BAEL-4718 using bytes array as key in HashMap (#10315)

2020-12-18 06:13:31 +01:00
parent efc1277b0a
commit 83e87aebc0
2 changed files with 132 additions and 0 deletions
@@ -0,0 +1,104 @@
+package com.baeldung.map.bytearrays;
+
+import com.google.common.collect.ImmutableList;
+import org.junit.jupiter.api.Test;
+
+import java.util.Base64;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+class ByteArrayKeyUnitTest {
+    @Test
+    void givenPrimitiveByteArrayKey_whenRetrievingFromMap_shouldRetrieveDifferentObjects() {
+        // given
+        byte[] key1 = {1, 2, 3};
+        byte[] key2 = {1, 2, 3};
+        String value1 = "value1";
+        String value2 = "value2";
+        Map<byte[], String> map = new HashMap<>();
+        map.put(key1, value1);
+        map.put(key2, value2);
+
+        // when
+        String retrievedValue1 = map.get(key1);
+        String retrievedValue2 = map.get(key2);
+        String retrievedValue3 = map.get(new byte[]{1, 2, 3});
+
+        // then
+        assertThat(retrievedValue1).isEqualTo(value1);
+        assertThat(retrievedValue2).isEqualTo(value2);
+        assertThat(retrievedValue3).isNull();
+    }
+
+    @Test
+    void givenEncodedStringKey_whenRetrievingFromMap_shouldRetrieveLastPutObject() {
+        // given
+        String key1 = Base64.getEncoder().encodeToString(new byte[]{1, 2, 3});
+        String key2 = Base64.getEncoder().encodeToString(new byte[]{1, 2, 3});
+        String value1 = "value1";
+        String value2 = "value2";
+        Map<String, String> map = new HashMap<>();
+        map.put(key1, value1);
+        map.put(key2, value2);
+
+        // when
+        String retrievedValue1 = map.get(key1);
+        String retrievedValue2 = map.get(key2);
+
+        // then
+        assertThat(key1).isEqualTo(key2);
+        assertThat(retrievedValue1).isEqualTo(value2);
+        assertThat(retrievedValue2).isEqualTo(value2);
+        assertThat(retrievedValue1).isEqualTo(retrievedValue2);
+    }
+
+    @Test
+    void givenByteListKey_whenRetrievingFromMap_shouldRetrieveLastPutObject() {
+        // given
+        List<Byte> key1 = ImmutableList.of((byte)1, (byte)2, (byte)3);
+        List<Byte> key2 = ImmutableList.of((byte)1, (byte)2, (byte)3);
+        String value1 = "value1";
+        String value2 = "value2";
+        Map<List<Byte>, String> map = new HashMap<>();
+        map.put(key1, value1);
+        map.put(key2, value2);
+
+        // when
+        String retrievedValue1 = map.get(key1);
+        String retrievedValue2 = map.get(key2);
+
+        // then
+        assertThat(key1).isEqualTo(key2);
+        assertThat(retrievedValue1).isEqualTo(value2);
+        assertThat(retrievedValue2).isEqualTo(value2);
+        assertThat(retrievedValue1).isEqualTo(retrievedValue2);
+    }
+
+    @Test
+    void givenCustomWrapperKey_whenRetrievingFromMap_shouldRetrieveLastPutObject() {
+        // given
+        BytesKey key1 = new BytesKey(new byte[]{1, 2, 3});
+        BytesKey key2 = new BytesKey(new byte[]{1, 2, 3});
+        String value1 = "value1";
+        String value2 = "value2";
+        Map<BytesKey, String> map = new HashMap<>();
+        map.put(key1, value1);
+        map.put(key2, value2);
+
+        // when
+        String retrievedValue1 = map.get(key1);
+        String retrievedValue2 = map.get(key2);
+        String retrievedValue3 = map.get(new BytesKey(new byte[]{1, 2, 3}));
+
+        // then
+        assertThat(key1).isEqualTo(key2);
+        assertThat(retrievedValue1).isEqualTo(value2);
+        assertThat(retrievedValue2).isEqualTo(value2);
+        assertThat(retrievedValue1).isEqualTo(retrievedValue2);
+        assertThat(retrievedValue3).isEqualTo(value2);
+
+    }
+}