Polishing #1122

Rename wrapper type to ComposedRedisCodec. Introduce RedisCodec.of(…) factory method.

Add tests.

Original pull request: #1123.

src/main/java/io/lettuce/core/codec/ComposedRedisCodec.java

@@ -0,0 +1,59 @@
+/*
+ * Copyright 2019 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 io.lettuce.core.codec;
+
+import java.nio.ByteBuffer;
+
+import io.lettuce.core.internal.LettuceAssert;
+
+/**
+ * A {@link ComposedRedisCodec} combines two {@link RedisCodec cdecs} to encode/decode key and value to the command output.
+ *
+ * @author Dimitris Mandalidis
+ * @since 5.2
+ */
+class ComposedRedisCodec<K, V> implements RedisCodec<K, V> {
+
+    private final RedisCodec<K, ?> keyCodec;
+    private final RedisCodec<?, V> valueCodec;
+
+    ComposedRedisCodec(RedisCodec<K, ?> keyCodec, RedisCodec<?, V> valueCodec) {
+        LettuceAssert.notNull(keyCodec, "Key codec must not be null");
+        LettuceAssert.notNull(valueCodec, "Value codec must not be null");
+        this.keyCodec = keyCodec;
+        this.valueCodec = valueCodec;
+    }
+
+    @Override
+    public K decodeKey(ByteBuffer bytes) {
+        return keyCodec.decodeKey(bytes);
+    }
+
+    @Override
+    public V decodeValue(ByteBuffer bytes) {
+        return valueCodec.decodeValue(bytes);
+    }
+
+    @Override
+    public ByteBuffer encodeKey(K key) {
+        return keyCodec.encodeKey(key);
+    }
+
+    @Override
+    public ByteBuffer encodeValue(V value) {
+        return valueCodec.encodeValue(value);
+    }
+}

src/main/java/io/lettuce/core/codec/RedisCodec.java

@@ -27,8 +27,24 @@
  *
  * @author Will Glozer
  * @author Mark Paluch
+ * @author Dimitris Mandalidis
  */
 public interface RedisCodec<K, V> {
+
+    /**
+     * Returns a composite {@link RedisCodec} that uses {@code keyCodec} for keys and {@code valueCodec} for values.
+     *
+     * @param <K> the type of the key
+     * @param <V> the type of the value
+     * @param keyCodec the codec to encode/decode the keys.
+     * @param valueCodec the codec to encode/decode the values.
+     * @return a composite {@link RedisCodec}.
+     * @since 5.2
+     */
+    static <K, V> RedisCodec<K, V> of(RedisCodec<K, ?> keyCodec, RedisCodec<?, V> valueCodec) {
+        return new ComposedRedisCodec<>(keyCodec, valueCodec);
+    }
+
     /**
      * Decode the key output by redis.
      *

src/test/java/io/lettuce/core/CustomCodecIntegrationTests.java

@@ -20,6 +20,7 @@
 import java.io.*;
 import java.nio.ByteBuffer;
 import java.nio.charset.Charset;
+import java.nio.charset.StandardCharsets;
 import java.util.List;
 
 import javax.crypto.Cipher;
@@ -95,8 +96,10 @@ void testJavaSerializerReactive() {
 
     @Test
     void testDeflateCompressedJavaSerializer() {
-        RedisCommands<String, Object> connection = client.connect(
-                CompressionCodec.valueCompressor(new SerializedObjectCodec(), CompressionCodec.CompressionType.DEFLATE)).sync();
+        RedisCommands<String, Object> connection = client
+                .connect(
+                        CompressionCodec.valueCompressor(new SerializedObjectCodec(), CompressionCodec.CompressionType.DEFLATE))
+                .sync();
         List<String> list = list("one", "two");
         connection.set(key, list);
         assertThat(connection.get(key)).isEqualTo(list);
@@ -106,8 +109,9 @@ void testDeflateCompressedJavaSerializer() {
 
     @Test
     void testGzipompressedJavaSerializer() {
-        RedisCommands<String, Object> connection = client.connect(
-                CompressionCodec.valueCompressor(new SerializedObjectCodec(), CompressionCodec.CompressionType.GZIP)).sync();
+        RedisCommands<String, Object> connection = client
+                .connect(CompressionCodec.valueCompressor(new SerializedObjectCodec(), CompressionCodec.CompressionType.GZIP))
+                .sync();
         List<String> list = list("one", "two");
         connection.set(key, list);
         assertThat(connection.get(key)).isEqualTo(list);
@@ -118,8 +122,8 @@ void testGzipompressedJavaSerializer() {
     @Test
     void testEncryptedCodec() {
 
-        RedisCommands<String, String> connection = client.connect(
-                CipherCodec.forValues(StringCodec.UTF8, encrypt, decrypt)).sync();
+        RedisCommands<String, String> connection = client.connect(CipherCodec.forValues(StringCodec.UTF8, encrypt, decrypt))
+                .sync();
 
         connection.set(key, "foobar");
         assertThat(connection.get(key)).isEqualTo("foobar");
@@ -163,9 +167,25 @@ void testByteBufferCodec() {
         connection.getStatefulConnection().close();
     }
 
+    @Test
+    void testComposedCodec() {
+
+        RedisCodec<String, Object> composed = RedisCodec.of(StringCodec.ASCII, new SerializedObjectCodec());
+        RedisCommands<String, Object> connection = client.connect(composed).sync();
+
+        connection.set(key, new Person());
+
+        List<String> keys = connection.keys(key);
+        assertThat(keys).hasSize(1);
+
+        assertThat(connection.get(key)).isInstanceOf(Person.class);
+
+        connection.getStatefulConnection().close();
+    }
+
     class SerializedObjectCodec implements RedisCodec<String, Object> {
 
-        private Charset charset = Charset.forName("UTF-8");
+        private Charset charset = StandardCharsets.UTF_8;
 
         @Override
         public String decodeKey(ByteBuffer bytes) {
@@ -201,4 +221,8 @@ public ByteBuffer encodeValue(Object value) {
             }
         }
     }
+
+    static class Person implements Serializable {
+
+    }
 }