Class MailcapCommandMap
Mailcap file search order:
The MailcapCommandMap looks in various places in the user's system for mailcap file entries. When requests are made to search for commands in the MailcapCommandMap, it searches mailcap files in the following order:
- Programatically added entries to the MailcapCommandMap instance.
- The file
.mailcap
in the user's home directory. - The file
mailcap
in the Java runtime. - The file or resources named
META-INF/mailcap
. - The file or resource named
META-INF/mailcap.default
(usually found only in theactivation.jar
file).
(The current implementation looks for the mailcap
file
in the Java runtime in the directory java.home/conf
if it exists, and otherwise in the directory
java.home/lib
, where java.home is the value
of the "java.home" System property. Note that the "conf" directory was
introduced in JDK 9.)
Mailcap file format:
Mailcap files must conform to the mailcap file specification (RFC 1524, A User Agent Configuration Mechanism For Multimedia Mail Format Information). The file format consists of entries corresponding to particular MIME types. In general, the specification specifies applications for clients to use when they themselves cannot operate on the specified MIME type. The MailcapCommandMap extends this specification by using a parameter mechanism in mailcap files that allows JavaBeans(tm) components to be specified as corresponding to particular commands for a MIME type.
When a mailcap file is
parsed, the MailcapCommandMap recognizes certain parameter signatures,
specifically those parameter names that begin with x-java-
.
The MailcapCommandMap uses this signature to find
command entries for inclusion into its registries.
Parameter names with the form x-java-<name>
are read by the MailcapCommandMap as identifying a command
with the name name. When the name is
content-handler
the MailcapCommandMap recognizes the class
signified by this parameter as a DataContentHandler.
All other commands are handled generically regardless of command
name. The command implementation is specified by a fully qualified
class name of a JavaBean(tm) component. For example; a command for viewing
some data can be specified as: x-java-view=com.foo.ViewBean
.
When the command name is fallback-entry
, the value of
the command may be true
or false
. An
entry for a MIME type that includes a parameter of
x-java-fallback-entry=true
defines fallback commands
for that MIME type that will only be used if no non-fallback entry
can be found. For example, an entry of the form text/*; ;
x-java-fallback-entry=true; x-java-view=com.sun.TextViewer
specifies a view command to be used for any text MIME type. This
view command would only be used if a non-fallback view command for
the MIME type could not be found.
MailcapCommandMap aware mailcap files have the following general form:
# Comments begin with a '#' and continue to the end of the line.
<mime type>; ; <parameter list>
# Where a parameter list consists of one or more parameters,
# where parameters look like: x-java-view=com.sun.TextViewer
# and a parameter list looks like:
text/plain; ; x-java-view=com.sun.TextViewer; x-java-edit=com.sun.TextEdit
# Note that mailcap entries that do not contain 'x-java' parameters
# and comply to RFC 1524 are simply ignored:
image/gif; /usr/dt/bin/sdtimage %s
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Field Summary
FieldsModifier and TypeFieldDescriptionprivate static final String
private MailcapFile[]
private static final int
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Constructor Summary
ConstructorsConstructorDescriptionThe default Constructor.Constructor that allows the caller to specify an InputStream containing a mailcap file.MailcapCommandMap
(String fileName) Constructor that allows the caller to specify the path of a mailcap file. -
Method Summary
Modifier and TypeMethodDescriptionvoid
addMailcap
(String mail_cap) Add entries to the registry.private void
appendCmdsToList
(Map typeHash, List cmdList) Put the commands that are in the hash table, into the list.private void
appendPrefCmdsToList
(Map cmdHash, List cmdList) Put the commands that are in the hash table, into the list.private boolean
checkForVerb
(List cmdList, String verb) Check the cmdList to see if this command exists, return true if the verb is there.createDataContentHandler
(String mimeType) Return the DataContentHandler for the specified MIME type.getAllCommands
(String mimeType) Get all the available commands in all mailcap files known to this instance of MailcapCommandMap for this MIME type.getCommand
(String mimeType, String cmdName) Get the command corresponding tocmdName
for the MIME type.private DataContentHandler
getDataContentHandler
(String name) String[]
Get all the MIME types known to this command map.String[]
getNativeCommands
(String mimeType) Get the native commands for the given MIME type.getPreferredCommands
(String mimeType) Get the preferred command list for a MIME Type.private void
loadAllResources
(List v, String name) Load all of the named resource.private MailcapFile
Load from the named file.private MailcapFile
loadResource
(String name) Load from the named resource.Methods inherited from class javax.activation.CommandMap
createDataContentHandler, getAllCommands, getCommand, getDefaultCommandMap, getPreferredCommands, setDefaultCommandMap
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Field Details
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DB
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PROG
private static final int PROG- See Also:
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confDir
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Constructor Details
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MailcapCommandMap
public MailcapCommandMap()The default Constructor. -
MailcapCommandMap
Constructor that allows the caller to specify the path of a mailcap file.- Parameters:
fileName
- The name of the mailcap file to open- Throws:
IOException
- if the file can't be accessed
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MailcapCommandMap
Constructor that allows the caller to specify an InputStream containing a mailcap file.- Parameters:
is
- InputStream of the mailcap file to open
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Method Details
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loadResource
Load from the named resource. -
loadAllResources
Load all of the named resource. -
loadFile
Load from the named file. -
getPreferredCommands
Get the preferred command list for a MIME Type. The MailcapCommandMap searches the mailcap files as described above under Mailcap file search order.The result of the search is a proper subset of available commands in all mailcap files known to this instance of MailcapCommandMap. The first entry for a particular command is considered the preferred command.
- Specified by:
getPreferredCommands
in classCommandMap
- Parameters:
mimeType
- the MIME type- Returns:
- the CommandInfo objects representing the preferred commands.
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appendPrefCmdsToList
Put the commands that are in the hash table, into the list. -
checkForVerb
Check the cmdList to see if this command exists, return true if the verb is there. -
getAllCommands
Get all the available commands in all mailcap files known to this instance of MailcapCommandMap for this MIME type.- Specified by:
getAllCommands
in classCommandMap
- Parameters:
mimeType
- the MIME type- Returns:
- the CommandInfo objects representing all the commands.
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appendCmdsToList
Put the commands that are in the hash table, into the list. -
getCommand
Get the command corresponding tocmdName
for the MIME type.- Specified by:
getCommand
in classCommandMap
- Parameters:
mimeType
- the MIME typecmdName
- the command name- Returns:
- the CommandInfo object corresponding to the command.
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addMailcap
Add entries to the registry. Programmatically added entries are searched before other entries.The string that is passed in should be in mailcap format.
- Parameters:
mail_cap
- a correctly formatted mailcap string
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createDataContentHandler
Return the DataContentHandler for the specified MIME type.- Specified by:
createDataContentHandler
in classCommandMap
- Parameters:
mimeType
- the MIME type- Returns:
- the DataContentHandler
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getDataContentHandler
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getMimeTypes
Get all the MIME types known to this command map.- Overrides:
getMimeTypes
in classCommandMap
- Returns:
- array of MIME types as strings
- Since:
- JAF 1.1
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getNativeCommands
Get the native commands for the given MIME type. Returns an array of strings where each string is an entire mailcap file entry. The application will need to parse the entry to extract the actual command as well as any attributes it needs. See RFC 1524 for details of the mailcap entry syntax. Only mailcap entries that specify a view command for the specified MIME type are returned.- Parameters:
mimeType
- the MIME type- Returns:
- array of native command entries
- Since:
- JAF 1.1
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