Expose contains, remove and clear methods on ConcurrentLruCache

Closes gh-25963

spring-core/src/test/java/org/springframework/util/ConcurrentLruCacheTests.java

@@ -0,0 +1,85 @@
+/*
+ * Copyright 2002-2020 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.util;
+
+import org.junit.jupiter.api.Test;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+/**
+ * @author Juergen Hoeller
+ */
+class ConcurrentLruCacheTests {
+
+	private final ConcurrentLruCache<String, String> cache = new ConcurrentLruCache<>(2, key -> key + "value");
+
+
+	@Test
+	void getAndSize() {
+		assertThat(this.cache.sizeLimit()).isEqualTo(2);
+		assertThat(this.cache.size()).isEqualTo(0);
+		assertThat(this.cache.get("k1")).isEqualTo("k1value");
+		assertThat(this.cache.size()).isEqualTo(1);
+		assertThat(this.cache.contains("k1")).isTrue();
+		assertThat(this.cache.get("k2")).isEqualTo("k2value");
+		assertThat(this.cache.size()).isEqualTo(2);
+		assertThat(this.cache.contains("k1")).isTrue();
+		assertThat(this.cache.contains("k2")).isTrue();
+		assertThat(this.cache.get("k3")).isEqualTo("k3value");
+		assertThat(this.cache.size()).isEqualTo(2);
+		assertThat(this.cache.contains("k1")).isFalse();
+		assertThat(this.cache.contains("k2")).isTrue();
+		assertThat(this.cache.contains("k3")).isTrue();
+	}
+
+	@Test
+	void removeAndSize() {
+		assertThat(this.cache.get("k1")).isEqualTo("k1value");
+		assertThat(this.cache.get("k2")).isEqualTo("k2value");
+		assertThat(this.cache.size()).isEqualTo(2);
+		assertThat(this.cache.contains("k1")).isTrue();
+		assertThat(this.cache.contains("k2")).isTrue();
+		this.cache.remove("k2");
+		assertThat(this.cache.size()).isEqualTo(1);
+		assertThat(this.cache.contains("k1")).isTrue();
+		assertThat(this.cache.contains("k2")).isFalse();
+		assertThat(this.cache.get("k3")).isEqualTo("k3value");
+		assertThat(this.cache.size()).isEqualTo(2);
+		assertThat(this.cache.contains("k1")).isTrue();
+		assertThat(this.cache.contains("k2")).isFalse();
+		assertThat(this.cache.contains("k3")).isTrue();
+	}
+
+	@Test
+	void clearAndSize() {
+		assertThat(this.cache.get("k1")).isEqualTo("k1value");
+		assertThat(this.cache.get("k2")).isEqualTo("k2value");
+		assertThat(this.cache.size()).isEqualTo(2);
+		assertThat(this.cache.contains("k1")).isTrue();
+		assertThat(this.cache.contains("k2")).isTrue();
+		this.cache.clear();
+		assertThat(this.cache.size()).isEqualTo(0);
+		assertThat(this.cache.contains("k1")).isFalse();
+		assertThat(this.cache.contains("k2")).isFalse();
+		assertThat(this.cache.get("k3")).isEqualTo("k3value");
+		assertThat(this.cache.size()).isEqualTo(1);
+		assertThat(this.cache.contains("k1")).isFalse();
+		assertThat(this.cache.contains("k2")).isFalse();
+		assertThat(this.cache.contains("k3")).isTrue();
+	}
+
+}