Package org.apache.juneau.http.header

Class ETag

java.lang.Object

org.apache.juneau.http.header.BasicHeader

org.apache.juneau.http.header.BasicEntityTagHeader

org.apache.juneau.http.header.ETag

All Implemented Interfaces:

Serializable, Cloneable, Header, NameValuePair

@Header("ETag")
public class ETag
extends BasicEntityTagHeader

Represents a parsed ETag HTTP response header.

An identifier for a specific version of a resource, often a message digest.

Example

ETag: "737060cd8c284d8af7ad3082f209582d"

RFC2616 Specification

The ETag response-header field provides the current value of the entity tag for the requested variant. The headers used with entity tags are described in sections 14.24, 14.26 and 14.44. The entity tag MAY be used for comparison with other entities from the same resource (see section 13.3.3).

ETag = "ETag" ":" entity-tag

Examples:

ETag: "xyzzy" ETag: W/"xyzzy" ETag: ""

See Also:

• juneau-rest-common
• Hypertext Transfer Protocol -- HTTP/1.1

Constructor Summary

Constructors

Constructor	Description
ETag(String value)	Constructor.
ETag(Supplier<EntityTag> value)	Constructor with delayed value.
ETag(EntityTag value)	Constructor.

Method Summary

Modifier and Type	Method	Description
static ETag	of(String value)	Static creator.
static ETag	of(Supplier<EntityTag> value)	Static creator with delayed value.
static ETag	of(EntityTag value)	Static creator.

Methods inherited from class org.apache.juneau.http.header.BasicEntityTagHeader

asEntityTag, getValue, of, of, of, orElse, toEntityTag

Methods inherited from class org.apache.juneau.http.header.BasicHeader

assertName, assertStringValue, asString, equals, equalsIgnoreCase, get, getElements, getName, hashCode, isNotEmpty, isPresent, of, of, orElse, toString

Methods inherited from class java.lang.Object

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

Constructor Details

ETag

public ETag(String value)

Constructor.

Parameters:

value - The header value.
Must be an entity tag value (e.g. "\"xyzzy\"").
Can be null.

ETag

public ETag(EntityTag value)

Constructor.

Parameters:

value - The header value.
Can be null.

ETag

public ETag(Supplier<EntityTag> value)

Constructor with delayed value.

Header value is re-evaluated on each call to BasicEntityTagHeader.getValue().

Parameters:

value - The supplier of the header value.
Can be null.

Method Details

of

public static ETag of(String value)

Static creator.

Parameters:

value - The header value.
Must be an entity tag value (e.g. "\"xyzzy\"").
Can be null.

Returns:

A new header bean, or null if the value is null.

of

public static ETag of(EntityTag value)

Static creator.

Parameters:

value - The header value.
Can be null.

Returns:

A new header bean, or null if the value is null.

of

public static ETag of(Supplier<EntityTag> value)

Static creator with delayed value.

Header value is re-evaluated on each call to BasicEntityTagHeader.getValue().

Parameters:

value - The supplier of the header value.
Can be null.

Returns:

A new header bean, or null if the value is null.