ClassCastException at Multipart mp = (Multipart) msg[i

Question

i want to get the attachments from emails. most of the times it works, but then i send a new mail and nothing works anymore. does anybody knows how to handle this problem, that it works really anything i need it.
here a short extract out of my code:
               Properties props = System.getProperties();
               Session session = Session.getDefaultInstance(props, null);
               Store store = session.getStore("pop3");
               store.connect(hostname, username, password);
               Folder folder = store.getFolder("INBOX");
               folder.open(Folder.READ_ONLY);
               System.out.println(folder.getMessageCount() + " Nachricht(en) vorhanden");
               Message [] msg = folder.getMessages();
               for (int i=0; i < msg.length; i++){
                    Files tmp = new Files();
                    Address[] adr = msg.getFrom();
                    tmp.setEmail(adr[0].toString());                    
                    Multipart multipart = (Multipart) msg[i].getContent();
                    String inputFile = null;
                    for(int j=0; j < multipart.getCount(); j++){
                         inputFile = processPart(multipart.getBodyPart(j));
                    }//for

Answer 1

Hi,
Only if the type of your content is multipart you should cast it to multipart.
msg.getContentType();
Tricae
maybe this code will help:
you should call the dumpPart method like this
dumpPart( msg );
Store store;
Folder folder;
static boolean verbose = false;
static boolean debug = false;
static boolean showStructure = true;
private static void dumpPart(Part part) throws
Exception {
if (part instanceof Message)
dumpEnvelope((Message) part);
/** //Dump input stream ..
InputStream is = part.getInputStream();
// If "is" is not already buffered, wrap a
BufferedInputStream
// around it.
if (!(is instanceof BufferedInputStream))
is = new BufferedInputStream(is);
int c;
while ((c = is.read()) != -1)
System.err.write(c);
pr("CONTENT-TYPE: " + part.getContentType());
* Using isMimeType to determine the content type
avoids
* fetching the actual content data until we need it.
if (part.isMimeType("text/plain")) {
pr("This is plain text");
pr("---------------------------");
if (!showStructure)
System.out.println((String) part.getContent());
} else if (part.isMimeType("multipart/*")) {
pr("This is a Multipart");
pr("---------------------------");
Multipart mp = (Multipart) part.getContent();
level++;
int count = mp.getCount();
for (int i = 0; i < count; i++)
dumpPart(mp.getBodyPart(i));
level--;
} else if (part.isMimeType("message/rfc822")) {
pr("This is a Nested Message");
pr("---------------------------");
level++;
dumpPart((Part) part.getContent());
level--;
} else if (!showStructure) {
* If we actually want to see the data, and it?s not a
* MIME type we know, fetch it and check its Java type.
Object o = part.getContent();
if (o instanceof String) {
pr("This is a string");
pr("---------------------------");
System.out.println((String) o);
} else if (o instanceof InputStream) {
System.err.println("HELLO CAU 1111");
pr("This is just an input stream");
pr("---------------------------");
InputStream is2 = (InputStream) o;
int c2;
while ((c2= is2.read()) != -1)
System.out.write(c2);
System.err.println("\nHELLO CAU");
} else {
pr("This is an unknown type");
pr("---------------------------");
pr(o.toString());
} else {
pr("This is an unknown type");
pr("---------------------------");
private static void dumpEnvelope(Message msg) throws
Exception {
pr("This is the message envelope");
pr("---------------------------");
Address[] a;
// FROM
if ((a = msg.getFrom()) != null) {
for (int j = 0; j < a.length; j++)
pr("FROM: " + a[j].toString());
//TO
if ((a = msg.getRecipients(Message.RecipientType.TO))
!= null) {
for (int j = 0; j < a.length; j++)
pr("TO: " + a[j].toString());
// SUBJECT
pr("SUBJECT: " + msg.getSubject());
// DATE
Date d = msg.getSentDate();
pr("SendDate: " + (d != null ? d.toString() :
"UNKNOWN"));
//FLAGS
Flags flags = msg.getFlags();
StringBuffer sb = new StringBuffer();
Flags.Flag[] sf = flags.getSystemFlags(); // get the
system flags
boolean first = true;
for (int i = 0; i < sf.length; i++) {
String s;
Flags.Flag f = sf;
if (f == Flags.Flag.ANSWERED)
s = "\\Answered";
else if (f == Flags.Flag.DELETED)
s = "\\Deleted";
else if (f == Flags.Flag.DRAFT)
s = "\\Draft";
else if (f == Flags.Flag.FLAGGED)
s = "\\Flagged";
else if (f == Flags.Flag.RECENT)
s = "\\Recent";
else if (f == Flags.Flag.SEEN)
s = "\\Seen";
else
continue; // skip it
if (first)
first = false;
else
sb.append(' ');
sb.append(s);
String[] uf = flags.getUserFlags(); // get user-flag
strings
for (int i = 0; i < uf.length; i++) {
if (first)
first = false;
else
sb.append(' ');
sb.append(uf[i]);
pr("FLAGS: " + sb.toString());
// X-MAILER
String[] hdrs = msg.getHeader("X-Mailer");
if (hdrs != null)
pr("X-Mailer: " + hdrs[0]);
else
pr("X-Mailer NOT available");
static String indentStr = " ";
static int level = 0;
* Print a, possibly indented, string.
public static void pr(String s) {
if (showStructure)
System.out.print(indentStr.substring(0, level * 2));
System.out.println(s);