Patterns in JavaTM, Volume 3 Java Enterprise Java Enterprise Design Patterns phần 5 potx

... thing that you should do to ensure the consis-tency of a transaction is testing. The Unit Testing and System Testing patterns described in Patterns in Java, Volume 2 are useful in designingappropriate ... FOURTransaction Patterns ■ 45 wrapper objects are simply discarded. The class diagram in Figure 4 .3 shows this sort of design. In this design, the objects that the transaction manipulates need notcontain ... ObjectInputStream object, you can write some codethat looks like this:FileInputStream fin = new FileInputSteam("filename.ser");ObjectInputStream obIn = new ObjectInputStream(fin);This...

... collaboration are worth examining in greater detail.Completion of Pending CallsIt may be possible for the new instance to finish what the oldinstance started if everything it needs to finish is copied ... way of doing things and Java s way of doing things.Remote Method Invocation (RMI) is a Java- based Object RequestBroker implementation that is part of the core Java API. Because RMI is Java- based, ... readConfirmFIGURE 5. 9 Migration of a mobile agent.124■CHAPTER FIVETABLE 5. 1 (Continued)Current Environment New Environment3A Since the instance of the (cont.) mobile agent in the new environment...

... writing software for a new kind of smart food processor that turnsraw ingredients into cooked, ready-to-eat food by slicing, dicing, mixing,boiling, baking, frying, and/or stirring the ingredients. ... CORBA naming service. Instead of bindingnames to proxies, it binds them to something called an InteroperableObject Reference (IOR). An IOR is a string that has, embedded in it, all of the information ... listeners.Distributed Computing Patterns ■1 85 java. security.Guard. This is not a role. It is an actual interfacedefined in the Java API. The ProtectionProxy class may havethe responsibility of determining whether...

... = this .in; int c1 = in. read();int c2 = in. read();int c3 = in. read();int c4 = in. read();if ((c1 | c2 | c3 | c4) < 0)throw new EOFException();Distributed Computing Patterns ■2273A. Call ... read(byte[], int, int)The read method uses the readInt method to read the byte countsthat the server inserts into the data stream.private final int readInt() throws IOException {InputStream in = ... of data bytes in the incoming message.4C .3. The Multiplexer object reads the data bytes in the incomingmessage into an internal buffer.4C.4. The Multiplexer object passes its internal buffer...

... object.InputStream in = actualSocket.getInputStream();int otherBufferSize= new DataInputStream (in) .readInt();BufferedInputStream bin;bin = new BufferedInputStream (in) ;actualIn = new DataInputStream(bin);// ... connection.266■CHAPTER SIXRELATED PATTERNS Singleton. The Singleton pattern (described in Volume 1) uses asingle instance of a class for an entire program. The Session pat-tern uses a single instance of a class ... occurs.*/protected InputStream getInputStream() throws IOException {checkClosed();if (in= =null || in. isClosed()) { in = new ChunkedInputStream(theSocket);} // ifreturn in; } // getInputStream()/***...

... findInsertionIndex(node);expirations.add(insertionIndex, node);} // scheduleRemoval(LinkedList)/*** Determine where in a LinkedList an object belongs* based on expiration times.*/private int findInsertionIndex(LinkedList ... TransactionHistory by* putting its LinkedList object in an ArrayList that* is sorted by expiration time.*/synchronized void scheduleRemoval(LinkedList node) {int insertionIndex = findInsertionIndex(node);expirations.add(insertionIndex, ... the machine that they are running on from beingswamped with too many threads.Concurrency Patterns ■ 30 5 «interface»Executorexecute(:Runnable) «interface»RunnableHolds-tasks-waiting-for-a-thread...

... ifint latestIndex = 0;Interval latestInterval = intervals[latestIndex];for (int i=1; i<length; i++) {if (intervals[i].endsAfter(latestInterval)) {latestIndex = i;latestInterval = intervals[i];Temporal ... ifint latestIndex = 0;Interval latestInterval = intervals[latestIndex];for (int i=1; i<length; i++) {if (intervals[i].endsAfter(latestInterval)) {latestIndex = i;latestInterval = intervals[i];} ... CHAPTERTemporal Patterns 34 7Time Server (34 9)Versioned Object ( 35 5) Temporal Property (37 3)The patterns in this chapter describe ways that applications managetime-related data. There are only a few patterns...