JavaObject
The type
of a wrapped Java object accessed from within JavaScript
code.
|
Core object
|
|
|
Implemented in
|
JavaScript 1.1, NES 2.0
|
Created by
Any Java
method which returns an object type. In addition, you can explicitly
construct a JavaObject using the
object's Java constructor with the Packages keyword:
new
Packages.JavaClass(parameterList)
where
JavaClass is the fully-specified name of the object's Java
class.
Parameters
|
parameterList
|
An
optional list of parameters, specified by the constructor in the
Java class.
|
Description
The
JavaObject
object is an instance of a Java class that is created in or passed to
JavaScript. JavaObject is a wrapper
for the instance; all references to the class instance are made through
the JavaObject.
Any Java
data brought into JavaScript is converted to JavaScript data types.
When the JavaObject is passed back
to Java, it is unwrapped and can be used by Java code. See the
Core
JavaScript Guide for more information about data type
conversions.
Property Summary
Inherits
public data members from the Java class of which it is an instance as
properties. It also inherits public data members from any superclass as
properties.
Method Summary
Inherits
public methods from the Java class of which it is an instance. The
JavaObject
also inherits methods from java.lang.Object and any
other superclass.
Examples
Example
1. Instantiating a Java object in JavaScript.
The
following code creates the JavaObject
theString,
which is an instance of the class java.lang.String:
var
theString = new Packages.java.lang.String("Hello, world")
Because
the String
class is in the java package, you can
also use the java synonym and omit the
Packages
keyword when you instantiate the class:
var
theString = new java.lang.String("Hello, world")
Example
2. Accessing methods of a Java object.
Because
the JavaObject
theString is
an instance of java.lang.String, it
inherits all the public methods of java.lang.String. The
following example uses the startsWith method to
check whether theString begins with
"Hello".
var
theString = new java.lang.String("Hello, world")
theString.startsWith("Hello") // returns true
Example
3. Accessing inherited methods.
Because
getClass is a
method of Object, and
java.lang.String
extends Object, the
String
class inherits the getClass method.
Consequently, getClass is also a
method of the JavaObject which
instantiates String in
JavaScript.
var
theString = new java.lang.String("Hello, world")
theString.getClass() // returns java.lang.String
See also
JavaArray,
JavaClass, JavaPackage, Packages
