NOTE: As this implementation returns only a hash of the parameters + * it is possible for key collisions to occur. Since Spring 4.0 the + * {@link SimpleKeyGenerator} is used when no explicit key generator + * has been defined. This class remains for applications that do not + * wish to migrate to the {@link SimpleKeyGenerator}. + * * @author Costin Leau * @author Chris Beams * @since 3.1 + * @see SimpleKeyGenerator + * @see org.springframework.cache.annotation.CachingConfigurer */ public class DefaultKeyGenerator implements KeyGenerator { diff --git a/spring-context/src/main/java/org/springframework/cache/interceptor/SimpleKey.java b/spring-context/src/main/java/org/springframework/cache/interceptor/SimpleKey.java new file mode 100644 index 00000000000..cc3b0e59048 --- /dev/null +++ b/spring-context/src/main/java/org/springframework/cache/interceptor/SimpleKey.java @@ -0,0 +1,72 @@ +/* + * Copyright 2002-2013 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 + * + * http://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.cache.interceptor; + +import java.io.Serializable; +import java.util.Arrays; + +import org.springframework.util.Assert; +import org.springframework.util.StringUtils; + +/** + * A simple key as returned from the {@link SimpleKeyGenerator}. + * + * @author Phillip Webb + * @see SimpleKeyGenerator + */ +public final class SimpleKey implements Serializable { + + private static final long serialVersionUID = 1; + + public static final SimpleKey EMPTY = new SimpleKey(new Object[] {}); + + + private final Object[] params; + + + /** + * Create a new {@link SimpleKey} instance. + * @param elements the elements of the key + */ + public SimpleKey(Object[] elements) { + Assert.notNull(elements, "Elements must not be null"); + this.params = new Object[elements.length]; + System.arraycopy(elements, 0, this.params, 0, elements.length); + } + + + @Override + public boolean equals(Object obj) { + if (obj == this) { + return true; + } + if (obj != null && getClass() == obj.getClass()) { + return Arrays.equals(this.params, ((SimpleKey) obj).params); + } + return false; + } + + @Override + public int hashCode() { + return Arrays.hashCode(params); + } + + @Override + public String toString() { + return "SimpleKey [" + StringUtils.arrayToCommaDelimitedString(this.params) + "]"; + } +} diff --git a/spring-context/src/main/java/org/springframework/cache/interceptor/SimpleKeyGenerator.java b/spring-context/src/main/java/org/springframework/cache/interceptor/SimpleKeyGenerator.java new file mode 100644 index 00000000000..7d6fc6f16d3 --- /dev/null +++ b/spring-context/src/main/java/org/springframework/cache/interceptor/SimpleKeyGenerator.java @@ -0,0 +1,50 @@ +/* + * Copyright 2002-2013 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 + * + * http://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.cache.interceptor; + +import java.lang.reflect.Method; + +/** + * Simple key generator. Returns the parameter itself if a single non-null value + * is given, otherwise returns a {@link SimpleKey} of the parameters. + * + *
Unlike {@link DefaultKeyGenerator}, no collisions will occur with the keys + * generated by this class. The returned {@link SimpleKey} object can be safely + * used with a {@link org.springframework.cache.concurrent.ConcurrentMapCache}, + * however, might not be suitable for all {@link org.springframework.cache.Cache} + * implementations. + * + * @author Phillip Webb + * @since 4.0 + * @see SimpleKey + * @see DefaultKeyGenerator + * @see org.springframework.cache.annotation.CachingConfigurer + */ +public class SimpleKeyGenerator implements KeyGenerator { + + @Override + public Object generate(Object target, Method method, Object... params) { + if(params.length == 0) { + return SimpleKey.EMPTY; + } + if(params.length == 1 && params[0] != null) { + return params[0]; + } + return new SimpleKey(params); + } + +} diff --git a/spring-context/src/test/java/org/springframework/cache/interceptor/SimpleKeyGeneratorTests.java b/spring-context/src/test/java/org/springframework/cache/interceptor/SimpleKeyGeneratorTests.java new file mode 100644 index 00000000000..2d5305dd610 --- /dev/null +++ b/spring-context/src/test/java/org/springframework/cache/interceptor/SimpleKeyGeneratorTests.java @@ -0,0 +1,89 @@ +/* + * Copyright 2002-2013 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 + * + * http://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.cache.interceptor; + +import org.junit.Test; + +import static org.hamcrest.Matchers.*; +import static org.junit.Assert.*; + +/** + * Tests for {@link SimpleKeyGenerator} and {@link SimpleKey}. + * + * @author Phillip Webb + */ +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" }); + 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 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" }); + assertThat(k1.hashCode(), equalTo(k2.hashCode())); + assertThat(k1.hashCode(), not(equalTo(k3.hashCode()))); + assertThat(k1, equalTo(k2)); + assertThat(k1, not(equalTo(k3))); + assertThat(k1, equalTo((Object) "a")); + } + + @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" }); + 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 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" }); + assertThat(k1.hashCode(), equalTo(k2.hashCode())); + assertThat(k1.hashCode(), not(equalTo(k3.hashCode()))); + assertThat(k1, equalTo(k2)); + assertThat(k1, not(equalTo(k3))); + assertThat(k1, instanceOf(SimpleKey.class)); + } + + @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" }); + assertThat(k1.hashCode(), equalTo(k2.hashCode())); + assertThat(k1.hashCode(), not(equalTo(k3.hashCode()))); + assertThat(k1, equalTo(k2)); + assertThat(k1, not(equalTo(k3))); + } +}