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

 /**
  * Copyright (C) 2015 DataTorrent, Inc.
  *
  * 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 com.datatorrent.api;

 import java.io.Serializable;
 import java.util.ArrayList;
 import java.util.Collection;
 import java.util.Collections;

 import org.apache.commons.beanutils.BeanUtils;
 import org.apache.commons.lang.StringUtils;

 import com.datatorrent.netlet.util.DTThrowable;
 import java.util.*;

 /**
  * 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);

   public class String2String implements StringCodec<String>, Serializable
   {
     @Override
     public String fromString(String string)
     {
       return string;
     }

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

     private static final long serialVersionUID = 201310141156L;
   }

   public class Integer2String implements StringCodec<Integer>, Serializable
   {
     @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;
   }

   public class Long2String implements StringCodec<Long>, Serializable
   {
     @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;
   }

   public class Boolean2String implements StringCodec<Boolean>, Serializable
   {
     @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(:)
    *
    * @param <T> Type of the object which is converted to/from String
    */
   public class Object2String<T> implements StringCodec<T>, Serializable
   {
     public final String separator;
     public final String propertySeparator;

     public Object2String()
     {
       separator = ":";
       propertySeparator = "=";
     }

     public Object2String(String separator)
     {
       this.separator = separator;
       this.propertySeparator = "=";
     }

     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<String, String>();
           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) {
         DTThrowable.rethrow(cause);
       }

       return null;
     }

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

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

     private static final long serialVersionUID = 201311141853L;
   }

   public class Map2String<K, V> implements StringCodec<Map<K, V>>, Serializable
   {
     private final StringCodec<K> keyCodec;
     private final StringCodec<V> valueCodec;
     private final String separator;
     private final String equal;

     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<K, V>();
       }

       String[] parts = string.split(separator);
       HashMap<K, V> map = new HashMap<K, V>();
       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;
   }

   public class Collection2String<T> implements StringCodec<Collection<T>>, Serializable
   {
     private final String separator;
     private final StringCodec<T> codec;

     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<T>(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;
   }

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

     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;
   }

   public class Class2String<T> implements StringCodec<Class<? extends T>>, Serializable
   {
     @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) {
         DTThrowable.rethrow(cause);
       }

       return null;
     }

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

     private static final long serialVersionUID = 201312082053L;
   }

 }
	/**
	* Copyright (C) 2015 DataTorrent, Inc.
	*
	* 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 com.datatorrent.api;

	import java.io.Serializable;
	import java.util.ArrayList;
	import java.util.Collection;
	import java.util.Collections;

	import org.apache.commons.beanutils.BeanUtils;
	import org.apache.commons.lang.StringUtils;

	import com.datatorrent.netlet.util.DTThrowable;
	import java.util.*;

	/**
	* 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);

	public class String2String implements StringCodec<String>, Serializable
	{
	@Override
	public String fromString(String string)
	{
	return string;
	}

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

	private static final long serialVersionUID = 201310141156L;
	}

	public class Integer2String implements StringCodec<Integer>, Serializable
	{
	@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;
	}

	public class Long2String implements StringCodec<Long>, Serializable
	{
	@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;
	}

	public class Boolean2String implements StringCodec<Boolean>, Serializable
	{
	@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(:)
	*
	* @param <T> Type of the object which is converted to/from String
	*/
	public class Object2String<T> implements StringCodec<T>, Serializable
	{
	public final String separator;
	public final String propertySeparator;

	public Object2String()
	{
	separator = ":";
	propertySeparator = "=";
	}

	public Object2String(String separator)
	{
	this.separator = separator;
	this.propertySeparator = "=";
	}

	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<String, String>();
	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) {
	DTThrowable.rethrow(cause);
	}

	return null;
	}

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

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

	private static final long serialVersionUID = 201311141853L;
	}

	public class Map2String<K, V> implements StringCodec<Map<K, V>>, Serializable
	{
	private final StringCodec<K> keyCodec;
	private final StringCodec<V> valueCodec;
	private final String separator;
	private final String equal;

	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<K, V>();
	}

	String[] parts = string.split(separator);
	HashMap<K, V> map = new HashMap<K, V>();
	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;
	}

	public class Collection2String<T> implements StringCodec<Collection<T>>, Serializable
	{
	private final String separator;
	private final StringCodec<T> codec;

	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<T>(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;
	}

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

	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;
	}

	public class Class2String<T> implements StringCodec<Class<? extends T>>, Serializable
	{
	@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) {
	DTThrowable.rethrow(cause);
	}

	return null;
	}

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

	private static final long serialVersionUID = 201312082053L;
	}

	}