Example usage for java.util IdentityHashMap clear

Introduction

In this page you can find the example usage for java.util IdentityHashMap clear.

Prototype

public void clear() 

Source Link

Document

Removes all of the mappings from this map.

Usage

From source file:Main.java

public static void main(String[] argv) throws Exception {
    IdentityHashMap<Object, Object> objMap = new IdentityHashMap<Object, Object>();

    Object o1 = new Integer(123);
    Object o2 = new Integer(123);
    objMap.put(o1, "first");
    objMap.put(o2, "from java2s.com");

    Object v1 = objMap.get(o1);//from  w w w .  j  av a  2  s.  c  o  m
    System.out.println(v1);
    Object v2 = objMap.get(o2);
    System.out.println(v2);

    objMap.clear();

    System.out.println("Map content after clear: " + objMap);

}

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From source file:com.google.gwt.emultest.java.util.IdentityHashMapTest.java

public void testClear() {
    IdentityHashMap hashMap = new IdentityHashMap();
    checkEmptyHashMapAssumptions(hashMap);

    hashMap.put("Hello", "Bye");
    assertFalse(hashMap.isEmpty());/*  www. ja v a 2 s.  c  o  m*/
    assertTrue(hashMap.size() == SIZE_ONE);

    hashMap.clear();
    assertTrue(hashMap.isEmpty());
    assertTrue(hashMap.size() == 0);
}

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From source file:com.google.gwt.emultest.java.util.IdentityHashMapTest.java

/**
 * Test method for 'java.util.IdentityHashMap.size()'.
 *//*ww w  . jav a2 s .c  o m*/
public void testSize() {
    IdentityHashMap hashMap = new IdentityHashMap();
    checkEmptyHashMapAssumptions(hashMap);

    // Test size behavior on put
    assertEquals(hashMap.size(), SIZE_ZERO);
    hashMap.put(KEY_1, VALUE_1);
    assertEquals(hashMap.size(), SIZE_ONE);
    hashMap.put(KEY_2, VALUE_2);
    assertEquals(hashMap.size(), SIZE_TWO);
    hashMap.put(KEY_3, VALUE_3);
    assertEquals(hashMap.size(), SIZE_THREE);

    // Test size behavior on remove
    hashMap.remove(KEY_1);
    assertEquals(hashMap.size(), SIZE_TWO);
    hashMap.remove(KEY_2);
    assertEquals(hashMap.size(), SIZE_ONE);
    hashMap.remove(KEY_3);
    assertEquals(hashMap.size(), SIZE_ZERO);

    // Test size behavior on putAll
    hashMap.put(KEY_1, VALUE_1);
    hashMap.put(KEY_2, VALUE_2);
    hashMap.put(KEY_3, VALUE_3);
    IdentityHashMap srcMap = new IdentityHashMap(hashMap);
    hashMap.putAll(srcMap);
    assertEquals(hashMap.size(), SIZE_THREE);

    // Test size behavior on clear
    hashMap.clear();
    assertEquals(hashMap.size(), SIZE_ZERO);
}

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