ObjectHelper Tutorial

ObjectHelper is an object utility class that provides common utility methods for working with Java objects, collections, maps, and various data structures.

Main Features

1. Text content checking and validation
2. Collection and array emptiness checks
3. Convenient factory methods for creating collections (maps, lists, sets)
4. Capacity calculation utilities

Text Checking Methods

1. hasText Method

Checks if the given string has actual text content:

// Check if string has non-whitespace content
boolean result1 = ObjectHelper.hasText("Hello");     // true
boolean result2 = ObjectHelper.hasText("   ");       // false
boolean result3 = ObjectHelper.hasText("");          // false
boolean result4 = ObjectHelper.hasText(null);        // false

2. isEmptyText Method

Checks if the given string is empty or contains only whitespace:

// Check if string is empty or contains only whitespace
boolean result1 = ObjectHelper.isEmptyText("Hello"); // false
boolean result2 = ObjectHelper.isEmptyText("   ");   // true
boolean result3 = ObjectHelper.isEmptyText("");      // true
boolean result4 = ObjectHelper.isEmptyText(null);    // true

Emptiness Checking Methods

1. Array Emptiness Check

// Check if array is empty
String[] array1 = null;
String[] array2 = new String[0];
String[] array3 = {"Hello"};

boolean result1 = ObjectHelper.isEmpty(array1); // true
boolean result2 = ObjectHelper.isEmpty(array2); // true
boolean result3 = ObjectHelper.isEmpty(array3); // false

2. Collection Emptiness Check

// Check if collection is empty
List<String> list1 = null;
List<String> list2 = new ArrayList<>();
List<String> list3 = Arrays.asList("Hello");

boolean result1 = ObjectHelper.isEmpty(list1); // true
boolean result2 = ObjectHelper.isEmpty(list2); // true
boolean result3 = ObjectHelper.isEmpty(list3); // false

3. Map Emptiness Check

// Check if map is empty
Map<String, String> map1 = null;
Map<String, String> map2 = new HashMap<>();
Map<String, String> map3 = new HashMap<>();
map3.put("key", "value");

boolean result1 = ObjectHelper.isEmpty(map1); // true
boolean result2 = ObjectHelper.isEmpty(map2); // true
boolean result3 = ObjectHelper.isEmpty(map3); // false

Collection Creation Methods

1. Creating Maps

// Create single key-value pair map
Map<String, String> map1 = ObjectHelper.mapOf("key1", "value1");

// Create double key-value pair map
Map<String, String> map2 = ObjectHelper.mapOf("key1", "value1", "key2", "value2");

// Create triple key-value pair map
Map<String, String> map3 = ObjectHelper.mapOf("key1", "value1", "key2", "value2", "key3", "value3");

// Create map with specified capacity
Map<String, String> map4 = ObjectHelper.mapOf(10); // HashMap with optimized capacity

2. Creating Lists

// Create immutable list
List<String> list1 = ObjectHelper.listOf("item1");
List<String> list2 = ObjectHelper.listOf("item1", "item2", "item3");
List<String> list3 = ObjectHelper.listOf(); // Empty list

3. Creating Sets

// Create immutable set
Set<String> set1 = ObjectHelper.setOf("item1");
Set<String> set2 = ObjectHelper.setOf("item1", "item2", "item3");
Set<String> set3 = ObjectHelper.setOf(); // Empty set

// Automatic deduplication
Set<String> set4 = ObjectHelper.setOf("item1", "item1", "item2"); // Contains only "item1" and "item2"

Constants

• EMPTY_PARAMS_MAP: An empty, immutable map useful as a default or sentinel value when no parameters are needed
• DEFAULT_LOAD_FACTOR: Default load factor for hash maps, optimized for time and space efficiency

Notes

1. listOf methods create immutable collections
2. setOf method does not allow null elements
3. mapOf methods optimize initial capacity based on expected size to minimize resizing operations