1 /* 2 * Copyright 2016 The Netty Project 3 * 4 * The Netty Project licenses this file to you under the Apache License, version 2.0 (the 5 * "License"); you may not use this file except in compliance with the License. You may obtain a 6 * copy of the License at: 7 * 8 * https://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software distributed under the License 11 * is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express 12 * or implied. See the License for the specific language governing permissions and limitations under 13 * the License. 14 */ 15 16 package io.netty.handler.codec.redis; 17 18 import io.netty.util.internal.StringUtil; 19 import io.netty.util.internal.UnstableApi; 20 21 /** 22 * Header of Redis Array Message. 23 */ 24 @UnstableApi 25 public class ArrayHeaderRedisMessage implements RedisMessage { 26 27 private final long length; 28 29 /** 30 * Creates a {@link ArrayHeaderRedisMessage} for the given {@code length}. 31 */ 32 public ArrayHeaderRedisMessage(long length) { 33 if (length < RedisConstants.NULL_VALUE) { 34 throw new RedisCodecException("length: " + length + " (expected: >= " + RedisConstants.NULL_VALUE + ")"); 35 } 36 this.length = length; 37 } 38 39 /** 40 * Get length of this array object. 41 */ 42 public final long length() { 43 return length; 44 } 45 46 /** 47 * Returns whether the content of this message is {@code null}. 48 * 49 * @return indicates whether the content of this message is {@code null}. 50 */ 51 public boolean isNull() { 52 return length == RedisConstants.NULL_VALUE; 53 } 54 55 @Override 56 public String toString() { 57 return new StringBuilder(StringUtil.simpleClassName(this)) 58 .append('[') 59 .append("length=") 60 .append(length) 61 .append(']').toString(); 62 } 63 }