Package org.mozilla.javascript

Class NativeJavaClass

java.lang.Object
org.mozilla.javascript.NativeJavaObject
org.mozilla.javascript.NativeJavaClass
All Implemented Interfaces:
Serializable, Callable, Constructable, Function, Scriptable, SymbolScriptable, Wrapper
public class NativeJavaClass extends NativeJavaObject implements Function
This class reflects Java classes into the JavaScript environment, mainly for constructors and static members. We lazily reflect properties, and currently do not guarantee that a single j.l.Class is only reflected once into the JS environment, although we should. The only known case where multiple reflections are possible occurs when a j.l.Class is wrapped as part of a method return or property access, rather than by walking the Packages/java tree.
Author:
Mike Shaver
See Also:

  • Constructor Details

    • NativeJavaClass

      public NativeJavaClass()

    • NativeJavaClass

      public NativeJavaClass(Scriptable scope, Class<?> cl)

    • NativeJavaClass

      public NativeJavaClass(Scriptable scope, Class<?> cl, boolean isAdapter)

  • Method Details

    • initMembers

      protected void initMembers()
      Overrides:
      initMembers in class NativeJavaObject

    • getClassName

      public String getClassName()
      Description copied from interface: Scriptable
      Get the name of the set of objects implemented by this Java class. This corresponds to the [[Class]] operation in ECMA and is used by Object.prototype.toString() in ECMA.

      See ECMA 8.6.2 and 15.2.4.2.

      Specified by:
      getClassName in interface Scriptable
      Overrides:
      getClassName in class NativeJavaObject

    • has

      public boolean has(String name, Scriptable start)
      Description copied from interface: Scriptable
      Indicates whether or not a named property is defined in an object.

      Does not traverse the prototype chain.

      The property is specified by a String name as defined for the get method.

      Specified by:
      has in interface Scriptable
      Overrides:
      has in class NativeJavaObject
      Parameters:
      name - the name of the property
      start - the object in which the lookup began
      Returns:
      true if and only if the named property is found in the object
      See Also:

    • get

      public Object get(String name, Scriptable start)
      Description copied from interface: Scriptable
      Get a named property from the object.

      Looks property up in this object and returns the associated value if found. Returns NOT_FOUND if not found. Note that this method is not expected to traverse the prototype chain. This is different from the ECMA [[Get]] operation.

      Depending on the property selector, the runtime will call this method or the form of get that takes an integer:

      Code examples
      JavaScript codeJava code
      a.b a.get("b", a)
      a["foo"] a.get("foo", a)
      a[3] a.get(3, a)
      a["3"] a.get(3, a)
      a[3.0] a.get(3, a)
      a["3.0"] a.get("3.0", a)
      a[1.1] a.get("1.1", a)
      a[-4] a.get(-4, a)

      The values that may be returned are limited to the following:

      • java.lang.Boolean objects
      • java.lang.String objects
      • java.lang.Number objects
      • org.mozilla.javascript.Scriptable objects
      • null
      • The value returned by Context.getUndefinedValue()
      • NOT_FOUND
      Specified by:
      get in interface Scriptable
      Overrides:
      get in class NativeJavaObject
      Parameters:
      name - the name of the property
      start - the object in which the lookup began
      Returns:
      the value of the property (may be null), or NOT_FOUND
      See Also:

    • put

      public void put(String name, Scriptable start, Object value)
      Description copied from interface: Scriptable
      Sets a named property in this object.

      The property is specified by a string name as defined for get.

      The possible values that may be passed in are as defined for get. A class that implements this method may choose to ignore calls to set certain properties, in which case those properties are effectively read-only.

      For properties defined in a prototype chain, use putProperty in ScriptableObject.

      Note that if a property a is defined in the prototype p of an object o, then evaluating o.a = 23 will cause set to be called on the prototype p with o as the start parameter. To preserve JavaScript semantics, it is the Scriptable object's responsibility to modify o.

      This design allows properties to be defined in prototypes and implemented in terms of getters and setters of Java values without consuming slots in each instance.

      The values that may be set are limited to the following:

      • java.lang.Boolean objects
      • java.lang.String objects
      • java.lang.Number objects
      • org.mozilla.javascript.Scriptable objects
      • null
      • The value returned by Context.getUndefinedValue()

      Arbitrary Java objects may be wrapped in a Scriptable by first calling Context.toObject. This allows the property of a JavaScript object to contain an arbitrary Java object as a value.

      Note that has will be called by the runtime first before set is called to determine in which object the property is defined. Note that this method is not expected to traverse the prototype chain, which is different from the ECMA [[Put]] operation.

      Specified by:
      put in interface Scriptable
      Overrides:
      put in class NativeJavaObject
      Parameters:
      name - the name of the property
      start - the object whose property is being set
      value - value to set the property to
      See Also:

    • getIds

      public Object[] getIds()
      Description copied from interface: Scriptable
      Get an array of property ids.

      Not all property ids need be returned. Those properties whose ids are not returned are considered non-enumerable.

      Specified by:
      getIds in interface Scriptable
      Overrides:
      getIds in class NativeJavaObject
      Returns:
      an array of Objects. Each entry in the array is either a java.lang.String or a java.lang.Number

    • getClassObject

      public Class<?> getClassObject()

    • getDefaultValue

      public Object getDefaultValue(Class<?> hint)
      Description copied from interface: Scriptable
      Get the default value of the object with a given hint. The hints are String.class for type String, Number.class for type Number, Scriptable.class for type Object, and Boolean.class for type Boolean.

      A hint of null means "no hint".

      See ECMA 8.6.2.6.

      Specified by:
      getDefaultValue in interface Scriptable
      Overrides:
      getDefaultValue in class NativeJavaObject
      Parameters:
      hint - the type hint
      Returns:
      the default value

    • call

      public Object call(Context cx, Scriptable scope, Scriptable thisObj, Object[] args)
      Description copied from interface: Function
      Call the function.

      Note that the array of arguments is not guaranteed to have length greater than 0.

      Specified by:
      call in interface Callable
      Specified by:
      call in interface Function
      Parameters:
      cx - the current Context for this thread
      scope - the scope to execute the function relative to. This is set to the value returned by getParentScope() except when the function is called from a closure.
      thisObj - the JavaScript this object
      args - the array of arguments
      Returns:
      the result of the call

    • construct

      public Scriptable construct(Context cx, Scriptable scope, Object[] args)
      Description copied from interface: Function
      Call the function as a constructor.

      This method is invoked by the runtime in order to satisfy a use of the JavaScript new operator. This method is expected to create a new object and return it.

      Specified by:
      construct in interface Constructable
      Specified by:
      construct in interface Function
      Parameters:
      cx - the current Context for this thread
      scope - an enclosing scope of the caller except when the function is called from a closure.
      args - the array of arguments
      Returns:
      the allocated object

    • toString

      public String toString()
      Overrides:
      toString in class Object

    • hasInstance

      public boolean hasInstance(Scriptable value)
      Determines if prototype is a wrapped Java object and performs a Java "instanceof". Exception: if value is an instance of NativeJavaClass, it isn't considered an instance of the Java class; this forestalls any name conflicts between java.lang.Class's methods and the static methods exposed by a JavaNativeClass.
      Specified by:
      hasInstance in interface Scriptable
      Overrides:
      hasInstance in class NativeJavaObject
      Parameters:
      value - The value that appeared on the LHS of the instanceof operator
      Returns:
      an implementation dependent value

    • equals

      public boolean equals(Object obj)
      Overrides:
      equals in class NativeJavaObject

    • hashCode

      public int hashCode()
      Overrides:
      hashCode in class NativeJavaObject