Messages and Parts - JavaMail API - page 39

There are two methods to set the recipients of the message while replacing any previous
recipients and two methods to add recipients to the message:
public abstract void setRecipients ( Message . RecipientType type ,
Address [] addresses ) throws MessagingException , IllegalWriteException ,
IllegalStateException
public void setRecipient ( Message . RecipientType type , Address address )
throws MessagingException , IllegalWriteException
public abstract void addRecipients ( Message . RecipientType type ,
Address [] addresses ) throws MessagingException ,
IllegalWriteException , IllegalStateException
public void addRecipient ( Message . RecipientType type , Address address )
throws MessagingException , IllegalWriteException
All four of these methods can throw a MessagingException , typically because one of
the addresses isn't in the right format. They can also throw an IllegalWriteExcep
tion if the specified field of the given Message object cannot be changed or an Ille
galStateException if the entire Message object is read-only.
The Subject of the Message
Since the subject is simply a single string of text, it's easy to get and set with these two
methods:
public abstract String getSubject () throws MessagingException
public abstract void setSubject ( String subject ) throws
MessagingException , IllegalWriteException , IllegalStateException
As with earlier setter methods, the getter returns null if the subject field isn't present
in the message. The setter throws an IllegalWriteException if the program isn't al‐
lowed to set the value of the Subject: field and an IllegalStateException if the
program isn't allowed to change the message at all.
The Date of the Message
Messages also have sent and received dates. Three methods allow programs to access
these fields:
public abstract Date getSentDate () throws MessagingException
public abstract void setSentDate ( Date date ) throws MessagingException ,
IllegalWriteException , IllegalStateException
public abstract Date getReceivedDate () throws MessagingException
The underlying implementation is responsible for converting the textual date format
found in a message header like “Wed, 20 Aug 2014 10:57:04 0700” to a java.util.Date
object. As usual, a MessagingException indicates some problem with the format of the
underlying message, an IllegalWriteException indicates that the field cannot be
changed, and an IllegalStateException indicates that the entire message cannot be
changed.