# Google Data APIs Client Library (1.43.0)

## com.google.gdata.client
Interface GDataProtocol.Header

Enclosing class:
  GDataProtocol

    public static interface GDataProtocol.Header

The Header interface defines various header names used within the GData protocol.

Field Summary
`static java.lang.String` `ACCEPT_LANGUAGE` The ACCEPT_LANGUAGE header is used to choose the best language for the output when the parameter `hl` is not specified.
`static java.lang.String` `CACHE_CONTROL` The CACHE_CONTROL header is used to specify how fresh a result should be in a request.
`static java.lang.String` `ETAG` The ETAG header is used to return an HTTP entity tag for a resource in a GData response.
`static java.lang.String` `IF_MATCH` The IF_MATCH header is used to request specific entity versions.
`static java.lang.String` `IF_MODIFIED_SINCE` The IF_MODIFIED_SINCE header is used to reject requests unmodified since the given date.
`static java.lang.String` `IF_NONE_MATCH` The IF_NONE_MATCH header is used to disallow specific entity versions.
`static java.lang.String` `IF_UNMODIFIED_SINCE` The IF_UNMODIFIED_SINCE header is used to reject requests modified since the given date.
`static java.lang.String` `LAST_MODIFIED` The ETAG header is used to return an last modification time for a resource in a GData response.
`static java.lang.String` `METHOD_OVERRIDE` The METHOD_OVERRIDE parameter overrides the normal HTTP method.
`static java.lang.String` `VERSION` The VERSION header is used to request a specific service version.
`static java.lang.String` `X_UPLOAD_CONTENT_LENGTH` The X_UPLOAD_CONTENT_LENGTH header is used in Scotty requests for the content length of the uploaded file.
`static java.lang.String` `X_UPLOAD_CONTENT_TYPE` The X_UPLOAD_CONTENT_TYPE header is used in Scotty requests for the content type of the uploaded file.

Field Detail

### ACCEPT_LANGUAGE

    static final java.lang.String ACCEPT_LANGUAGE

  The ACCEPT_LANGUAGE header is used to choose the best language for the output when the parameter `hl` is not specified.

  See Also:
    Constant Field Values

### ETAG

    static final java.lang.String ETAG

  The ETAG header is used to return an HTTP entity tag for a resource in a GData response.

  See Also:
    Constant Field Values

### IF_MATCH

    static final java.lang.String IF_MATCH

  The IF_MATCH header is used to request specific entity versions. The value of the parameter will be a space-separated list of Etags.

  See Also:
    Constant Field Values

### IF_MODIFIED_SINCE

    static final java.lang.String IF_MODIFIED_SINCE

  The IF_MODIFIED_SINCE header is used to reject requests unmodified since the given date.

  See Also:
    Constant Field Values

### IF_UNMODIFIED_SINCE

    static final java.lang.String IF_UNMODIFIED_SINCE

  The IF_UNMODIFIED_SINCE header is used to reject requests modified since the given date.

  See Also:
    Constant Field Values

### IF_NONE_MATCH

    static final java.lang.String IF_NONE_MATCH

  The IF_NONE_MATCH header is used to disallow specific entity versions. The value of the parameter will be a space-separated list of Etags.

  See Also:
    Constant Field Values

### LAST_MODIFIED

    static final java.lang.String LAST_MODIFIED

  The ETAG header is used to return an last modification time for a resource in a GData response.

  See Also:
    Constant Field Values

### METHOD_OVERRIDE

    static final java.lang.String METHOD_OVERRIDE

  The METHOD_OVERRIDE parameter overrides the normal HTTP method. The value is the HTTP method that should be used to process the request. This is used to allow clients that are unable to issue PUT or DELETE methods to emulate such methods. The client would issue a POST method with this header value set to "PUT" or "DELETE", and the service translates the invocation to the corresponding request type.

  See Also:
    Constant Field Values

### VERSION

    static final java.lang.String VERSION

  The VERSION header is used to request a specific service version. The value of the parameter will be in the format `<major>.<minor>` and will be interpreted relative to the version model of the target service.

  See Also:
    Constant Field Values

### CACHE_CONTROL

    static final java.lang.String CACHE_CONTROL

  The CACHE_CONTROL header is used to specify how fresh a result should be in a request.

  See Also:
    Constant Field Values

### X_UPLOAD_CONTENT_TYPE

    static final java.lang.String X_UPLOAD_CONTENT_TYPE

  The X_UPLOAD_CONTENT_TYPE header is used in Scotty requests for the content type of the uploaded file.

  See Also:
    Constant Field Values

### X_UPLOAD_CONTENT_LENGTH

    static final java.lang.String X_UPLOAD_CONTENT_LENGTH

  The X_UPLOAD_CONTENT_LENGTH header is used in Scotty requests for the content length of the uploaded file.

  See Also:
    Constant Field Values