Core Java Technology Section Index | Page 4

TypeCasting is a feature of the language whereby you are telling the compiler (and readers of your source code :-) that you explicitly want it to treat the object as if it were really of the type ...more

There is a pretty standard way to check for this type of thing. You'll have to re-check your condition after the call to wait(timeout) returns: public synchronized boolean acquire(long waitfor){ ...more

    All Exceptions and Errors can be captured by the user using catch (Throwable t) The question might be better put 'Which types of exceptions should NOT be captured by the user?'. You...more

Precision and accuracy. double uses a fixed-size data format so it can't always be precise or accurate in its representation of numbers. On the other hand, the BigDecimal class will use as much ...more

The solution is to use a different monitor. When you make a method synchronized, you are specifying that the currently running thread should obtain a monitor (lock) on the object which has the me...more

I am looking for a monitoring tool that will give me the status of the threads inside Weblogic? We are running Weblogic Server 5.1.0 service pack 8 on HPUX 11 servers in our production environment....more

No. The local variable only holds a pointer to an object; if other threads can also point to this object, then it needs to be made thread-safe. See also How do I ensure that my servlet is thread-...more

There isn't anything very portable, but (if you're willing to provide an implementation for each of your target platforms) you can either: Have the host OS execute a new JVM (typically by calling...more

I'm in the group that pronounces it "Rhine-dahl". Some folks pronounce it "reign-dahl". Native Dutch speakers pronounce it correctly. :-)

They are in the file $JAVA_HOME/jre/lib/security/java.security. Looks like: ####################### security.provider.1=sun.security.provider.Sun security.provider.2=com.sun.crypto.provider.SunJC...more

Strings are represented as character array. Therefore, theoretical limit of String length is java.lang.Integer.MAX_VALUE. However, in most machines you will run out of memory before you could crea...more

In my knowledge, there is no special construct in Java language that allows for passing optional parameters. However, there are some workarounds that are worth considering: Use of Collections: ...more

WinZip, and the ZIP file format in particular, only supports ASCII characters for file names. The Java class ZipOutputStream can't give you a capabillity which is not supported by the underlying ...more

No, there's no structures to represent a Tree. You can use collections. A collection can contain more objects (leafs), and each leaf can be again a collection (node) and contain more leafs and so ...more

Normally web servers have their own protection system already in place. If you are running Apache, for example, or anothe NCSA compliant web server, you can rely on the standard basic authenticati...more