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/*
* Copyright (c) Balajee TM 2016.
* All rights reserved.
* License - @see
*/
/*
* Created on 25 Aug, 2016 by balajeetm
* http://www.balajeetm.com
*/
package com.balajeetm.mystique.util.gson.convertor;
import com.balajeetm.mystique.util.gson.GsonFactory;
import com.balajeetm.mystique.util.gson.lever.JsonLever;
import com.balajeetm.mystique.util.json.convertor.JsonConvertor;
import com.balajeetm.mystique.util.json.error.ConvertorException;
import com.google.gson.Gson;
import com.google.gson.GsonBuilder;
import com.google.gson.JsonElement;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.util.List;
import java.util.Objects;
import lombok.Getter;
import lombok.Setter;
import lombok.extern.slf4j.Slf4j;
import org.apache.commons.lang3.ArrayUtils;
import static com.google.gson.internal.$Gson$Preconditions.checkArgument;
/** The Class GsonConvertor. */
@Slf4j
public class GsonConvertor implements JsonConvertor {
/**
* Gets the gson.
*
* @return the gson
*/
@Getter
/**
* Sets the gson.
*
* @param gson the new gson
*/
@Setter
private Gson gson;
/** The gson builder. */
private GsonBuilder gsonBuilder;
/** The json lever. */
private JsonLever jsonLever;
/** Instantiates a new gson convertor. */
private GsonConvertor() {
GsonFactory factory = GsonFactory.getInstance();
gsonBuilder = factory.getGsonBuilder();
gson = factory.getGson();
jsonLever = JsonLever.getInstance();
}
// Efficient Thread safe Lazy Initialization
// works only if the singleton constructor is non parameterized
/**
* Gets the single instance of GsonConvertor.
*
* @return single instance of GsonConvertor
*/
public static JsonConvertor getInstance() {
return Creator.INSTANCE;
}
/** Update gson. */
private void updateGson() {
gson = gsonBuilder.create();
}
/**
* Register type adapter.
*
* @param adapters the adapters
*/
public void registerTypeAdapter(GsonTypeAdapter... adapters) {
if (!ArrayUtils.isEmpty(adapters)) {
for (GsonTypeAdapter gsonTypeAdapter : adapters) {
gsonBuilder.registerTypeAdapter(gsonTypeAdapter.getType(), gsonTypeAdapter.getAdapter());
}
updateGson();
}
}
/*
* (non-Javadoc)
*
* @see
* com.futuresight.util.mystique.lever.ConvertorInterface#deserialize(java.
* lang.String, java.lang.Class)
*/
@Override
public T deserialize(String jsonString, Class pojoType) throws ConvertorException {
T result = null;
try {
if (Objects.nonNull(jsonString)) {
result = gson.fromJson(jsonString, pojoType);
}
} catch (Exception e) {
log.error(
String.format(
"Error during deserialisation of json string %s to class %s.", jsonString, pojoType));
throw getConvertorException(e);
}
return result;
}
/*
* (non-Javadoc)
*
* @see
* com.futuresight.util.mystique.lever.ConvertorInterface#deserialize(java.
* io.InputStream, java.lang.Class)
*/
@Override
public T deserialize(InputStream inputStream, Class pojoType) throws ConvertorException {
T result = null;
try {
if (Objects.nonNull(inputStream)) {
result = gson.fromJson(new InputStreamReader(inputStream), pojoType);
}
} catch (Exception e) {
log.error(
String.format(
"Error during deserialisation of json input stream %s to class %s.",
inputStream, pojoType));
throw getConvertorException(e);
}
return result;
}
/*
* (non-Javadoc)
*
* @see
* com.futuresight.util.mystique.lever.ConvertorInterface#deserialize(java.
* lang.Object, java.lang.Class)
*/
@Override
public T deserialize(Object object, Class pojoType) throws ConvertorException {
T result = null;
if (Objects.nonNull(object)) {
if (object instanceof String) {
result = deserialize((String) object, pojoType);
} else if (object instanceof InputStream) {
result = deserialize((InputStream) object, pojoType);
} else {
try {
JsonElement jsonElement = getJsonElement(object);
result = gson.fromJson(jsonElement, pojoType);
} catch (Exception e) {
log.error(
String.format(
"Error during deserialisation of object %s to class %s.", object, pojoType));
throw getConvertorException(e);
}
}
}
return result;
}
/*
* (non-Javadoc)
*
* @see
* com.futuresight.util.mystique.lever.ConvertorInterface#serialize(java.
* lang.Object)
*/
@Override
public String serialize(Object pojo) throws ConvertorException {
String result = null;
try {
if (Objects.nonNull(pojo)) {
result = gson.toJson(pojo);
}
} catch (Exception e) {
log.error(String.format("Error during serialisation of object %s.", pojo));
throw getConvertorException(e);
}
return result;
}
/*
* (non-Javadoc)
*
* @see
* com.futuresight.util.mystique.lever.ConvertorInterface#deserializeGroup(
* java.lang.String, java.lang.Class, java.lang.Class)
*/
@Override
public T deserializeGroup(String jsonString, Class groupClass, Class pojoType)
throws ConvertorException {
T result = null;
if (Objects.nonNull(jsonString)) {
try {
checkArgument(groupClass != null && pojoType != null);
GsonParametrizedType parametrizedType =
new GsonParametrizedType(groupClass.getName(), pojoType.getName());
result = gson.fromJson(jsonString, parametrizedType);
} catch (Exception e) {
log.error(
String.format(
"Error during deserialisation of json string %s to %s<%s>.",
jsonString, groupClass.getSimpleName(), pojoType.getSimpleName()));
throw getConvertorException(e);
}
}
return result;
}
/*
* (non-Javadoc)
*
* @see
* com.futuresight.util.mystique.lever.ConvertorInterface#deserializeGroup(
* java.io.InputStream, java.lang.Class, java.lang.Class)
*/
@Override
public T deserializeGroup(InputStream inputStream, Class groupClass, Class pojoType)
throws ConvertorException {
T result = null;
if (Objects.nonNull(inputStream)) {
try {
checkArgument(groupClass != null && pojoType != null);
GsonParametrizedType parametrizedType =
new GsonParametrizedType(groupClass.getName(), pojoType.getName());
result = gson.fromJson(new InputStreamReader(inputStream), parametrizedType);
} catch (Exception e) {
log.error(
String.format(
"Error during deserialisation of json inputstream %s to %s<%s>.",
inputStream, groupClass.getSimpleName(), pojoType.getSimpleName()));
throw getConvertorException(e);
}
}
return result;
}
/*
* (non-Javadoc)
*
* @see
* com.futuresight.util.mystique.lever.ConvertorInterface#deserializeList(
* java.io.InputStream, java.lang.Class)
*/
@Override
public List deserializeList(InputStream inputStream, Class pojoType)
throws ConvertorException {
List result = null;
if (Objects.nonNull(inputStream)) {
try {
checkArgument(pojoType != null);
GsonParametrizedType parametrizedType =
new GsonParametrizedType(List.class.getName(), pojoType.getName());
result = gson.fromJson(new InputStreamReader(inputStream), parametrizedType);
} catch (Exception e) {
log.error(
String.format(
"Error during deserialisation of json inputstream %s to List<%s>.",
inputStream, pojoType.getSimpleName()));
throw getConvertorException(e);
}
}
return result;
}
/*
* (non-Javadoc)
*
* @see
* com.futuresight.util.mystique.lever.ConvertorInterface#deserializeList(
* java.lang.String, java.lang.Class)
*/
@Override
public List deserializeList(String jsonString, Class pojoType)
throws ConvertorException {
List result = null;
if (Objects.nonNull(jsonString)) {
try {
checkArgument(pojoType != null);
GsonParametrizedType parametrizedType =
new GsonParametrizedType(List.class.getName(), pojoType.getName());
result = gson.fromJson(jsonString, parametrizedType);
} catch (Exception e) {
log.error(
String.format(
"Error during deserialisation of json string %s to List<%s>.",
jsonString, pojoType.getSimpleName()));
throw getConvertorException(e);
}
}
return result;
}
/*
* (non-Javadoc)
*
* @see
* com.futuresight.util.mystique.lever.ConvertorInterface#deserializeList(
* java.lang.Object, java.lang.Class)
*/
@Override
public List deserializeList(Object object, Class pojoType) throws ConvertorException {
List result = null;
if (Objects.nonNull(object)) {
try {
checkArgument(pojoType != null);
JsonElement jsonElement = getJsonElement(object);
GsonParametrizedType parametrizedType =
new GsonParametrizedType(List.class.getName(), pojoType.getName());
result = gson.fromJson(jsonElement, parametrizedType);
} catch (Exception e) {
log.error(
String.format(
"Error during deserialisation of object %s to List<%s>.",
object, pojoType.getSimpleName()));
throw getConvertorException(e);
}
}
return result;
}
/**
* Gets the convertor exception.
*
* @param e the exception
* @return the convertor exception
*/
private ConvertorException getConvertorException(Exception e) {
log.debug("Error occured during conversion", e);
return new ConvertorException(e);
}
/**
* Gets the json element from a Java POJO.
*
* @param obj the obj
* @return the json element
*/
private JsonElement getJsonElement(Object obj) {
JsonElement jsonElement =
(obj instanceof JsonElement) ? (JsonElement) obj : gson.toJsonTree(obj);
return jsonLever.isNull(jsonElement) ? null : jsonElement;
}
/** The Class Creator. */
private static class Creator {
/** The instance. */
private static JsonConvertor INSTANCE = new GsonConvertor();
}
}