oracle.adfmf.framework.api

Class JSONBeanSerializationHelper

Object

oracle.adfmf.framework.api.JSONBeanSerializationHelper

public class JSONBeanSerializationHelper
extends Object

JSONBeanSerializationHelper will (de)serialize objects in and out of a JSON object.

The following classes are used to support this functionality:

• JSONSerializable - allows object developer the ability to implement their own custom JSON serialization
• PostJSONSerializable - provides object developers a hook to alter the JSON post the JSON serialization process
• JSONDeserializable - allows object developer the ability to implement their own custom JSON deserialization
• PostJSONDeserializable - provides object developers a hook to alter the JSON post the JSON deserialization process

Supported types:

• primitives : boolean, byte, char, double, float, int, long, and short
• Boxed types : Boolean, Byte, Character, Double, Float, Integer, Long, and Short
• Base objects: ISO8601DateTime, BigDecimal, BigInteger, and Collection
• Null objects: JSON object with defined ".null" properties
• Beans : using standard Java Bean reflection rules
• NOTE: transient fields will be ignored in the serialization process

See Also:

JSONSerializable, PostJSONSerializable, JSONDeserializable, PostJSONDeserializable, Example of usage:

  public class MyBean
  {
    private String  string;
    private Integer integer;

    public String getString()
    {
      return string;
    }

    public void setString(String str)
    {
      this.string = str;
    }

    public Integer getInteger()
    {
      return integer;
    }

    public void setInteger(Integer i)
    {
      this.integer = i;
    }

    public String toString()
    {
      String retStr = "";

      if (null != this.string && this.string.length() > 0)
      {
        retStr = retStr + "string = " + this.string + "; ";
      }

      retStr = retStr + "integer = " + String.valueOf(this.integer) + ";";

      return retStr;
    }
  }

  public void simpleExampleOfSerializationDeserialization()
  {
    Object jsonObj = null;

    try
    {
      MyBean beanObj = new MyBean();
      beanObj.setString("Test");
      beanObj.setInteger(new Integer(30));

      // Convert String to JSON form.
      jsonObj = JSONBeanSerializationHelper.toJSON(beanObj);
      System.out.println("JSON Object received after serializing is: " + jsonObj.toString());
      // This will print => JSON Object received after serializing is: {".type":"oracle.adfmf.test.MyBean","integer":30,"string":"Test"}

      // Convert JSON back to String form.
      MyBean beanObjReceived = (MyBean) JSONBeanSerializationHelper.fromJSON(MyBean.class, jsonObj);
      System.out.println("MyBean class object received after deserializing is: " + beanObjReceived.toString());
      // This will print => MyBean class object received after deserializing is: string = Test; integer = 30;
    }
    catch (Exception e)
    {
      // Handle exception
    }
  }
 

Constructor Summary

Constructors

Constructor and Description
JSONBeanSerializationHelper()

Method Summary

Modifier and Type	Method and Description
static Object	fromJSON(Class type, Object json) Method used to deserialize the passed-in Object to Java object.
static Object	fromJSON(Class type, String jsonString) Method used to deserialize the passed-in Object to Java object.
static boolean	getBoolean(Object object) Used to coerce an object into a boolean if possible.
static byte	getByte(Object object) Used to coerce an object into a byte if possible.
static char	getCharacter(Object object) Used to coerce an object into a char if possible.
static double	getDouble(Object object) Used to coerce an object into a double if possible.
static float	getFloat(Object object) Used to coerce an object into a float if possible.
static int	getIdFromJSONObject(JSONObject jsonObj) Gets id from the json object and returns the corresponding int value Internal Utility Function
static int	getInteger(Object object) Used to coerce an object into a int if possible.
static long	getLong(Object object) Used to coerce an object into a long if possible.
static JSONObject	getNullJSONObj() Method to create and return JSON object representing null object.
static short	getShort(Object object) Used to coerce an object into a short if possible.
static String	getString(Object object) Used to coerce an object into a String if possible.
static boolean	isObjectNull(Object json) Utility method to determine if the JSON object is null.
static void	removeBooleanFromJSON(JSONObject jsonObj, boolean bValue, String[] keys) Normalizes the JSON object by removing the objects which contain specified boolean value.
static void	removeNegativesFromJSON(JSONObject jsonObj, String[] keys) Normalizes the JSON object by removing the objects which contain value: -1.
static void	removeNullsFromJSON(JSONObject jsonObj, String[] keys) Normalizes the JSON object by removing the objects which contain null's.
static void	replaceNullObjectWithNullLiteral(JSONObject root) An utility method to replace {".null":true} values with JSONObject.NULL literal.
static Object	toJSON(Object obj) Method used to serialize the passed in Java object to JSON.

Methods inherited from class Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

JSONBeanSerializationHelper

public JSONBeanSerializationHelper()

Method Detail

fromJSON

public static Object fromJSON(Class type,
                              String jsonString)
                       throws Exception

Method used to deserialize the passed-in Object to Java object.

Parameters:

type - Class to which JSON Object should be deserialized to

jsonString - String representing a JSON object.

Throws:

Exception

See Also:

fromJSON(Class type, Object json)

fromJSON

public static Object fromJSON(Class type,
                              Object json)
                       throws Exception

Method used to deserialize the passed-in Object to Java object.

Please refer to the following for more advanced ideas:

• JSONDeserializable - If the application developer wants to override the functionality of this method, he can implement JSONDeserializable and can add his custom deserialization code in JSONDeserializable.fromJSON().
• PostJSONDeserializable - If the application developer wants a hook to alter the object after the deserialization process, he can implement PostJSONDeserializable and add his custom code in PostJSONDeserializable.modifyObject().

The basic deserialize method provide the following out of the box conversions:

• Primitives --> Boxed
• BigDecimal, BigInteger --> BigDecimal
• ISO8601DateTime --> String representation of date
• Vector --> List
• JSONObject --> null, JSONObject, or an instance of the fully qualified class name specified by JSONTokens.TYPE_PROPERTY
• JSONArray --> Object Array

For additional details, please refer to JSONBeanSerializationHelper for details of all object types.

Parameters:

type - Class to which JSON Object should be deserialized to

json - Object to be deserialized

Returns:

Java Object for the corresponding object passed in. (This java object is of type 'class' passed in.)

Throws:

Exception

See Also:

JSONDeserializable, PostJSONDeserializable, JSONBeanSerializationHelper, ISO8601DateTimeUtil

toJSON

public static Object toJSON(Object obj)
                     throws Exception

Method used to serialize the passed in Java object to JSON.

Please refer to the following for more advanced ideas:

• JSONSerializable - If the application developer wants to override the functionality of this method, he can implement JSONSerializable and can add his custom serialization code in JSONSerializable.toJSON(). In that case, he bears the complete responsibility for detecting and avoiding cyclic objects as well.
• PostJSONSerializable - If the application developer wants a hook to alter the JSON after the JSON serialization process, he can implement PostJSONSerializable and add his custom code in PostJSONSerializable.modifyJSON(). In that case, he bears the complete responsibility for detecting and avoiding cyclic objects for his code.

The basic deserialize method provide the following out of the box conversions:

• Primitives --> Boxed
• BigDecimal --> Double (If the object value is outside the boundaries of what Double can hold or is a NaN, we throw an IllegalArgumentException)
• BigInteger --> Long (If the object value is outside the boundaries of Long, it flips the sign-bit and returns the corresponding value within the boundary)
• java.util.Date --> ISO8601DateTime (@see ISO8601DateTimeUtil)
• List --> Vector
• null, Map, GenericType, Class Instance Object --> JSONObject
• Arrays --> JSONArray
• NOTE: transient fields will be ignored in the serialization process

For additional details, please refer to JSONBeanSerializationHelper for details of all object types.

Parameters:

obj - Object to be serialized

Returns:

Object

Throws:

Exception

See Also:

JSONSerializable, PostJSONSerializable

getNullJSONObj

public static JSONObject getNullJSONObj()
                                 throws Exception

Method to create and return JSON object representing null object.

Returns:

JSONObject representing null

Throws:

Exception

isObjectNull

public static boolean isObjectNull(Object json)

Utility method to determine if the JSON object is null. Internal Utility Function

removeNullsFromJSON

public static void removeNullsFromJSON(JSONObject jsonObj,
                                       String[] keys)

Normalizes the JSON object by removing the objects which contain null's. Internal Utility Function

replaceNullObjectWithNullLiteral

public static void replaceNullObjectWithNullLiteral(JSONObject root)

An utility method to replace {".null":true} values with JSONObject.NULL literal. The result JSON can have {"key":null}.

MAF treats null objects as special case values, and, represents them with a special JSON object {".null":true}. But sometimes it is required to have null literal in the JSON string for some backend REST services. For example: "some-key":null

By default, adding a null value will create {"some-key":{".null":true}}

This method can be used to convert all {".null":true} into null literals in entire tree of given JSON object.

Example code.

 Map dep = new HashMap();
 dep.put("id", "1");
 dep.put("name", null);

 JSONObject json = (JSONObject) JSONBeanSerializationHelper.toJSON(dep);

 System.out.println(json); // This prints {"id":"1", "name":{".null":true}}
 replaceNullObjectWithNullLiteral(json);
 System.out.println(json); // This prints {"id":"1", "name":null}
 

Parameters:

root - the root JSON object that needs to be normalized.

removeNegativesFromJSON

public static void removeNegativesFromJSON(JSONObject jsonObj,
                                           String[] keys)

Normalizes the JSON object by removing the objects which contain value: -1. Internal Utility Function

removeBooleanFromJSON

public static void removeBooleanFromJSON(JSONObject jsonObj,
                                         boolean bValue,
                                         String[] keys)

Normalizes the JSON object by removing the objects which contain specified boolean value. Internal Utility Function

getIdFromJSONObject

public static int getIdFromJSONObject(JSONObject jsonObj)
                               throws oracle.adfmf.json.JSONException

Gets id from the json object and returns the corresponding int value Internal Utility Function

Throws:

oracle.adfmf.json.JSONException

getBoolean

public static boolean getBoolean(Object object)
                          throws Exception

Used to coerce an object into a boolean if possible.

Parameters:

object - to coerce

Returns:

the coerced value

Throws:

Exception

getByte

public static byte getByte(Object object)

Used to coerce an object into a byte if possible.

Parameters:

object - to coerce

Returns:

the coerced value

Throws:

Exception

getCharacter

public static char getCharacter(Object object)

Used to coerce an object into a char if possible.

Parameters:

object - to coerce

Returns:

the coerced value

Throws:

Exception

getDouble

public static double getDouble(Object object)

Used to coerce an object into a double if possible.

Parameters:

object - to coerce

Returns:

the coerced value

Throws:

Exception

getFloat

public static float getFloat(Object object)

Used to coerce an object into a float if possible.

Parameters:

object - to coerce

Returns:

the coerced value

Throws:

Exception

getInteger

public static int getInteger(Object object)

Used to coerce an object into a int if possible.

Parameters:

object - to coerce

Returns:

the coerced value

Throws:

Exception

getLong

public static long getLong(Object object)

Used to coerce an object into a long if possible.

Parameters:

object - to coerce

Returns:

the coerced value

Throws:

Exception

getShort

public static short getShort(Object object)

Used to coerce an object into a short if possible.

Parameters:

object - to coerce

Returns:

the coerced value

Throws:

Exception

getString

public static String getString(Object object)

Used to coerce an object into a String if possible.

Parameters:

object - to coerce

Returns:

the coerced value

Throws:

Exception