Extension (Apache Ant API)

java.lang.Object
- org.apache.tools.ant.taskdefs.optional.extension.Extension

```
public final class Extension
extends java.lang.Object
```
Utility class that represents either an available "Optional Package" (formerly known as "Standard Extension") as described in the manifest of a JAR file, or the requirement for such an optional package.

For more information about optional packages, see the document Optional Package Versioning in the documentation bundle for your Java2 Standard Edition package, in file guide/extensions/versioning.html.

Field Summary

Fields
Modifier and Type	Field and Description
`static Compatibility`	`COMPATIBLE` Enum indicating that extension is compatible with other extension.
`static java.util.jar.Attributes.Name`	`EXTENSION_LIST` Manifest Attribute Name object for EXTENSION_LIST.
`static java.util.jar.Attributes.Name`	`EXTENSION_NAME` Manifest Attribute Name object for EXTENSION_NAME.
`static java.util.jar.Attributes.Name`	`IMPLEMENTATION_URL` Manifest Attribute Name object for IMPLEMENTATION_URL.
`static java.util.jar.Attributes.Name`	`IMPLEMENTATION_VENDOR` Manifest Attribute Name object for IMPLEMENTATION_VENDOR.
`static java.util.jar.Attributes.Name`	`IMPLEMENTATION_VENDOR_ID` Manifest Attribute Name object for IMPLEMENTATION_VENDOR_ID.
`static java.util.jar.Attributes.Name`	`IMPLEMENTATION_VERSION` Manifest Attribute Name object for IMPLEMENTATION_VERSION.
`static Compatibility`	`INCOMPATIBLE` Enum indicating that extension is incompatible with other extension in ways other than other enums indicate).
`static java.util.jar.Attributes.Name`	`OPTIONAL_EXTENSION_LIST` `Name` object for `Optional-Extension-List` manifest attribute used for declaring optional dependencies on installed extensions.
`static Compatibility`	`REQUIRE_IMPLEMENTATION_UPGRADE` Enum indicating that extension requires an upgrade of implementation to be compatible with other extension.
`static Compatibility`	`REQUIRE_SPECIFICATION_UPGRADE` Enum indicating that extension requires an upgrade of specification to be compatible with other extension.
`static Compatibility`	`REQUIRE_VENDOR_SWITCH` Enum indicating that extension requires a vendor switch to be compatible with other extension.
`static java.util.jar.Attributes.Name`	`SPECIFICATION_VENDOR` Manifest Attribute Name object for SPECIFICATION_VENDOR.
`static java.util.jar.Attributes.Name`	`SPECIFICATION_VERSION` Manifest Attribute Name object for SPECIFICATION_VERSION.

Constructor Summary

Constructors
Constructor and Description
`Extension(java.lang.String extensionName, java.lang.String specificationVersion, java.lang.String specificationVendor, java.lang.String implementationVersion, java.lang.String implementationVendor, java.lang.String implementationVendorId, java.lang.String implementationURL)` The constructor to create Extension object.

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`static void`	`addExtension(Extension extension, java.util.jar.Attributes attributes)` Add Extension to the specified manifest Attributes.
`static void`	`addExtension(Extension extension, java.lang.String prefix, java.util.jar.Attributes attributes)` Add Extension to the specified manifest Attributes.
`static Extension[]`	`getAvailable(java.util.jar.Manifest manifest)` Return an array of `Extension` objects representing optional packages that are available in the JAR file associated with the specified `Manifest`.
`Compatibility`	`getCompatibilityWith(Extension required)` Return a Compatibility enum indicating the relationship of this `Extension` with the specified `Extension`.
`java.lang.String`	`getExtensionName()` Get the name of the extension.
`java.lang.String`	`getImplementationURL()` Get the url of the extensions implementation.
`java.lang.String`	`getImplementationVendor()` Get the vendor of the extensions implementation.
`java.lang.String`	`getImplementationVendorID()` Get the vendorID of the extensions implementation.
`DeweyDecimal`	`getImplementationVersion()` Get the version of the extensions implementation.
`static Extension[]`	`getOptions(java.util.jar.Manifest manifest)` Return the set of `Extension` objects representing "Optional Packages" that the application declares they will use if present.
`static Extension[]`	`getRequired(java.util.jar.Manifest manifest)` Return the set of `Extension` objects representing optional packages that are required by the application contained in the JAR file associated with the specified `Manifest`.
`java.lang.String`	`getSpecificationVendor()` Get the vendor of the extensions specification.
`DeweyDecimal`	`getSpecificationVersion()` Get the version of the extensions specification.
`boolean`	`isCompatibleWith(Extension required)` Return `true` if the specified `Extension` (which represents an optional package required by an application) is satisfied by this `Extension` (which represents an optional package that is already installed.
`java.lang.String`	`toString()` Return a String representation of this object.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

- Field Detail
  - EXTENSION_LIST
```
public static final java.util.jar.Attributes.Name EXTENSION_LIST
```
    Manifest Attribute Name object for EXTENSION_LIST.
  - OPTIONAL_EXTENSION_LIST
```
public static final java.util.jar.Attributes.Name OPTIONAL_EXTENSION_LIST
```
    Name object for Optional-Extension-List manifest attribute used for declaring optional dependencies on installed extensions. Note that the dependencies declared by this method are not required for the library to operate but if present will be used. It is NOT part of the official "Optional Package" specification.
    
    See Also:
    
    Installed extension dependency
  - EXTENSION_NAME
```
public static final java.util.jar.Attributes.Name EXTENSION_NAME
```
    Manifest Attribute Name object for EXTENSION_NAME.
  - SPECIFICATION_VERSION
```
public static final java.util.jar.Attributes.Name SPECIFICATION_VERSION
```
    Manifest Attribute Name object for SPECIFICATION_VERSION.
  - SPECIFICATION_VENDOR
```
public static final java.util.jar.Attributes.Name SPECIFICATION_VENDOR
```
    Manifest Attribute Name object for SPECIFICATION_VENDOR.
  - IMPLEMENTATION_VERSION
```
public static final java.util.jar.Attributes.Name IMPLEMENTATION_VERSION
```
    Manifest Attribute Name object for IMPLEMENTATION_VERSION.
  - IMPLEMENTATION_VENDOR
```
public static final java.util.jar.Attributes.Name IMPLEMENTATION_VENDOR
```
    Manifest Attribute Name object for IMPLEMENTATION_VENDOR.
  - IMPLEMENTATION_URL
```
public static final java.util.jar.Attributes.Name IMPLEMENTATION_URL
```
    Manifest Attribute Name object for IMPLEMENTATION_URL.
  - IMPLEMENTATION_VENDOR_ID
```
public static final java.util.jar.Attributes.Name IMPLEMENTATION_VENDOR_ID
```
    Manifest Attribute Name object for IMPLEMENTATION_VENDOR_ID.
  - COMPATIBLE
```
public static final Compatibility COMPATIBLE
```
    Enum indicating that extension is compatible with other extension.
  - REQUIRE_SPECIFICATION_UPGRADE
```
public static final Compatibility REQUIRE_SPECIFICATION_UPGRADE
```
    Enum indicating that extension requires an upgrade of specification to be compatible with other extension.
  - REQUIRE_VENDOR_SWITCH
```
public static final Compatibility REQUIRE_VENDOR_SWITCH
```
    Enum indicating that extension requires a vendor switch to be compatible with other extension.
  - REQUIRE_IMPLEMENTATION_UPGRADE
```
public static final Compatibility REQUIRE_IMPLEMENTATION_UPGRADE
```
    Enum indicating that extension requires an upgrade of implementation to be compatible with other extension.
  - INCOMPATIBLE
```
public static final Compatibility INCOMPATIBLE
```
    Enum indicating that extension is incompatible with other extension in ways other than other enums indicate). For example the other extension may have a different ID.
- Constructor Detail
  - Extension
```
public Extension(java.lang.String extensionName,
                 java.lang.String specificationVersion,
                 java.lang.String specificationVendor,
                 java.lang.String implementationVersion,
                 java.lang.String implementationVendor,
                 java.lang.String implementationVendorId,
                 java.lang.String implementationURL)
```
    The constructor to create Extension object. Note that every component is allowed to be specified but only the extensionName is mandatory.
    
    Parameters:
    
    extensionName - the name of extension.
    
    specificationVersion - the specification Version of extension.
    
    specificationVendor - the specification Vendor of extension.
    
    implementationVersion - the implementation Version of extension.
    
    implementationVendor - the implementation Vendor of extension.
    
    implementationVendorId - the implementation VendorId of extension.
    
    implementationURL - the implementation URL of extension.
- Method Detail
  - getAvailable
```
public static Extension[] getAvailable(java.util.jar.Manifest manifest)
```
    Return an array of Extension objects representing optional packages that are available in the JAR file associated with the specified Manifest. If there are no such optional packages, a zero-length array is returned.
    
    Parameters:
    
    manifest - Manifest to be parsed
    
    Returns:
    
    the "available" extensions in specified manifest
  - getRequired
```
public static Extension[] getRequired(java.util.jar.Manifest manifest)
```
    Return the set of Extension objects representing optional packages that are required by the application contained in the JAR file associated with the specified Manifest. If there are no such optional packages, a zero-length list is returned.
    
    Parameters:
    
    manifest - Manifest to be parsed
    
    Returns:
    
    the dependencies that are specified in manifest
  - getOptions
```
public static Extension[] getOptions(java.util.jar.Manifest manifest)
```
    Return the set of Extension objects representing "Optional Packages" that the application declares they will use if present. If there are no such optional packages, a zero-length list is returned.
    
    Parameters:
    
    manifest - Manifest to be parsed
    
    Returns:
    
    the optional dependencies that are specified in manifest
  - addExtension
```
public static void addExtension(Extension extension,
                                java.util.jar.Attributes attributes)
```
    Add Extension to the specified manifest Attributes.
    
    Parameters:
    
    attributes - the attributes of manifest to add to
    
    extension - the extension
  - addExtension
```
public static void addExtension(Extension extension,
                                java.lang.String prefix,
                                java.util.jar.Attributes attributes)
```
    Add Extension to the specified manifest Attributes. Use the specified prefix so that dependencies can added with a prefix such as "java3d-" etc.
    
    Parameters:
    
    attributes - the attributes of manifest to add to
    
    extension - the extension
    
    prefix - the name to prefix to extension
  - getExtensionName
```
public java.lang.String getExtensionName()
```
    Get the name of the extension.
    
    Returns:
    
    the name of the extension
  - getSpecificationVendor
```
public java.lang.String getSpecificationVendor()
```
    Get the vendor of the extensions specification.
    
    Returns:
    
    the vendor of the extensions specification.
  - getSpecificationVersion
```
public DeweyDecimal getSpecificationVersion()
```
    Get the version of the extensions specification.
    
    Returns:
    
    the version of the extensions specification.
  - getImplementationURL
```
public java.lang.String getImplementationURL()
```
    Get the url of the extensions implementation.
    
    Returns:
    
    the url of the extensions implementation.
  - getImplementationVendor
```
public java.lang.String getImplementationVendor()
```
    Get the vendor of the extensions implementation.
    
    Returns:
    
    the vendor of the extensions implementation.
  - getImplementationVendorID
```
public java.lang.String getImplementationVendorID()
```
    Get the vendorID of the extensions implementation.
    
    Returns:
    
    the vendorID of the extensions implementation.
  - getImplementationVersion
```
public DeweyDecimal getImplementationVersion()
```
    Get the version of the extensions implementation.
    
    Returns:
    
    the version of the extensions implementation.
  - getCompatibilityWith
```
public Compatibility getCompatibilityWith(Extension required)
```
    Return a Compatibility enum indicating the relationship of this Extension with the specified Extension.
    
    Parameters:
    
    required - Description of the required optional package
    
    Returns:
    
    the enum indicating the compatibility (or lack thereof) of specified extension
  - isCompatibleWith
```
public boolean isCompatibleWith(Extension required)
```
    Return true if the specified Extension (which represents an optional package required by an application) is satisfied by this Extension (which represents an optional package that is already installed. Otherwise, return false.
    
    Parameters:
    
    required - Description of the required optional package
    
    Returns:
    
    true if the specified extension is compatible with this extension
  - toString
```
public java.lang.String toString()
```
    Return a String representation of this object.
    
    Overrides:
    
    toString in class java.lang.Object
    
    Returns:
    
    string representation of object.

Class Extension

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

EXTENSION_LIST

OPTIONAL_EXTENSION_LIST

EXTENSION_NAME

SPECIFICATION_VERSION

SPECIFICATION_VENDOR

IMPLEMENTATION_VERSION

IMPLEMENTATION_VENDOR

IMPLEMENTATION_URL

IMPLEMENTATION_VENDOR_ID

COMPATIBLE

REQUIRE_SPECIFICATION_UPGRADE

REQUIRE_VENDOR_SWITCH

REQUIRE_IMPLEMENTATION_UPGRADE

INCOMPATIBLE

Constructor Detail

Extension

Method Detail

getAvailable

getRequired

getOptions

addExtension

addExtension

getExtensionName

getSpecificationVendor

getSpecificationVersion

getImplementationURL

getImplementationVendor

getImplementationVendorID

getImplementationVersion

getCompatibilityWith

isCompatibleWith

toString