Java Newsletters: Java Newsletters Archive: 154

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=== [ The Java FAQ Daily Tips, weekly publication ] ===

Foreword: Excuse me for possible mistakes. English is not native language for me.

In this issue:

Hello dear friends!

Question: What is the difference between applets loaded over the net and applets loaded via the file system?

Answer: There are two different ways that applets are loaded by a Java system. The way an applet enters the system affects what it is allowed to do.

If an applet is loaded over the net, then it is loaded by the applet class loader, and is subject to the restrictions enforced by the applet security manager.

If an applet resides on the client's local disk, and in a directory that is on the client's CLASSPATH, then it is loaded by the file system loader. The most important differences are

• applets loaded via the file system are allowed to read and write files
• applets loaded via the file system are allowed to load libraries on the client
• applets loaded via the file system are allowed to exec processes
• applets loaded via the file system are allowed to exit the virtual machine
• applets loaded via the file system are not passed through the byte code verifier
• Java-enabled browsers use the applet class loader to load applets specified with file: URLs. So, the restrictions and protections that accrue from the class loader and its associated security manager are now in effect for applets loaded via file: URLs.

This means that if you specify the URL like so:

Location: file:/home/me/public_html/something.html
and the file something.html contains an applet, the browser loads it using its applet class loader.

-
From Java Applet Security FAQ

Question: How do I encode a binary file before sending it and how do I decode it when I receive it?

Answer: You don't need to. JavaMail will automatically determine an appropriate encoding to use for your message parts before sending the message, and will automatically decode message parts when reading them. The getInputStream method will return the decoded data.

how to write into a file?!
could anyone show me how to write into a file via a socket using client-server program ! ? ? thank you..
topic here...

Stop before shutdown
Hi evebody,
I need to stop the browser shutoff before close it (like when we close the Operating System and there is a modified document opened).
Is there something like this?
topic here

banking system-please help!
Hi everyone,
I've got an assignment to hand in a week time, i was just wondering if anyone is willing to help me out with it.
the problem iam facing at the moment is to take the input from a text field and insert it into a file.
the whole program is about a banking system which the user is able to Credit, Debit and check the balance of his or her account. the following is the specification of the program.
topic here....

Database connectivity using J2EE Server
Hello All,
I'm using J2EE server (v1.3) , While connecting to the Sql Server 2000 / Oracle 8 database I'm getting an RMI Exception.
If any of you have worked on similar lines.
one more thing to add , It connects with cloudscape database very well. I know there is some discripnancy in my settings.
Kindly guide me. Thanks in advance.
topic here...

Java File Explorer implementation
Does anyone know where to get open source for a java implemented file explorer?
topic here ...

Capture and Management Key Event ...
Hi!
I'm writting a program for edit images. My problem is how to capture key events like 'ctrl+c' o something like this. I use a JFrame where are the menu options a menu bar and in others JWindows I paint and have a Tool window. The JFrame are the 'father' o this JWindows, of course. The problem is that I can't capture the key events anyway.
I've tried two different ways. First, I thought, of course badly, to use this code in the JFrame:

...
topic here...

regexp problem - smallest possible match on string
I need some help on simple regular expression.
Just say I have a string for example:
String str = "start start start match1 finish finish finish";
I would like to extract the smallest string that is bounded by "start" and "finish"... ie. in this case I would like to extract the string "match1".
My first guess was to use:
pattern = "start (.*?) finish";
however this matches the
topic here...

Please ask your questions and help each other at our Java Forum:
http://javafaq.nu/forum/

The Java FAQ Daily Tips is a newsletter that is only sent to those who have specifically subscribed to it (double opt-in).

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You will get the answer immediately from autoresponder!

Send your comments, questions, praise and complaints to us: comments@javafaq.nu

Copyright (c) 2000 - 2003 John Andersson, All rights reserved.

16 comments |    | Java Newsletters | Score: 0

Java Newsletters: Java Newsletters Archive: 153

  Click here to read full story

=== [ The Java FAQ Daily Tips, weekly publication ] ===

Foreword: Excuse me for possible mistakes. English is not native language for me.

In this issue:

Hello dear friends!

Question: How do I hide system properties that applets are allowed to read by default?

Answer: There's no way to hide the ten system properties (see below) from applets loaded into a Java-enabled browser. The reason is that the browsers don't consult any external files as part their Java configuration, as a security precaution, including the ~/.hotjava/properties file.

From the appletviewer, you can prevent applets from finding out anything about your system by redefining the property in your ~/.hotjava/properties file. For example, to hide the name of the operating system that you are using, add this line to your ~/.hotjava/properties file:

os.name=null

Ten OS propertis that accessible by applet:
java.version
java.vendor
java.vendor.url
java.class.version
os.name
os.arch
os.version
file.separator
path.separator
line.separator

-
From Java Applet Security FAQ
Java wimps please close your ears ... For the Java programmer who
thought he knew everything there was to know about Java, have a
look at the most advanced Java newsletter archived on the website
http://www.smotricz.com/kabutz Guess what, it won't even cost you
anything! Subscribe today - you won't be disappointed.

Question: Is text file binary?

Joke, not answer:
Yes, ALL FILES are binary, even text files... Because a file is a series of bits...
And bits are binary...

Question: I want to to have a listener for a String's change event. Is it possible?

Answer: String has no such listener because you can not change a String.
Strictly saying a String can not be changed. Each time when you change a value of an "old" String Java creates a new String and then refers to "old" one.
However you can write a wrapper class which has two methods - setString() and getString(). The body of those two methods could have additional code that notifies about String's "change" event. Something like this:

public void setString (String aString) {
this.aString = aString;
stringValueChanged();
}

The method stringValueChanged() is responsible for notification

how to write into a file?!
could anyone show me how to write into a file via a socket using client-server program ! ? ? thank you..
topic here...

Stop before shutdown
Hi evebody,
I need to stop the browser shutoff before close it (like when we close the Operating System and there is a modified document opened).
Is there something like this?
topic here

banking system-please help!
Hi everyone,
I've got an assignment to hand in a week time, i was just wondering if anyone is willing to help me out with it.
the problem iam facing at the moment is to take the input from a text field and insert it into a file.
the whole program is about a banking system which the user is able to Credit, Debit and check the balance of his or her account. the following is the specification of the program.
topic here....

Database connectivity using J2EE Server
Hello All,
I'm using J2EE server (v1.3) , While connecting to the Sql Server 2000 / Oracle 8 database I'm getting an RMI Exception.
If any of you have worked on similar lines.
one more thing to add , It connects with cloudscape database very well. I know there is some discripnancy in my settings.
Kindly guide me. Thanks in advance.
topic here...

Java File Explorer implementation
Does anyone know where to get open source for a java implemented file explorer?
topic here ...

Capture and Management Key Event ...
Hi!
I'm writting a program for edit images. My problem is how to capture key events like 'ctrl+c' o something like this. I use a JFrame where are the menu options a menu bar and in others JWindows I paint and have a Tool window. The JFrame are the 'father' o this JWindows, of course. The problem is that I can't capture the key events anyway.
I've tried two different ways. First, I thought, of course badly, to use this code in the JFrame:

...
topic here...

regexp problem - smallest possible match on string
I need some help on simple regular expression.
Just say I have a string for example:
String str = "start start start match1 finish finish finish";
I would like to extract the smallest string that is bounded by "start" and "finish"... ie. in this case I would like to extract the string "match1".
My first guess was to use:
pattern = "start (.*?) finish";
however this matches the
topic here...

Please ask your questions and help each other at our Java Forum:
http://javafaq.nu/forum/

The Java FAQ Daily Tips is a newsletter that is only sent to those who have specifically subscribed to it (double opt-in).

To subscribe/unsubscribe to "The Java FAQ Daily Tips" weekly edition newsletter visit our page here:
http://www.javafaq.nu/plm2html/my_subscription.shtml

If you have troubles please contact us: subscription@javafaq.nu

If you have added a link to http://javafaq.nu on your WEB-site, please let us know and you will get listed on our
"pages linking to us" pages! If your page is a programming is programming relates you will of course get listed in the WEB-directory as well. Also, if you link to us, you have a chance to be listed in this newsletter as well.

More information and graphics artworks can be found here
http://javafaq.nu/other/linktous.shtml

For information on advertising on the Java FAQ's Daily Tips Newsletter, send an email to: adv@javafaq.nu
You will get the answer immediately from autoresponder!

Send your comments, questions, praise and complaints to us: comments@javafaq.nu

Copyright (c) 2000 - 2003 John Andersson, All rights reserved.

18 comments |    | Java Newsletters | Score: 0