Part (Java EE 5 SDK)

Java

Java EE 5 SDK

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javax.mail Interface Part

所有已知子接口:
MimePart
所有已知实现子孙类:
BodyPart, Message, MimeBodyPart, MimeMessage, PreencodedMimeBodyPart

public interface Part

The Part interface is the common base interface for Messages and BodyParts.

Part consists of a set of attributes and a "Content".

Attributes:

The JavaMail API defines a set of standard Part attributes that are considered to be common to most existing Mail systems. These attributes have their own settor and gettor methods. Mail systems may support other Part attributes as well, these are represented as name-value pairs where both the name and value are Strings.

Content:

The data type of the "content" is returned by the getContentType() method. The MIME typing system is used to name data types.

The "content" of a Part is available in various formats:

  • As a DataHandler - using the getDataHandler() method. The "content" of a Part is also available through a javax.activation.DataHandler object. The DataHandler object allows clients to discover the operations available on the content, and to instantiate the appropriate component to perform those operations.
  • As an input stream - using the getInputStream() method. Any mail-specific encodings are decoded before this stream is returned.
  • As a Java object - using the getContent() method. This method returns the "content" as a Java object. The returned object is of course dependent on the content itself. In particular, a "multipart" Part's content is always a Multipart or subclass thereof. That is, getContent() on a "multipart" type Part will always return a Multipart (or subclass) object.
Part provides the writeTo() method that streams out its bytestream in mail-safe form suitable for transmission. This bytestream is typically an aggregation of the Part attributes and its content's bytestream.

Message and BodyPart implement the Part interface. Note that in MIME parlance, Part models an Entity (RFC 2045, Section 2.4).

作者:
John Mani

字段摘要
static String ATTACHMENT
          This part should be presented as an attachment.
static String INLINE
          This part should be presented inline.
 
方法摘要
 void addHeader(String header_name, String header_value)
          Add this value to the existing values for this header_name.
 Enumeration getAllHeaders()
          Return all the headers from this part as an Enumeration of Header objects.
 Object getContent()
          Return the content as a Java object.
 String getContentType()
          Returns the Content-Type of the content of this part.
 DataHandler getDataHandler()
          Return a DataHandler for the content within this part.
 String getDescription()
          Return a description String for this part.
 String getDisposition()
          Return the disposition of this part.
 String getFileName()
          Get the filename associated with this part, if possible.
 String[] getHeader(String header_name)
          Get all the headers for this header name.
 InputStream getInputStream()
          Return an input stream for this part's "content".
 int getLineCount()
          Return the number of lines in the content of this part.
 Enumeration getMatchingHeaders(String[] header_names)
          Return matching headers from this part as an Enumeration of Header objects.
 Enumeration getNonMatchingHeaders(String[] header_names)
          Return non-matching headers from this envelope as an Enumeration of Header objects.
 int getSize()
          Return the size of the content of this part in bytes.
 boolean isMimeType(String mimeType)
          Is this Part of the specified MIME type?
 void removeHeader(String header_name)
          Remove all headers with this name.
 void setContent(Multipart mp)
          This method sets the given Multipart object as this message's content.
 void setContent(Object obj, String type)
          A convenience method for setting this part's content.
 void setDataHandler(DataHandler dh)
          This method provides the mechanism to set this part's content.
 void setDescription(String description)
          Set a description String for this part.
 void setDisposition(String disposition)
          Set the disposition of this part.
 void setFileName(String filename)
          Set the filename associated with this part, if possible.
 void setHeader(String header_name, String header_value)
          Set the value for this header_name.
 void setText(String text)
          A convenience method that sets the given String as this part's content with a MIME type of "text/plain".
 void writeTo(OutputStream os)
          Output a bytestream for this Part.
 

字段详细信息

ATTACHMENT

static final String ATTACHMENT
This part should be presented as an attachment.

另请参见:
getDisposition(), setDisposition(java.lang.String), 常量字段


INLINE

static final String INLINE
This part should be presented inline.

另请参见:
getDisposition(), setDisposition(java.lang.String), 常量字段

方法详细信息

getSize

int getSize()
            throws MessagingException
Return the size of the content of this part in bytes. Return -1 if the size cannot be determined.

Note that the size may not be an exact measure of the content size and may or may not account for any transfer encoding of the content. The size is appropriate for display in a user interface to give the user a rough idea of the size of this part.

返回:
size of content in bytes
抛出异常:
MessagingException

getLineCount

int getLineCount()
                 throws MessagingException
Return the number of lines in the content of this part. Return -1 if the number cannot be determined. Note that this number may not be an exact measure of the content length and may or may not account for any transfer encoding of the content.

返回:
number of lines in the content.
抛出异常:
MessagingException

getContentType

String getContentType()
                      throws MessagingException
Returns the Content-Type of the content of this part. Returns null if the Content-Type could not be determined.

The MIME typing system is used to name Content-types.

返回:
The ContentType of this part
抛出异常:
MessagingException
另请参见:
DataHandler

isMimeType

boolean isMimeType(String mimeType)
                   throws MessagingException
Is this Part of the specified MIME type? This method compares only the primaryType and subType. The parameters of the content types are ignored.

For example, this method will return true when comparing a Part of content type "text/plain" with "text/plain; charset=foobar".

If the subType of mimeType is the special character '*', then the subtype is ignored during the comparison.

抛出异常:
MessagingException

getDisposition

String getDisposition()
                      throws MessagingException
Return the disposition of this part. The disposition describes how the part should be presented to the user. (See RFC 2183.) The return value should be considered without regard to case. For example:

 String disp = part.getDisposition();
 if (disp == null || disp.equalsIgnoreCase(Part.ATTACHMENT))
        // treat as attachment if not first part
 

返回:
disposition of this part, or null if unknown
抛出异常:
MessagingException
另请参见:
ATTACHMENT, INLINE, getFileName()

setDisposition

void setDisposition(String disposition)
                    throws MessagingException
Set the disposition of this part.

参数:
disposition - disposition of this part
抛出异常:
MessagingException
IllegalWriteException - if the underlying implementation does not support modification of this header
IllegalStateException - if this Part is obtained from a READ_ONLY folder
另请参见:
ATTACHMENT, INLINE, setFileName(java.lang.String)

getDescription

String getDescription()
                      throws MessagingException
Return a description String for this part. This typically associates some descriptive information with this part. Returns null if none is available.

返回:
description of this part
抛出异常:
MessagingException

setDescription

void setDescription(String description)
                    throws MessagingException
Set a description String for this part. This typically associates some descriptive information with this part.

参数:
description - description of this part
抛出异常:
MessagingException
IllegalWriteException - if the underlying implementation does not support modification of this header
IllegalStateException - if this Part is obtained from a READ_ONLY folder

getFileName

String getFileName()
                   throws MessagingException
Get the filename associated with this part, if possible. Useful if this part represents an "attachment" that was loaded from a file. The filename will usually be a simple name, not including directory components.

返回:
Filename to associate with this part
抛出异常:
MessagingException

setFileName

void setFileName(String filename)
                 throws MessagingException
Set the filename associated with this part, if possible. Useful if this part represents an "attachment" that was loaded from a file. The filename will usually be a simple name, not including directory components.

参数:
filename - Filename to associate with this part
抛出异常:
IllegalWriteException - if the underlying implementation does not support modification of this header
IllegalStateException - if this Part is obtained from a READ_ONLY folder
MessagingException

getInputStream

InputStream getInputStream()
                           throws IOException,
                                  MessagingException
Return an input stream for this part's "content". Any mail-specific transfer encodings will be decoded before the input stream is provided.

This is typically a convenience method that just invokes the DataHandler's getInputStream() method.

返回:
an InputStream
抛出异常:
IOException - this is typically thrown by the DataHandler. Refer to the documentation for javax.activation.DataHandler for more details.
MessagingException
另请参见:
getDataHandler(), DataHandler.getInputStream()

getDataHandler

DataHandler getDataHandler()
                           throws MessagingException
Return a DataHandler for the content within this part. The DataHandler allows clients to operate on as well as retrieve the content.

返回:
DataHandler for the content
抛出异常:
MessagingException

getContent

Object getContent()
                  throws IOException,
                         MessagingException
Return the content as a Java object. The type of the returned object is of course dependent on the content itself. For example, the object returned for "text/plain" content is usually a String object. The object returned for a "multipart" content is always a Multipart subclass. For content-types that are unknown to the DataHandler system, an input stream is returned as the content

This is a convenience method that just invokes the DataHandler's getContent() method

返回:
Object
抛出异常:
MessagingException
IOException - this is typically thrown by the DataHandler. Refer to the documentation for javax.activation.DataHandler for more details.
另请参见:
DataHandler.getContent()

setDataHandler

void setDataHandler(DataHandler dh)
                    throws MessagingException
This method provides the mechanism to set this part's content. The DataHandler wraps around the actual content.

参数:
dh - The DataHandler for the content.
抛出异常:
MessagingException
IllegalWriteException - if the underlying implementation does not support modification of existing values
IllegalStateException - if this Part is obtained from a READ_ONLY folder

setContent

void setContent(Object obj,
                String type)
                throws MessagingException
A convenience method for setting this part's content. The part internally wraps the content in a DataHandler.

Note that a DataContentHandler class for the specified type should be available to the JavaMail implementation for this to work right. i.e., to do setContent(foobar, "application/x-foobar"), a DataContentHandler for "application/x-foobar" should be installed. Refer to the Java Activation Framework for more information.

参数:
obj - A java object.
type - MIME type of this object.
抛出异常:
IllegalWriteException - if the underlying implementation does not support modification of existing values
IllegalStateException - if this Part is obtained from a READ_ONLY folder
MessagingException

setText

void setText(String text)
             throws MessagingException
A convenience method that sets the given String as this part's content with a MIME type of "text/plain".

参数:
text - The text that is the Message's content.
抛出异常:
IllegalWriteException - if the underlying implementation does not support modification of existing values
IllegalStateException - if this Part is obtained from a READ_ONLY folder
MessagingException

setContent

void setContent(Multipart mp)
                throws MessagingException
This method sets the given Multipart object as this message's content.

参数:
mp - The multipart object that is the Message's content
抛出异常:
IllegalWriteException - if the underlying implementation does not support modification of existing values
IllegalStateException - if this Part is obtained from a READ_ONLY folder
MessagingException

writeTo

void writeTo(OutputStream os)
             throws IOException,
                    MessagingException
Output a bytestream for this Part. This bytestream is typically an aggregration of the Part attributes and an appropriately encoded bytestream from its 'content'.

Classes that implement the Part interface decide on the appropriate encoding algorithm to be used.

The bytestream is typically used for sending.

抛出异常:
IOException - if an error occurs writing to the stream or if an error is generated by the javax.activation layer.
MessagingException - if an error occurs fetching the data to be written
另请参见:
DataHandler.writeTo(java.io.OutputStream)

getHeader

String[] getHeader(String header_name)
                   throws MessagingException
Get all the headers for this header name. Returns null if no headers for this header name are available.

参数:
header_name - the name of this header
返回:
the value fields for all headers with this name
抛出异常:
MessagingException

setHeader

void setHeader(String header_name,
               String header_value)
               throws MessagingException
Set the value for this header_name. Replaces all existing header values with this new value.

参数:
header_name - the name of this header
header_value - the value for this header
抛出异常:
MessagingException
IllegalWriteException - if the underlying implementation does not support modification of existing values
IllegalStateException - if this Part is obtained from a READ_ONLY folder

addHeader

void addHeader(String header_name,
               String header_value)
               throws MessagingException
Add this value to the existing values for this header_name.

参数:
header_name - the name of this header
header_value - the value for this header
抛出异常:
MessagingException
IllegalWriteException - if the underlying implementation does not support modification of existing values
IllegalStateException - if this Part is obtained from a READ_ONLY folder

removeHeader

void removeHeader(String header_name)
                  throws MessagingException
Remove all headers with this name.

参数:
header_name - the name of this header
抛出异常:
MessagingException
IllegalWriteException - if the underlying implementation does not support modification of existing values
IllegalStateException - if this Part is obtained from a READ_ONLY folder

getAllHeaders

Enumeration getAllHeaders()
                          throws MessagingException
Return all the headers from this part as an Enumeration of Header objects.

返回:
enumeration of Header objects
抛出异常:
MessagingException

getMatchingHeaders

Enumeration getMatchingHeaders(String[] header_names)
                               throws MessagingException
Return matching headers from this part as an Enumeration of Header objects.

返回:
enumeration of Header objects
抛出异常:
MessagingException

getNonMatchingHeaders

Enumeration getNonMatchingHeaders(String[] header_names)
                                  throws MessagingException
Return non-matching headers from this envelope as an Enumeration of Header objects.

返回:
enumeration of Header objects
抛出异常:
MessagingException

Java EE 5 SDK

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