/*
    * Licensed to the Apache Software Foundation (ASF) under one or more
    * contributor license agreements. See the NOTICE file distributed with
    * this work for additional information regarding copyright ownership.
    * The ASF licenses this file to You 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.apache.logging.log4j.core.util;
  
  import java.io.InvalidObjectException;
  import java.io.ObjectInputStream;
  import java.io.ObjectStreamException;
  import java.io.Serializable;
  
  import org.apache.logging.log4j.core.config.Node;
  import org.apache.logging.log4j.core.config.plugins.Plugin;
  import org.apache.logging.log4j.core.config.plugins.PluginBuilderAttribute;
  import org.apache.logging.log4j.core.config.plugins.PluginBuilderFactory;
  
  /**
   * Key/Value pair configuration item.
   *
   * @since 2.1 implements {@link Serializable}
   * @since 2.1 implements {@link #hashCode()} and {@link #equals(Object)}
   */
  @Plugin(name = "KeyValuePair", category = Node.CATEGORY, printObject = true)
  public final class KeyValuePair implements Serializable {
  
      private static final long serialVersionUID = 4331228262821046866L;
  
      private final String key;
      private final String value;
  
      /**
       * Constructs a key/value pair. The constructor should only be called from test classes.
       * @param key The key.
       * @param value The value.
       */
      public KeyValuePair(final String key, final String value) {
          this.key = key;
          this.value = value;
      }
  
      /**
       * Returns the key.
       * @return the key.
       */
      public String getKey() {
          return key;
      }
  
      /**
       * Returns the value.
       * @return The value.
       */
      public String getValue() {
          return value;
      }
  
      @Override
      public String toString() {
          return key + '=' + value;
      }
  
      @PluginBuilderFactory
      public static Builder newBuilder() {
          return new Builder();
      }
  
      protected Object writeReplace() throws ObjectStreamException {
          return newBuilder().setKey(this.key).setValue(this.value);
      }
  
      private void readObject(final ObjectInputStream stream) throws InvalidObjectException {
          throw new InvalidObjectException("Builder proxy required");
      }
  
      public static class Builder implements org.apache.logging.log4j.core.util.Builder<KeyValuePair>, Serializable {
  
          private static final long serialVersionUID = 1L;
  
          @PluginBuilderAttribute
          private String key;
  
          @PluginBuilderAttribute
          private String value;
  
          public Builder setKey(final String key) {
              this.key = key;
             return this;
         }
 
         public Builder setValue(final String value) {
             this.value = value;
             return this;
         }
 
         @Override
         public KeyValuePair build() {
             return new KeyValuePair(key, value);
         }
 
         protected Object readResolve() throws ObjectStreamException {
             return new KeyValuePair(key, value);
         }
     }
 
     @Override
     public int hashCode() {
         final int prime = 31;
         int result = 1;
         result = prime * result + ((key == null) ? 0 : key.hashCode());
         result = prime * result + ((value == null) ? 0 : value.hashCode());
         return result;
     }
 
     @Override
     public boolean equals(final Object obj) {
         if (this == obj) {
             return true;
         }
         if (obj == null) {
             return false;
         }
         if (getClass() != obj.getClass()) {
             return false;
         }
         final KeyValuePair other = (KeyValuePair) obj;
         if (key == null) {
             if (other.key != null) {
                 return false;
             }
         } else if (!key.equals(other.key)) {
             return false;
         }
         if (value == null) {
             if (other.value != null) {
                 return false;
             }
         } else if (!value.equals(other.value)) {
             return false;
         }
         return true;
     }
 }