api/src/main/java/com/datatorrent/api/StringCodec.java - apex-core - Git at Google

 /**
  * 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 com.datatorrent.api;

 import java.io.IOException;
 import java.io.Serializable;
 import java.util.ArrayList;
 import java.util.Collection;
 import java.util.Collections;
 import java.util.HashMap;
 import java.util.Map;

 import org.codehaus.jackson.map.DeserializationConfig;
 import org.codehaus.jackson.map.ObjectMapper;
 import org.codehaus.jackson.map.ObjectReader;
 import org.codehaus.jackson.map.ObjectWriter;
 import org.apache.commons.beanutils.BeanUtils;
 import org.apache.commons.lang.StringUtils;

 import com.google.common.base.Throwables;

 /**
  * This interface is essentially serializer/deserializer interface which works with String as
  * the serialized type. When initializing the attributes from the properties file, attribute
  * values represented as Strings are needed to be converted to POJO. This class facilitates the
  * conversion from and to String for attribute values.
  *
  * @param <T> Type of the object which can be converted to/from String.
  * @since 0.9.0
  */
 public interface StringCodec<T>
 {
   /**
    * Given a string representation (typically from properties file) for an object , create object from it.
    *
    * @param string Type of the POJO which is created from String representation.
    * @return POJO obtained as a result of deserialization
    */
   T fromString(String string);

   /**
    * Given a POJO, serialize it to a String object (typically to be stored in properties file).
    *
    * @param pojo The object which needs to be serialized.
    * @return Serialized representation of pojo..
    */
   String toString(T pojo);

   class Factory
   {
     public static StringCodec<?> getInstance(Class<?> cls)
     {
       if (cls == String.class) {
         return String2String.getInstance();
       } else if (cls == Integer.class) {
         return Integer2String.getInstance();
       } else if (cls == Long.class) {
         return Long2String.getInstance();
       } else if (cls == Boolean.class) {
         return Boolean2String.getInstance();
       } else if (Enum.class.isAssignableFrom(cls)) {
         return Enum2String.getInstance(cls);
       } else {
         return null;
       }
     }
   }

   class String2String implements StringCodec<String>, Serializable
   {
     @SuppressWarnings("deprecation")
     private static final String2String instance = new String2String();

     public static StringCodec<String> getInstance()
     {
       return instance;
     }

     /**
      * @deprecated As of release 3.5.0, replaced by {@link #getInstance()}
      */
     @Deprecated
     public String2String()
     {
     }

     @Override
     public String fromString(String string)
     {
       return string;
     }

     @Override
     public String toString(String pojo)
     {
       return pojo;
     }

     private static final long serialVersionUID = 201310141156L;
   }

   class Integer2String implements StringCodec<Integer>, Serializable
   {
     @SuppressWarnings("deprecation")
     private static final Integer2String instance = new Integer2String();

     public static StringCodec<Integer> getInstance()
     {
       return instance;
     }

     /**
      * @deprecated As of release 3.5.0, replaced by {@link #getInstance()}
      */
     @Deprecated
     public Integer2String()
     {
     }

     @Override
     public Integer fromString(String string)
     {
       return Integer.valueOf(string);
     }

     @Override
     public String toString(Integer pojo)
     {
       return String.valueOf(pojo);
     }

     private static final long serialVersionUID = 201310141157L;
   }

   class Long2String implements StringCodec<Long>, Serializable
   {
     @SuppressWarnings("deprecation")
     private static final Long2String instance = new Long2String();

     public static StringCodec<Long> getInstance()
     {
       return instance;
     }

     /**
      * @deprecated As of release 3.5.0, replaced by {@link #getInstance()}
      */
     @Deprecated
     public Long2String()
     {
     }

     @Override
     public Long fromString(String string)
     {
       return Long.valueOf(string);
     }

     @Override
     public String toString(Long pojo)
     {
       return String.valueOf(pojo);
     }

     private static final long serialVersionUID = 201310141158L;
   }

   class Boolean2String implements StringCodec<Boolean>, Serializable
   {
     @SuppressWarnings("deprecation")
     private static final Boolean2String instance = new Boolean2String();

     public static StringCodec<Boolean> getInstance()
     {
       return instance;
     }

     /**
      * @deprecated As of release 3.5.0, replaced by {@link #getInstance()}
      */
     @Deprecated
     public Boolean2String()
     {
     }

     @Override
     public Boolean fromString(String string)
     {
       return Boolean.valueOf(string);
     }

     @Override
     public String toString(Boolean pojo)
     {
       return String.valueOf(pojo);
     }

     private static final long serialVersionUID = 201310141159L;
   }

   /**
    * The attributes which represent arbitrary objects for which the schema cannot be
    * standardized, we allow them to be represented as <ClassName>:<Constructor_String>:<Property_String> representation.
    * This allows us to instantiate the class by invoking its constructor which takes
    * <String> as argument.  If only the <ClassName> is specified, then just the class is instantiated using default
    * constructor. If colon is specified then class is instantiated using constructor with
    * string as an argument.If properties are specified then properties will be set on the object. The properties
    * are defined in property=value format separated by colon(:)
    *
    * Note that the {@link #toString(Object) toString} method is by default NOT the proper reverse of the {@link
    * #fromString(String) fromString} method. In order for the {@link #toString(Object) toString} method to become a
    * proper reverse of the {@link #fromString(String) fromString} method, T's {@link T#toString() toString} method
    * must output null or <Constructor_String> or the <Constructor_String>:<Property_String> format as stated above.
    *
    * @param <T> Type of the object which is converted to/from String
    */
   class Object2String<T> implements StringCodec<T>, Serializable
   {
     @SuppressWarnings("deprecation")
     private static final Object2String instance = new Object2String();

     public static <T> StringCodec<T> getInstance()
     {
       return instance;
     }

     public static <T> StringCodec<T> getInstance(String separator)
     {
       return getInstance(separator, "=");
     }

     @SuppressWarnings("deprecation")
     public static <T> StringCodec<T> getInstance(String separator, String propertySeparator)
     {
       return new Object2String<>(separator, propertySeparator);
     }

     public final String separator;
     public final String propertySeparator;

     /**
      * @deprecated As of release 3.5.0, replaced by {@link #getInstance()}
      */
     @SuppressWarnings("deprecation")
     @Deprecated
     public Object2String()
     {
       this(":", "=");
     }

     /**
      * @deprecated As of release 3.5.0, replaced by {@link #getInstance(String)}
      */
     @SuppressWarnings("deprecation")
     @Deprecated
     public Object2String(String separator)
     {
       this(separator, "=");
     }

     /**
      * @deprecated As of release 3.5.0, replaced by {@link #getInstance(String, String)}
      */
     @Deprecated
     public Object2String(String separator, String propertySeparator)
     {
       this.separator = separator;
       this.propertySeparator = propertySeparator;
     }

     @Override
     @SuppressWarnings({"UseSpecificCatch", "BroadCatchBlock", "TooBroadCatch"})
     public T fromString(String string)
     {
       String[] parts = string.split(separator);

       try {
         @SuppressWarnings("unchecked")
         Class<? extends T> clazz = (Class<? extends T>)Thread.currentThread().getContextClassLoader().loadClass(parts[0]);
         if (parts.length == 1) {
           return clazz.newInstance();
         }

         //String[] properties = parts[1].split(separator, 2);
         if (parts.length == 2) {
           return clazz.getConstructor(String.class).newInstance(parts[1]);
         } else {
           T object = clazz.getConstructor(String.class).newInstance(parts[1]);
           HashMap<String, String> hashMap = new HashMap<>();
           for (int i = 2; i < parts.length; i++) {
             String[] keyValPair = parts[i].split(propertySeparator, 2);
             hashMap.put(keyValPair[0], keyValPair[1]);
           }
           BeanUtils.populate(object, hashMap);
           return object;
         }
       } catch (Throwable cause) {
         throw Throwables.propagate(cause);
       }
     }

     @Override
     public String toString(T pojo)
     {
       if (pojo == null) {
         return null;
       }
       String arg = pojo.toString();
       if (arg == null) {
         return pojo.getClass().getCanonicalName();
       }

       return pojo.getClass().getCanonicalName() + separator + arg;
     }

     private static final long serialVersionUID = 201311141853L;
   }

   class Map2String<K, V> implements StringCodec<Map<K, V>>, Serializable
   {
     @SuppressWarnings("deprecation")
     public static <K, V> StringCodec<Map<K, V>> getInstance(String separator, String equal, StringCodec<K> keyCodec, StringCodec<V> valueCodec)
     {
       return new Map2String<>(separator, equal, keyCodec, valueCodec);
     }

     private final StringCodec<K> keyCodec;
     private final StringCodec<V> valueCodec;
     private final String separator;
     private final String equal;

     /**
      * @deprecated As of release 3.5.0, replaced by {@link #getInstance(String, String, StringCodec, StringCodec)}
      */
     @Deprecated
     public Map2String(String separator, String equal, StringCodec<K> keyCodec, StringCodec<V> valueCodec)
     {
       this.equal = equal;
       this.separator = separator;
       this.keyCodec = keyCodec;
       this.valueCodec = valueCodec;
     }

     @Override
     public Map<K, V> fromString(String string)
     {
       if (string == null) {
         return null;
       }

       if (string.isEmpty()) {
         return new HashMap<>();
       }

       String[] parts = string.split(separator);
       HashMap<K, V> map = new HashMap<>();
       for (String part : parts) {
         String[] kvpair = part.split(equal, 2);
         map.put(keyCodec.fromString(kvpair[0]), valueCodec.fromString(kvpair[1]));
       }

       return map;
     }

     @Override
     public String toString(Map<K, V> map)
     {
       if (map == null) {
         return null;
       }

       if (map.isEmpty()) {
         return "";
       }
       String[] parts = new String[map.size()];
       int i = 0;
       for (Map.Entry<K, V> entry : map.entrySet()) {
         parts[i++] = keyCodec.toString(entry.getKey()) + equal + valueCodec.toString(entry.getValue());
       }
       return StringUtils.join(parts, separator);
     }

     private static final long serialVersionUID = 201402272053L;
   }

   class Collection2String<T> implements StringCodec<Collection<T>>, Serializable
   {
     @SuppressWarnings("deprecation")
     public static <T> StringCodec<Collection<T>> getInstance(String separator, StringCodec<T> codec)
     {
       return new Collection2String<>(separator, codec);
     }

     private final String separator;
     private final StringCodec<T> codec;

     /**
      * @deprecated As of release 3.5.0, replaced by {@link #getInstance(String, StringCodec)}
      */
     @Deprecated
     public Collection2String(String separator, StringCodec<T> codec)
     {
       this.separator = separator;
       this.codec = codec;
     }

     @Override
     @SuppressWarnings("unchecked")
     public Collection<T> fromString(String string)
     {
       if (string == null) {
         return null;
       }

       if (string.isEmpty()) {
         return Collections.EMPTY_LIST;
       }

       String[] parts = string.split(separator);
       ArrayList<T> arrayList = new ArrayList<>(parts.length);
       for (String part : parts) {
         arrayList.add(codec.fromString(part));
       }

       return arrayList;
     }

     @Override
     public String toString(Collection<T> pojo)
     {
       if (pojo == null) {
         return null;
       }

       if (pojo.isEmpty()) {
         return "";
       }

       String[] parts = new String[pojo.size()];

       int i = 0;
       for (T o : pojo) {
         parts[i++] = codec.toString(o);
       }

       return StringUtils.join(parts, separator);
     }

     private static final long serialVersionUID = 201401091806L;
   }

   class Enum2String<T extends Enum<T>> implements StringCodec<T>, Serializable
   {
     private final Class<T> clazz;

     @SuppressWarnings("deprecation")
     public static Enum2String getInstance(Class clazz)
     {
       return new Enum2String(clazz);
     }

     /**
      * @deprecated As of release 3.5.0, replaced by {@link #getInstance(Class<T>)}
      */
     @Deprecated
     public Enum2String(Class<T> clazz)
     {
       this.clazz = clazz;
     }

     @Override
     public T fromString(String string)
     {
       return Enum.valueOf(clazz, string);
     }

     @Override
     public String toString(T pojo)
     {
       return pojo.name();
     }

     private static final long serialVersionUID = 201310181757L;
   }

   class Class2String<T> implements StringCodec<Class<? extends T>>, Serializable
   {
     @SuppressWarnings("deprecation")
     private static final StringCodec instance = new Class2String<>();

     public static <T> StringCodec<Class<? extends T>> getInstance()
     {
       return (StringCodec<Class<? extends T>>)instance;
     }

     /**
      * @deprecated As of release 3.5.0, replaced by {@link #getInstance()}
      */
     public Class2String()
     {
     }

     @Override
     @SuppressWarnings({"BroadCatchBlock", "TooBroadCatch"})
     public Class<? extends T> fromString(String string)
     {
       try {
         @SuppressWarnings({"rawtypes", "unchecked"})
         Class<? extends T> clazz = (Class)Thread.currentThread().getContextClassLoader().loadClass(string);
         return clazz;
       } catch (Throwable cause) {
         throw Throwables.propagate(cause);
       }
     }

     @Override
     public String toString(Class<? extends T> clazz)
     {
       return clazz.getCanonicalName();
     }

     private static final long serialVersionUID = 201312082053L;
   }

   class JsonStringCodec<T> implements StringCodec<T>, Serializable
   {
     private static final long serialVersionUID = 2513932518264776006L;

     @SuppressWarnings("deprecation")
     public static <T> StringCodec<T> getInstance(Class<T> clazz)
     {
       return new JsonStringCodec<>(clazz);
     }

     Class<?> clazz;

     /**
      * @deprecated As of release 3.5.0, replaced by {@link #getInstance(Class)}
      */
     public JsonStringCodec(Class<T> clazz)
     {
       this.clazz = clazz;
     }

     @Override
     public T fromString(String string)
     {
       try {
         ObjectMapper mapper = new ObjectMapper();
         mapper.configure(DeserializationConfig.Feature.FAIL_ON_UNKNOWN_PROPERTIES, false);
         ObjectReader reader = mapper.reader(clazz);
         return reader.readValue(string);
       } catch (IOException e) {
         throw Throwables.propagate(e);
       }
     }

     @Override
     public String toString(T pojo)
     {
       try {
         ObjectMapper mapper = new ObjectMapper();
         mapper.configure(DeserializationConfig.Feature.FAIL_ON_UNKNOWN_PROPERTIES, false);
         ObjectWriter writer = mapper.writer();
         return writer.writeValueAsString(pojo);
       } catch (IOException e) {
         throw Throwables.propagate(e);
       }
     }
   }
 }
	/**
	* 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 com.datatorrent.api;

	import java.io.IOException;
	import java.io.Serializable;
	import java.util.ArrayList;
	import java.util.Collection;
	import java.util.Collections;
	import java.util.HashMap;
	import java.util.Map;

	import org.codehaus.jackson.map.DeserializationConfig;
	import org.codehaus.jackson.map.ObjectMapper;
	import org.codehaus.jackson.map.ObjectReader;
	import org.codehaus.jackson.map.ObjectWriter;
	import org.apache.commons.beanutils.BeanUtils;
	import org.apache.commons.lang.StringUtils;

	import com.google.common.base.Throwables;

	/**
	* This interface is essentially serializer/deserializer interface which works with String as
	* the serialized type. When initializing the attributes from the properties file, attribute
	* values represented as Strings are needed to be converted to POJO. This class facilitates the
	* conversion from and to String for attribute values.
	*
	* @param <T> Type of the object which can be converted to/from String.
	* @since 0.9.0
	*/
	public interface StringCodec<T>
	{
	/**
	* Given a string representation (typically from properties file) for an object , create object from it.
	*
	* @param string Type of the POJO which is created from String representation.
	* @return POJO obtained as a result of deserialization
	*/
	T fromString(String string);

	/**
	* Given a POJO, serialize it to a String object (typically to be stored in properties file).
	*
	* @param pojo The object which needs to be serialized.
	* @return Serialized representation of pojo..
	*/
	String toString(T pojo);

	class Factory
	{
	public static StringCodec<?> getInstance(Class<?> cls)
	{
	if (cls == String.class) {
	return String2String.getInstance();
	} else if (cls == Integer.class) {
	return Integer2String.getInstance();
	} else if (cls == Long.class) {
	return Long2String.getInstance();
	} else if (cls == Boolean.class) {
	return Boolean2String.getInstance();
	} else if (Enum.class.isAssignableFrom(cls)) {
	return Enum2String.getInstance(cls);
	} else {
	return null;
	}
	}
	}

	class String2String implements StringCodec<String>, Serializable
	{
	@SuppressWarnings("deprecation")
	private static final String2String instance = new String2String();

	public static StringCodec<String> getInstance()
	{
	return instance;
	}

	/**
	* @deprecated As of release 3.5.0, replaced by {@link #getInstance()}
	*/
	@Deprecated
	public String2String()
	{
	}

	@Override
	public String fromString(String string)
	{
	return string;
	}

	@Override
	public String toString(String pojo)
	{
	return pojo;
	}

	private static final long serialVersionUID = 201310141156L;
	}

	class Integer2String implements StringCodec<Integer>, Serializable
	{
	@SuppressWarnings("deprecation")
	private static final Integer2String instance = new Integer2String();

	public static StringCodec<Integer> getInstance()
	{
	return instance;
	}

	/**
	* @deprecated As of release 3.5.0, replaced by {@link #getInstance()}
	*/
	@Deprecated
	public Integer2String()
	{
	}

	@Override
	public Integer fromString(String string)
	{
	return Integer.valueOf(string);
	}

	@Override
	public String toString(Integer pojo)
	{
	return String.valueOf(pojo);
	}

	private static final long serialVersionUID = 201310141157L;
	}

	class Long2String implements StringCodec<Long>, Serializable
	{
	@SuppressWarnings("deprecation")
	private static final Long2String instance = new Long2String();

	public static StringCodec<Long> getInstance()
	{
	return instance;
	}

	/**
	* @deprecated As of release 3.5.0, replaced by {@link #getInstance()}
	*/
	@Deprecated
	public Long2String()
	{
	}

	@Override
	public Long fromString(String string)
	{
	return Long.valueOf(string);
	}

	@Override
	public String toString(Long pojo)
	{
	return String.valueOf(pojo);
	}

	private static final long serialVersionUID = 201310141158L;
	}

	class Boolean2String implements StringCodec<Boolean>, Serializable
	{
	@SuppressWarnings("deprecation")
	private static final Boolean2String instance = new Boolean2String();

	public static StringCodec<Boolean> getInstance()
	{
	return instance;
	}

	/**
	* @deprecated As of release 3.5.0, replaced by {@link #getInstance()}
	*/
	@Deprecated
	public Boolean2String()
	{
	}

	@Override
	public Boolean fromString(String string)
	{
	return Boolean.valueOf(string);
	}

	@Override
	public String toString(Boolean pojo)
	{
	return String.valueOf(pojo);
	}

	private static final long serialVersionUID = 201310141159L;
	}

	/**
	* The attributes which represent arbitrary objects for which the schema cannot be
	* standardized, we allow them to be represented as <ClassName>:<Constructor_String>:<Property_String> representation.
	* This allows us to instantiate the class by invoking its constructor which takes
	* <String> as argument. If only the <ClassName> is specified, then just the class is instantiated using default
	* constructor. If colon is specified then class is instantiated using constructor with
	* string as an argument.If properties are specified then properties will be set on the object. The properties
	* are defined in property=value format separated by colon(:)
	*
	* Note that the {@link #toString(Object) toString} method is by default NOT the proper reverse of the {@link
	* #fromString(String) fromString} method. In order for the {@link #toString(Object) toString} method to become a
	* proper reverse of the {@link #fromString(String) fromString} method, T's {@link T#toString() toString} method
	* must output null or <Constructor_String> or the <Constructor_String>:<Property_String> format as stated above.
	*
	* @param <T> Type of the object which is converted to/from String
	*/
	class Object2String<T> implements StringCodec<T>, Serializable
	{
	@SuppressWarnings("deprecation")
	private static final Object2String instance = new Object2String();

	public static <T> StringCodec<T> getInstance()
	{
	return instance;
	}

	public static <T> StringCodec<T> getInstance(String separator)
	{
	return getInstance(separator, "=");
	}

	@SuppressWarnings("deprecation")
	public static <T> StringCodec<T> getInstance(String separator, String propertySeparator)
	{
	return new Object2String<>(separator, propertySeparator);
	}

	public final String separator;
	public final String propertySeparator;

	/**
	* @deprecated As of release 3.5.0, replaced by {@link #getInstance()}
	*/
	@SuppressWarnings("deprecation")
	@Deprecated
	public Object2String()
	{
	this(":", "=");
	}

	/**
	* @deprecated As of release 3.5.0, replaced by {@link #getInstance(String)}
	*/
	@SuppressWarnings("deprecation")
	@Deprecated
	public Object2String(String separator)
	{
	this(separator, "=");
	}

	/**
	* @deprecated As of release 3.5.0, replaced by {@link #getInstance(String, String)}
	*/
	@Deprecated
	public Object2String(String separator, String propertySeparator)
	{
	this.separator = separator;
	this.propertySeparator = propertySeparator;
	}

	@Override
	@SuppressWarnings({"UseSpecificCatch", "BroadCatchBlock", "TooBroadCatch"})
	public T fromString(String string)
	{
	String[] parts = string.split(separator);

	try {
	@SuppressWarnings("unchecked")
	Class<? extends T> clazz = (Class<? extends T>)Thread.currentThread().getContextClassLoader().loadClass(parts[0]);
	if (parts.length == 1) {
	return clazz.newInstance();
	}

	//String[] properties = parts[1].split(separator, 2);
	if (parts.length == 2) {
	return clazz.getConstructor(String.class).newInstance(parts[1]);
	} else {
	T object = clazz.getConstructor(String.class).newInstance(parts[1]);
	HashMap<String, String> hashMap = new HashMap<>();
	for (int i = 2; i < parts.length; i++) {
	String[] keyValPair = parts[i].split(propertySeparator, 2);
	hashMap.put(keyValPair[0], keyValPair[1]);
	}
	BeanUtils.populate(object, hashMap);
	return object;
	}
	} catch (Throwable cause) {
	throw Throwables.propagate(cause);
	}
	}

	@Override
	public String toString(T pojo)
	{
	if (pojo == null) {
	return null;
	}
	String arg = pojo.toString();
	if (arg == null) {
	return pojo.getClass().getCanonicalName();
	}

	return pojo.getClass().getCanonicalName() + separator + arg;
	}

	private static final long serialVersionUID = 201311141853L;
	}

	class Map2String<K, V> implements StringCodec<Map<K, V>>, Serializable
	{
	@SuppressWarnings("deprecation")
	public static <K, V> StringCodec<Map<K, V>> getInstance(String separator, String equal, StringCodec<K> keyCodec, StringCodec<V> valueCodec)
	{
	return new Map2String<>(separator, equal, keyCodec, valueCodec);
	}

	private final StringCodec<K> keyCodec;
	private final StringCodec<V> valueCodec;
	private final String separator;
	private final String equal;

	/**
	* @deprecated As of release 3.5.0, replaced by {@link #getInstance(String, String, StringCodec, StringCodec)}
	*/
	@Deprecated
	public Map2String(String separator, String equal, StringCodec<K> keyCodec, StringCodec<V> valueCodec)
	{
	this.equal = equal;
	this.separator = separator;
	this.keyCodec = keyCodec;
	this.valueCodec = valueCodec;
	}

	@Override
	public Map<K, V> fromString(String string)
	{
	if (string == null) {
	return null;
	}

	if (string.isEmpty()) {
	return new HashMap<>();
	}

	String[] parts = string.split(separator);
	HashMap<K, V> map = new HashMap<>();
	for (String part : parts) {
	String[] kvpair = part.split(equal, 2);
	map.put(keyCodec.fromString(kvpair[0]), valueCodec.fromString(kvpair[1]));
	}

	return map;
	}

	@Override
	public String toString(Map<K, V> map)
	{
	if (map == null) {
	return null;
	}

	if (map.isEmpty()) {
	return "";
	}
	String[] parts = new String[map.size()];
	int i = 0;
	for (Map.Entry<K, V> entry : map.entrySet()) {
	parts[i++] = keyCodec.toString(entry.getKey()) + equal + valueCodec.toString(entry.getValue());
	}
	return StringUtils.join(parts, separator);
	}

	private static final long serialVersionUID = 201402272053L;
	}

	class Collection2String<T> implements StringCodec<Collection<T>>, Serializable
	{
	@SuppressWarnings("deprecation")
	public static <T> StringCodec<Collection<T>> getInstance(String separator, StringCodec<T> codec)
	{
	return new Collection2String<>(separator, codec);
	}

	private final String separator;
	private final StringCodec<T> codec;

	/**
	* @deprecated As of release 3.5.0, replaced by {@link #getInstance(String, StringCodec)}
	*/
	@Deprecated
	public Collection2String(String separator, StringCodec<T> codec)
	{
	this.separator = separator;
	this.codec = codec;
	}

	@Override
	@SuppressWarnings("unchecked")
	public Collection<T> fromString(String string)
	{
	if (string == null) {
	return null;
	}

	if (string.isEmpty()) {
	return Collections.EMPTY_LIST;
	}

	String[] parts = string.split(separator);
	ArrayList<T> arrayList = new ArrayList<>(parts.length);
	for (String part : parts) {
	arrayList.add(codec.fromString(part));
	}

	return arrayList;
	}

	@Override
	public String toString(Collection<T> pojo)
	{
	if (pojo == null) {
	return null;
	}

	if (pojo.isEmpty()) {
	return "";
	}

	String[] parts = new String[pojo.size()];

	int i = 0;
	for (T o : pojo) {
	parts[i++] = codec.toString(o);
	}

	return StringUtils.join(parts, separator);
	}

	private static final long serialVersionUID = 201401091806L;
	}

	class Enum2String<T extends Enum<T>> implements StringCodec<T>, Serializable
	{
	private final Class<T> clazz;

	@SuppressWarnings("deprecation")
	public static Enum2String getInstance(Class clazz)
	{
	return new Enum2String(clazz);
	}

	/**
	* @deprecated As of release 3.5.0, replaced by {@link #getInstance(Class<T>)}
	*/
	@Deprecated
	public Enum2String(Class<T> clazz)
	{
	this.clazz = clazz;
	}

	@Override
	public T fromString(String string)
	{
	return Enum.valueOf(clazz, string);
	}

	@Override
	public String toString(T pojo)
	{
	return pojo.name();
	}

	private static final long serialVersionUID = 201310181757L;
	}

	class Class2String<T> implements StringCodec<Class<? extends T>>, Serializable
	{
	@SuppressWarnings("deprecation")
	private static final StringCodec instance = new Class2String<>();

	public static <T> StringCodec<Class<? extends T>> getInstance()
	{
	return (StringCodec<Class<? extends T>>)instance;
	}

	/**
	* @deprecated As of release 3.5.0, replaced by {@link #getInstance()}
	*/
	public Class2String()
	{
	}

	@Override
	@SuppressWarnings({"BroadCatchBlock", "TooBroadCatch"})
	public Class<? extends T> fromString(String string)
	{
	try {
	@SuppressWarnings({"rawtypes", "unchecked"})
	Class<? extends T> clazz = (Class)Thread.currentThread().getContextClassLoader().loadClass(string);
	return clazz;
	} catch (Throwable cause) {
	throw Throwables.propagate(cause);
	}
	}

	@Override
	public String toString(Class<? extends T> clazz)
	{
	return clazz.getCanonicalName();
	}

	private static final long serialVersionUID = 201312082053L;
	}

	class JsonStringCodec<T> implements StringCodec<T>, Serializable
	{
	private static final long serialVersionUID = 2513932518264776006L;

	@SuppressWarnings("deprecation")
	public static <T> StringCodec<T> getInstance(Class<T> clazz)
	{
	return new JsonStringCodec<>(clazz);
	}

	Class<?> clazz;

	/**
	* @deprecated As of release 3.5.0, replaced by {@link #getInstance(Class)}
	*/
	public JsonStringCodec(Class<T> clazz)
	{
	this.clazz = clazz;
	}

	@Override
	public T fromString(String string)
	{
	try {
	ObjectMapper mapper = new ObjectMapper();
	mapper.configure(DeserializationConfig.Feature.FAIL_ON_UNKNOWN_PROPERTIES, false);
	ObjectReader reader = mapper.reader(clazz);
	return reader.readValue(string);
	} catch (IOException e) {
	throw Throwables.propagate(e);
	}
	}

	@Override
	public String toString(T pojo)
	{
	try {
	ObjectMapper mapper = new ObjectMapper();
	mapper.configure(DeserializationConfig.Feature.FAIL_ON_UNKNOWN_PROPERTIES, false);
	ObjectWriter writer = mapper.writer();
	return writer.writeValueAsString(pojo);
	} catch (IOException e) {
	throw Throwables.propagate(e);
	}
	}
	}
	}