Headers (commons-httpclient 1.4.1 API)

java.lang.Object
- net.lenni0451.commons.httpclient.constants.Headers

public class Headers
extends java.lang.Object

Field Summary

Fields
Modifier and Type	Field and Description
`static java.lang.String`	`ACCEPT` Informs the server about the mime types of data that can be sent back.
`static java.lang.String`	`ACCEPT_CH` Servers can advertise support for Client Hints using the `Accept-CH` header field or an equivalent HTML `<meta>` element with http-equiv attribute.
`static java.lang.String`	`ACCEPT_ENCODING` The encoding algorithm, usually a compression algorithm, that can be used on the resource sent back.
`static java.lang.String`	`ACCEPT_LANGUAGE` Informs the server about the human language the server is expected to send back.
`static java.lang.String`	`ACCEPT_PUSH_POLICY` A client can express the desired push policy for a request by sending an Accept-Push-Policy header field in the request.
`static java.lang.String`	`ACCEPT_RANGES` Indicates if the server supports range requests, and if so in which unit the range can be expressed.
`static java.lang.String`	`ACCEPT_SIGNATURE` A client can send the Accept-Signature header field to indicate intention to take advantage of any available signatures and to indicate what kinds of signatures it supports.
`static java.lang.String`	`ACCESS_CONTROL_ALLOW_CREDENTIALS` Indicates whether the response to the request can be exposed when the credentials flag is true.
`static java.lang.String`	`ACCESS_CONTROL_ALLOW_HEADERS` Used in response to a preflight request to indicate which HTTP headers can be used when making the actual request.
`static java.lang.String`	`ACCESS_CONTROL_ALLOW_METHODS` Specifies the methods allowed when accessing the resource in response to a preflight request.
`static java.lang.String`	`ACCESS_CONTROL_ALLOW_ORIGIN` Indicates whether the response can be shared.
`static java.lang.String`	`ACCESS_CONTROL_EXPOSE_HEADERS` Indicates which headers can be exposed as part of the response by listing their names.
`static java.lang.String`	`ACCESS_CONTROL_MAX_AGE` Indicates how long the results of a preflight request can be cached.
`static java.lang.String`	`ACCESS_CONTROL_REQUEST_HEADERS` Used when issuing a preflight request to let the server know which HTTP headers will be used when the actual request is made.
`static java.lang.String`	`ACCESS_CONTROL_REQUEST_METHOD` Used when issuing a preflight request to let the server know which HTTP method will be used when the actual request is made.
`static java.lang.String`	`AGE` The time, in seconds, that the object has been in a proxy cache.
`static java.lang.String`	`ALLOW` Lists the set of HTTP request methods supported by a resource.
`static java.lang.String`	`ALT_SVC` Used to list alternate ways to reach this service.
`static java.lang.String`	`ALT_USED` Used to identify the alternative service in use.
`static java.lang.String`	`AUTHORIZATION` Contains the credentials to authenticate a user-agent with a server.
`static java.lang.String`	`CACHE_CONTROL` Directives for caching mechanisms in both requests and responses.
`static java.lang.String`	`CLEAR_SITE_DATA` Clears browsing data (e.g. cookies, storage, cache) associated with the requesting website.
`static java.lang.String`	`CONNECTION` Controls whether the network connection stays open after the current transaction finishes.
`static java.lang.String`	`CONTENT_DISPOSITION` Indicates if the resource transmitted should be displayed inline (default behavior without the header), or if it should be handled like a download and the browser should present a "Save As" dialog.
`static java.lang.String`	`CONTENT_ENCODING` Used to specify the compression algorithm.
`static java.lang.String`	`CONTENT_LANGUAGE` Describes the human language(s) intended for the audience, so that it allows a user to differentiate according to the users' own preferred language.
`static java.lang.String`	`CONTENT_LENGTH` The size of the resource, in decimal number of bytes.
`static java.lang.String`	`CONTENT_LOCATION` Indicates an alternate location for the returned data.
`static java.lang.String`	`CONTENT_RANGE` Indicates where in a full body message a partial message belongs.
`static java.lang.String`	`CONTENT_SECURITY_POLICY` Controls resources the user agent is allowed to load for a given page.
`static java.lang.String`	`CONTENT_SECURITY_POLICY_REPORT_ONLY` Allows web developers to experiment with policies by monitoring, but not enforcing, their effects.
`static java.lang.String`	`CONTENT_TYPE` Indicates the media type of the resource.
`static java.lang.String`	`COOKIE` Contains stored HTTP cookies previously sent by the server with the `SET_COOKIE` header.
`static java.lang.String`	`CRITICAL_CH` Servers use `Critical-CH` along with `ACCEPT_CH` to specify that accepted client hints are also critical client hints.
`static java.lang.String`	`CROSS_ORIGIN_EMBEDDER_POLICY` Allows a server to declare an embedder policy for a given document.
`static java.lang.String`	`CROSS_ORIGIN_OPENER_POLICY` Prevents other domains from opening/controlling a window.
`static java.lang.String`	`CROSS_ORIGIN_RESOURCE_POLICY` Prevents other domains from reading the response of the resources to which this header is applied.
`static java.lang.String`	`DATE` Contains the date and time at which the message was originated.
`static java.lang.String`	`DEVICE_MEMORY` Approximate amount of available client RAM memory.
`static java.lang.String`	`DOWNLINK` Approximate bandwidth of the client's connection to the server, in Mbps.
`static java.lang.String`	`EARLY_DATA` Indicates that the request has been conveyed in TLS early data.
`static java.lang.String`	`ECT` The `effective connection type` ("network profile") that best matches the connection's latency and bandwidth.
`static java.lang.String`	`ETAG` A unique string identifying the version of the resource.
`static java.lang.String`	`EXPECT` Indicates expectations that need to be fulfilled by the server to properly handle the request.
`static java.lang.String`	`EXPIRES` The date/time after which the response is considered stale.
`static java.lang.String`	`FORWARDED` Contains information from the client-facing side of proxy servers that is altered or lost when a proxy is involved in the path of the request.
`static java.lang.String`	`FROM` Contains an Internet email address for a human user who controls the requesting user agent.
`static java.lang.String`	`HOST` Specifies the domain name of the server (for virtual hosting), and (optionally) the TCP port number on which the server is listening.
`static java.lang.String`	`IF_MATCH` Makes the request conditional, and applies the method only if the stored resource matches one of the given ETags.
`static java.lang.String`	`IF_MODIFIED_SINCE` Makes the request conditional, and expects the resource to be transmitted only if it has been modified after the given date.
`static java.lang.String`	`IF_NONE_MATCH` Makes the request conditional, and applies the method only if the stored resource doesn't match any of the given ETags.
`static java.lang.String`	`IF_RANGE` Creates a conditional range request that is only fulfilled if the given etag or date matches the remote resource.
`static java.lang.String`	`IF_UNMODIFIED_SINCE` Makes the request conditional, and expects the resource to be transmitted only if it has not been modified after the given date.
`static java.lang.String`	`KEEP_ALIVE` Controls how long a persistent connection should stay open.
`static java.lang.String`	`LAST_MODIFIED` The last modification date of the resource, used to compare several versions of the same resource.
`static java.lang.String`	`LINK` This entity-header field provides a means for serializing one or more links in HTTP headers.
`static java.lang.String`	`LOCATION` Indicates the URL to redirect a page to.
`static java.lang.String`	`MAX_FORWARDS` When using https://developer.mozilla.org/en-US/docs/Web/HTTP/Methods/TRACE, indicates the maximum number of hops the request can do before being reflected to the sender.
`static java.lang.String`	`NEL` Defines a mechanism that enables developers to declare a network error reporting policy.
`static java.lang.String`	`ORIGIN` Indicates where a fetch originates from.
`static java.lang.String`	`ORIGIN_ISOLATION` Provides a mechanism to allow web applications to isolate their origins.
`static java.lang.String`	`PERMISSIONS_POLICY` Provides a mechanism to allow and deny the use of browser features in a website's own frame, and in `iframe`s that it embeds.
`static java.lang.String`	`PRAGMA` Implementation-specific header that may have various effects anywhere along the request-response chain.
`static java.lang.String`	`PROXY_AUTHENTICATE` Defines the authentication method that should be used to access a resource behind a proxy server.
`static java.lang.String`	`PROXY_AUTHORIZATION` Contains the credentials to authenticate a user agent with a proxy server.
`static java.lang.String`	`PUSH_POLICY` A Push-Policy defines the server behavior regarding push when processing a request.
`static java.lang.String`	`RANGE` Indicates the part of a document that the server should return.
`static java.lang.String`	`REFERER` The address of the previous web page from which a link to the currently requested page was followed.
`static java.lang.String`	`REFERRER_POLICY` Governs which referrer information sent in the `REFERER` header should be included with requests made.
`static java.lang.String`	`REFRESH` Directs the browser to reload the page or redirect to another.
`static java.lang.String`	`REPORT_TO` Used to specify a server endpoint for the browser to send warning and error reports to.
`static java.lang.String`	`RETRY_AFTER` Indicates how long the user agent should wait before making a follow-up request.
`static java.lang.String`	`RTT` Application layer round trip time (RTT) in milliseconds, which includes the server processing time.
`static java.lang.String`	`SAVE_DATA` A string `on` that indicates the user agent's preference for reduced data usage.
`static java.lang.String`	`SEC_CH_UA` User agent's branding and version.
`static java.lang.String`	`SEC_CH_UA_ARCH` User agent's underlying platform architecture.
`static java.lang.String`	`SEC_CH_UA_BITNESS` User agent's underlying CPU architecture bitness (for example "64" bit).
`static java.lang.String`	`SEC_CH_UA_FULL_VERSION_LIST` Full version for each brand in the user agent's brand list.
`static java.lang.String`	`SEC_CH_UA_MOBILE` User agent is running on a mobile device or, more generally, prefers a "mobile" user experience.
`static java.lang.String`	`SEC_CH_UA_MODEL` User agent's device model.
`static java.lang.String`	`SEC_CH_UA_PLATFORM` User agent's underlying operation system/platform.
`static java.lang.String`	`SEC_CH_UA_PLATFORM_VERSION` User agent's underlying operation system version.
`static java.lang.String`	`SEC_CH_UA_PREFERS_COLOR_SCHEME` User's preference of dark or light color scheme.
`static java.lang.String`	`SEC_CH_UA_PREFERS_REDUCED_MOTION` User's preference to see fewer animations and content layout shifts.
`static java.lang.String`	`SEC_FETCH_DEST` Indicates the request's destination.
`static java.lang.String`	`SEC_FETCH_MODE` Indicates the request's mode to a server.
`static java.lang.String`	`SEC_FETCH_SITE` Indicates the relationship between a request initiator's origin and its target's origin.
`static java.lang.String`	`SEC_FETCH_USER` Indicates whether or not a navigation request was triggered by user activation.
`static java.lang.String`	`SEC_GPC` Indicates whether the user consents to a website or service selling or sharing their personal information with third parties.
`static java.lang.String`	`SEC_PURPOSE` Indicates the purpose of the request, when the purpose is something other than immediate use by the user-agent.
`static java.lang.String`	`SERVER` Contains information about the software used by the origin server to handle the request.
`static java.lang.String`	`SERVER_TIMING` Communicates one or more metrics and descriptions for the given request-response cycle.
`static java.lang.String`	`SERVICE_WORKER_ALLOWED` Used to remove the path restriction by including this header in the response of the Service Worker script.
`static java.lang.String`	`SERVICE_WORKER_NAVIGATION_PRELOAD` A request header sent in preemptive request to `fetch()` a resource during service worker boot.
`static java.lang.String`	`SET_COOKIE` Send cookies from the server to the user-agent.
`static java.lang.String`	`SIGNATURE` The Signature header field conveys a list of signatures for an exchange, each one accompanied by information about how to determine the authority of and refresh that signature.
`static java.lang.String`	`SIGNED_HEADERS` The Signed-Headers header field identifies an ordered list of response header fields to include in a signature.
`static java.lang.String`	`SOURCEMAP` Links generated code to a source map.
`static java.lang.String`	`STRICT_TRANSPORT_SECURITY` Force communication using HTTPS instead of HTTP.
`static java.lang.String`	`SUPPORTS_LOADING_MODE` Set by a navigation target to opt-in to using various higher-risk loading modes.
`static java.lang.String`	`TE` Specifies the transfer encodings the user agent is willing to accept.
`static java.lang.String`	`TIMING_ALLOW_ORIGIN` Specifies origins that are allowed to see values of attributes retrieved via features of the Resource Timing API, which would otherwise be reported as zero due to cross-origin restrictions.
`static java.lang.String`	`TRAILER` Allows the sender to include additional fields at the end of chunked message.
`static java.lang.String`	`TRANSFER_ENCODING` Specifies the form of encoding used to safely transfer the resource to the user.
`static java.lang.String`	`UPGRADE` This HTTP/1.1 (only) header can be used to upgrade an already established client/server connection to a different protocol (over the same transport protocol).
`static java.lang.String`	`UPGRADE_INSECURE_REQUESTS` Sends a signal to the server expressing the client's preference for an encrypted and authenticated response, and that it can successfully handle the `upgrade-insecure-requests` directive.
`static java.lang.String`	`USER_AGENT` Contains a characteristic string that allows the network protocol peers to identify the application type, operating system, software vendor or software version of the requesting software user agent.
`static java.lang.String`	`VARY` Determines how to match request headers to decide whether a cached response can be used rather than requesting a fresh one from the origin server.
`static java.lang.String`	`VIA` Added by proxies, both forward and reverse proxies, and can appear in the request headers and the response headers.
`static java.lang.String`	`WARNING` General warning information about possible problems.
`static java.lang.String`	`WWW_AUTHENTICATE` Defines the authentication method that should be used to access a resource.
`static java.lang.String`	`X_CONTENT_TYPE_OPTIONS` Disables MIME sniffing and forces browser to use the type given in `CONTENT_TYPE`.
`static java.lang.String`	`X_DNS_PREFETCH_CONTROL` Controls DNS prefetching, a feature by which browsers proactively perform domain name resolution on both links that the user may choose to follow as well as URLs for items referenced by the document, including images, CSS, JavaScript, and so forth.
`static java.lang.String`	`X_FORWARDED_FOR` Identifies the originating IP addresses of a client connecting to a web server through an HTTP proxy or a load balancer.
`static java.lang.String`	`X_FORWARDED_HOST` Identifies the original host requested that a client used to connect to your proxy or load balancer.
`static java.lang.String`	`X_FORWARDED_PROTO` Identifies the protocol (HTTP or HTTPS) that a client used to connect to your proxy or load balancer.
`static java.lang.String`	`X_FRAME_OPTIONS` Indicates whether a browser should be allowed to render a page in a `frame`, `iframe`, `embed` or `object`.
`static java.lang.String`	`X_PERMITTED_CROSS_DOMAIN_POLICIES` Specifies if a cross-domain policy file (`crossdomain.xml`) is allowed.
`static java.lang.String`	`X_POWERED_BY` May be set by hosting environments or other frameworks and contains information about them while not providing any usefulness to the application or its visitors.
`static java.lang.String`	`X_ROBOTS_TAG` The X-Robots-Tag HTTP header is used to indicate how a web page is to be indexed within public search engine results.
`static java.lang.String`	`X_XSS_PROTECTION` Enables cross-site scripting filtering.

Constructor Summary

Constructors
Constructor and Description

Headers()

Constructors
Constructor and Description
`Headers()`

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

- Field Detail
  - WWW_AUTHENTICATE
```
public static final java.lang.String WWW_AUTHENTICATE
```
    Defines the authentication method that should be used to access a resource.
    
    See Also:
    
    Constant Field Values
  - AUTHORIZATION
```
public static final java.lang.String AUTHORIZATION
```
    Contains the credentials to authenticate a user-agent with a server.
    
    See Also:
    
    Constant Field Values
  - PROXY_AUTHENTICATE
```
public static final java.lang.String PROXY_AUTHENTICATE
```
    Defines the authentication method that should be used to access a resource behind a proxy server.
    
    See Also:
    
    Constant Field Values
  - PROXY_AUTHORIZATION
```
public static final java.lang.String PROXY_AUTHORIZATION
```
    Contains the credentials to authenticate a user agent with a proxy server.
    
    See Also:
    
    Constant Field Values
  - AGE
```
public static final java.lang.String AGE
```
    The time, in seconds, that the object has been in a proxy cache.
    
    See Also:
    
    Constant Field Values
  - CACHE_CONTROL
```
public static final java.lang.String CACHE_CONTROL
```
    Directives for caching mechanisms in both requests and responses.
    
    See Also:
    
    Constant Field Values
  - CLEAR_SITE_DATA
```
public static final java.lang.String CLEAR_SITE_DATA
```
    Clears browsing data (e.g. cookies, storage, cache) associated with the requesting website.
    
    See Also:
    
    Constant Field Values
  - EXPIRES
```
public static final java.lang.String EXPIRES
```
    The date/time after which the response is considered stale.
    
    See Also:
    
    Constant Field Values
  - LAST_MODIFIED
```
public static final java.lang.String LAST_MODIFIED
```
    The last modification date of the resource, used to compare several versions of the same resource. It is less accurate than ETAG, but easier to calculate in some environments.
    Conditional requests using IF_MODIFIED_SINCE and IF_UNMODIFIED_SINCE use this value to change the behavior of the request.
    
    See Also:
    
    Constant Field Values
  - ETAG
```
public static final java.lang.String ETAG
```
    A unique string identifying the version of the resource. Conditional requests using IF_MATCH and IF_NONE_MATCH use this value to change the behavior of the request.
    
    See Also:
    
    Constant Field Values
  - IF_MATCH
```
public static final java.lang.String IF_MATCH
```
    Makes the request conditional, and applies the method only if the stored resource matches one of the given ETags.
    
    See Also:
    
    Constant Field Values
  - IF_NONE_MATCH
```
public static final java.lang.String IF_NONE_MATCH
```
    Makes the request conditional, and applies the method only if the stored resource doesn't match any of the given ETags.
    This is used to update caches (for safe requests), or to prevent uploading a new resource when one already exists.
    
    See Also:
    
    Constant Field Values
  - IF_MODIFIED_SINCE
```
public static final java.lang.String IF_MODIFIED_SINCE
```
    Makes the request conditional, and expects the resource to be transmitted only if it has been modified after the given date.
    This is used to transmit data only when the cache is out of date.
    
    See Also:
    
    Constant Field Values
  - IF_UNMODIFIED_SINCE
```
public static final java.lang.String IF_UNMODIFIED_SINCE
```
    Makes the request conditional, and expects the resource to be transmitted only if it has not been modified after the given date.
    This ensures the coherence of a new fragment of a specific range with previous ones, or to implement an optimistic concurrency control system when modifying existing documents.
    
    See Also:
    
    Constant Field Values
  - VARY
```
public static final java.lang.String VARY
```
    Determines how to match request headers to decide whether a cached response can be used rather than requesting a fresh one from the origin server.
    
    See Also:
    
    Constant Field Values
  - CONNECTION
```
public static final java.lang.String CONNECTION
```
    Controls whether the network connection stays open after the current transaction finishes.
    
    See Also:
    
    Constant Field Values
  - KEEP_ALIVE
```
public static final java.lang.String KEEP_ALIVE
```
    Controls how long a persistent connection should stay open.
    
    See Also:
    
    Constant Field Values
  - ACCEPT
```
public static final java.lang.String ACCEPT
```
    Informs the server about the mime types of data that can be sent back.
    
    See Also:
    
    Constant Field Values
  - ACCEPT_ENCODING
```
public static final java.lang.String ACCEPT_ENCODING
```
    The encoding algorithm, usually a compression algorithm, that can be used on the resource sent back.
    
    See Also:
    
    Constant Field Values
  - ACCEPT_LANGUAGE
```
public static final java.lang.String ACCEPT_LANGUAGE
```
    Informs the server about the human language the server is expected to send back. This is a hint and is not necessarily under the full control of the user: the server should always pay attention not to override an explicit user choice (like selecting a language from a dropdown).
    
    See Also:
    
    Constant Field Values
  - EXPECT
```
public static final java.lang.String EXPECT
```
    Indicates expectations that need to be fulfilled by the server to properly handle the request.
    
    See Also:
    
    Constant Field Values
  - MAX_FORWARDS
```
public static final java.lang.String MAX_FORWARDS
```
    When using https://developer.mozilla.org/en-US/docs/Web/HTTP/Methods/TRACE, indicates the maximum number of hops the request can do before being reflected to the sender.
    
    See Also:
    
    Constant Field Values
  - COOKIE
```
public static final java.lang.String COOKIE
```
    Contains stored HTTP cookies previously sent by the server with the SET_COOKIE header.
    
    See Also:
    
    Constant Field Values
  - SET_COOKIE
```
public static final java.lang.String SET_COOKIE
```
    Send cookies from the server to the user-agent.
    
    See Also:
    
    Constant Field Values
  - ACCESS_CONTROL_ALLOW_CREDENTIALS
```
public static final java.lang.String ACCESS_CONTROL_ALLOW_CREDENTIALS
```
    Indicates whether the response to the request can be exposed when the credentials flag is true.
    
    See Also:
    
    Constant Field Values
  - ACCESS_CONTROL_ALLOW_HEADERS
```
public static final java.lang.String ACCESS_CONTROL_ALLOW_HEADERS
```
    Used in response to a preflight request to indicate which HTTP headers can be used when making the actual request.
    
    See Also:
    
    Constant Field Values
  - ACCESS_CONTROL_ALLOW_METHODS
```
public static final java.lang.String ACCESS_CONTROL_ALLOW_METHODS
```
    Specifies the methods allowed when accessing the resource in response to a preflight request.
    
    See Also:
    
    Constant Field Values
  - ACCESS_CONTROL_ALLOW_ORIGIN
```
public static final java.lang.String ACCESS_CONTROL_ALLOW_ORIGIN
```
    Indicates whether the response can be shared.
    
    See Also:
    
    Constant Field Values
  - ACCESS_CONTROL_EXPOSE_HEADERS
```
public static final java.lang.String ACCESS_CONTROL_EXPOSE_HEADERS
```
    Indicates which headers can be exposed as part of the response by listing their names.
    
    See Also:
    
    Constant Field Values
  - ACCESS_CONTROL_MAX_AGE
```
public static final java.lang.String ACCESS_CONTROL_MAX_AGE
```
    Indicates how long the results of a preflight request can be cached.
    
    See Also:
    
    Constant Field Values
  - ACCESS_CONTROL_REQUEST_HEADERS
```
public static final java.lang.String ACCESS_CONTROL_REQUEST_HEADERS
```
    Used when issuing a preflight request to let the server know which HTTP headers will be used when the actual request is made.
    
    See Also:
    
    Constant Field Values
  - ACCESS_CONTROL_REQUEST_METHOD
```
public static final java.lang.String ACCESS_CONTROL_REQUEST_METHOD
```
    Used when issuing a preflight request to let the server know which HTTP method will be used when the actual request is made.
    
    See Also:
    
    Constant Field Values
  - ORIGIN
```
public static final java.lang.String ORIGIN
```
    Indicates where a fetch originates from.
    
    See Also:
    
    Constant Field Values
  - TIMING_ALLOW_ORIGIN
```
public static final java.lang.String TIMING_ALLOW_ORIGIN
```
    Specifies origins that are allowed to see values of attributes retrieved via features of the Resource Timing API, which would otherwise be reported as zero due to cross-origin restrictions.
    
    See Also:
    
    Constant Field Values
  - CONTENT_DISPOSITION
```
public static final java.lang.String CONTENT_DISPOSITION
```
    Indicates if the resource transmitted should be displayed inline (default behavior without the header), or if it should be handled like a download and the browser should present a "Save As" dialog.
    
    See Also:
    
    Constant Field Values
  - CONTENT_LENGTH
```
public static final java.lang.String CONTENT_LENGTH
```
    The size of the resource, in decimal number of bytes.
    
    See Also:
    
    Constant Field Values
  - CONTENT_TYPE
```
public static final java.lang.String CONTENT_TYPE
```
    Indicates the media type of the resource.
    
    See Also:
    
    Constant Field Values
  - CONTENT_ENCODING
```
public static final java.lang.String CONTENT_ENCODING
```
    Used to specify the compression algorithm.
    
    See Also:
    
    Constant Field Values
  - CONTENT_LANGUAGE
```
public static final java.lang.String CONTENT_LANGUAGE
```
    Describes the human language(s) intended for the audience, so that it allows a user to differentiate according to the users' own preferred language.
    
    See Also:
    
    Constant Field Values
  - CONTENT_LOCATION
```
public static final java.lang.String CONTENT_LOCATION
```
    Indicates an alternate location for the returned data.
    
    See Also:
    
    Constant Field Values
  - FORWARDED
```
public static final java.lang.String FORWARDED
```
    Contains information from the client-facing side of proxy servers that is altered or lost when a proxy is involved in the path of the request.
    
    See Also:
    
    Constant Field Values
  - VIA
```
public static final java.lang.String VIA
```
    Added by proxies, both forward and reverse proxies, and can appear in the request headers and the response headers.
    
    See Also:
    
    Constant Field Values
  - LOCATION
```
public static final java.lang.String LOCATION
```
    Indicates the URL to redirect a page to.
    
    See Also:
    
    Constant Field Values
  - REFRESH
```
public static final java.lang.String REFRESH
```
    Directs the browser to reload the page or redirect to another. Takes the same value as the `meta` element with refresh.
    
    See Also:
    
    Constant Field Values
  - FROM
```
public static final java.lang.String FROM
```
    Contains an Internet email address for a human user who controls the requesting user agent.
    
    See Also:
    
    Constant Field Values
  - HOST
```
public static final java.lang.String HOST
```
    Specifies the domain name of the server (for virtual hosting), and (optionally) the TCP port number on which the server is listening.
    
    See Also:
    
    Constant Field Values
  - REFERER
```
public static final java.lang.String REFERER
```
    The address of the previous web page from which a link to the currently requested page was followed.
    
    See Also:
    
    Constant Field Values
  - REFERRER_POLICY
```
public static final java.lang.String REFERRER_POLICY
```
    Governs which referrer information sent in the REFERER header should be included with requests made.
    
    See Also:
    
    Constant Field Values
  - USER_AGENT
```
public static final java.lang.String USER_AGENT
```
    Contains a characteristic string that allows the network protocol peers to identify the application type, operating system, software vendor or software version of the requesting software user agent.
    
    See Also:
    
    Constant Field Values
  - ALLOW
```
public static final java.lang.String ALLOW
```
    Lists the set of HTTP request methods supported by a resource.
    
    See Also:
    
    Constant Field Values
  - SERVER
```
public static final java.lang.String SERVER
```
    Contains information about the software used by the origin server to handle the request.
    
    See Also:
    
    Constant Field Values
  - ACCEPT_RANGES
```
public static final java.lang.String ACCEPT_RANGES
```
    Indicates if the server supports range requests, and if so in which unit the range can be expressed.
    
    See Also:
    
    Constant Field Values
  - RANGE
```
public static final java.lang.String RANGE
```
    Indicates the part of a document that the server should return.
    
    See Also:
    
    Constant Field Values
  - IF_RANGE
```
public static final java.lang.String IF_RANGE
```
    Creates a conditional range request that is only fulfilled if the given etag or date matches the remote resource. Used to prevent downloading two ranges from incompatible version of the resource.
    
    See Also:
    
    Constant Field Values
  - CONTENT_RANGE
```
public static final java.lang.String CONTENT_RANGE
```
    Indicates where in a full body message a partial message belongs.
    
    See Also:
    
    Constant Field Values
  - CROSS_ORIGIN_EMBEDDER_POLICY
```
public static final java.lang.String CROSS_ORIGIN_EMBEDDER_POLICY
```
    Allows a server to declare an embedder policy for a given document.
    
    See Also:
    
    Constant Field Values
  - CROSS_ORIGIN_OPENER_POLICY
```
public static final java.lang.String CROSS_ORIGIN_OPENER_POLICY
```
    Prevents other domains from opening/controlling a window.
    
    See Also:
    
    Constant Field Values
  - CROSS_ORIGIN_RESOURCE_POLICY
```
public static final java.lang.String CROSS_ORIGIN_RESOURCE_POLICY
```
    Prevents other domains from reading the response of the resources to which this header is applied.
    
    See Also:
    
    CORP explainer article, Constant Field Values
  - CONTENT_SECURITY_POLICY
```
public static final java.lang.String CONTENT_SECURITY_POLICY
```
    Controls resources the user agent is allowed to load for a given page.
    
    See Also:
    
    Constant Field Values
  - CONTENT_SECURITY_POLICY_REPORT_ONLY
```
public static final java.lang.String CONTENT_SECURITY_POLICY_REPORT_ONLY
```
    Allows web developers to experiment with policies by monitoring, but not enforcing, their effects. These violation reports consist of JSON documents sent via an HTTP POST request to the specified URI.
    
    See Also:
    
    Constant Field Values
  - PERMISSIONS_POLICY
```
public static final java.lang.String PERMISSIONS_POLICY
```
    Provides a mechanism to allow and deny the use of browser features in a website's own frame, and in iframes that it embeds.
    
    See Also:
    
    Constant Field Values
  - STRICT_TRANSPORT_SECURITY
```
public static final java.lang.String STRICT_TRANSPORT_SECURITY
```
    Force communication using HTTPS instead of HTTP.
    
    See Also:
    
    Constant Field Values
  - UPGRADE_INSECURE_REQUESTS
```
public static final java.lang.String UPGRADE_INSECURE_REQUESTS
```
    Sends a signal to the server expressing the client's preference for an encrypted and authenticated response, and that it can successfully handle the upgrade-insecure-requests directive.
    
    See Also:
    
    Constant Field Values
  - X_CONTENT_TYPE_OPTIONS
```
public static final java.lang.String X_CONTENT_TYPE_OPTIONS
```
    Disables MIME sniffing and forces browser to use the type given in CONTENT_TYPE.
    
    See Also:
    
    Constant Field Values
  - X_FRAME_OPTIONS
```
public static final java.lang.String X_FRAME_OPTIONS
```
    Indicates whether a browser should be allowed to render a page in a frame, iframe, embed or object.
    
    See Also:
    
    Constant Field Values
  - X_PERMITTED_CROSS_DOMAIN_POLICIES
```
public static final java.lang.String X_PERMITTED_CROSS_DOMAIN_POLICIES
```
    Specifies if a cross-domain policy file (crossdomain.xml) is allowed.
    The file may define a policy to grant clients, such as Adobe's Flash Player (now obsolete), Adobe Acrobat, Microsoft Silverlight (now obsolete), or Apache Flex, permission to handle data across domains that would otherwise be restricted due to the Same-Origin Policy.
    
    See Also:
    
    Constant Field Values
  - X_POWERED_BY
```
public static final java.lang.String X_POWERED_BY
```
    May be set by hosting environments or other frameworks and contains information about them while not providing any usefulness to the application or its visitors.
    Unset this header to avoid exposing potential vulnerabilities.
    
    See Also:
    
    Constant Field Values
  - X_XSS_PROTECTION
```
public static final java.lang.String X_XSS_PROTECTION
```
    Enables cross-site scripting filtering.
    
    See Also:
    
    Constant Field Values
  - SEC_FETCH_SITE
```
public static final java.lang.String SEC_FETCH_SITE
```
    Indicates the relationship between a request initiator's origin and its target's origin. It is a Structured Header whose value is a token with possible values cross-site, same-origin, same-site, and none.
    
    See Also:
    
    Constant Field Values
  - SEC_FETCH_MODE
```
public static final java.lang.String SEC_FETCH_MODE
```
    Indicates the request's mode to a server. It is a Structured Header whose value is a token with possible values cors, navigate, no-cors, same-origin, and websocket.
    
    See Also:
    
    Constant Field Values
  - SEC_FETCH_USER
```
public static final java.lang.String SEC_FETCH_USER
```
    Indicates whether or not a navigation request was triggered by user activation. It is a Structured Header whose value is a boolean so possible values are ?0 for false and ?1 for true.
    
    See Also:
    
    Constant Field Values
  - SEC_FETCH_DEST
```
public static final java.lang.String SEC_FETCH_DEST
```
    Indicates the request's destination. It is a Structured Header whose value is a token with possible values audio, audioworklet, document, embed, empty, font, image, manifest, object, paintworklet, report, script, serviceworker, sharedworker, style, track, video, worker, and xslt.
    
    See Also:
    
    Constant Field Values
  - SEC_PURPOSE
```
public static final java.lang.String SEC_PURPOSE
```
    Indicates the purpose of the request, when the purpose is something other than immediate use by the user-agent.
    The header currently has one possible value, prefetch, which indicates that the resource is being fetched preemptively for a possible future navigation.
    
    See Also:
    
    Constant Field Values
  - SERVICE_WORKER_NAVIGATION_PRELOAD
```
public static final java.lang.String SERVICE_WORKER_NAVIGATION_PRELOAD
```
    A request header sent in preemptive request to fetch() a resource during service worker boot.
    The value, which is set with NavigationPreloadManager.setHeaderValue()", can be used to inform a server that a different resource should be returned than in a normal fetch() operation.
    
    See Also:
    
    Constant Field Values
  - REPORT_TO
```
public static final java.lang.String REPORT_TO
```
    Used to specify a server endpoint for the browser to send warning and error reports to.
    
    See Also:
    
    Constant Field Values
  - TRANSFER_ENCODING
```
public static final java.lang.String TRANSFER_ENCODING
```
    Specifies the form of encoding used to safely transfer the resource to the user.
    
    See Also:
    
    Constant Field Values
  - TE
```
public static final java.lang.String TE
```
    Specifies the transfer encodings the user agent is willing to accept.
    
    See Also:
    
    Constant Field Values
  - TRAILER
```
public static final java.lang.String TRAILER
```
    Allows the sender to include additional fields at the end of chunked message.
    
    See Also:
    
    Constant Field Values
  - ALT_SVC
```
public static final java.lang.String ALT_SVC
```
    Used to list alternate ways to reach this service.
    
    See Also:
    
    Constant Field Values
  - ALT_USED
```
public static final java.lang.String ALT_USED
```
    Used to identify the alternative service in use.
    
    See Also:
    
    Constant Field Values
  - DATE
```
public static final java.lang.String DATE
```
    Contains the date and time at which the message was originated.
    
    See Also:
    
    Constant Field Values
  - LINK
```
public static final java.lang.String LINK
```
    This entity-header field provides a means for serializing one or more links in HTTP headers. It is semantically equivalent to the HTML link element.
    
    See Also:
    
    Constant Field Values
  - RETRY_AFTER
```
public static final java.lang.String RETRY_AFTER
```
    Indicates how long the user agent should wait before making a follow-up request.
    
    See Also:
    
    Constant Field Values
  - SERVER_TIMING
```
public static final java.lang.String SERVER_TIMING
```
    Communicates one or more metrics and descriptions for the given request-response cycle.
    
    See Also:
    
    Constant Field Values
  - SERVICE_WORKER_ALLOWED
```
public static final java.lang.String SERVICE_WORKER_ALLOWED
```
    Used to remove the path restriction by including this header in the response of the Service Worker script.
    
    See Also:
    
    Constant Field Values
  - SOURCEMAP
```
public static final java.lang.String SOURCEMAP
```
    Links generated code to a source map.
    
    See Also:
    
    Constant Field Values
  - UPGRADE
```
public static final java.lang.String UPGRADE
```
    This HTTP/1.1 (only) header can be used to upgrade an already established client/server connection to a different protocol (over the same transport protocol).
    For example, it can be used by a client to upgrade a connection from HTTP 1.1 to HTTP 2.0, or an HTTP or HTTPS connection into a WebSocket.
    
    See Also:
    
    Constant Field Values
  - ACCEPT_CH
```
public static final java.lang.String ACCEPT_CH
```
    Servers can advertise support for Client Hints using the Accept-CH header field or an equivalent HTML <meta> element with http-equiv attribute.
    
    See Also:
    
    Constant Field Values
  - CRITICAL_CH
```
public static final java.lang.String CRITICAL_CH
```
    Servers use Critical-CH along with ACCEPT_CH to specify that accepted client hints are also critical client hints.
    
    See Also:
    
    Constant Field Values
  - SEC_CH_UA
```
public static final java.lang.String SEC_CH_UA
```
    User agent's branding and version.
    
    See Also:
    
    Constant Field Values
  - SEC_CH_UA_ARCH
```
public static final java.lang.String SEC_CH_UA_ARCH
```
    User agent's underlying platform architecture.
    
    See Also:
    
    Constant Field Values
  - SEC_CH_UA_BITNESS
```
public static final java.lang.String SEC_CH_UA_BITNESS
```
    User agent's underlying CPU architecture bitness (for example "64" bit).
    
    See Also:
    
    Constant Field Values
  - SEC_CH_UA_FULL_VERSION_LIST
```
public static final java.lang.String SEC_CH_UA_FULL_VERSION_LIST
```
    Full version for each brand in the user agent's brand list.
    
    See Also:
    
    Constant Field Values
  - SEC_CH_UA_MOBILE
```
public static final java.lang.String SEC_CH_UA_MOBILE
```
    User agent is running on a mobile device or, more generally, prefers a "mobile" user experience.
    
    See Also:
    
    Constant Field Values
  - SEC_CH_UA_MODEL
```
public static final java.lang.String SEC_CH_UA_MODEL
```
    User agent's device model.
    
    See Also:
    
    Constant Field Values
  - SEC_CH_UA_PLATFORM
```
public static final java.lang.String SEC_CH_UA_PLATFORM
```
    User agent's underlying operation system/platform.
    
    See Also:
    
    Constant Field Values
  - SEC_CH_UA_PLATFORM_VERSION
```
public static final java.lang.String SEC_CH_UA_PLATFORM_VERSION
```
    User agent's underlying operation system version.
    
    See Also:
    
    Constant Field Values
  - SEC_CH_UA_PREFERS_COLOR_SCHEME
```
public static final java.lang.String SEC_CH_UA_PREFERS_COLOR_SCHEME
```
    User's preference of dark or light color scheme.
    
    See Also:
    
    Constant Field Values
  - SEC_CH_UA_PREFERS_REDUCED_MOTION
```
public static final java.lang.String SEC_CH_UA_PREFERS_REDUCED_MOTION
```
    User's preference to see fewer animations and content layout shifts.
    
    See Also:
    
    Constant Field Values
  - DEVICE_MEMORY
```
public static final java.lang.String DEVICE_MEMORY
```
    Approximate amount of available client RAM memory.
    This is part of the Device Memory API.
    
    See Also:
    
    Constant Field Values
  - DOWNLINK
```
public static final java.lang.String DOWNLINK
```
    Approximate bandwidth of the client's connection to the server, in Mbps.
    This is part of the Network Information API.
    
    See Also:
    
    Constant Field Values
  - ECT
```
public static final java.lang.String ECT
```
    The effective connection type ("network profile") that best matches the connection's latency and bandwidth.
    This is part of the Network Information API.
    
    See Also:
    
    Constant Field Values
  - RTT
```
public static final java.lang.String RTT
```
    Application layer round trip time (RTT) in milliseconds, which includes the server processing time.
    This is part of the Network Information API.
    
    See Also:
    
    Constant Field Values
  - SAVE_DATA
```
public static final java.lang.String SAVE_DATA
```
    A string on that indicates the user agent's preference for reduced data usage.
    
    See Also:
    
    Constant Field Values
  - SEC_GPC
```
public static final java.lang.String SEC_GPC
```
    Indicates whether the user consents to a website or service selling or sharing their personal information with third parties.
    
    See Also:
    
    Constant Field Values
  - ORIGIN_ISOLATION
```
public static final java.lang.String ORIGIN_ISOLATION
```
    Provides a mechanism to allow web applications to isolate their origins.
    
    See Also:
    
    Constant Field Values
  - NEL
```
public static final java.lang.String NEL
```
    Defines a mechanism that enables developers to declare a network error reporting policy.
    
    See Also:
    
    Constant Field Values
  - ACCEPT_PUSH_POLICY
```
public static final java.lang.String ACCEPT_PUSH_POLICY
```
    A client can express the desired push policy for a request by sending an Accept-Push-Policy header field in the request.
    
    See Also:
    
    Constant Field Values
  - ACCEPT_SIGNATURE
```
public static final java.lang.String ACCEPT_SIGNATURE
```
    A client can send the Accept-Signature header field to indicate intention to take advantage of any available signatures and to indicate what kinds of signatures it supports.
    
    See Also:
    
    Constant Field Values
  - EARLY_DATA
```
public static final java.lang.String EARLY_DATA
```
    Indicates that the request has been conveyed in TLS early data.
    
    See Also:
    
    Constant Field Values
  - PUSH_POLICY
```
public static final java.lang.String PUSH_POLICY
```
    A Push-Policy defines the server behavior regarding push when processing a request.
    
    See Also:
    
    Constant Field Values
  - SIGNATURE
```
public static final java.lang.String SIGNATURE
```
    The Signature header field conveys a list of signatures for an exchange, each one accompanied by information about how to determine the authority of and refresh that signature.
    
    See Also:
    
    Constant Field Values
  - SIGNED_HEADERS
```
public static final java.lang.String SIGNED_HEADERS
```
    The Signed-Headers header field identifies an ordered list of response header fields to include in a signature.
    
    See Also:
    
    Constant Field Values
  - SUPPORTS_LOADING_MODE
```
public static final java.lang.String SUPPORTS_LOADING_MODE
```
    Set by a navigation target to opt-in to using various higher-risk loading modes.
    For example, cross-origin, same-site prerendering requires a Supports-Loading-Mode value of credentialed-prerender.
    
    See Also:
    
    Constant Field Values
  - X_FORWARDED_FOR
```
public static final java.lang.String X_FORWARDED_FOR
```
    Identifies the originating IP addresses of a client connecting to a web server through an HTTP proxy or a load balancer.
    
    See Also:
    
    Constant Field Values
  - X_FORWARDED_HOST
```
public static final java.lang.String X_FORWARDED_HOST
```
    Identifies the original host requested that a client used to connect to your proxy or load balancer.
    
    See Also:
    
    Constant Field Values
  - X_FORWARDED_PROTO
```
public static final java.lang.String X_FORWARDED_PROTO
```
    Identifies the protocol (HTTP or HTTPS) that a client used to connect to your proxy or load balancer.
    
    See Also:
    
    Constant Field Values
  - X_DNS_PREFETCH_CONTROL
```
public static final java.lang.String X_DNS_PREFETCH_CONTROL
```
    Controls DNS prefetching, a feature by which browsers proactively perform domain name resolution on both links that the user may choose to follow as well as URLs for items referenced by the document, including images, CSS, JavaScript, and so forth.
    
    See Also:
    
    Constant Field Values
  - X_ROBOTS_TAG
```
public static final java.lang.String X_ROBOTS_TAG
```
    The X-Robots-Tag HTTP header is used to indicate how a web page is to be indexed within public search engine results.
    The header is effectively equivalent to <meta name="robots" content="…">.
    
    See Also:
    
    Constant Field Values
  - PRAGMA
```
public static final java.lang.String PRAGMA
```
    Implementation-specific header that may have various effects anywhere along the request-response chain.
    Used for backwards compatibility with HTTP/1.0 caches where the Cache-Control header is not yet present.
    
    See Also:
    
    Constant Field Values
  - WARNING
```
public static final java.lang.String WARNING
```
    General warning information about possible problems.
    
    See Also:
    
    Constant Field Values
- Constructor Detail
  - Headers
```
public Headers()
```

Class Headers

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

WWW_AUTHENTICATE

AUTHORIZATION

PROXY_AUTHENTICATE

PROXY_AUTHORIZATION

AGE

CACHE_CONTROL

CLEAR_SITE_DATA

EXPIRES

LAST_MODIFIED

ETAG

IF_MATCH

IF_NONE_MATCH

IF_MODIFIED_SINCE

IF_UNMODIFIED_SINCE

VARY

CONNECTION

KEEP_ALIVE

ACCEPT

ACCEPT_ENCODING

ACCEPT_LANGUAGE

EXPECT

MAX_FORWARDS

COOKIE

SET_COOKIE

ACCESS_CONTROL_ALLOW_CREDENTIALS

ACCESS_CONTROL_ALLOW_HEADERS

ACCESS_CONTROL_ALLOW_METHODS

ACCESS_CONTROL_ALLOW_ORIGIN

ACCESS_CONTROL_EXPOSE_HEADERS

ACCESS_CONTROL_MAX_AGE

ACCESS_CONTROL_REQUEST_HEADERS

ACCESS_CONTROL_REQUEST_METHOD

ORIGIN

TIMING_ALLOW_ORIGIN

CONTENT_DISPOSITION

CONTENT_LENGTH

CONTENT_TYPE

CONTENT_ENCODING

CONTENT_LANGUAGE

CONTENT_LOCATION

FORWARDED

VIA

LOCATION

REFRESH

FROM

HOST

REFERER

REFERRER_POLICY

USER_AGENT

ALLOW

SERVER

ACCEPT_RANGES

RANGE

IF_RANGE

CONTENT_RANGE

CROSS_ORIGIN_EMBEDDER_POLICY

CROSS_ORIGIN_OPENER_POLICY

CROSS_ORIGIN_RESOURCE_POLICY

CONTENT_SECURITY_POLICY

CONTENT_SECURITY_POLICY_REPORT_ONLY

PERMISSIONS_POLICY

STRICT_TRANSPORT_SECURITY

UPGRADE_INSECURE_REQUESTS

X_CONTENT_TYPE_OPTIONS

X_FRAME_OPTIONS

X_PERMITTED_CROSS_DOMAIN_POLICIES

X_POWERED_BY

X_XSS_PROTECTION

SEC_FETCH_SITE

SEC_FETCH_MODE

SEC_FETCH_USER

SEC_FETCH_DEST

SEC_PURPOSE

SERVICE_WORKER_NAVIGATION_PRELOAD