Description
The ObjectReader class allows you to examine the properties of an object (property instrospection) and to dynamically read them.
Important points
- In contrast to PropertyReflector which only introspects regular objects, this ObjectReader is also able to handle maps and arrays.
- For maps, properties are key-pairs identified by string keys.
- For arrays, properties are elements identified by integer indexes.
- This class has a symmetric implementation across all languages supported by the Pip.Services toolkit and it is used to support dynamic data processing.
- Because all languages have different casing and case sensitivity rules, this ObjectReader treats all property names as case insensitive.
Static methods
getProperties
Get values of all properties in a specified object and returns them as a map.
The object can be a user defined object, map or array. Returned properties correspondently are object properties, map key-pairs or array elements with their indexes.
public static
Map<String, Object> getProperties(Object obj)
- obj: Object - object to get properties from.
- returns: Map<String, Object> - map, containing the names of the object’s properties and their values.
getProperty
Gets the value of an object’s property specified by its name.
The object can be a user defined object, map or array. The property name correspondently must be an object property, map key or array index.
public static
getProperty(obj: any, name: string): any
- obj: any - object to read property from.
- name: string - name of the property to get.
- returns: any - property value or null if the property doesn’t exist or introspection failed.
getPropertyNames
Gets the names of all the properties implemented in a specified object.
The object can be a user defined object, map or array. Returned property names correspondently are object properties, map keys or array indexes.
public static
ListgetPropertyNames(Object obj)
- obj: Object - object to introspect.
- returns: List
- list with property names.
getValue
Gets an object’s value. If object is a wrapper, it unwraps the value behind it. Otherwise it returns the same object value.
public static
Object getValue(Object obj)
- obj: Object - object to unwrap..
- returns: Object - actual (unwrapped) object value.
hasProperty
Checks if an object has a property with a specified name.
The object can be a user defined object, map or array. The property name correspondently must be an object property, map key or array index.
public static
boolean hasProperty(Object obj, String name)
- obj: Object - object to introspect.
- name: String - name of the property to check.
- returns: boolean - true if the object has the property and false if it doesn’t.
Examples
{
MyObject myObj = new MyObject();
List<String> properties = ObjectReader.getPropertyNames();
ObjectReader.hasProperty(myObj, "myProperty");
Object value = PropertyReflector.getProperty(myObj, "myProperty");
Map<String, Object> myMap = new HashMap<String, Object>(){
{
put("key1", 123);
put("key2", "ABC");
}
};
ObjectReader.hasProperty(myMap, "key1");
Object value = ObjectReader.getProperty(myMap, "key1");
int[] myArray = new int[] {1, 2, 3};
ObjectReader.hasProperty(myArrat, "0");
Object value = ObjectReader.getProperty(myArray, "0");
}