Serializable
, Cloneable
, Descriptor
public class DescriptorSupport extends Object implements Descriptor
A descriptor consists of a collection of fields. Each field is in fieldname=fieldvalue format. Field names are not case sensitive, case will be preserved on field values.
All field names and values are not predefined. New fields can be defined and added by any program. Some fields have been predefined for consistency of implementation and support by the ModelMBeanInfo, ModelMBeanAttributeInfo, ModelMBeanConstructorInfo, ModelMBeanNotificationInfo, ModelMBeanOperationInfo and ModelMBean classes.
The serialVersionUID of this class is -6292969195866300415L
.
Constructor | Description |
---|---|
DescriptorSupport() |
Descriptor default constructor. |
DescriptorSupport |
Descriptor constructor. |
DescriptorSupport |
Descriptor constructor taking an XML String. |
DescriptorSupport |
Constructor taking fields in the fieldName=fieldValue format. |
DescriptorSupport |
Constructor taking field names and field values. |
DescriptorSupport |
Descriptor constructor taking a Descriptor as parameter. |
Modifier and Type | Method | Description |
---|---|---|
Object |
clone() |
Returns a new Descriptor which is a duplicate of the Descriptor. |
boolean |
equals |
Compares this descriptor to the given object. |
String[] |
getFieldNames() |
Returns all the field names in the descriptor. |
String[] |
getFields() |
Returns all of the fields contained in this descriptor as a string array. |
Object |
getFieldValue |
Returns the value for a specific field name, or null if no value is present for that name. |
Object[] |
getFieldValues |
Returns all the field values in the descriptor as an array of Objects. |
int |
hashCode() |
Returns the hash code value for this descriptor. |
boolean |
isValid() |
Returns true if all of the fields have legal values given their names. |
void |
removeField |
Removes a field from the descriptor. |
void |
setField |
Sets the value for a specific field name. |
void |
setFields |
Sets all fields in the field names array to the new value with the same index in the field values array. |
String |
toString() |
Returns a human readable string representing the descriptor. |
String |
toXMLString() |
Returns an XML String representing the descriptor. |
public DescriptorSupport()
isValid
returns false
)public DescriptorSupport(int initNumFields) throws MBeanException, RuntimeOperationsException
isValid
returns false
).initNumFields
- The initial capacity of the Map that stores the descriptor fields.RuntimeOperationsException
- for illegal value for initNumFields (<= 0)MBeanException
- Wraps a distributed communication Exception.public DescriptorSupport(DescriptorSupport inDescr)
inDescr
- the descriptor to be used to initialize the constructed descriptor. If it is null or contains no descriptor fields, an empty Descriptor will be created.public DescriptorSupport(String inStr) throws MBeanException, RuntimeOperationsException, XMLParseException
Descriptor constructor taking an XML String.
The format of the XML string is not defined, but an implementation must ensure that the string returned by toXMLString()
on an existing descriptor can be used to instantiate an equivalent descriptor using this constructor.
In this implementation, all field values will be created as Strings. If the field values are not Strings, the programmer will have to reset or convert these fields correctly.
inStr
- An XML-formatted string used to populate this Descriptor. The format is not defined, but any implementation must ensure that the string returned by method toXMLString
on an existing descriptor can be used to instantiate an equivalent descriptor when instantiated using this constructor.RuntimeOperationsException
- If the String inStr passed in parameter is nullXMLParseException
- XML parsing problem while parsing the input StringMBeanException
- Wraps a distributed communication Exception.public DescriptorSupport(String[] fieldNames, Object[] fieldValues) throws RuntimeOperationsException
fieldNames
- String array of field names. No elements of this array can be null.fieldValues
- Object array of the corresponding field values. Elements of the array can be null. The fieldValue
must be valid for the fieldName
(as defined in method isValid
) Note: array sizes of parameters should match. If both arrays are empty, then an empty descriptor is created.
RuntimeOperationsException
- for illegal value for field Names or field Values. The array lengths must be equal. If the descriptor construction fails for any reason, this exception will be thrown.public DescriptorSupport(String... fields)
fields
- String array with each element containing a field name and value. If this array is null or empty, then the default constructor will be executed. Null strings or empty strings will be ignored. All field values should be Strings. If the field values are not Strings, the programmer will have to reset or convert these fields correctly.
Note: Each string should be of the form fieldName=fieldValue. The field name ends at the first =
character; for example if the String is a=b=c
then the field name is a
and its value is b=c
.
RuntimeOperationsException
- for illegal value for field Names or field Values. The field must contain an "=". "=fieldValue", "fieldName", and "fieldValue" are illegal. FieldName cannot be null. "fieldName=" will cause the value to be null. If the descriptor construction fails for any reason, this exception will be thrown.public Object getFieldValue(String fieldName) throws RuntimeOperationsException
Descriptor
getFieldValue
in interface Descriptor
fieldName
- the field name.RuntimeOperationsException
- if the field name is illegal.public void setField(String fieldName, Object fieldValue) throws RuntimeOperationsException
Descriptor
Sets the value for a specific field name. This will modify an existing field or add a new field.
The field value will be validated before it is set. If it is not valid, then an exception will be thrown. The meaning of validity is dependent on the descriptor implementation.
setField
in interface Descriptor
fieldName
- The field name to be set. Cannot be null or empty.fieldValue
- The field value to be set for the field name. Can be null if that is a valid value for the field.RuntimeOperationsException
- if the field name or field value is illegal (wrapped exception is IllegalArgumentException
); or if the descriptor is immutable (wrapped exception is UnsupportedOperationException
).public String[] getFields()
Descriptor
getFields
in interface Descriptor
public String[] getFieldNames()
Descriptor
getFieldNames
in interface Descriptor
public Object[] getFieldValues(String... fieldNames)
Descriptor
fieldNames
String array parameter.getFieldValues
in interface Descriptor
fieldNames
- String array of the names of the fields that the values should be returned for. If the array is empty then an empty array will be returned. If the array is null then all values will be returned, as if the parameter were the array returned by Descriptor.getFieldNames()
. If a field name in the array does not exist, including the case where it is null or the empty string, then null is returned for the matching array element being returned.fieldNames
is empty, you will get an empty array.public void setFields(String[] fieldNames, Object[] fieldValues) throws RuntimeOperationsException
Descriptor
Sets all fields in the field names array to the new value with the same index in the field values array. Array sizes must match.
The field value will be validated before it is set. If it is not valid, then an exception will be thrown. If the arrays are empty, then no change will take effect.
setFields
in interface Descriptor
fieldNames
- String array of field names. The array and array elements cannot be null.fieldValues
- Object array of the corresponding field values. The array cannot be null. Elements of the array can be null.RuntimeOperationsException
- if the change fails for any reason. Wrapped exception is IllegalArgumentException
if fieldNames
or fieldValues
is null, or if the arrays are of different lengths, or if there is an illegal value in one of them. Wrapped exception is UnsupportedOperationException
if the descriptor is immutable, and the call would change its contents.public Object clone() throws RuntimeOperationsException
clone
in interface Descriptor
clone
in class Object
RuntimeOperationsException
- for illegal value for field Names or field Values. If the descriptor construction fails for any reason, this exception will be thrown.public void removeField(String fieldName)
Descriptor
removeField
in interface Descriptor
fieldName
- String name of the field to be removed. If the field name is illegal or the field is not found, no exception is thrown.public boolean equals(Object o)
Arrays.deepEquals
must return true.Object.equals(Object)
must return true.equals
in interface Descriptor
equals
in class Object
o
- the object to compare with.true
if the objects are the same; false
otherwise.public int hashCode()
Returns the hash code value for this descriptor. The hash code is computed as the sum of the hash codes for each field in the descriptor. The hash code of a field with name n
and value v
is n.toLowerCase().hashCode() ^ h
. Here h
is the hash code of v
, computed as follows:
v
is null then h
is 0.v
is a primitive array then h
is computed using the appropriate overloading of java.util.Arrays.hashCode
.v
is an object array then h
is computed using Arrays.deepHashCode
.h
is v.hashCode()
.hashCode
in interface Descriptor
hashCode
in class Object
public boolean isValid() throws RuntimeOperationsException
This implementation does not support interoperating with a directory or lookup service. Thus, conforming to the specification, no checking is done on the "export" field.
Otherwise this implementation returns false if:
isValid
in interface Descriptor
RuntimeOperationsException
- If the validity checking fails for any reason, this exception will be thrown.public String toXMLString()
Returns an XML String representing the descriptor.
The format is not defined, but an implementation must ensure that the string returned by this method can be used to build an equivalent descriptor when instantiated using the constructor DescriptorSupport(String inStr)
.
Fields which are not String objects will have toString() called on them to create the value. The value will be enclosed in parentheses. It is not guaranteed that you can reconstruct these objects unless they have been specifically set up to support toString() in a meaningful format and have a matching constructor that accepts a String in the same format.
If the descriptor is empty the following String is returned: <Descriptor></Descriptor>
RuntimeOperationsException
- for illegal value for field Names or field Values. If the XML formatted string construction fails for any reason, this exception will be thrown.public String toString()
toString
in class Object
RuntimeOperationsException
- for illegal value for field Names or field Values. If the descriptor string fails for any reason, this exception will be thrown.
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Documentation extracted from Debian's OpenJDK Development Kit package.
Licensed under the GNU General Public License, version 2, with the Classpath Exception.
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https://docs.oracle.com/en/java/javase/21/docs/api/java.management/javax/management/modelmbean/DescriptorSupport.html