Module java.management

Package javax.management.openmbean

Class ArrayType<T>

java.lang.Object

javax.management.openmbean.OpenType<T>

javax.management.openmbean.ArrayType<T>

Type Parameters:

T - the Java component type that arrays described by this ArrayType must have.

All Implemented Interfaces:

Serializable

public class ArrayType<T>
extends OpenType<T>

The ArrayType class is the open type class whose instances describe all open data values which are n-dimensional arrays of open data values.

Examples of valid ArrayType instances are:

 // 2-dimension array of java.lang.String
 ArrayType<String[][]> a1 = new ArrayType<String[][]>(2, SimpleType.STRING);

 // 1-dimension array of int
 ArrayType<int[]> a2 = new ArrayType<int[]>(SimpleType.INTEGER, true);

 // 1-dimension array of java.lang.Integer
 ArrayType<Integer[]> a3 = new ArrayType<Integer[]>(SimpleType.INTEGER, false);

 // 4-dimension array of int
 ArrayType<int[][][][]> a4 = new ArrayType<int[][][][]>(3, a2);

 // 4-dimension array of java.lang.Integer
 ArrayType<Integer[][][][]> a5 = new ArrayType<Integer[][][][]>(3, a3);

 // 1-dimension array of java.lang.String
 ArrayType<String[]> a6 = new ArrayType<String[]>(SimpleType.STRING, false);

 // 1-dimension array of long
 ArrayType<long[]> a7 = new ArrayType<long[]>(SimpleType.LONG, true);

 // 1-dimension array of java.lang.Integer
 ArrayType<Integer[]> a8 = ArrayType.getArrayType(SimpleType.INTEGER);

 // 2-dimension array of java.lang.Integer
 ArrayType<Integer[][]> a9 = ArrayType.getArrayType(a8);

 // 2-dimension array of int
 ArrayType<int[][]> a10 = ArrayType.getPrimitiveArrayType(int[][].class);

 // 3-dimension array of int
 ArrayType<int[][][]> a11 = ArrayType.getArrayType(a10);

 // 1-dimension array of float
 ArrayType<float[]> a12 = ArrayType.getPrimitiveArrayType(float[].class);

 // 2-dimension array of float
 ArrayType<float[][]> a13 = ArrayType.getArrayType(a12);

 // 1-dimension array of javax.management.ObjectName
 ArrayType<ObjectName[]> a14 = ArrayType.getArrayType(SimpleType.OBJECTNAME);

 // 2-dimension array of javax.management.ObjectName
 ArrayType<ObjectName[][]> a15 = ArrayType.getArrayType(a14);

 // 3-dimension array of java.lang.String
 ArrayType<String[][][]> a16 = new ArrayType<String[][][]>(3, SimpleType.STRING);

 // 1-dimension array of java.lang.String
 ArrayType<String[]> a17 = new ArrayType<String[]>(1, SimpleType.STRING);

 // 2-dimension array of java.lang.String
 ArrayType<String[][]> a18 = new ArrayType<String[][]>(1, a17);

 // 3-dimension array of java.lang.String
 ArrayType<String[][][]> a19 = new ArrayType<String[][][]>(1, a18);
 

Since:

1.5

See Also:

• Serialized Form

Field Summary

Fields declared in class javax.management.openmbean.OpenType

ALLOWED_CLASSNAMES, ALLOWED_CLASSNAMES_LIST

Constructor Summary

Constructors

Constructor	Description
ArrayType(int dimension, OpenType<?> elementType)	Constructs an ArrayType instance describing open data values which are arrays with dimension dimension of elements whose open type is elementType.
ArrayType(SimpleType<?> elementType, boolean primitiveArray)	Constructs a unidimensional ArrayType instance for the supplied SimpleType.

Method Summary

Modifier and Type	Method	Description
boolean	equals(Object obj)	Compares the specified obj parameter with this ArrayType instance for equality.
static <E> ArrayType<E[]>	getArrayType(OpenType<E> elementType)	Create an ArrayType instance in a type-safe manner.
int	getDimension()	Returns the dimension of arrays described by this ArrayType instance.
OpenType<?>	getElementOpenType()	Returns the open type of element values contained in the arrays described by this ArrayType instance.
static <T> ArrayType<T>	getPrimitiveArrayType(Class<T> arrayClass)	Create an ArrayType instance in a type-safe manner.
int	hashCode()	Returns the hash code value for this ArrayType instance.
boolean	isPrimitiveArray()	Returns true if the open data values this open type describes are primitive arrays, false otherwise.
boolean	isValue(Object obj)	Tests whether obj is a value for this ArrayType instance.
String	toString()	Returns a string representation of this ArrayType instance.

Methods declared in class javax.management.openmbean.OpenType

getClassName, getDescription, getTypeName, isArray

Methods declared in class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Details

ArrayType

public ArrayType(int dimension,
 OpenType<?> elementType)
          throws OpenDataException

Constructs an ArrayType instance describing open data values which are arrays with dimension dimension of elements whose open type is elementType.

When invoked on an ArrayType instance, the getClassName method returns the class name of the array instances it describes (following the rules defined by the getName method of java.lang.Class), not the class name of the array elements (which is returned by a call to getElementOpenType().getClassName()).

The internal field corresponding to the type name of this ArrayType instance is also set to the class name of the array instances it describes. In other words, the methods getClassName and getTypeName return the same string value. The internal field corresponding to the description of this ArrayType instance is set to a string value which follows the following template:

• if non-primitive array: <dimension>-dimension array of <element_class_name>
• if primitive array: <dimension>-dimension array of <primitive_type_of_the_element_class_name>

As an example, the following piece of code:

 ArrayType<String[][][]> t = new ArrayType<String[][][]>(3, SimpleType.STRING);
 System.out.println("array class name       = " + t.getClassName());
 System.out.println("element class name     = " + t.getElementOpenType().getClassName());
 System.out.println("array type name        = " + t.getTypeName());
 System.out.println("array type description = " + t.getDescription());
 

would produce the following output:

 array class name       = [[[Ljava.lang.String;
 element class name     = java.lang.String
 array type name        = [[[Ljava.lang.String;
 array type description = 3-dimension array of java.lang.String
 

And the following piece of code which is equivalent to the one listed above would also produce the same output:

 ArrayType<String[]> t1 = new ArrayType<String[]>(1, SimpleType.STRING);
 ArrayType<String[][]> t2 = new ArrayType<String[][]>(1, t1);
 ArrayType<String[][][]> t3 = new ArrayType<String[][][]>(1, t2);
 System.out.println("array class name       = " + t3.getClassName());
 System.out.println("element class name     = " + t3.getElementOpenType().getClassName());
 System.out.println("array type name        = " + t3.getTypeName());
 System.out.println("array type description = " + t3.getDescription());
 

Parameters:

dimension - the dimension of arrays described by this ArrayType instance; must be greater than or equal to 1.

elementType - the open type of element values contained in the arrays described by this ArrayType instance; must be an instance of either SimpleType, CompositeType, TabularType or another ArrayType with a SimpleType, CompositeType or TabularType as its elementType.

Throws:

IllegalArgumentException - if dimension is not a positive integer.

OpenDataException - if elementType's className is not one of the allowed Java class names for open data.

ArrayType

public ArrayType(SimpleType<?> elementType,
 boolean primitiveArray)
          throws OpenDataException

Constructs a unidimensional ArrayType instance for the supplied SimpleType.

This constructor supports the creation of arrays of primitive types when primitiveArray is true.

For primitive arrays the getElementOpenType() method returns the SimpleType corresponding to the wrapper type of the primitive type of the array.

When invoked on an ArrayType instance, the getClassName method returns the class name of the array instances it describes (following the rules defined by the getName method of java.lang.Class), not the class name of the array elements (which is returned by a call to getElementOpenType().getClassName()).

The internal field corresponding to the type name of this ArrayType instance is also set to the class name of the array instances it describes. In other words, the methods getClassName and getTypeName return the same string value. The internal field corresponding to the description of this ArrayType instance is set to a string value which follows the following template:

• if non-primitive array: 1-dimension array of <element_class_name>
• if primitive array: 1-dimension array of <primitive_type_of_the_element_class_name>

As an example, the following piece of code:

 ArrayType<int[]> t = new ArrayType<int[]>(SimpleType.INTEGER, true);
 System.out.println("array class name       = " + t.getClassName());
 System.out.println("element class name     = " + t.getElementOpenType().getClassName());
 System.out.println("array type name        = " + t.getTypeName());
 System.out.println("array type description = " + t.getDescription());
 

would produce the following output:

 array class name       = [I
 element class name     = java.lang.Integer
 array type name        = [I
 array type description = 1-dimension array of int
 

Parameters:

elementType - the SimpleType of the element values contained in the arrays described by this ArrayType instance.

primitiveArray - true when this array describes primitive arrays.

Throws:

IllegalArgumentException - if dimension is not a positive integer.

OpenDataException - if primitiveArray is true and elementType is not a valid SimpleType for a primitive type.

Since:

1.6

Method Details

getDimension

public int getDimension()

Returns the dimension of arrays described by this ArrayType instance.

Returns:

the dimension.

getElementOpenType

public OpenType<?> getElementOpenType()

Returns the open type of element values contained in the arrays described by this ArrayType instance.

Returns:

the element type.

isPrimitiveArray

public boolean isPrimitiveArray()

Returns true if the open data values this open type describes are primitive arrays, false otherwise.

Returns:

true if this is a primitive array type.

Since:

1.6

isValue

public boolean isValue(Object obj)

Tests whether obj is a value for this ArrayType instance.

This method returns true if and only if obj is not null, obj is an array and any one of the following is true:

• if this ArrayType instance describes an array of SimpleType elements or their corresponding primitive types, obj's class name is the same as the className field defined for this ArrayType instance (i.e. the class name returned by the getClassName method, which includes the dimension information),
  
• if this ArrayType instance describes an array of classes implementing the TabularData interface or the CompositeData interface, obj is assignable to such a declared array, and each element contained in {obj is either null or a valid value for the element's open type specified by this ArrayType instance.

Specified by:

isValue in class OpenType<T>

Parameters:

obj - the object to be tested.

Returns:

true if obj is a value for this ArrayType instance.

equals

public boolean equals(Object obj)

Compares the specified obj parameter with this ArrayType instance for equality.

Two ArrayType instances are equal if and only if they describe array instances which have the same dimension, elements' open type and primitive array flag.

Specified by:

equals in class OpenType<T>

Parameters:

obj - the object to be compared for equality with this ArrayType instance; if obj is null or is not an instance of the class ArrayType this method returns false.

Returns:

true if the specified object is equal to this ArrayType instance.

See Also:

• Object.hashCode()
• HashMap

hashCode

public int hashCode()

Returns the hash code value for this ArrayType instance.

The hash code of an ArrayType instance is the sum of the hash codes of all the elements of information used in equals comparisons (i.e. dimension, elements' open type and primitive array flag). The hashcode for a primitive value is the hashcode of the corresponding boxed object (e.g. the hashcode for true is Boolean.TRUE.hashCode()). This ensures that t1.equals(t2) implies that t1.hashCode()==t2.hashCode() for any two ArrayType instances t1 and t2, as required by the general contract of the method Object.hashCode().

As ArrayType instances are immutable, the hash code for this instance is calculated once, on the first call to hashCode, and then the same value is returned for subsequent calls.

Overrides:

hashCode in class Object

Returns:

the hash code value for this ArrayType instance

See Also:

• Object.equals(java.lang.Object)
• System.identityHashCode(java.lang.Object)

toString

public String toString()

Returns a string representation of this ArrayType instance.

The string representation consists of the name of this class (i.e. javax.management.openmbean.ArrayType), the type name, the dimension, the elements' open type and the primitive array flag defined for this instance.

As ArrayType instances are immutable, the string representation for this instance is calculated once, on the first call to toString, and then the same value is returned for subsequent calls.

Specified by:

toString in class OpenType<T>

Returns:

a string representation of this ArrayType instance

getArrayType

public static <E> ArrayType<E[]> getArrayType(OpenType<E> elementType)
                                       throws OpenDataException

Create an ArrayType instance in a type-safe manner.

Multidimensional arrays can be built up by calling this method as many times as necessary.

Calling this method twice with the same parameters may return the same object or two equal but not identical objects.

As an example, the following piece of code:

 ArrayType<String[]> t1 = ArrayType.getArrayType(SimpleType.STRING);
 ArrayType<String[][]> t2 = ArrayType.getArrayType(t1);
 ArrayType<String[][][]> t3 = ArrayType.getArrayType(t2);
 System.out.println("array class name       = " + t3.getClassName());
 System.out.println("element class name     = " + t3.getElementOpenType().getClassName());
 System.out.println("array type name        = " + t3.getTypeName());
 System.out.println("array type description = " + t3.getDescription());
 

would produce the following output:

 array class name       = [[[Ljava.lang.String;
 element class name     = java.lang.String
 array type name        = [[[Ljava.lang.String;
 array type description = 3-dimension array of java.lang.String
 

Type Parameters:

E - the Java type that described instances must have

Parameters:

elementType - the open type of element values contained in the arrays described by this ArrayType instance; must be an instance of either SimpleType, CompositeType, TabularType or another ArrayType with a SimpleType, CompositeType or TabularType as its elementType.

Returns:

an ArrayType instance

Throws:

OpenDataException - if elementType's className is not one of the allowed Java class names for open data.

Since:

1.6

getPrimitiveArrayType

public static <T> ArrayType<T> getPrimitiveArrayType(Class<T> arrayClass)

Create an ArrayType instance in a type-safe manner.

Calling this method twice with the same parameters may return the same object or two equal but not identical objects.

As an example, the following piece of code:

 ArrayType<int[][][]> t = ArrayType.getPrimitiveArrayType(int[][][].class);
 System.out.println("array class name       = " + t.getClassName());
 System.out.println("element class name     = " + t.getElementOpenType().getClassName());
 System.out.println("array type name        = " + t.getTypeName());
 System.out.println("array type description = " + t.getDescription());
 

would produce the following output:

 array class name       = [[[I
 element class name     = java.lang.Integer
 array type name        = [[[I
 array type description = 3-dimension array of int
 

Type Parameters:

T - the Java type that described instances must have

Parameters:

arrayClass - a primitive array class such as int[].class, boolean[][].class, etc. The getElementOpenType() method of the returned ArrayType returns the SimpleType corresponding to the wrapper type of the primitive type of the array.

Returns:

an ArrayType instance

Throws:

IllegalArgumentException - if arrayClass is not a primitive array.

Since:

1.6