Java tutorial
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If you don't indicate a single choice of license, a * recipient has the option to distribute your version of this file under * either the CDDL, the GPL Version 2 or to extend the choice of license to * its licensees as provided above. However, if you add GPL Version 2 code * and therefore, elected the GPL Version 2 license, then the option applies * only if the new code is made subject to such option by the copyright * holder. */ package javax.mail; import java.util.Vector; import java.io.InputStream; import java.io.OutputStream; import java.io.IOException; import javax.activation.DataSource; /** * Multipart is a container that holds multiple body parts. Multipart * provides methods to retrieve and set its subparts. <p> * * Multipart also acts as the base class for the content object returned * by most Multipart DataContentHandlers. For example, invoking getContent() * on a DataHandler whose source is a "multipart/signed" data source may * return an appropriate subclass of Multipart. <p> * * Some messaging systems provide different subtypes of Multiparts. For * example, MIME specifies a set of subtypes that include "alternative", * "mixed", "related", "parallel", "signed", etc. <p> * * Multipart is an abstract class. Subclasses provide actual implementations. * * @author John Mani */ public abstract class Multipart { /** * Vector of BodyPart objects. */ protected Vector<BodyPart> parts = new Vector<>(); // Holds BodyParts /** * This field specifies the content-type of this multipart * object. It defaults to "multipart/mixed". */ protected String contentType = "multipart/mixed"; // Content-Type /** * The <code>Part</code> containing this <code>Multipart</code>, * if known. * @since JavaMail 1.1 */ protected Part parent; /** * Default constructor. An empty Multipart object is created. */ protected Multipart() { } /** * Setup this Multipart object from the given MultipartDataSource. <p> * * The method adds the MultipartDataSource's BodyPart * objects into this Multipart. This Multipart's contentType is * set to that of the MultipartDataSource. <p> * * This method is typically used in those cases where one * has a multipart data source that has already been pre-parsed into * the individual body parts (for example, an IMAP datasource), but * needs to create an appropriate Multipart subclass that represents * a specific multipart subtype. * * @param mp Multipart datasource * @exception MessagingException for failures */ protected synchronized void setMultipartDataSource(MultipartDataSource mp) throws MessagingException { contentType = mp.getContentType(); int count = mp.getCount(); for (int i = 0; i < count; i++) addBodyPart(mp.getBodyPart(i)); } /** * Return the content-type of this Multipart. <p> * * This implementation just returns the value of the * <code>contentType</code> field. * * @return content-type * @see #contentType */ public synchronized String getContentType() { return contentType; } /** * Return the number of enclosed BodyPart objects. <p> * * @return number of parts * @exception MessagingException for failures * @see #parts */ public synchronized int getCount() throws MessagingException { if (parts == null) return 0; return parts.size(); } /** * Get the specified Part. Parts are numbered starting at 0. * * @param index the index of the desired Part * @return the Part * @exception IndexOutOfBoundsException if the given index * is out of range. * @exception MessagingException for other failures */ public synchronized BodyPart getBodyPart(int index) throws MessagingException { if (parts == null) throw new IndexOutOfBoundsException("No such BodyPart"); return parts.elementAt(index); } /** * Remove the specified part from the multipart message. * Shifts all the parts after the removed part down one. * * @param part The part to remove * @return true if part removed, false otherwise * @exception MessagingException if no such Part exists * @exception IllegalWriteException if the underlying * implementation does not support modification * of existing values */ public synchronized boolean removeBodyPart(BodyPart part) throws MessagingException { if (parts == null) throw new MessagingException("No such body part"); boolean ret = parts.removeElement(part); part.setParent(null); return ret; } /** * Remove the part at specified location (starting from 0). * Shifts all the parts after the removed part down one. * * @param index Index of the part to remove * @exception IndexOutOfBoundsException if the given index * is out of range. * @exception IllegalWriteException if the underlying * implementation does not support modification * of existing values * @exception MessagingException for other failures */ public synchronized void removeBodyPart(int index) throws MessagingException { if (parts == null) throw new IndexOutOfBoundsException("No such BodyPart"); BodyPart part = parts.elementAt(index); parts.removeElementAt(index); part.setParent(null); } /** * Adds a Part to the multipart. The BodyPart is appended to * the list of existing Parts. * * @param part The Part to be appended * @exception IllegalWriteException if the underlying * implementation does not support modification * of existing values * @exception MessagingException for other failures */ public synchronized void addBodyPart(BodyPart part) throws MessagingException { if (parts == null) parts = new Vector<>(); parts.addElement(part); part.setParent(this); } /** * Adds a BodyPart at position <code>index</code>. * If <code>index</code> is not the last one in the list, * the subsequent parts are shifted up. If <code>index</code> * is larger than the number of parts present, the * BodyPart is appended to the end. * * @param part The BodyPart to be inserted * @param index Location where to insert the part * @exception IllegalWriteException if the underlying * implementation does not support modification * of existing values * @exception MessagingException for other failures */ public synchronized void addBodyPart(BodyPart part, int index) throws MessagingException { if (parts == null) parts = new Vector<>(); parts.insertElementAt(part, index); part.setParent(this); } /** * Output an appropriately encoded bytestream to the given * OutputStream. The implementation subclass decides the * appropriate encoding algorithm to be used. The bytestream * is typically used for sending. * * @param os the stream to write to * @exception IOException if an IO related exception occurs * @exception MessagingException for other failures */ public abstract void writeTo(OutputStream os) throws IOException, MessagingException; /** * Return the <code>Part</code> that contains this <code>Multipart</code> * object, or <code>null</code> if not known. * * @return the parent Part * @since JavaMail 1.1 */ public synchronized Part getParent() { return parent; } /** * Set the parent of this <code>Multipart</code> to be the specified * <code>Part</code>. Normally called by the <code>Message</code> * or <code>BodyPart</code> <code>setContent(Multipart)</code> method. * <code>parent</code> may be <code>null</code> if the * <code>Multipart</code> is being removed from its containing * <code>Part</code>. * * @param parent the parent Part * @since JavaMail 1.1 */ public synchronized void setParent(Part parent) { this.parent = parent; } }