- * Interface MultiDoc provides an abstraction similar to a "linked list" of - * docs. A multidoc object is like a node in the linked list, containing the + * is a group of several docs. The client passes to the Print Job an object that + * implements interface {@code MultiDoc}, and the Print Job calls methods on + * that object to obtain the print data. + *
+ * Interface {@code MultiDoc} provides an abstraction similar to a "linked list" + * of docs. A multidoc object is like a node in the linked list, containing the * current doc in the list and a pointer to the next node (multidoc) in the - * list. The Print Job can call the multidoc's {@link #getDoc() - * getDoc()} method to get the current doc. When it's ready to go - * on to the next doc, the Print Job can call the multidoc's {@link #next() - * next()} method to get the next multidoc, which contains the - * next doc. So Print Job code for accessing a multidoc might look like this: - *
+ * list. The Print Job can call the multidoc's {@link #getDoc() getDoc()} method
+ * to get the current doc. When it's ready to go on to the next doc, the Print
+ * Job can call the multidoc's {@link #next() next()} method to get the next
+ * multidoc, which contains the next doc. So Print Job code for accessing a
+ * multidoc might look like this:
+ *
+ *
* void processMultiDoc(MultiDoc theMultiDoc) {
*
* MultiDoc current = theMultiDoc;
-
+ *
* while (current != null) {
* processDoc (current.getDoc());
* current = current.next();
* }
* }
- *
- *
- * Of course, interface MultiDoc can be implemented in any way that fulfills
- * the contract; it doesn't have to use a linked list in the implementation.
- *
- * To get all the print data for a multidoc print job, a Print Service
- * proxy could use either of two patterns:
- *
- * -
- * The interleaved pattern: Get the doc from the current multidoc. Get
- * the print data representation object from the current doc. Get all the print
- * data from the print data representation object. Get the next multidoc from
- * the current multidoc, and repeat until there are no more. (The code example
- * above uses the interleaved pattern.)
- *
- *
-
- * The all-at-once pattern: Get the doc from the current multidoc, and
- * save the doc in a list. Get the next multidoc from the current multidoc, and
- * repeat until there are no more. Then iterate over the list of saved docs. Get
- * the print data representation object from the current doc. Get all the print
- * data from the print data representation object. Go to the next doc in the
- * list, and repeat until there are no more.
- *
+ *
+ * Of course, interface {@code MultiDoc} can be implemented in any way that
+ * fulfills the contract; it doesn't have to use a linked list in the
+ * implementation.
+ * + * To get all the print data for a multidoc print job, a Print Service proxy + * could use either of two patterns: + *
+ *
* To address this problem, and to simplify the design of clients providing -* multiple docs to a Print Job, every Print Service proxy that supports - * multidoc print jobs is required to access a MultiDoc object using the - * interleaved pattern. That is, given a MultiDoc object, the print service - * proxy will call {@link #getDoc() getDoc()} one or more times - * until it successfully obtains the current Doc object. The print service proxy + * multiple docs to a Print Job, every Print Service proxy that supports + * multidoc print jobs is required to access a {@code MultiDoc} object using the + * interleaved pattern. That is, given a {@code MultiDoc} object, the print + * service proxy will call {@link #getDoc() getDoc()} one or more times until it + * successfully obtains the current {@code Doc} object. The print service proxy * will then obtain the current doc's print data, not proceeding until all the * print data is obtained or an unrecoverable error occurs. If it is able to - * continue, the print service proxy will then call {@link #next() - * next()} one or more times until it successfully obtains either - * the next MultiDoc object or an indication that there are no more. An - * implementation of interface MultiDoc can assume the print service proxy will - * follow this interleaved pattern; for any other pattern of usage, the MultiDoc - * implementation's behavior is unspecified. - *
+ * continue, the print service proxy will then call {@link #next() next()} one + * or more times until it successfully obtains either the next {@code MultiDoc} + * object or an indication that there are no more. An implementation of + * interface {@code MultiDoc} can assume the print service proxy will follow + * this interleaved pattern; for any other pattern of usage, the + * {@code MultiDoc} implementation's behavior is unspecified. + *
* There is no restriction on the number of client threads that may be * simultaneously accessing the same multidoc. Therefore, all implementations of * interface MultiDoc must be designed to be multiple thread safe. In fact, a * client thread could be adding docs to the end of the (conceptual) list while * a Print Job thread is simultaneously obtaining docs from the beginning of the * list; provided the multidoc object synchronizes the threads properly, the two - * threads will not interfere with each other + * threads will not interfere with each other. */ - public interface MultiDoc { - /** * Obtain the current doc object. * - * @return Current doc object. - * - * @exception IOException - * Thrown if a error occurred reading the document. + * @return current doc object + * @throws IOException if an error occurred when reading the document */ public Doc getDoc() throws IOException; @@ -125,12 +119,9 @@ * Go to the multidoc object that contains the next doc object in the * sequence of doc objects. * - * @return Multidoc object containing the next doc object, or null if - * there are no further doc objects. - * - * @exception IOException - * Thrown if an error occurred locating the next document + * @return multidoc object containing the next doc object, or {@code null} + * if there are no further doc objects + * @throws IOException if an error occurred locating the next document */ public MultiDoc next() throws IOException; - }