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Created by voodoo on August 03, 2012 08:42:38    Last update: August 03, 2012 09:31:25
The C function getsockopt lets you get the error codes with the option SO_ERROR . The possible error numbers are defined in the global errno.h . The relevant values are: #define ETIMEDOUT 110 /* Connection timed out */ ... But here's the whole list on my Linux system ( /usr/include/asm-generic/errno.h ): #ifndef _ASM_GENERIC_ERRNO_H #define _ASM_GENER...
Created by Dr. Xi on July 11, 2011 12:24:10    Last update: July 11, 2011 12:25:44
This code snippet import java.util.*; public class UncheckedCast ... fails with a compilation error and a warning: $ javac -Xlint:unchecked UncheckedCast.java Unc... Because List<String> is not a reifiable type, the Java Runtime does not have enough information to verify the type or do the type casting. This is fixed by changing List<String> to List<?> (or to the raw type List ): public static void main(String[] args) { Ob...
Created by jinx on April 25, 2011 12:43:40    Last update: April 25, 2011 12:43:40
Use the PHP function method_exists to check if the class or object has a certain method. It returns TRUE if the method exists (even when the value of the property is NULL), FALSE if the method does not exist. Example: <?php class A { var $p = 'A property'; ... Outputs: Class A has method f1: bool(true) Object $a has... Also note that C++-like method overloading does not exist in PHP. Thus there's no ambiguity about which version of the method exists, i.e., with no argument, with one argument... etc. The following code generates Fatal error: <?php class A { var $p = 'A property'; ...
Created by Dr. Xi on February 09, 2009 23:14:15    Last update: February 09, 2009 23:14:15
This example demonstrates the general steps in creating a custom Java class loader. Normally a class loader would consult its parent class loader when asked to load a class. If it's not loaded by the parent class loader, then the class loader would try to load the class on its own. This class loader tries to load the requested class on its own first, and delegates to the parent only when a java.lang.SecurityException is thrown (which happens when it tries to load core Java classes such as java.lang.String ). The classes are loaded from CLASSPATH through the getResourceAsStream call. It's important to note that when a class is loaded with a certain class loader, all classes referenced from that class are also loaded through the...
Created by Dr. Xi on January 30, 2009 16:57:12    Last update: January 30, 2009 17:25:36
The scriptable attribute defaults to false . However, even when you set it to true , there is a time delay between when the applet is loaded and when it becomes scriptable . The following code may fail: <html><body> <object classid="clsid:8AD9C840-04... You need to wrap the JavaScript like this: <script language="JavaScript" type="text/javascrip...