Java Network Programming

Errata for Java Network Programming

Submit your own errata for this product.


The errata list is a list of errors and their corrections that were found after the product was released. If the error was corrected in a later version or reprint the date of the correction will be displayed in the column titled "Date Corrected".

The following errata were submitted by our customers and approved as valid errors by the author or editor.

Color Key: Serious Technical Mistake Minor Technical Mistake Language or formatting error Typo Question Note Update



Version Location Description Submitted By Date Submitted Date Corrected
Printed
Page xxi
4th paragraph

At the bottom of the page it says "You can download the source code from http://metalab.unc.edu/javafaq/books/jnp2e and http://www.reilly.com/catalog/9781565928701/." http://www.reilly.com/catalog/9781565928701/. SHOULD SAY http://www.oreilly.com/catalog/9781565928701/.

Anonymous   
Printed
Page xvii
In Figure P-1, the box between Chapter 15 and Chapter 17 now

reads: Chapter 16, Protocol Handlers

Anonymous    Dec 01, 2000
Printed
Page xxi
At the very bottom of the page the URL for the O'Reilly web site is

has been changed to: http://www.oreilly.com/catalog/9781565928701/ The "o" was missing in oreilly.

Anonymous    Dec 01, 2000
Printed
Page 7
first paragraph

"content handers" should read "content handlers"

Anonymous   
Printed
Page 20
In the contents box at the top of page 20

"The Layers of a Netowrk" now reads: "The Layers of a Network."

Anonymous    Dec 01, 2000
Printed
Page 42
Table 2-2 (Last Selection on that Page; RFC 792)

Page 42 in "Table 2-2. Selected Internet RFCs" on the last RFC of that page: RFC 792 Internet Control Message Protocol (ICMF) It should be "ICMP" not ICMF :-) p. 60: In the first line of the first text paragraph, "HTT 1.0" should be "HTTP 1.0" p. 88: In the first sentence of the second paragraph, "servers as a buffer" should be "serves as a buffer".

Anonymous   
Printed
Page 51
The last sentence on the page now reads, "Although there's some

hierarchy to the newsgroup names indicated by the . between netscape and netscape.devs-java, it's not visible as part of the URI." That is, the period after "between netscape" has been removed.

Anonymous    Dec 01, 2000
Printed
Page 60
In the first line of the first paragraph,

"(HTT 1.0)" now reads "(HTTP 1.0)".

Anonymous    Dec 01, 2000
Printed
Page 69
The last sentence in the first paragraph

now reads, "Furthermore, the client side interface to servlets is almost exactly like the client side interface to CGI programs, so what we say about talking to CGI programs will apply equally to talking to servlets."

Anonymous    Dec 01, 2000
Printed
Page 69
First full sentence

The sentence used to read: Furthermore, the client-side interface to servlets is almost exactly like the client-side interface to servlets, so what I say about talking to CGI programs will apply equally to talking to servlets. The sentence now reads: Furthermore, the client-side interface to CGI is almost exactly like the client-side interface to servlets, so what I say about talking to CGI programs will apply equally to talking to servlets. The second line: "connection is open" Now reads: "URLConnection is connected"

Anonymous    Aug 01, 2001
Printed
Page 99
last code

The CipherOutputStream() signature is wrong , it reads : public CipherOutputStream(InputStream in, Cipher c); should be public CipherOutputStream(OutputStream out,Cipher c);

Anonymous   
Printed
Page 99
The first complete sentence on this page

now reads, "The sender can calculate the digest as it sends data, while the receiver calculates the digest as it receives data."

Anonymous    Dec 01, 2000
Printed
Page 99
In line 7

In line 7, "Alternativly" now reads "Alternatively".

Anonymous    Dec 01, 2000
Printed
Page 101
The first sentence of the Readers and Writers section

The first sentence of the Readers and Writers section now reads: "Most programmers have a bad habit of writing code as if all text were ASCII, or at the least in the native encoding of the platform."

Anonymous    Dec 01, 2000
Printed
Page 121
Last paragraph

A period was missing between the third and fourth sentences of the last paragraph. It now reads: Most of the time, however, you'll want to pass the information to other parts of the program. You can store the result of the calculation in a field and provide a getter method to return the value of that field.

Anonymous    Dec 01, 2000
Printed
Page 133
In the first paragraph:

"Notice the addition of a <code>start()</code> method" now reads: "Notice the addition of the <code>calculateDigest()</code> method to start the thread."

Anonymous    Mar 01, 2001
Printed
Page 134
Code segment

one definate error is that the method declaration is out of order for "public void synchronized sendDigest (byte[] digest) {" it should read: "public synchronized void sendDigest (byte[] digest) {" AUTHOR: This is correct. p. 161: If there are directories, already gzipped files, or other incompressible files, the thread is likely not to exit when it should. To fix this, move the call to incrementFilesCompressed() from the fifth line on p. 162 to right after the line that removes a file from the pool on p. 161. Then the run() method should read as follows: public void run() { while (filesCompressed != GZipAllFiles.getNumberOfFilesToBeCompressed()) { File input = null; synchronized (pool) { while (pool.isEmpty()) { if (filesCompressed == GZipAllFiles.getNumberOfFilesToBeCompressed()) { System.out.println("Thread ending"); return; } try { pool.wait(); } catch (InterruptedException ex) { } } input = (File) pool.remove(pool.size()-1); incrementFilesCompressed(); } // don't compress an already compressed file if (!input.getName().endsWith(".gz")) { try { InputStream in = new FileInputStream(input); in = new BufferedInputStream(in); File output = new File(input.getParent(), input.getName() + ".gz"); if (!output.exists()) { // Don't overwrite an existing file OutputStream out = new FileOutputStream(output); out = new GZIPOutputStream(out); out = new BufferedOutputStream(out); int b; while ((b = in.read()) != -1) out.write(b); out.flush(); out.close(); in.close(); } } catch (IOException e) { System.err.println(e); } } // end if } // end while } // end run p. 163: The example is not always adding files at the begining of the queue like it should. In the synchronized block change pool.add(files[j]); to pool.add(0, files[j]);

Anonymous   
Printed
Page 151

All three versions of the join() method including the noargs variant can throw an InterruptedException. Thus the first method signature on the page now reads: public final void join() throws InterruptedException

Anonymous    Dec 01, 2000
Printed
Page 159
Thread Pools

In line 6 of the first paragraph of the Thread Pools section, "for a even a low-" now reads "for even a low".

Anonymous    Dec 01, 2000
Printed
Page 163
Towards the bottom of the main method.

This code may enter an infinite wait state. When the main method finishes adding all the files to the pool it calls for (int i = 0; i < threads.length; i++) threads[i].interrupt(); } If a thread picks up the last file and is still processing it when this loop is called, all the threads will wake up, notice that the pool is empty, but the condition (filesCompressed == GZipAllFiles.getNumberOfFilesToBeCompressed()) will still be false until the running thread finishes the last file. This will place all other threads in a wait state never to be woken up. This happened to me which is how I was alerted to the problem. A way to fix this is to ammend the loop to read: while(threads[0].getFilesCompressed() != filesToBeCompressed); for (int i = 0; i < threads.length; i++ ) { threads[i].interrupt(); } Of course this will necessitate adding a public int getFilesCompressed() method to the GZipThread class. AUTHOR: This is correct. p. 170: In the third text paragraph, "explicitly via getAddress" should be "explicitly via getHostName". p. 189: In the processLogFile() method in Example 6-11, PooledWeblog, the body of the try block should read as follows: String entry = in.readLine(); while (entry != null) { if (entries.size() > numberOfThreads) { try { Thread.sleep((long) (1000.0/numberOfThreads)); } catch (InterruptedException e) {} continue; } synchronized (entries) { entries.add(0, entry); entries.notifyAll(); } entry = in.readLine(); Thread.yield(); } // end while

Anonymous   
Printed
Page 177
The second sentence of the third paragraph

The second sentence of the third paragraph now reads, "The conditional operator ? tests whether signedByte is negative." That is, unsignedByte has been changed to signedByte.

Anonymous    Mar 01, 2001
Printed
Page 189
Example 6-11

In the processLogFile() method in Example 6-11, PooledWeblog, bin.readLine() now reads in.readLine().

Anonymous    Dec 01, 2000
Printed
Page 195
3rd Para

In the third paragraph, "foloowing" now reads "following".

Anonymous    Mar 01, 2001
Printed
Page 220
In Example 7-8, the line

System.out.println(URLEncoder.encode("Thisstring"has"quote"marks")); was missing a quote mark after the first slash. It now reads: System.out.println(URLEncoder.encode("This"string"has"quote"marks"));

Anonymous    Mar 01, 2001
Printed
Page 252
First paragraph

Text refers to ParserGetter class from example 8-5 This class is in fact from example 8-6 p. 265: Two changes should be made to Example 8-10 on this page. First you need to test if the local directory exists before trying to make it. That is, change if (localDirectory.mkdirs()) { to if (localDirectory.exists() || localDirectory.mkdirs()) { Next, to make PageSaver work with documents that use a meta tag such as <meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1">, you need to change parser.parse(r, callback, false); to parser.parse(r, callback, true);

Anonymous   
Printed
Page 275
1st paragraph

Example 9-5 is a complete applet that downloads a sound file called gong.au, which is located in the same directory as the applet, ... should be: Example 9-5 is a complete applet that downloads a sound file called beep.au, which is located in the sounds directory just below the document base, ...

Anonymous   
Printed
Page 307
The first code fragment now reads

try { InetAddress OReilly = InetAddress.getByName("www.oreilly.com"); Socket OReillySocket = new Socket(OReilly, 80); // send and receive data... } catch (UnknownHostException e) { System.err.println(e); } catch (IOException e) { System.err.println(e); }

Anonymous    Dec 01, 2000
Printed
Page 308
The code fragment at the bottom of the page now reads

try { InetAddress fddi = InetAddress.getByName("fddisunsite.oit.unc.edu"); Socket OReillySocket = new Socket("www.oreilly.com", 80, fddi, 0); // work with the sockets... } catch (UnknownHostException e) { System.err.println(e); } catch (IOException e) { System.err.println(e); }

Anonymous    Dec 01, 2000
Printed
Page 309
The code fragment toward the bottom of the page now reads

try { InetAddress metalab = InetAddress.getByName("metalab.unc.edu"); InetAddress oreilly = InetAddress.getByName("www.oreilly.com"); Socket oreillySocket = new Socket(oreilly, 80, metalab, 0); } catch (UnknownHostException e) { System.err.println(e); } catch (IOException e) { System.err.println(e); }

Anonymous    Dec 01, 2000
Printed
Page 312
first code fragment

Uses deprecated Socket constructor AUTHOR: The fix is to change Socket theSocket = new Socket("java.sun.com", 80, true); to Socket theSocket = new Socket("java.sun.com", 80, true); That is, delete the third argument. p. 364: In the first line, jServerSocket should be ServerSocket (delete the initial j).

Anonymous   
Printed
Page 323-324
In Example 10-7

the finally block was attached to the wrong try block. It is now inside the for loop. Here's the corrected program: import java.net.*; import java.io.*; public class PortScanner { public static void main(String[] args) { String host = "localhost"; if (args.length > 0) { host = args[0]; } try { InetAddress theAddress = InetAddress.getByName(host); for (int i = 1; i < 65536; i++) { Socket connection = null; try { connection = new Socket(host, i); System.out.println("There is a server on port " + i + " of " + host); } catch (IOException e) { // must not be a server on this port } finally { try { if (connection != null) connection.close(); } catch (IOException e) {} } } // end for } // end try catch (UnknownHostException e) { System.err.println(e); } } // end main } // end PortScanner

Anonymous    Mar 01, 2001
Printed
Page 327

InterruptedException has been changed to: InterruptedIOException

Anonymous    Mar 01, 2001
Printed
Page 354
In the code fragment in the middle of the page,

InetAddress.getHostByName now reads InetAddress.getByName

Anonymous    Mar 01, 2001
Printed
Page 372
In the main() method, on the last line of the page,

"args.length >= 2" should be "args.length > 2".

Anonymous   
Printed
Page 374
Last sentence of the 1st paragraph

"However, that would raise some additional issues of thread safety that Example 11-5 doesn't have to address because it's immutable." should be: "However, that would raise some additional issues of thread safety that Example 11-6 doesn't have to address because it's p. 384: In order to better handle unexpected network failures (broken sockets), near the bottom of the page change if (c == ' ' || c == ' ') break; to if (c == ' ' || c == ' ' || c == -1) break;

Anonymous   
Printed
Page 385
About three quarters of the way down the page, at the end of the second code block:

} // end try now reads: } // end if

Anonymous    Mar 01, 2001
Printed
Page 391
Note, last sentence

"...Scott Oak's 'Java Security'..." SHOULD BE: "...Scott Oaks' 'Java Security'..." p. 392: In the third paragraph, jre/lib/ext/security/java.security should be jre/lib/security/java.security. That is, delete ext/ from the path. p. 392: In the second to last paragraph, java.policy should be java.security.

Anonymous   
Printed
Page 414
Figure 13-1; Eighth byte

"destination port" Should read: "checksum"

Anonymous   
Printed
Page 427-429
Examples 13-3 and 13-4

Example 13-3 and 13-4 share a mutual bug. Both assume they're using the local host's default encoding. However, is these two programs run of different hosts (for instance, one is a Japanese system and one is a French system) that may well not be the same for each. The encoding needs to be explicitly specified in both programs. On p. 427 in Example 13-3 change byte[] data = theLine.getBytes() to byte[] data = theLine.getBytes("UTF-8") On p. 429 in Example 13-4 change String s = new String(packet.getData(), 0, packet.getLength()) to String s = new String(packet.getData(), 0, packet.getLength(), "UTF-8") This will allow the two hosts to exchange data regardless of differing encodings. p. 433: In the fith code line, change new ServerSocket(2048) to new DatagramSocket(2048). It should read: DatagramSocket ds = new DatagramSocket(2048) p. 448: In the second paragraph, EchoInputThread should be SenderThread.

Anonymous   
Printed
Page 465
3rd code snippet

in the 3rd code snippet it says: ia = new InetAddress("metalab.unc.edu"); shouldn't it say ia = InetAddress.getByName("metalab.unc.edu"); Their is no public constructor for InetAddress(jdk 1.3)

Anonymous   
Printed
Page 476
1st paragraph, 1st line

Example 15-5 is not right exmaple in this paragraph. instead of Example 15-5, Example 7-5 is right example that should be written. p. 485: In the second line of the first code fragment on the page, last-modification should be last-modified. That is, change long lastModified = uc.getHeaderFieldDate("last-modification", 0); to long lastModified = uc.getHeaderFieldDate("last-modified", 0);

Anonymous   
Printed
Page 492
The first line of the second to last code fragment on the page

"GET / HTTP 1.1" Now reads: "GET / HTTP/1.1"

Anonymous    Aug 01, 2001
Printed
Page 498
The first line of thesecond to last code fragment on the page

"POST /cgi-bin/register.pl HTTP 1.0" Now reads: "POST /cgi-bin/register.pl HTTP/1.0"

Anonymous    Aug 01, 2001
Printed
Page 499
The first bold line on the page

"POST /cgi-bin/post-query HTTP 1.0" Now reads: "POST /cgi-bin/post-query HTTP/1.0"

Anonymous    Aug 01, 2001
Printed
Page 502
in item 1,

change "you'll use send data to the CGI program" to "you'll send to the CGI program".

Anonymous   
Printed
Page 506
1st paragraph

java.io.Permission should be: java.security.Permission

Anonymous   
Printed
Page 509
In the first row of the table on this page

"! XPM2" should be "!XPM2", and should be placed in the ASCII column, not the hexadecimal column.

Anonymous   
Printed
Page 510
The first line of the code fragment at the bottom of the page

"HEAD / catalog/jfcnut/index.html HTTP 1.1" Now reads: "HEAD / catalog/jfcnut/index.html HTTP/1.1"

Anonymous    Aug 01, 2001
Printed
Page 512
The first line of the code fragment at the bottom of the page

"OPTIONS /xml/ HTTP 1.1" Now reads: "OPTIONS /xml/ HTTP/1.1"

Anonymous    Aug 01, 2001
Printed
Page 513
The first line of the first code fragment in the DELETE section

"DELETE /javafaq/1999march.html HTTP 1.1" Now reads: "DELETE /javafaq/1999march.html HTTP/1.1"

Anonymous    Aug 01, 2001
Printed
Page 514
The first line of the large code fragment in the middle of the page

"PUT /hello.html HTTP 1.0" Now reads: "PUT /hello.html HTTP/1.0"

Anonymous    Aug 01, 2001
Printed
Page 515
The first code fragment

"TRACE /xml/ HTTP 1.1" Now reads: "TRACE /xml/ HTTP/1.1"

Anonymous    Aug 01, 2001
Printed
Page 515
The following line

"TRACE /xml/ HTTP 1.1" Now reads: "TRACE /xml/ HTTP/1.1"

Anonymous    Aug 01, 2001
Printed
Page 515
The third text paragraph

"TRACE /xml/ HTTP 1.1" Now reads: "TRACE /xml/ HTTP/1.1"

Anonymous    Aug 01, 2001
Printed
Page 516
At the end of the first paragraph of the "Handling Server responses" section,

delete ", and follows the response MIME header".

Anonymous   
Printed
Page 516
The code fragment in the middle of the page

"HTTP 1.1 200 OK" Now reads: "HTTP/1.1 200 OK"

Anonymous    Aug 01, 2001
Printed
Page 516
The last code fragment on the page

"HTTP 1.1 404 Not Found" Now reads: "HTTP/1.1 404 Not Found"

Anonymous    Aug 01, 2001
Printed
Page 517
The second code fragment

"HTTP 1.1 301 Moved Permanently" Now reads: "HTTP/1.1 301 Moved Permanently"

Anonymous    Aug 01, 2001
Printed
Page 520
In Table 15-3, in the 406 row

"Allow field of the MIME request header" should be "Accept field of the MIME request header"

Anonymous   
Printed
Page 522
Example 15-10

"HTTP 1.x" Now reads: "HTTP/1.x"

Anonymous    Aug 01, 2001
Printed
Page 523
The first code fragment change

"HTTP 1.x" Now reads: "HTTP/1.x"

Anonymous    Aug 01, 2001
Printed
Page 534
In the last heading on the page,

change "Protected" to "protected"

Anonymous   
Printed
Page 536
In the last heading on the page,

change "Protected" to "protected"

Anonymous   
Printed
Page 536
In the last paragraph,

change "has been stored in the URL's host field" to "has been stored in the URL's file field"

Anonymous   
Printed
Page 537-540
In all the headings on these pages,

change "Protected" to "protected"

Anonymous   
Printed
Page 564

In point 5 change "URLConnectiongetContent() method" to "URLConnection.getContent() method". Also, note that the word "method" should not be monospaced here

Anonymous   
Printed
Page 603
3rd paragraph

The source code for the FibonacciImpl.java (Chapter 18 , Example 18.2): This class extends UnicastRemoteObject and also calls the exportObject(this) on this class, which results in doing the same thing twice.(Which results in an exception stating object already exported..) This is a mistake only in the source code suppiled on the web site, in the text book this class doesn't extend UnicastRemoteObject. Here is the code snippet from web site: public class FibonacciImpl extends UnicastRemoteObject implements Fibonacci { public FibonacciImpl() throws RemoteException { UnicastRemoteObject.exportObject(this); // setLog(System.out); } Fix: Only one of the two things shd be done:- 1) Extend the UnicastRemoteObject class 2) use exportObject() method

Anonymous   
Printed
Page 606
12th line of the example 18-4

The error message of the first System.err.println should be "Usage: java FibonacciClient ..." instead of "Usage: java Fibonacci client ...", because class' name is FibonacciClient.

Anonymous   
Printed
Page 614
12th line of the example 18-8

The error message of the first System.err.println should be "Usage: java FibonacciClient ..." instead of "Usage: java Fibonacci client ...", because the class' name is FibonacciClient.

Anonymous   
Printed
Page 622
In the 3rd paragraph,

"perfomed" should be "performed" p. 636: In the third paragraph, delete "like the one shown in Figure 19-1".

Anonymous   
Printed
Page 648
In the last paragraph,

"a simple HELLO command" should be "a simple HELO command"

Anonymous   
Printed
Page 654
In the note,

"java.netPasswordAuthentication" should be "java.net.PasswordAuthentication" and "javax.mailPasswordAuthentication" should be "javax.mail.PasswordAuthentication" p. 693: In Example 19-12, AllPartsClient, I have a couple of small improvements. Change the two lines: if (fileName == null && (disposition.equals(Part.ATTACHMENT) || !contentType.equals("text/plain"))) { to if (fileName == null && (Part.ATTACHMENT.equalsIgnoreCase(disposition) || !contentType.equalsIgnoreCase("text/plain"))) { This avoids a possible NullPointerException and handles case insensitive MIME type and disposition matching. p. 727: In the second column the reference to "SO TIMEOUT socket optionn" should be "SO_TIMEOUT socket option"; that is, use an underscore instead of a space..

Anonymous   
Printed
Page 693
In Example 19-12

"if (fileName == null && (disposition.equals(Part.ATTACHMENT) || !contentType.equals("text/plain"))) {" Now reads: "if (fileName == null && (Part.ATTACHMENT.equals(disposition) || !contentType.equalsIgnoreCase("text/plain"))) {"x

Anonymous    Aug 01, 2001