Fix SimpleKey equality with array argument

Prior to this commit, an array argument was not handled properly in
SimpleKey#equals and SimpleKey#hashCode. As a result, two method
invocations with the same array argument lead to two different keys
and therefore two different entries in the cache.

This commit uses deepEquals and deepHashCode to properly handle
methods that have arguments that are array types.

Issue: SPR-11505

spring-context/src/main/java/org/springframework/cache/interceptor/SimpleKey.java

@@ -50,12 +50,13 @@ public final class SimpleKey implements Serializable {
 
 	@Override
 	public boolean equals(Object obj) {
-		return (this == obj || (obj instanceof SimpleKey && Arrays.equals(this.params, ((SimpleKey) obj).params)));
+		return (this == obj || (obj instanceof SimpleKey
+				&& Arrays.deepEquals(this.params, ((SimpleKey) obj).params)));
 	}
 
 	@Override
 	public int hashCode() {
-		return Arrays.hashCode(this.params);
+		return Arrays.deepHashCode(this.params);
 	}
 
 	@Override

spring-context/src/test/java/org/springframework/cache/interceptor/SimpleKeyGeneratorTests.java

@@ -25,16 +25,17 @@ import static org.junit.Assert.*;
  * Tests for {@link SimpleKeyGenerator} and {@link SimpleKey}.
  *
  * @author Phillip Webb
+ * @author Stephane Nicoll
  */
 public class SimpleKeyGeneratorTests {
 
 	private SimpleKeyGenerator generator = new SimpleKeyGenerator();
 
 	@Test
-	public void noValues() throws Exception {
-		Object k1 = generator.generate(null, null, new Object[] {});
-		Object k2 = generator.generate(null, null, new Object[] {});
-		Object k3 = generator.generate(null, null, new Object[] { "different" });
+	public void noValues() {
+		Object k1 = generateKey(new Object[] {});
+		Object k2 = generateKey(new Object[] {});
+		Object k3 = generateKey(new Object[] { "different" });
 		assertThat(k1.hashCode(), equalTo(k2.hashCode()));
 		assertThat(k1.hashCode(), not(equalTo(k3.hashCode())));
 		assertThat(k1, equalTo(k2));
@@ -42,10 +43,10 @@ public class SimpleKeyGeneratorTests {
 	}
 
 	@Test
-	public void singleValue() throws Exception {
-		Object k1 = generator.generate(null, null, new Object[] { "a" });
-		Object k2 = generator.generate(null, null, new Object[] { "a" });
-		Object k3 = generator.generate(null, null, new Object[] { "different" });
+	public void singleValue(){
+		Object k1 = generateKey(new Object[] { "a" });
+		Object k2 = generateKey(new Object[] { "a" });
+		Object k3 = generateKey(new Object[] { "different" });
 		assertThat(k1.hashCode(), equalTo(k2.hashCode()));
 		assertThat(k1.hashCode(), not(equalTo(k3.hashCode())));
 		assertThat(k1, equalTo(k2));
@@ -54,10 +55,10 @@ public class SimpleKeyGeneratorTests {
 	}
 
 	@Test
-	public void multipleValues() throws Exception {
-		Object k1 = generator.generate(null, null, new Object[] { "a", 1, "b" });
-		Object k2 = generator.generate(null, null, new Object[] { "a", 1, "b" });
-		Object k3 = generator.generate(null, null, new Object[] { "b", 1, "a" });
+	public void multipleValues()  {
+		Object k1 = generateKey(new Object[] { "a", 1, "b" });
+		Object k2 = generateKey(new Object[] { "a", 1, "b" });
+		Object k3 = generateKey(new Object[] { "b", 1, "a" });
 		assertThat(k1.hashCode(), equalTo(k2.hashCode()));
 		assertThat(k1.hashCode(), not(equalTo(k3.hashCode())));
 		assertThat(k1, equalTo(k2));
@@ -65,10 +66,10 @@ public class SimpleKeyGeneratorTests {
 	}
 
 	@Test
-	public void singleNullValue() throws Exception {
-		Object k1 = generator.generate(null, null, new Object[] { null });
-		Object k2 = generator.generate(null, null, new Object[] { null });
-		Object k3 = generator.generate(null, null, new Object[] { "different" });
+	public void singleNullValue() {
+		Object k1 = generateKey(new Object[] { null });
+		Object k2 = generateKey(new Object[] { null });
+		Object k3 = generateKey(new Object[] { "different" });
 		assertThat(k1.hashCode(), equalTo(k2.hashCode()));
 		assertThat(k1.hashCode(), not(equalTo(k3.hashCode())));
 		assertThat(k1, equalTo(k2));
@@ -77,13 +78,28 @@ public class SimpleKeyGeneratorTests {
 	}
 
 	@Test
-	public void multiplNullValues() throws Exception {
-		Object k1 = generator.generate(null, null, new Object[] { "a", null, "b", null });
-		Object k2 = generator.generate(null, null, new Object[] { "a", null, "b", null });
-		Object k3 = generator.generate(null, null, new Object[] { "a", null, "b" });
+	public void multipleNullValues() {
+		Object k1 = generateKey(new Object[] { "a", null, "b", null });
+		Object k2 = generateKey(new Object[] { "a", null, "b", null });
+		Object k3 = generateKey(new Object[] { "a", null, "b" });
 		assertThat(k1.hashCode(), equalTo(k2.hashCode()));
 		assertThat(k1.hashCode(), not(equalTo(k3.hashCode())));
 		assertThat(k1, equalTo(k2));
 		assertThat(k1, not(equalTo(k3)));
 	}
+
+	@Test
+	public void arrays() {
+		Object k1 = generateKey(new Object[] { new String[]{"a", "b"}, "c" });
+		Object k2 = generateKey(new Object[] { new String[]{"a", "b"}, "c"  });
+		Object k3 = generateKey(new Object[] { new String[]{"b", "a"}, "c" });
+		assertThat(k1.hashCode(), equalTo(k2.hashCode()));
+		assertThat(k1.hashCode(), not(equalTo(k3.hashCode())));
+		assertThat(k1, equalTo(k2));
+		assertThat(k1, not(equalTo(k3)));
+	}
+
+	private Object generateKey(Object[] arguments) {
+		return generator.generate(null, null, arguments);
+	}
 }