Home » Open-JDK-6.b17-src » javax » activation » [javadoc | source]
public class: MailcapCommandMap [javadoc | source]
MailcapCommandMap extends the CommandMap abstract class. It implements a CommandMap whose configuration is based on mailcap files (RFC 1524). The MailcapCommandMap can be configured both programmatically and via configuration files.

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:

  1. Programatically added entries to the MailcapCommandMap instance.
  2. The file .mailcap in the user's home directory.
  3. The file <java.home>/lib/mailcap.
  4. The file or resources named META-INF/mailcap.
  5. The file or resource named META-INF/mailcap.default (usually found only in the activation.jar file).

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

 public MailcapCommandMap() 
 public MailcapCommandMap(String fileName) throws IOException 
    Constructor that allows the caller to specify the path of a mailcap file.
    fileName - The name of the mailcap file to open
    IOException - if the file can't be accessed
    exception: IOException - if the file can't be accessed
 public MailcapCommandMap(InputStream is) 
    Constructor that allows the caller to specify an InputStream containing a mailcap file.
    is - InputStream of the mailcap file to open
Method from javax.activation.MailcapCommandMap Summary:
addMailcap,   createDataContentHandler,   getAllCommands,   getCommand,   getMimeTypes,   getNativeCommands,   getPreferredCommands
Methods from javax.activation.CommandMap:
createDataContentHandler,   createDataContentHandler,   getAllCommands,   getAllCommands,   getCommand,   getCommand,   getDefaultCommandMap,   getMimeTypes,   getPreferredCommands,   getPreferredCommands,   setDefaultCommandMap
Methods from java.lang.Object:
clone,   equals,   finalize,   getClass,   hashCode,   notify,   notifyAll,   toString,   wait,   wait,   wait
Method from javax.activation.MailcapCommandMap Detail:
 public synchronized  void addMailcap(String mail_cap) 
    Add entries to the registry. Programmatically added entries are searched before other entries.

    The string that is passed in should be in mailcap format.

 public synchronized DataContentHandler createDataContentHandler(String mimeType) 
    Return the DataContentHandler for the specified MIME type.
 public synchronized CommandInfo[] getAllCommands(String mimeType) 
    Get all the available commands in all mailcap files known to this instance of MailcapCommandMap for this MIME type.
 public synchronized CommandInfo getCommand(String mimeType,
    String cmdName) 
    Get the command corresponding to cmdName for the MIME type.
 public synchronized String[] getMimeTypes() 
    Get all the MIME types known to this command map.
 public synchronized String[] getNativeCommands(String mimeType) 
    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.
 public synchronized CommandInfo[] getPreferredCommands(String mimeType) 
    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.