jsr166-tests/src/test/java/jsr166/EntryTest.java

/*
 * Written by Doug Lea with assistance from members of JCP JSR-166
 * Expert Group and released to the public domain, as explained at
 * http://creativecommons.org/publicdomain/zero/1.0/
 */

package jsr166;

import junit.framework.*;
import java.util.*;

public class EntryTest extends JSR166TestCase {

    static final String k1 = "1";
    static final String v1 = "a";
    static final String k2 = "2";
    static final String v2 = "b";

    /**
     * A new SimpleEntry(k, v) holds k, v.
     */
    public void testConstructor1() {
        Map.Entry e = new AbstractMap.SimpleEntry(k1, v1);
        assertEquals(k1, e.getKey());
        assertEquals(v1, e.getValue());
    }

    /**
     * A new SimpleImmutableEntry(k, v) holds k, v.
     */
    public void testConstructor2() {
        Map.Entry s = new AbstractMap.SimpleImmutableEntry(k1, v1);
        assertEquals(k1, s.getKey());
        assertEquals(v1, s.getValue());
    }

    /**
     * A new SimpleEntry(entry(k, v)) holds k, v.
     */
    public void testConstructor3() {
        Map.Entry e2 = new AbstractMap.SimpleEntry(k1, v1);
        Map.Entry e = new AbstractMap.SimpleEntry(e2);
        assertEquals(k1, e.getKey());
        assertEquals(v1, e.getValue());
    }

    /**
     * A new SimpleImmutableEntry(entry(k, v)) holds k, v.
     */
    public void testConstructor4() {
        Map.Entry s2 = new AbstractMap.SimpleImmutableEntry(k1, v1);
        Map.Entry s = new AbstractMap.SimpleImmutableEntry(s2);
        assertEquals(k1, s.getKey());
        assertEquals(v1, s.getValue());
    }

    /**
     * Entries with same key-value pairs are equal and have same
     * hashcodes
     */
    public void testEquals() {
        Map.Entry e2 = new AbstractMap.SimpleEntry(k1, v1);
        Map.Entry e = new AbstractMap.SimpleEntry(e2);
        Map.Entry s2 = new AbstractMap.SimpleImmutableEntry(k1, v1);
        Map.Entry s = new AbstractMap.SimpleImmutableEntry(s2);
        assertEquals(e2, e);
        assertEquals(e2.hashCode(), e.hashCode());
        assertEquals(s2, s);
        assertEquals(s2.hashCode(), s.hashCode());
        assertEquals(e2, s2);
        assertEquals(e2.hashCode(), s2.hashCode());
        assertEquals(e, s);
        assertEquals(e.hashCode(), s.hashCode());
    }

    /**
     * Entries with different key-value pairs are not equal
     */
    public void testNotEquals() {
        Map.Entry e2 = new AbstractMap.SimpleEntry(k1, v1);
        Map.Entry e = new AbstractMap.SimpleEntry(k2, v1);
        assertFalse(e2.equals(e));
        e = new AbstractMap.SimpleEntry(k1, v2);
        assertFalse(e2.equals(e));
        e = new AbstractMap.SimpleEntry(k2, v2);
        assertFalse(e2.equals(e));

        Map.Entry s2 = new AbstractMap.SimpleImmutableEntry(k1, v1);
        Map.Entry s = new AbstractMap.SimpleImmutableEntry(k2, v1);
        assertFalse(s2.equals(s));
        s = new AbstractMap.SimpleImmutableEntry(k1, v2);
        assertFalse(s2.equals(s));
        s = new AbstractMap.SimpleImmutableEntry(k2, v2);
        assertFalse(s2.equals(s));
    }

    /**
     * getValue returns last setValue for SimpleEntry
     */
    public void testSetValue1() {
        Map.Entry e2 = new AbstractMap.SimpleEntry(k1, v1);
        Map.Entry e = new AbstractMap.SimpleEntry(e2);
        assertEquals(k1, e.getKey());
        assertEquals(v1, e.getValue());
        e.setValue(k2);
        assertEquals(k2, e.getValue());
        assertFalse(e2.equals(e));
    }

    /**
     * setValue for SimpleImmutableEntry throws UnsupportedOperationException
     */
    public void testSetValue2() {
        Map.Entry s2 = new AbstractMap.SimpleImmutableEntry(k1, v1);
        Map.Entry s = new AbstractMap.SimpleImmutableEntry(s2);
        assertEquals(k1, s.getKey());
        assertEquals(v1, s.getValue());
        try {
            s.setValue(k2);
            shouldThrow();
        } catch (UnsupportedOperationException success) {}
    }
}