My problem came from using Mockito to mock the javax.mail.Folder
required by javax.mail.internet.MimeMessage
's constructor MimeMessage(Folder, InputStream, int)
. This calls the constructor for javax.mail.Message
Message(Folder, int)
which then accesses folder.store.session
. This resulted in a NullPointerException
being thrown by the constructor for MimeMessage
.
Solution:
class ClasspathMimeMessage extends MimeMessage {
private ClasspathMimeMessage(Folder folder, InputStream is, int msgnum) throws MessagingException {
super(folder, is, 0);
}
public static MimeMessage create(String resourceName) {
Class<PopEmailMmsReceiverTest> loaderClass = PopEmailMmsReceiverTest.class;
InputStream is = loaderClass.getResourceAsStream(resourceName);
Folder inbox = new MyFolder();
try {
return new ClasspathMimeMessage(inbox, is, 0);
} catch (MessagingException ex) {
throw new RuntimeException("Unable to load email from classpath at " + loaderClass.getResource(resourceName).toString());
}
}
}
class MyFolder extends Folder {
MyFolder() {
super(createMockStore());
}
private static Store createMockStore() {
return mock(Store.class);
}
public void appendMessages(Message[] msgs) throws MessagingException {
}
public void close(boolean expunge) throws MessagingException {
}
public boolean create(int type) throws MessagingException {
return false;
}
public boolean delete(boolean recurse) throws MessagingException {
return false;
}
public boolean exists() throws MessagingException {
return false;
}
public Message[] expunge() throws MessagingException {
return null;
}
public Folder getFolder(String name) throws MessagingException {
return null;
}
public String getFullName() {
return null;
}
public Message getMessage(int msgnum) throws MessagingException {
return null;
}
public int getMessageCount() throws MessagingException {
return 0;
}
public String getName() {
return null;
}
public Folder getParent() throws MessagingException {
return null;
}
public Flags getPermanentFlags() {
return null;
}
public char getSeparator() throws MessagingException {
return 0;
}
public int getType() throws MessagingException {
return 0;
}
public boolean hasNewMessages() throws MessagingException {
return false;
}
public boolean isOpen() {
return false;
}
public Folder[] list(String pattern) throws MessagingException {
return null;
}
public void open(int mode) throws MessagingException {
}
public boolean renameTo(Folder f) throws MessagingException {
return false;
}
}
This looks very ugly to me, so if anyone has a better suggestion, I'd be delighted to hear it.