string.
static String	stripAndTrim(String str, String replaceWith)	Strips all symbols, punctuation, whitespace and control chars from a string.
static String	stripAndTrim(String str, String replaceWith, boolean asciiOnly)	Strips all symbols, punctuation, whitespace and control chars from a string.
static String	stripHtml(String html)	Strips all HTML tags from a string.
static long	timestamp()	Java timestamp.
static String	type(Class<? extends ParaObject> clazz)	Returns the simple name of a class in lowercase (AKA the type).
static String	urlDecode(String s)	Decodes a URL-encoded string.
static String	urlEncode(String s)	URL-encodes a string.

Methods inherited from class java.lang.Object

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

Method Details

getInstance

public static Utils getInstance()

Returns an instance of this class.

Returns:

an instance

getHumanTime

public static HumanTime getHumanTime()

HumanTime - a relative time formatter.

Returns:

humantime instance

md5

public static String md5(String s)

md5 hash function.

Parameters:

s - the string to be hashed

Returns:

an md5 hash

hmacSHA256

public static String hmacSHA256(String message,
 String secret)

Computes the HmacSHA256 hash of a message.

Parameters:

message - a message as UTF-8 encoded string

secret - a secret key

Returns:

base64(hmacSHA256(message, secret))

bcrypt

public static String bcrypt(String s)

bcrypt hash function implemented by Spring Security.

Parameters:

s - the string to be hashed

Returns:

the hash

bcryptMatches

public static boolean bcryptMatches(String plain,
 String storedHash)

Checks if a hash matches a string.

Parameters:

plain - plain text string

storedHash - hashed string

Returns:

true if the hash matches

generateSecurityToken

public static String generateSecurityToken(int length,
 boolean urlSafe)

Generates an authentication token - a random string encoded in Base64.

Parameters:

length - the length of the generated token

urlSafe - switches to a URL safe encoding

Returns:

a random string

generateSecurityToken

public static String generateSecurityToken(int length)

Generates an authentication token - a random string encoded in Base64.

Parameters:

length - the length of the generated token

Returns:

a random string

generateSecurityToken

public static String generateSecurityToken()

Generates an authentication token - a random 32 byte string encoded in Base64.

Returns:

a random string

stripHtml

public static String stripHtml(String html)

Strips all HTML tags from a string.

Parameters:

html - HTML string

Returns:

just the text

markdownToHtml

public static String markdownToHtml(String markdownString)

Converts Markdown to HTML.

Parameters:

markdownString - Markdown

Returns:

HTML

markdownToHtml

public static String markdownToHtml(String markdownString,
 boolean htmlTagsRenderingEnabled)

Converts Markdown to HTML.

Parameters:

markdownString - Markdown

htmlTagsRenderingEnabled - if true, basic HTML tags will be rendered instead of escaped

Returns:

HTML

compileMustache

public static String compileMustache(Map<String,Object> context,
 String template,
 boolean escapeHtml)

Compiles a mustache template with a given scope (map of fields and values).

Parameters:

context - a map of fields and values

template - a Mustache template

escapeHtml - enable/disable escaping of HTML

Returns:

the compiled template string

compileMustache

public static String compileMustache(Map<String,Object> context,
 String template)

Parameters:

context - a map of fields and values

template - a Mustache template

Returns:

the compiled template string

See Also:

• compileMustache(java.util.Map, java.lang.String, boolean)

abbreviate

public static String abbreviate(String str,
 int max)

Abbreviates a string.

Parameters:

str - a string

max - max length

Returns:

a substring of that string

arrayJoin

public static String arrayJoin(List<String> arr,
 String separator)

Joins a list of strings to String using a separator.

Parameters:

arr - a list of strings

separator - a separator string

Returns:

a string

stripAndTrim

public static String stripAndTrim(String str)

Strips all symbols, punctuation, whitespace and control chars from a string.

Parameters:

str - a dirty string

Returns:

a clean string

stripAndTrim

public static String stripAndTrim(String str,
 String replaceWith)

Strips all symbols, punctuation, whitespace and control chars from a string.

Parameters:

str - a dirty string

replaceWith - a string to replace spaces with

Returns:

a clean string

stripAndTrim

public static String stripAndTrim(String str,
 String replaceWith,
 boolean asciiOnly)

Strips all symbols, punctuation, whitespace and control chars from a string.

Parameters:

str - a dirty string

replaceWith - a string to replace spaces with

asciiOnly - if true, all non-ASCII characters will be stripped

Returns:

a clean string

noSpaces

public static String noSpaces(String str,
 String replaceWith)

Converts spaces to dashes.

Parameters:

str - a string with spaces

replaceWith - a string to replace spaces with

Returns:

a string with dashes

formatMessage

public static String formatMessage(String msg,
 Object... params)

Formats a messages containing {0}, {1}... etc. Used for translation.

Parameters:

msg - a message with placeholders

params - objects used to populate the placeholders

Returns:

a formatted message

base64enc

public static String base64enc(byte[] str)

Encodes a byte array to Base64.

Parameters:

str - the byte array

Returns:

an encoded string

base64encURL

public static String base64encURL(byte[] str)

Encodes a byte array to Base64. URL safe.

Parameters:

str - the byte array

Returns:

an encoded string

base64dec

public static String base64dec(String str)

Decodes a string from Base64.

Parameters:

str - the encoded string

Returns:

a decoded string

formatDate

public static String formatDate(Long timestamp,
 String format,
 Locale loc)

Formats a date in a specific format.

Parameters:

timestamp - the Java timestamp

format - the date format

loc - the locale instance

Returns:

a formatted date

formatDate

public static String formatDate(String format,
 Locale loc)

Formats the date for today, in a specific format.

Parameters:

format - the date format

loc - the locale instance

Returns:

today's date formatted

getCurrentYear

public static int getCurrentYear()

Returns the current year.

Returns:

this year

timestamp

public static long timestamp()

Java timestamp.

Returns:

System.currentTimeMillis()

getMonths

public static String[] getMonths(Locale locale)

Returns an array of the months in the Gregorian calendar.

Parameters:

locale - the locale used for the months' names

Returns:

an array of the 12 months

getLocale

public static Locale getLocale(String localeStr)

Parameters:

localeStr - locale string

Returns:

a Locale instance from a locale string.

round

public static int round(float d)

Rounds a float to an int.

Parameters:

d - a float

Returns:

a rounded int

formatPrice

public static String formatPrice(double price)

Returns the price with two fractional digits at the end.

Parameters:

price - a price

Returns:

$###.##

roundHalfUp

public static double roundHalfUp(double d)

Round up a double using the "half up" method.

Parameters:

d - a double

Returns:

a double

roundHalfUp

public static double roundHalfUp(double d,
 int scale)

Round up a double using the "half up" method.

Parameters:

d - a double

scale - the scale

Returns:

a double

abbreviateInt

public static String abbreviateInt(Number number,
 int decPlaces)

Abbreviates an integer by adding a letter suffix at the end. E.g. "M" for millions, "K" for thousands, etc.

Parameters:

number - a big integer

decPlaces - decimal places

Returns:

the rounded integer as a string

urlDecode

public static String urlDecode(String s)

Decodes a URL-encoded string.

Parameters:

s - a string

Returns:

the decoded string

urlEncode

public static String urlEncode(String s)

URL-encodes a string.

Parameters:

s - a string

Returns:

the encoded string

isValidURL

public static boolean isValidURL(String url)

URL validation.

Parameters:

url - a URL

Returns:

true if the URL is valid

isValidEmail

public static boolean isValidEmail(String email)

Email validation.

Parameters:

email - email address

Returns:

true if the URL is valid

getHostFromURL

public static String getHostFromURL(String url)

Returns the host part of the URL.

Parameters:

url - a URL

Returns:

just the host

getBaseURL

public static String getBaseURL(String url)

The basic URL without any parameters: >scheme<:>authority<.

Parameters:

url - a full URL

Returns:

the basic URL

getObjectURI

public static String getObjectURI(ParaObject obj,
 boolean includeName,
 boolean includeId)

Returns the default URL for a given domain object.

Parameters:

obj - the domain object

includeName - true if we want to include the name of the object in the URL

includeId - true if we want to include the ID of the object in the URL

Returns:

the object's URL - e.g. /users/123-name, /users/, /users/123

getSystemProperty

public static String getSystemProperty(String name)

Same as System.getProperty(java.lang.String).

Parameters:

name - the name of the property

Returns:

the property value

isJsonType

public static boolean isJsonType(String contentType)

Checks if a response is of type JSON.

Parameters:

contentType - the value of "Content-Type" header

Returns:

true if JSON

singularToPlural

public static String singularToPlural(String singul)

Quick and dirty singular to plural conversion.

Parameters:

singul - a word

Returns:

a guess of its plural form

isBasicType

public static boolean isBasicType(Class<?> clazz)

Checks if a class is primitive, String or a primitive wrapper.

Parameters:

clazz - a class

Returns:

true if primitive or wrapper

type

public static String type(Class<? extends ParaObject> clazz)

Returns the simple name of a class in lowercase (AKA the type).

Parameters:

clazz - a core class

Returns:

just the name in lowercase or an empty string if clazz is null

getAllDeclaredFields

public static List<Field> getAllDeclaredFields(Class<? extends ParaObject> clazz)

Returns a list of all declared fields in a class. Transient and serialVersionUID fields are skipped. This method scans parent classes as well.

Parameters:

clazz - a class to scan

Returns:

a list of fields including those of the parent classes excluding the Object class.

getNewId

public static String getNewId()

Distributed id generator. Relies on node/worker ids and datacenter ids to prevent collisions.

Returns:

a long unique ID string of digits