MailcapCommandMap (Java EE 5)

java.lang.Object
  javax.activation.CommandMap
      javax.activation.MailcapCommandMap

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


Author:

Bart Calder, Bill Shannon

public MailcapCommandMap()
默认的构造方法。

英文文档：

MailcapCommandMap

public MailcapCommandMap()

The default Constructor.

public MailcapCommandMap(String fileName) throws java.io.IOException
允许调用者指定 mailcap 文件路径的构造方法。

fileName	要打开的 mailcap 文件的名称
Throws	java.io.IOException: 如果不能访问该文件

英文文档：

MailcapCommandMap

public MailcapCommandMap(String fileName)
                  throws IOException

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

public MailcapCommandMap(java.io.InputStream is)
允许调用者指定一个包含 mailcap 文件的 InputStream 的构造方法。

is	要打开的 mailcap 文件的 InputStream

英文文档：

MailcapCommandMap

public MailcapCommandMap(InputStream is)

Constructor that allows the caller to specify an InputStream containing a mailcap file.

Parameters:

is - InputStream of the mailcap file to open

public CommandInfo[] getPreferredCommands(String mimeType)
获取 MIME 类型的首选命令列表。MailcapCommandMap 以如上所述的 mailcap 文件搜索顺序 来搜索 mailcap 文件。

搜索的结果是此 MailcapCommandMap 实例已知的所有 mailmap 文件中可用命令的适当子集。特定命令的第一个条目被视为首选命令。

mimeType	MIME 类型
return	表示首选命令的 CommandInfo 对象。

英文文档：

getPreferredCommands

public 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.

Specified by:

getPreferredCommands in class CommandMap

Parameters:

mimeType - the MIME type

Returns:

the CommandInfo objects representing the preferred commands.

public CommandInfo[] getAllCommands(String mimeType)
针对此 MIME 类型获取此 MailcapCommandMap 实例已知的所有 mailcap 文件中的所有可用命令。

mimeType	MIME 类型
return	表示所有命令的 CommandInfo 对象

英文文档：

getAllCommands

public CommandInfo[] getAllCommands(String mimeType)

Get all the available commands in all mailcap files known to this instance of MailcapCommandMap for this MIME type.

Specified by:

getAllCommands in class CommandMap

Parameters:

mimeType - the MIME type

Returns:

the CommandInfo objects representing all the commands.

public CommandInfo getCommand(String mimeType, String cmdName)
针对 MIME 类型获取与 cmdName 对应的命令。

mimeType	MIME 类型
cmdName	命令名
return	与命令对应的 CommandInfo 对象。

英文文档：

getCommand

public CommandInfo getCommand(String mimeType,
                              String cmdName)

Get the command corresponding to cmdName for the MIME type.

Specified by:

getCommand in class CommandMap

Parameters:

mimeType - the MIME type

cmdName - the command name

Returns:

the CommandInfo object corresponding to the command.

public void addMailcap(String mail_cap)
将条目添加到注册表。搜索其他条目之前，先搜索以编程方式添加的条目。

传入的字符串应该是 mailcap 格式。

mail_cap

已正确格式化的 mailcap 字符串

英文文档：

addMailcap

public 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.

Parameters:

mail_cap - a correctly formatted mailcap string

public DataContentHandler createDataContentHandler(String mimeType)
返回指定 MIME 类型的 DataContentHandler。

mimeType	MIME 类型
return	DataContentHandler

英文文档：

createDataContentHandler

public DataContentHandler createDataContentHandler(String mimeType)

Return the DataContentHandler for the specified MIME type.

Specified by:

createDataContentHandler in class CommandMap

Parameters:

mimeType - the MIME type

Returns:

the DataContentHandler

public String[] getMimeTypes()
获取此命令映射已知的所有 MIME 类型。

return	字符串形式的 MIME 类型数组
since	JAF 1.1

英文文档：

getMimeTypes

public String[] getMimeTypes()

Get all the MIME types known to this command map.

Overrides:

getMimeTypes in class CommandMap

Returns:

array of MIME types as strings

Since:

JAF 1.1

public String[] getNativeCommands(String mimeType)
获取给定 MIME 类型的本地命令。返回一个字符串数组，其中每个字符串都是一个完整的 mailcap 文件条目。应用程序需要解析条目以提取实际命令以及它需要的所有属性。关于 mailcap 条目语法的详细信息，请参阅 RFC 1524。只返回为指定的 MIME 类型指定查看命令的 mailcap 条目。

return	本地命令条目数组
since	JAF 1.1

英文文档：

getNativeCommands

public 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.

Returns:

array of native command entries

Since:

JAF 1.1

Copyright 2007 Sun Microsystems, Inc. All rights reserved. Use is subject to license terms.