Interface/enum listing standard mime-type constants

Guava library

We have a Guava class for this: com.google.common.net.MediaType.

It was released with Guava 12 as stated in the source code and in Issue 823. Sources are available, too.

If you are using Spring Framework then there is a MediaType class for common content types:

MediaType.TEXT_HTML 
MediaType.TEXT_PLAIN 
MediaType.TEXT_XML 
MediaType.APPLICATION_JSON 
MediaType.IMAGE_JPEG 
...

From https://docs.oracle.com/javaee/7/api/javax/ws/rs/core/MediaType.html :

staticjava.lang.String APPLICATION_ATOM_XML             "application/atom+xml"
staticMediaType        APPLICATION_ATOM_XML_TYPE        "application/atom+xml"
staticjava.lang.String APPLICATION_FORM_URLENCODED      "application/x-www-form-urlencoded"
staticMediaType        APPLICATION_FORM_URLENCODED_TYPE "application/x-www-form-urlencoded"
staticjava.lang.String APPLICATION_JSON                 "application/json"
staticMediaType        APPLICATION_JSON_TYPE            "application/json"
staticjava.lang.String APPLICATION_OCTET_STREAM         "application/octet-stream"
staticMediaType        APPLICATION_OCTET_STREAM_TYPE    "application/octet-stream"
staticjava.lang.String APPLICATION_SVG_XML              "application/svg+xml"
staticMediaType        APPLICATION_SVG_XML_TYPE         "application/svg+xml"
staticjava.lang.String APPLICATION_XHTML_XML            "application/xhtml+xml"
staticMediaType        APPLICATION_XHTML_XML_TYPE       "application/xhtml+xml"
staticjava.lang.String APPLICATION_XML                  "application/xml"
staticMediaType        APPLICATION_XML_TYPE             "application/xml"
staticjava.lang.String MEDIA_TYPE_WILDCARD              The value of a type or subtype wildcard: "*"
staticjava.lang.String MULTIPART_FORM_DATA              "multipart/form-data"
staticMediaType        MULTIPART_FORM_DATA_TYPE         "multipart/form-data"
staticjava.lang.String TEXT_HTML                        "text/html"
staticMediaType        TEXT_HTML_TYPE                   "text/html"
staticjava.lang.String TEXT_PLAIN                       "text/plain"
staticMediaType        TEXT_PLAIN_TYPE                  "text/plain"
staticjava.lang.String TEXT_XML                         "text/xml"
staticMediaType        TEXT_XML_TYPE                    "text/xml"
staticjava.lang.String WILDCARD                         "*/*"
staticMediaType        WILDCARD_TYPE                    "*/*"