public interface JsArray extends JsObject
An array object can be passed between Java and JavaScript as a method argument or a return value. The object lifetime is bound to the lifetime of the frame this object belongs to. When the owner frame is unloaded, all the JavaScript objects are automatically disposed.
An attempt to access a disposed JavaScript object will result in
IllegalStateException
.
Modifier and Type | Method and Description |
---|---|
<T> T |
get(long index)
Returns the element by the specified
index . |
long |
length()
Returns the number of elements in this array.
|
boolean |
set(long index,
java.lang.Object element)
Inserts the specified
element into the array at the specified index . |
java.util.List<java.lang.Object> |
toList()
Converts this array to a
List . |
<T> java.util.List<T> |
toList(java.lang.Class<T> type)
Converts this array to a
List with the elements of the specified type . |
call, close, frame, hasProperty, ownPropertyNames, property, propertyNames, putProperty, removeProperty
boolean set(long index, @Nullable java.lang.Object element)
element
into the array at the specified index
.
If there is an existing element at the specified index
, it will be replaced.
If the index
exceeds the array size, the array will be extended and the elements
between the last inserted item and the index
will be set to undefined
.
The type mapping rules are the following:
| Java | JavaScript |
|--------------------|-------------------------------|
| Double | Number |
| String | String |
| Boolean | Boolean |
| null | null |
| JsObject | Object |
| Node | Node |
| List<?> | Array or Proxy Object |
| Set<?> | Set or Proxy Object |
| Map<?,?> | Map or Proxy Object |
| byte[] | ArrayBuffer |
| Object | Proxy Object |
If you pass a non-primitive Java object to JavaScript, it will be converted into a
"proxy" JavaScript object. Method and property calls to this object will be delegated to
the Java object. For security reasons, JavaScript can access only those methods and fields
of the injected Java object that are explicitly marked as accessible either using the
JsAccessible
annotation or via the JsAccessibleTypes
class.
Java collections that are not made accessible to JavaScript using the JsAccessible
annotation or via the JsAccessibleTypes
class are converted to JavaScript
collections. The content of the converted collection is a deep copy of the Java collection.
Modifications of the converted collection in JavaScript do not affect the collection in Java.
Java collections that are made accessible to JavaScript using the JsAccessible
annotation or via the JsAccessibleTypes
class are wrapped into a JavaScript proxy
object. Such proxy objects can be used to modify the collection in Java.
index
- the index in the array to insert the element. Cannot be negative or exceed the
maximum array size (232-1)element
- the element to inserttrue
if the element is successfully inserted, false
otherwisejava.lang.IllegalArgumentException
- if the element
is negative or exceeds the maximum array size
(232-1)java.lang.IllegalArgumentException
- when element
is a JsObject
from a different
web page or a frameObjectClosedException
- when the JavaScript object is already disposed or invalid@Nullable <T> T get(long index)
index
.
The type mapping rules are the following:
| JavaScript | Java | |--------------------|----------------| | Number | Double | | String | String | | Boolean | Boolean | | null and undefined | null | | Node | JsObject, Node | | ArrayBuffer | JsArrayBuffer | | Array | JsArray | | Set | JsSet | | Map | JsMap | | Object | JsObject | | Proxy Object | Object |
For proxy objects, the corresponding injected Java object is returned.
T
- the result type according to the type mapping rulesindex
- the element's indexindex
java.lang.IllegalArgumentException
- when index
is negative or exceeds the array sizeObjectClosedException
- when the JavaScript object is already disposed or invalidlong length()
The maximum size of an array in JavaScript equals to 232-1
ObjectClosedException
- when the JavaScript object is already disposed or invalidjava.util.List<java.lang.Object> toList()
List
.
The type mapping rules for the array elements are the following:
| JavaScript | Java |
|--------------------|----------------|
| Number | Double |
| String | String |
| Boolean | Boolean |
| null and undefined | null |
| Node | Node, JsObject |
| ArrayBuffer | byte[] |
| Array | List<?> |
| Set | Set<?> |
| Map | Map<?,?> |
| Object | JsObject |
| Proxy Object | Object |
Proxy objects are mapped to the corresponding injected Java object.
ObjectClosedException
- when the JavaScript object is already disposed or invalid<T> java.util.List<T> toList(java.lang.Class<T> type)
List
with the elements of the specified type
.
The type mapping rules for the array elements are the following:
| JavaScript | Java |
|--------------------|----------------|
| Number | Double |
| String | String |
| Boolean | Boolean |
| null and undefined | null |
| Node | Node, JsObject |
| ArrayBuffer | byte[] |
| Array | List<?> |
| Set | Set<?> |
| Map | Map<?,?> |
| Object | JsObject |
| Proxy Object | Object |
Proxy objects are mapped to the corresponding injected Java object.
All elements in the array must be of a type convertible to the type T
according to the mapping rules.
T
- the type of the converted elementstype
- the Java type to convert elements in this array to, according to the mapping rulesjava.lang.IllegalArgumentException
- if the elements in this array cannot be converted to the specified type
ObjectClosedException
- when the JavaScript object is already disposed or invalid