The closest thing (not exactly the same, [`final` has other meanings](http://renaud.waldura.com/doc/java/final-keyword.shtml) too) for Java `final` fields I can think of is [`readonly`][1]: 

    public static readonly MyClass field = new MyClass(&quot;foo&quot;);

If you have a primitive type (string, int, boolean), you may want to use `const` instead.

    public const string MAGIC_STRING = &quot;Foo&quot;;

[1]: http://msdn.microsoft.com/en-us/library/acdd6hb7(VS.71).aspx

    sealed class finalClass
    {
       ...
    }



I would like to take the original URL, truncate the query string parameters, and return a cleaned up version of the URL. I would like it to occur across the whole application, so performing through the global.asax would be ideal. Also, I think a 301 redirect would be in order as well.

ie.

in: www.website.com/default.aspx?utm_source=twitter&amp;utm_medium=social-media

out: www.website.com/default.aspx


What would be the best way to achieve this?



Truncating Query String &amp; Returning Clean URL C# ASP.net

Does anyone have experience profiling a Python/SQLAlchemy app? And what are the best way to find bottlenecks and design flaws?

We have a Python application where the database layer is handled by SQLAlchemy. The application uses a batch design, so a lot of database requests is done sequentially and in a limited timespan. It currently takes a bit too long to run, so some optimization is needed. We don&#39;t use the ORM functionality, and the database is PostgreSQL.



How can I profile a SQLAlchemy powered application?

In Java I can write: 

    public final static MyClass foo = new MyClass(&quot;foo&quot;);

Is there any equivalent in C#?

What is the c# equivalent of public final static in java

In Java I can write:
<pre><code class="hljs language-java">public final static MyClass foo = new MyClass("foo");
</code></pre>
Is there any equivalent in C#?

I make a file in PC, and I want to transfer it to a [PPC][1] ([Windows Mobile][2]).

How can I get the modified date of this file?

(I need it on Windows Mobile.)

  [1]: https://en.wikipedia.org/wiki/Pocket_PC
  [2]: https://en.wikipedia.org/wiki/Windows_Mobile


How do I get modified date from file in C# on Windows Mobile?

I have a variable which I am using to represent state. It can be read and written to from multiple threads.

I am using `Interlocked.Exchange` and `Interlocked.CompareExchange` to change it. However I am reading it from multiple threads.

I know that `volatile` can be used to make sure the variable is not cached locally but always reads directly from memory.

However if I set the variable to volatile then it generates a warning about using volatile and passing using ref to the Interlocked methods.

I want to ensure that each thread is reading the most recent value of the variable and not some cached version, but I can&#39;t use volatile.

There is a `Interlocked.Read`  but it is for 64 bit types and is not available on the compact framework. The documentation for it says that it is not needed for 32 bit types as they are already performed in a single operation.

There are statements made across the internet that you don&#39;t need volatile if you are using the Interlocked methods for all your access. However you can&#39;t read a 32 bit variable using the Interlocked methods, so there is no way you can use Interlocked methods for all your access.

Is there some way to accomplish the thread safe read and write of my variable without using lock?

Interlocked and volatile

I have a string I am writing to the outputstream of the response. After I save this document and open it in Notepad++ or WordPad I get nicely formatted line breaks where they are intended, but when I open this document with the regular old Windows Notepad, I get one long text string with □ (square like symbols) where the line breaks should be.

Has anyone had any experience with this?

C# Encoding a text string with line breaks

The StreamWriter.Close() says it also closes the underlying stream of the StreamWriter. What about StreamWriter.Dispose ? Does Dispose also dispose and/or close the underlying stream

Does .Disposing a StreamWriter close the underlying stream?

I am using the String split method and I want to have the last element.
The size of the Array can change.

**Example:**

    String one = &quot;D&#252;sseldorf - Zentrum - G&#252;nnewig Uebachs&quot;
    String two = &quot;D&#252;sseldorf - Madison&quot;

I want to split the above Strings and get the last item:
   

    lastone = one.split(&quot;-&quot;)[here the last item] // &lt;- how?
    lasttwo = two.split(&quot;-&quot;)[here the last item] // &lt;- how?

I don&#39;t know the sizes of the arrays at runtime :(

   



Java: Get last element after split

There are a few topics similar to this, but I couldn&#39;t find one with a sufficient answer.

I would like to know what is the best practice for constructor overloading in Java. I already have my own thoughts on the subject, but I&#39;d like to hear more advice.

I&#39;m referring to both constructor overloading in a simple class and constructor overloading while inheriting an already overloaded class (meaning the base class has overloaded constructors).

Thanks :)





Constructor overloading in Java - best practice

Can Scala be used to script a Java application?

I need to load a piece of Scala code from Java, set up an execution scope for it (data exposed by the host application), evaluate it and retrieve a result object from it. 

The Scala documentation shows how easy it is to call compiled Scala code from Java (because it gets turned into to regular JVM bytecode).

But how can I evaluate a Scala expression on the fly (from Java or if that is easier, from within Scala) ? 

For many other languages, there is the javax.scripting interface. Scala does not seem to support it, and I could not find anything in the Java/Scala interoperability docs that does not rely on ahead-of-time compilation.





&quot;eval&quot; in Scala

I followed [the Maven tutorial](http://maven.apache.org/download.html#Installation) to the letter but I still can&#39;t get Maven installed on Windows.

When I run the following in command prompt:

    E:\Documents and Settings\zach&gt;mvn --version

I get:

    &#39;mvn&#39; is not recognized as an internal or external command, operable program or batch file.

I navigated to the maven install folder and ran `mvn --version` and got:

    E:\java resources\apache-maven-2.2.0\bin&gt;mvn --version
    ERROR: JAVA_HOME is set to an invalid directory.
    JAVA_HOME = &quot;E:\Sun\SDK\jdk\bin&quot;
    Please set the JAVA_HOME variable in your environment to match the
    location of your Java installation

but when I run `java -version` I get:

    java version &quot;1.6.0_14&quot;
    Java(TM) SE Runtime Environment (build 1.6.0_14-b08)
    Java HotSpot(TM) Client VM (build 14.0-b16, mixed mode)

So I do have Java installed. Anyone know what the problem is?


Unable to install Maven on Windows: &quot;JAVA_HOME is set to an invalid directory&quot;

I&#39;m receiving a string from an external process. I want to use that String to make a filename, and then write to that file. Here&#39;s my code snippet to do this:

        String s = ... // comes from external source
        File currentFile = new File(System.getProperty(&quot;user.home&quot;), s);
        PrintWriter currentWriter = new PrintWriter(currentFile);

If s contains an invalid character, such as &#39;/&#39; in a Unix-based OS, then a java.io.FileNotFoundException is (rightly) thrown.

How can I safely encode the String so that it can be used as a filename?

Edit: What I&#39;m hoping for is an API call that does this for me.

I can do this:

        String s = ... // comes from external source
        File currentFile = new File(System.getProperty(&quot;user.home&quot;), URLEncoder.encode(s, &quot;UTF-8&quot;));
        PrintWriter currentWriter = new PrintWriter(currentFile);

But I&#39;m not sure whether URLEncoder it is reliable for this purpose.


How can I safely encode a string in Java to use as a filename?

I want to have a class with a private static data member (a vector that contains all the characters a-z). In java or C#, I can just make a &quot;static constructor&quot; that will run before I make any instances of the class, and sets up the static data members of the class. It only gets run once (as the variables are read only and only need to be set once) and since it&#39;s a function of the class it can access its private members. I could add code in the constructor that checks to see if the vector is initialized, and initialize it if it&#39;s not, but that introduces many necessary checks and doesn&#39;t seem like the optimal solution to the problem.

The thought occurs to me that since the variables will be read only, they can just be public static const, so I can set them once outside the class, but once again, it seems sort of like an ugly hack. 

**Is it possible to have private static data members in a class if I don&#39;t want to initialize them in the instance constructor?**


static constructors in C++? I need to initialize private static objects

I am refreshing myself on OOP with PHP and I saw an example of setting functions and/or variables as static.  When and why would I set a variable/function to static?  I&#39;ve done other languages and don&#39;t really recall ever using static, I never found a real purpose to it. I know what it does but why not just use a variable instead?


When do I use static variables/functions in php?

In the example code

    void foo()
    {
      static Bar b;
      ...
    }

compiled with **GCC** is it guaranteed that `b` will be created and initialized in a thread-safe manner ?

In gcc&#39;s man page, found the **-fno-threadsafe-statics** command line option:

&gt; Do not emit the extra code to use the
&gt; routines specified in the C++ ABI for
&gt; thread-safe initialization of local
&gt; statics. You can use this option to
&gt; reduce code size slightly in code that
&gt; doesn&#39;t need to be thread-safe.

1. Does it mean, that local statics are thread-safe by default with GCC ? So no reason to put explicit guarding e.g. with `pthread_mutex_lock/unlock` ?

2. How to write portable code - how to check if compiler will add its guards ? Or is it better to turn off this feature of GCC ?

Are function static variables thread-safe in GCC?

I have this:

- one string variable which holds the class name (`$classname`)
- one string variable with holds the property name (`$propertyname`)

I want to get that property from that class, the problem is, the property is static and I don&#39;t know how to do that.

If the property weren&#39;t static, it would have been:

    $classname-&gt;$propertyname;
if the property were a method, I could have used call_user_function

    call_user_func(array($classname, $propertyname));

But in my case, am I just lost. I am however hoping that it is possible. With the thousands of functions that PHP has, he&#39;d better have something for this as well. Maybe I&#39;m missing something?


Thanks!

Edit:

- for those with [eval()][1] solutions: thanks, but it is out of the question
- for those with [get _class _vars()][2] solutions: thanks, but it seems it returns **&quot;the default properties of the given class&quot;** (php.net), and yes, I would like that value to be changable (even though it does help me in some of the cases)


  [1]: http://php.net/manual/en/function.eval.php
  [2]: http://php.net/manual/en/function.get-class-vars.php

Getting static property from a class with dynamic class name in PHP

What is the difference between static and non-static nested class?

Java: Static vs inner class

Edited:
I need to change the values of several variables as they run several times thorugh a timer. I need to keep updating the values with every iteration through the timer. I cannot set the values to final as that will prevent me from updating the values however I am getting the error I describe in the initial question below:

I had previously written what is below:

&gt;I am getting the error &quot;cannot refer to a non-final variable inside an inner class defined in a different method&quot;.
&gt;
&gt;This is happening for the double called price and the Price called priceObject. Do you know why I get this problem. I do not understand why I need to have a final declaration. Also if you can see what it is I am trying to do, what do I have to do to get around this problem.

    public static void main(String args[]) {

        int period = 2000;
        int delay = 2000;

        double lastPrice = 0;
        Price priceObject = new Price();
        double price = 0;

        Timer timer = new Timer();

        timer.scheduleAtFixedRate(new TimerTask() {
            public void run() {
                price = priceObject.getNextPrice(lastPrice);
                System.out.println();
                lastPrice = price;
            }
        }, delay, period);
    }

Cannot refer to a non-final variable inside an inner class defined in a different method

In Java, what&#39;s the difference between:

    private final static int NUMBER = 10;

and

    private final int NUMBER = 10;

Both are `private` and `final`, the difference is the `static` attribute.

What&#39;s better? And why?

private final static attribute vs private final attribute

In Java, static final variables are constants and the convention is that they should be in upper-case. However, I have seen that most people declare loggers in lower-case which comes up as a violation in [PMD][1]. 

e.g:

    private static final Logger logger = Logger.getLogger(MyClass.class);

Just search [google][2]or [SO][3] for &quot;static final logger&quot; and you will see this for yourself.

Should we be using LOGGER instead? 


  [1]: http://pmd.sourceforge.net/
  [2]: http://www.google.co.uk/search?q=%22static+final+logger%22&amp;ie=utf-8&amp;oe=utf-8&amp;aq=t&amp;rls=org.mozilla:en-GB:official&amp;client=firefox-a
  [3]: https://stackoverflow.com/search?q=%22static+final+logger%22

Should a &quot;static final Logger&quot; be declared in UPPER-CASE?

I am just trying to understand why all fields defined in an Interface are implicitly `static` and `final`. The idea of keeping fields `static` makes sense to me as you can&#39;t have objects of an interface but why they are `final` (implicitly)?

Any one knows why Java designers went with making the fields in an interface `static` and `final`?

Why are all fields in an interface implicitly static and final?

Let&#39;s start with a simple test case:

    import java.lang.reflect.Field;
    
    public class Test {
      private final int primitiveInt = 42;
      private final Integer wrappedInt = 42;
      private final String stringValue = &quot;42&quot;;
    
      public int getPrimitiveInt()   { return this.primitiveInt; }
      public int getWrappedInt()     { return this.wrappedInt; }
      public String getStringValue() { return this.stringValue; }
      
      public void changeField(String name, Object value) throws IllegalAccessException, NoSuchFieldException {
        Field field = Test.class.getDeclaredField(name);
        field.setAccessible(true);
        field.set(this, value);
        System.out.println(&quot;reflection: &quot; + name + &quot; = &quot; + field.get(this));
      }
    
      public static void main(String[] args) throws IllegalAccessException, NoSuchFieldException {
        Test test = new Test();
    
        test.changeField(&quot;primitiveInt&quot;, 84);
        System.out.println(&quot;direct: primitiveInt = &quot; + test.getPrimitiveInt());
    
        test.changeField(&quot;wrappedInt&quot;, 84);
        System.out.println(&quot;direct: wrappedInt = &quot; + test.getWrappedInt());
    
        test.changeField(&quot;stringValue&quot;, &quot;84&quot;);
        System.out.println(&quot;direct: stringValue = &quot; + test.getStringValue());
      }
    }

Anybody care to guess what will be printed as output (shown at the bottom as to not spoil the surprise immediately).

The questions are:

 1. Why do primitive and wrapped integer behave differently?
 2. Why does reflective vs direct access return different results?
 3. The one that plagues me most - why does String behave like primitive `int` and not like `Integer`?

Results (java 1.5):

    reflection: primitiveInt = 84
    direct: primitiveInt = 42
    reflection: wrappedInt = 84
    direct: wrappedInt = 84
    reflection: stringValue = 84
    direct: stringValue = 42

Modifying final fields in Java

Ok, so this may be a bit of a silly question, and there&#39;s certainly the obvious answer, but I was curious if I&#39;ve missed any subtleties here.

Is there any difference in terms of visibility/usability between a `public` member declared in an `internal` class and an `internal` member declared in an `internal` class?

i.e. between

    internal class Foo
    {
        public void Bar()
        {
        }
    }

and

    internal class Foo
    {
        internal void Bar()
        {
        }
    }

If you declared the method as `public` and also `virtual`, and then overrode it in a derived class that is `public`, the reason for using this modifier is clear. However, is this the only situation... am I missing something else?

Public and Internal members in an Internal class?

When and why should I use `public`, `private`, and `protected` functions and variables inside a class? What is the difference between them?

Examples:

    // Public
    public $variable;
    public function doSomething() {
      // ...
    }

    // Private
    private $variable;
    private function doSomething() {
      // ...
    }

    // Protected
    protected $variable;
    protected function doSomething() {
      // ...
    }

What is the difference between public, private, and protected?

I want to do this but it won&#39;t compile:

    Public MyVariable as Integer = 123

What&#39;s the best way of achieving this?


Is it possible to declare a public variable in vba and assign a default value?

Is there a difference between declaring a friend function/class as private or public? I can&#39;t seem to find anything about this online.

I mean the difference between:

    class A
    {
     public: 
          friend class B;
     };


and

    class A
    {
     private: //or nothing as the default is private
          friend class B;
     };

Is there a difference?

Friend declaration in C++ - difference between public and private

I&#39;m currently on a public WIFI spot and I&#39;m unable to use SSH (they probably blocked that port). However, I need that connection to do a `git push`.

    ➜ ssh -T git@github.com
    ssh: connect to host github.com port 22: Connection refused

Is it possible to bypass this restriction by setting up a SSH tunnel via port 80 and tell `github push` to use that connection? How to do that? I&#39;m on OSX (lion). This must be a common problem?


Content Type	Original Author	Original Content on Stackoverflow
Question	peter.murray.rust	View Question on Stackoverflow
Solution 1 - C#	mmx	View Answer on Stackoverflow
Solution 2 - C#	Steve	View Answer on Stackoverflow

What is the c# equivalent of public final static in java

C# Problem Overview

C# Solutions

Solution 1 - C#

Solution 2 - C#

How can I profile a SQLAlchemy powered application?

Truncating Query String & Returning Clean URL C# ASP.net

Attributions