Add common methods to DeliveryState.

sdk/core/azure-core-amqp/src/main/java/com/azure/core/amqp/models/DeliveryState.java

@@ -5,6 +5,8 @@
 
 import com.azure.core.util.ExpandableStringEnum;
 
+import java.util.Collection;
+
 /**
  * States for a message delivery.
  *
@@ -38,4 +40,24 @@ public final class DeliveryState extends ExpandableStringEnum<DeliveryState> {
      * Indicates that this delivery is part of a transaction.
      */
     public static final DeliveryState TRANSACTIONAL = fromString("TRANSACTIONAL", DeliveryState.class);
+
+    /**
+     * Gets the corresponding delivery state from its string representation.
+     *
+     * @param name The delivery state to convert.
+     *
+     * @return The corresponding delivery state.
+     */
+    public static DeliveryState fromString(String name) {
+        return fromString(name, DeliveryState.class);
+    }
+
+    /**
+     * Gets all the current delivery states.
+     *
+     * @return Gets the current delivery states.
+     */
+    public static Collection<DeliveryState> values() {
+        return values(DeliveryState.class);
+    }
 }

sdk/core/azure-core-amqp/src/test/java/com/azure/core/amqp/models/DeliveryStateTest.java

@@ -0,0 +1,64 @@
+// Copyright (c) Microsoft Corporation. All rights reserved.
+// Licensed under the MIT License.
+
+package com.azure.core.amqp.models;
+
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.MethodSource;
+
+import java.util.Collection;
+import java.util.stream.Stream;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertNotNull;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+/**
+ * Tests {@link DeliveryState}
+ */
+public class DeliveryStateTest {
+    /**
+     * Tests that all the values are available.
+     */
+    @Test
+    public void values() {
+        // Arrange
+        final DeliveryState[] expected = new DeliveryState[] {
+            DeliveryState.ACCEPTED, DeliveryState.MODIFIED, DeliveryState.RECEIVED, DeliveryState.REJECTED,
+            DeliveryState.RELEASED, DeliveryState.TRANSACTIONAL
+        };
+
+        // Act
+        final Collection<DeliveryState> actual = DeliveryState.values();
+
+        // Assert
+        for (DeliveryState state : expected) {
+            assertTrue(actual.contains(state));
+        }
+    }
+
+    /**
+     * Arguments for fromString.
+     * @return Test arguments.
+     */
+    public static Stream<String> fromString() {
+        return Stream.of("MODIFIED", "FOO-BAR-NEW");
+    }
+
+    /**
+     * Tests that we can get the corresponding value and a new one if it does not exist.
+     *
+     * @param deliveryState Delivery states to test.
+     */
+    @MethodSource
+    @ParameterizedTest
+    public void fromString(String deliveryState) {
+        // Act
+        final DeliveryState state = DeliveryState.fromString(deliveryState);
+
+        // Assert
+        assertNotNull(state);
+        assertEquals(deliveryState, state.toString());
+    }
+}