JarCastingutils
Collection of commonly used utilities (pure Java - without external dependencies)
Setup
<dependency>
<groupId>com.zandero</groupId>
<artifactId>utils</artifactId>
<version>1.2.10</version>
</dependency>
Assert
Assertion utilities to check input parameters and throw IllegalArgumentException in case arguments are invalid.
true / false test
Assert.isTrue(text.length >= 15, "Text is to short, must be at least 15 characters long!");
Assert.isFalse(text.length < 15, "Text is to long, must be less than 15 characters long!");
null / not null test
Assert.isNull(value, "Value was given, but null was expected!");
Assert.notNull(value, "Value expected, but null was given!");
String null / empty tests
Assert.notNullOrEmptyTrimmed(value, "Expected value but was not given!");
Collection, array, set, list ... tests
Assert.notNullOrEmpty(array, "Expected array but null or empty provided!");
Assert.notNullOrEmpty(list, "Expected list but null or empty provided!");
Assert.notNullOrEmpty(set, "Expected set but null or empty provided!");
Assert.notNullOrEmpty(map, "Expected map but null or empty provided!");
Assert.isNullOrEmpty(array, "Expected empty array!");
Assert.isNullOrEmpty(list, "Expected empty list!");
Assert.isNullOrEmpty(set, "Expected empty set!");
Assert.isNullOrEmpty(map, "Expected empty map!");
Date time
Time conversion between long, Date and String
- Date time formatting,
- Timezone support
- Some handy functions to get the start/end of a period
Utils
// return UTC initialized instance of Calendar
DateTimeUtils.getCalendar();
DateTimeUtils.getCalendar(long time); // returns UTC initialized instance of Calendar with set time provided in milliseconds
Date time formatting
// formats time to yyyy-MM-dd HH:mm:ss Z
DateTimeUtils.formatDateTime(long time);
// formats time to yyyy-MM-dd HH:mm:ss
DateTimeUtils.formatDateTimeShort(long time);
// formats time to yyyy-MM-dd
DateTimeUtils.formatDate(long time);
// format time with custom format or to yyyy-MM-dd HH:mm:ss Z if format not provided
DateTimeUtils.format(long time, SimpleDateFormat format);
Timezone helpers
// Returns time for given time zone (-12 / +12)
DateTimeUtils.getTimezoneTime(long time, int timezone);
// Converts local hour back to UTC hour
DateTimeUtils.getUtcHour(int hour, int timezone);
// Converts UTC hour to local hour
DateTimeUtils.getTimezoneHour(int hour, int timezone);
Conversions
// Converts timestamp into OffsetDatetime
DateTimeUtils.toOffsetDateTime(long timestamp);
// Converts offset date time to long timestamp
DateTimeUtils.fromOffsetDateTime(OffsetDateTime timestamp);
// Gets first millisecond of first day in month for given time
DateTimeUtils.getMonthStart(long time);
// Returns last millisecond of last day in month
DateTimeUtils.getMonthEnd(long time);
// Returns day in month, where first day of month == 1
DateTimeUtils.getDayInMonth(long time);
// Gets first millisecond of first day in week for given time
DateTimeUtils.getWeekStart(long time);
// Returns last millisecond of last day in week for given time
DateTimeUtils.getWeekEnd(long time);
// Returns number of day in week, where monday is the first day of the week (monday = 1, tuesday = 2 ..., sunday = 7)
DateTimeUtils.getDayInWeek(long time);
// Check if it is a weekend day (Saturday or Sunday)
DateTimeUtils.isWeekend(long time);
// Removes time component from date time
DateTimeUtils.getDateOnly(long time);
// Convert any given timestamp string to long trying a list of provided formats
DateTimeUtils.getTimestamp(String value, SimpleDateFormat[] formats);
Dir
Directory, path and file utilities
// Gets file extension: someFile.zip -> zip
DirUtils.getFileExtension(String file);
// Lists all files in given directory recursive (with option to filter by extension)
DirUtils.getAllFilesRecursive(File rootDir, String fileExtension);
DirUtils.getAllFilesRecursive(File rootDir, String[] fileExtensions);
// Lists all files in single directory, (with option to filter by extension)
DirUtils.getAllFilesInDir(File rootDir, String fileExtension)
DirUtils.getAllFilesInDir(File rootDir, String[] fileExtensions);
// Calculates size of all files in given directory and it's sub-directories.
DirUtils.dirSize(File directory);
Equality utils
- NPE safe checks to compare two objects of same type: Long, Integer ...
// compare integers
Integer one = null;
Integer two = 3;
EqualsUtils.equals(one, two);
// compare longs
Integer longOne = null;
Integer longTwo = 3;
EqualsUtils.equals(longOne, longTwo);
// compare strings (case sensitive)
EqualsUtils.equals("Some string", null);
// Compares if two maps hold the same set of keys and same values
// comparison of values utilizes the equals call, so make sure equals is implemented
// position of key is not considered (like in LinkedHashMap)
Map<String, T> one;
Map<String, T> two;
EqualsUtils.equals(mapOne, mapTwo);
JUnit probe
Checks if code runs inside a JUnit test or not
// Checks if code is run inside a unit test
JUnitProbe.isUnitTest();
KeyGenerator
Generates random keys of given length.
// Generates random string from A-Z, a-z, 0-9 set of chars and numbers
// with lenght from 1-100
KeyGenerator.generateString(int length);
// Generates non negative long key of maximum length 18
KeyGenerator.generateLong(int length);
Maps
Map helpers and manipulation utils
Merging two maps
Map outputMap = MapUtils.mergeMaps(firatMap, mergeFunction, otherMap);
// Example
Map<String, Long> m1 = new HashMap<>();
m1.put("A", 10L);
m1.put("B", 20L);
Map<String, Long> m2 = new HashMap<>();
m2.put("C", 2L);
m2.put("D", 3L);
m2.put("E", 1L);
// sum those two maps together
Map<String, Long> result = MapUtils.mergeMaps(Stream.of(m1, m2), Long::sum, HashMap::new);
Sorting
// sort map with given comparator ...
LinkedHashMap sorted = sort(map, comparator);
// example
LinkedHashMap sortedMap = MapUtils.sort(map, Comparator.comparing(Map.Entry::getValue));
Compare maps
// compare maps by keys
MapUtils.equals(mapOne, mapTwo);
// compare maps by keys and values
MapUtils.equals(mapOne, mapTwo, true);
Resources
Loading of resource files
// Loads resource into string
String output = ResourceUtils.getResourceAsString(String resourceFile, Class clazz);
// Loads resource as a set of Strings, where each word is added to the set
Set<String> output = ResourceUtils.getResourceWords(file, clazz);
// Get resource absolute path
String output = ResourceUtils.getResourceAbsolutePath(String resource, Class clazz);
Reading streams and files into strings
// Loads resource to String
String output = ResourceUtils.readFileToString(file);
// Get resource last modified time stamp
Long time = ResourceUtils.getLastModifiedTime(file);
// Load input stream into string
String output = ResourceUtils.getString(inputStream);
// Load input stream into string
String output = ResourceUtils.getString(inputStream, encoding);
// Load input stream into byte array
byte[] output = ResourceUtils.getBytes(InputStream is);
Strings
Various handy string utilities.
NPE safe String comparison
// NPE safe compare of two strings (case sensitive)
StringUtils.equals(original, compare);
// NPE safe compare of two strings - case sensitive or insensitive
StringUtils.equals(original, compare, ignoreCase);
// NPE safe compare same as String.compare()
int result = StringUtils.compare(one, two);
Null and empty checks
// Checks if string is null or empty == ""
StringUtils.isNullOrEmpty(value);
// Checks if string is null, empty or contains only spaces
StringUtils.isNullOrEmptyTrimmed(value);
String trimming
// NPE safe String.trim()
StringUtils.trim(String value);
// Trim with inner double space trim
StringUtils.trimDoubleSpaces(text);
// Complete trim of all spaces
StringUtils.trimInner(text);
// Trims only end of text
StringUtils.trimEnd(text);
// Trims only start of text
StringUtils.trimStart(text);
// Trims specific text only
StringUtils.trimAll(text, toBeTrimmed);
// Trims to null if empty
StringUtils.trimToNull(text);
String transformation
// Capitalizes first found character in given string
// "123 abc" -> "123 Abc"
String TEXT = StringUtils.capitalize(text);
// Removes punctuation from text
// "test!" -> "test"
StringUtils.removePunctuation(text);
// Removes all multiple-consecutive whitespace characters (space, tab, newline) and replaces them with single space.
// Also removes leading and trailing spaces.
Stirng out = StringUtils.sanitizeWhitespace(text)
byte[] out = sanitizeWhitespace(byte[] input);
// Reduces text to max given size preserving words
StringUtils.trimTextDown(text, maxWidth);
// Reduces text size to a given size preserving words with appendix
StringUtils.trimTextDown(text, widthMinusAppend, append)
// Simple enumeration: first, second, third ... 5th, 6th .. etc for given number
StringUtils.enumerate(number);
// Removes double quotes if any are present (in begging and end)
StringUtils.unQuote(text);
String joining
// Joins list of string items to a single string, where items are separated
// with a defined separator. Limiting number of included items.
StringUtils.join(List<?> list, separator);
StringUtils.join(List<?> list, separator, includeMaxLimit);
// Joins array of objects to a single string, where items are separated
// with a defined separator. Limiting number of included items.
StringUtils.join(Object[] args, separator);
StringUtils.join(Object[] args, separator, includeMaxLimit);
// Joins set of objects to a single string, where items are separated
// with a defined separator.
StringUtils.join(Set<?> items, separator);
StringUtils.join(Set<?> items, separator, includeMaxLimit);
// Joins map of items to a single string, where items are separated with a defined separator.
StringUtils.join(Map<String, String> map, separator);
Word extraction
// Extracts words from text removing non alpha characters
List<String> words = StringUtils.getWords(text);
// Converts text to list of characters
List<String> chars = asListOfChars(text);
// Checks if given string is a single word (doesn't accepts words with "-" as a single word!)
isWord(word);
Search by relevance
// Calculates matching relevance between given string and search expression
// -1 not relevant, 0..N - where lower values represents more relevant results
relevance(text, search);
