moxy/json-processing/src/main/java/eclipselink/example/moxy/json/jsonprocessing/Main.java - eclipselink/examples - Git at Google

 /*******************************************************************************
  * Copyright (c) 2015 Oracle and/or its affiliates. All rights reserved.
  * This program and the accompanying materials are made available under the
  * terms of the Eclipse Public License v1.0 and Eclipse Distribution License v. 1.0
  * which accompanies this distribution.
  *
  * The Eclipse Public License is available at http://www.eclipse.org/legal/epl-v10.html
  * and the Eclipse Distribution License is available at
  * http://www.eclipse.org/org/documents/edl-v10.php.
  ******************************************************************************/

 package eclipselink.example.moxy.json.jsonprocessing;

 import java.io.File;
 import java.io.FileInputStream;
 import java.io.FileNotFoundException;
 import java.io.FileOutputStream;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.List;

 import javax.json.Json;
 import javax.json.JsonArray;
 import javax.json.JsonArrayBuilder;
 import javax.json.JsonObject;
 import javax.json.JsonObjectBuilder;
 import javax.json.JsonReader;
 import javax.json.JsonWriter;
 import javax.json.stream.JsonGenerator;
 import javax.json.stream.JsonParser;

 import eclipselink.example.moxy.json.jsonprocessing.model.Customer;
 import eclipselink.example.moxy.json.jsonprocessing.model.PhoneNumber;

 /**
  * This example executes the following basic steps:
  *
  * 1) Create a Customer instance that embeds a list of Phone Numbers
  *
  * 2) Use the JSON Writer API to write the customer from a file in JSON format
  *
  * 3) Use the JSON Reader API to read the JSON representation of a customer from
  * a file
  *
  * 4) Use the JSON Generator API to write a Customer to a file in JSON format
  *
  * 5) Use the JSON Parser API to read the JSON representation of a customer
  * from a file
  *
  * @author johnclingan
  * @since EclipseLink 2.6.0
  */

 public class Main {
 	public static final String FILENAME_WRITER = "target" + File.separator
 			+ "customer.writer.json";

 	public static final String FILENAME_GENERATOR = "target"
 			+ File.separator + "customer.generator.json";

 	public static void main(String[] args) throws Exception {

 		System.out.println();
 		System.out.println("Running EclipseLink MOXy JSON Processing Example");

 		// Step 1 - Create a customer
 		Customer customer = createCustomer();

 		// Step 2 - Write Customer to a file in JSON format using JsonWriter
 		try (JsonWriter writer = Json.createWriter(new FileOutputStream(
 				FILENAME_WRITER))) {
 			JsonObject jsonCustomer = createCustomerJsonObject(customer);
 			writer.writeObject(jsonCustomer);
 			System.out.println();
 			System.out.println("Customer instance written to " + FILENAME_WRITER
 					+ " using JsonWriter");
 		}

 		// Step 3 - Read JSON representation of a customer from a file using
 		// JsonReader and create a customer instance
 		try (JsonReader reader = Json.createReader(new FileInputStream(
 				FILENAME_WRITER))) {
 			JsonObject jsonObject = reader.readObject();
 			Customer customer2 = createCustomerFromJsonObject(jsonObject);
 			System.out.println();
 			System.out.println("Customer read from "
 			     + FILENAME_WRITER + " using JsonReader:");
 			System.out.println(customer2);
 		}

 		// Step 4 - Write a Customer to a file using the JsonGenerator API
 		try (JsonGenerator generator = Json
 				.createGenerator(new FileOutputStream(FILENAME_GENERATOR))) {
 			generateCustomer(customer, generator);
 			System.out.println();
 			System.out.println("Customer instance written to " + FILENAME_GENERATOR
 					+ " using JsonGenerator");
 		}

 		// Step 5 - Read JSON representation of customer from a file
 		// using JsonParser
 		Customer parsedCustomer = parseJsonCustomer(FILENAME_GENERATOR);
 		System.out.println();
 		System.out.println("Customer read from "
 		         + FILENAME_GENERATOR + " using JsonParser:");
 		System.out.println(parsedCustomer);

 		System.out.println();
 		System.out.println();
 	}

 	/********************************************
 	 * Create an instance of a customer
 	 ********************************************/

 	private static Customer createCustomer() {
 		PhoneNumber p1 = new PhoneNumber("555-1111", "Mobile");
 		PhoneNumber p2 = new PhoneNumber("555-2222", "Home");

 		return new Customer(1, "John", "Doe", Arrays.asList(p1, p2));
 	}

 	/********************************************
 	 * Creates a JsonObject from Customer instance
 	 ********************************************/

 	private static JsonObject createCustomerJsonObject(Customer customer) {

 		JsonArrayBuilder phoneArrayBuilder = Json.createArrayBuilder();

 		for (PhoneNumber p : customer.getPhoneNumbers()) {
 			JsonObjectBuilder phoneBuilder = Json.createObjectBuilder();
 			phoneBuilder.add("number", p.getNumber()).add("type", p.getType());
 			phoneArrayBuilder.add(phoneBuilder);
 		}

 		JsonObjectBuilder builder = Json.createObjectBuilder();
 		builder.add("id", customer.getId())
 				.add("firstName", customer.getFirstName())
 				.add("lastName", customer.getLastName())
 				.add("phoneNumbers", phoneArrayBuilder);

 		return builder.build();
 	}

 	/*****************************************************
 	 * Create an instance of a customer from a jsonObject
 	 *****************************************************/

 	private static Customer createCustomerFromJsonObject(JsonObject jsonObject) {
 		Customer customer = new Customer();

 		customer.setId(jsonObject.getInt("id"));
 		customer.setFirstName(jsonObject.getString("firstName"));
 		customer.setLastName(jsonObject.getString("lastName"));

 		JsonArray jsonPhoneArray = jsonObject.getJsonArray("phoneNumbers");

 		for (JsonObject jsonPhone : jsonPhoneArray
 				.getValuesAs(JsonObject.class)) {
 			PhoneNumber phoneNumber = new PhoneNumber();

 			phoneNumber.setNumber(jsonPhone.getString("number"));
 			phoneNumber.setType(jsonPhone.getString("type"));

 			customer.getPhoneNumbers().add(phoneNumber);
 		}

 		return customer;
 	}

 	/*************************************************************************
 	 * Read a JSON-formatted customer into a Customer instance using the JSON
 	 * parsing API. Parsing JSON takes more work (more code), but has two
 	 * distinct advantages:
 	 *
 	 * 1) A potentially very large JsonObject does not have to be stored in
 	 * memory
 	 *
 	 * 2) If only a subset of data is needed, parsing can immediately
 	 * return
 	 *
 	 *************************************************************************/

 	private static Customer parseJsonCustomer(String filename) {
 		Customer customer = new Customer();
 		String key = ""; // They key of the JSON key/value pair
 		PhoneNumber phoneNumber = new PhoneNumber();
 		boolean inPhoneNumberArray = false;

 		try (JsonParser parser = Json
 				.createParser(new FileInputStream(filename))) {

 			while (parser.hasNext()) {
 				switch (parser.next()) {
 				case KEY_NAME:
 					key = parser.getString();
 					break;

 				case VALUE_NUMBER:
 					// There is only one "number" in customer - id - so just
 					// assume it is the id
 					customer.setId(parser.getInt());
 					break;

 				case VALUE_STRING:
 					// Get the "value" of the key/value pair
 					String value = parser.getString();

 					switch (key) {
 					case "firstName":
 						customer.setFirstName(value);
 						break;
 					case "lastName":
 						customer.setLastName(value);
 						break;

 					case "number":
 						phoneNumber.setNumber(value);
 						break;

 					case "type":
 						phoneNumber.setType(value);
 						break;
 					}

 					break;

 				case START_OBJECT:
 					if (inPhoneNumberArray) {
 						phoneNumber = new PhoneNumber();
 					}
 					break;

 				case END_OBJECT:
 					if (inPhoneNumberArray) {
 						customer.getPhoneNumbers().add(phoneNumber);
 					}
 					break;

 				case START_ARRAY:
 					// There is only one JSON Array in Customer - the list of
 					// phone numbers so we can hard-code this
 					inPhoneNumberArray = true;
 					break;

 				case END_ARRAY:
 					// There is only one JSON Array in Customer - the list of
 					// phone numbers, so we can hard-code adding phone number
 					inPhoneNumberArray = false;
 					break;

 				}
 			}
 		} catch (FileNotFoundException ex) {
 			System.out.println(ex);
 		}

 		return customer;
 	}

 	/*************************************************************************
 	 * Write a customer instance to a file using the JsonGenerator API
 	 *************************************************************************/
 	private static void generateCustomer(Customer customer,
 			JsonGenerator generator) {
 		generator.writeStartObject()
 				.write("id", customer.getId())
 				.write("firstName", customer.getFirstName())
 				.write("lastName", customer.getLastName())
 				.writeStartArray("phoneNumbers");

 		for (PhoneNumber phoneNumber : customer.getPhoneNumbers()) {
 			generator.writeStartObject()
 					.write("number", phoneNumber.getNumber())
 					.write("type", phoneNumber.getType()).writeEnd();
 		}

 		generator.writeEnd()   // Write end of phone number array
 				.writeEnd();	// Write end of customer
 	}

 }
	/*******************************************************************************
	* Copyright (c) 2015 Oracle and/or its affiliates. All rights reserved.
	* This program and the accompanying materials are made available under the
	* terms of the Eclipse Public License v1.0 and Eclipse Distribution License v. 1.0
	* which accompanies this distribution.
	*
	* The Eclipse Public License is available at http://www.eclipse.org/legal/epl-v10.html
	* and the Eclipse Distribution License is available at
	* http://www.eclipse.org/org/documents/edl-v10.php.
	******************************************************************************/

	package eclipselink.example.moxy.json.jsonprocessing;

	import java.io.File;
	import java.io.FileInputStream;
	import java.io.FileNotFoundException;
	import java.io.FileOutputStream;
	import java.util.ArrayList;
	import java.util.Arrays;
	import java.util.List;

	import javax.json.Json;
	import javax.json.JsonArray;
	import javax.json.JsonArrayBuilder;
	import javax.json.JsonObject;
	import javax.json.JsonObjectBuilder;
	import javax.json.JsonReader;
	import javax.json.JsonWriter;
	import javax.json.stream.JsonGenerator;
	import javax.json.stream.JsonParser;

	import eclipselink.example.moxy.json.jsonprocessing.model.Customer;
	import eclipselink.example.moxy.json.jsonprocessing.model.PhoneNumber;

	/**
	* This example executes the following basic steps:
	*
	* 1) Create a Customer instance that embeds a list of Phone Numbers
	*
	* 2) Use the JSON Writer API to write the customer from a file in JSON format
	*
	* 3) Use the JSON Reader API to read the JSON representation of a customer from
	* a file
	*
	* 4) Use the JSON Generator API to write a Customer to a file in JSON format
	*
	* 5) Use the JSON Parser API to read the JSON representation of a customer
	* from a file
	*
	* @author johnclingan
	* @since EclipseLink 2.6.0
	*/

	public class Main {
	public static final String FILENAME_WRITER = "target" + File.separator
	+ "customer.writer.json";

	public static final String FILENAME_GENERATOR = "target"
	+ File.separator + "customer.generator.json";

	public static void main(String[] args) throws Exception {

	System.out.println();
	System.out.println("Running EclipseLink MOXy JSON Processing Example");

	// Step 1 - Create a customer
	Customer customer = createCustomer();

	// Step 2 - Write Customer to a file in JSON format using JsonWriter
	try (JsonWriter writer = Json.createWriter(new FileOutputStream(
	FILENAME_WRITER))) {
	JsonObject jsonCustomer = createCustomerJsonObject(customer);
	writer.writeObject(jsonCustomer);
	System.out.println();
	System.out.println("Customer instance written to " + FILENAME_WRITER
	+ " using JsonWriter");
	}

	// Step 3 - Read JSON representation of a customer from a file using
	// JsonReader and create a customer instance
	try (JsonReader reader = Json.createReader(new FileInputStream(
	FILENAME_WRITER))) {
	JsonObject jsonObject = reader.readObject();
	Customer customer2 = createCustomerFromJsonObject(jsonObject);
	System.out.println();
	System.out.println("Customer read from "
	+ FILENAME_WRITER + " using JsonReader:");
	System.out.println(customer2);
	}

	// Step 4 - Write a Customer to a file using the JsonGenerator API
	try (JsonGenerator generator = Json
	.createGenerator(new FileOutputStream(FILENAME_GENERATOR))) {
	generateCustomer(customer, generator);
	System.out.println();
	System.out.println("Customer instance written to " + FILENAME_GENERATOR
	+ " using JsonGenerator");
	}

	// Step 5 - Read JSON representation of customer from a file
	// using JsonParser
	Customer parsedCustomer = parseJsonCustomer(FILENAME_GENERATOR);
	System.out.println();
	System.out.println("Customer read from "
	+ FILENAME_GENERATOR + " using JsonParser:");
	System.out.println(parsedCustomer);

	System.out.println();
	System.out.println();
	}

	/********************************************
	* Create an instance of a customer
	********************************************/

	private static Customer createCustomer() {
	PhoneNumber p1 = new PhoneNumber("555-1111", "Mobile");
	PhoneNumber p2 = new PhoneNumber("555-2222", "Home");

	return new Customer(1, "John", "Doe", Arrays.asList(p1, p2));
	}

	/********************************************
	* Creates a JsonObject from Customer instance
	********************************************/

	private static JsonObject createCustomerJsonObject(Customer customer) {

	JsonArrayBuilder phoneArrayBuilder = Json.createArrayBuilder();

	for (PhoneNumber p : customer.getPhoneNumbers()) {
	JsonObjectBuilder phoneBuilder = Json.createObjectBuilder();
	phoneBuilder.add("number", p.getNumber()).add("type", p.getType());
	phoneArrayBuilder.add(phoneBuilder);
	}

	JsonObjectBuilder builder = Json.createObjectBuilder();
	builder.add("id", customer.getId())
	.add("firstName", customer.getFirstName())
	.add("lastName", customer.getLastName())
	.add("phoneNumbers", phoneArrayBuilder);

	return builder.build();
	}

	/*****************************************************
	* Create an instance of a customer from a jsonObject
	*****************************************************/

	private static Customer createCustomerFromJsonObject(JsonObject jsonObject) {
	Customer customer = new Customer();

	customer.setId(jsonObject.getInt("id"));
	customer.setFirstName(jsonObject.getString("firstName"));
	customer.setLastName(jsonObject.getString("lastName"));

	JsonArray jsonPhoneArray = jsonObject.getJsonArray("phoneNumbers");

	for (JsonObject jsonPhone : jsonPhoneArray
	.getValuesAs(JsonObject.class)) {
	PhoneNumber phoneNumber = new PhoneNumber();

	phoneNumber.setNumber(jsonPhone.getString("number"));
	phoneNumber.setType(jsonPhone.getString("type"));

	customer.getPhoneNumbers().add(phoneNumber);
	}

	return customer;
	}

	/*************************************************************************
	* Read a JSON-formatted customer into a Customer instance using the JSON
	* parsing API. Parsing JSON takes more work (more code), but has two
	* distinct advantages:
	*
	* 1) A potentially very large JsonObject does not have to be stored in
	* memory
	*
	* 2) If only a subset of data is needed, parsing can immediately
	* return
	*
	*************************************************************************/

	private static Customer parseJsonCustomer(String filename) {
	Customer customer = new Customer();
	String key = ""; // They key of the JSON key/value pair
	PhoneNumber phoneNumber = new PhoneNumber();
	boolean inPhoneNumberArray = false;

	try (JsonParser parser = Json
	.createParser(new FileInputStream(filename))) {

	while (parser.hasNext()) {
	switch (parser.next()) {
	case KEY_NAME:
	key = parser.getString();
	break;

	case VALUE_NUMBER:
	// There is only one "number" in customer - id - so just
	// assume it is the id
	customer.setId(parser.getInt());
	break;

	case VALUE_STRING:
	// Get the "value" of the key/value pair
	String value = parser.getString();

	switch (key) {
	case "firstName":
	customer.setFirstName(value);
	break;
	case "lastName":
	customer.setLastName(value);
	break;

	case "number":
	phoneNumber.setNumber(value);
	break;

	case "type":
	phoneNumber.setType(value);
	break;
	}

	break;

	case START_OBJECT:
	if (inPhoneNumberArray) {
	phoneNumber = new PhoneNumber();
	}
	break;

	case END_OBJECT:
	if (inPhoneNumberArray) {
	customer.getPhoneNumbers().add(phoneNumber);
	}
	break;

	case START_ARRAY:
	// There is only one JSON Array in Customer - the list of
	// phone numbers so we can hard-code this
	inPhoneNumberArray = true;
	break;

	case END_ARRAY:
	// There is only one JSON Array in Customer - the list of
	// phone numbers, so we can hard-code adding phone number
	inPhoneNumberArray = false;
	break;

	}
	}
	} catch (FileNotFoundException ex) {
	System.out.println(ex);
	}

	return customer;
	}

	/*************************************************************************
	* Write a customer instance to a file using the JsonGenerator API
	*************************************************************************/
	private static void generateCustomer(Customer customer,
	JsonGenerator generator) {
	generator.writeStartObject()
	.write("id", customer.getId())
	.write("firstName", customer.getFirstName())
	.write("lastName", customer.getLastName())
	.writeStartArray("phoneNumbers");

	for (PhoneNumber phoneNumber : customer.getPhoneNumbers()) {
	generator.writeStartObject()
	.write("number", phoneNumber.getNumber())
	.write("type", phoneNumber.getType()).writeEnd();
	}

	generator.writeEnd() // Write end of phone number array
	.writeEnd(); // Write end of customer
	}

	}