It will be:

    UTF8

See [here][1] for the definitions.


  [1]: http://download.oracle.com/javase/6/docs/technotes/guides/intl/encoding.doc.html

If, running an Oracle HotSpot JDK 1.7.x, on a Linux platform where your locale suggests UTF-8 (e.g. `LANG=en_US.utf8`), if you don&#39;t set it on the command-line with `-Dfile.encoding`, the JDK will default `file.encoding` and the default `Charset` like this:

    System.out.println(String.format(&quot;file.encoding: %s&quot;, System.getProperty(&quot;file.encoding&quot;)));
    System.out.println(String.format(&quot;defaultCharset: %s&quot;, Charset.defaultCharset().name()));

... yields:

    file.encoding: UTF-8
    defaultCharset: UTF-8

... suggesting the default is `UTF-8` on such a platform.

Additionally, if `java.nio.charset.Charset.defaultCharset()` finds `file.encoding` not-set, it looks for `java.nio.charset.Charset.forName(&quot;UTF-8&quot;)`, suggesting it prefers that string, although it is well-aliased, so &quot;UTF8&quot; will also work fine.

If you run the same program on the same platform with `java -Dfile.encoding=UTF8`, without the hypen, it yields:

    file.encoding: UTF8
    defaultCharset: UTF-8

... noting that the default charset has been canonicalized from `UTF8` to `UTF-8`.

This is not a direct answer, but very useful if you don&#39;t have access to how java starts: you can set the environment variable `JAVA_TOOLS_OPTIONS` to `-Dfile.encoding=&quot;UTF-8&quot;` and every time the jvm starts it will pick up that option.

`
[INFO] BUILD SUCCESS  
Picked up JAVA_TOOL_OPTIONS: -Dfile.encoding=UTF8  
`
Anyway, it works for me:)

In c++ I would do

    class A
    {
    public:
        virtual void stuff()
        {
            //something
        }
    };

    class B : public A
    public:
        virtual void stuff()
        {
            //something2
            A::stuff() //something
        }
    };

How would I do this in C#?
I&#39;ve tried

    public void stuff()
    {
        //something2
        A.stuff(); //something
    }

but that doesn&#39;t work

Calling a base class&#39; method

Whats the difference between multitasking, multiprogramming &amp; multiprocessing

This comes regularly for my university OS exams and I can&#39;t find a good answer.
I know quite a bit about multitasking and multiprogramming, but need to confirm it.

Difference between multitasking, multithreading and multiprocessing?

I would like to know what is the value of the Java Virtual Machine (JVM) property to set my file encoding to UTF-8.

Do I put `-Dfile.encoding=UTF8` or `-Dfile.encoding=UTF-8`?


JVM property -Dfile.encoding=UTF8 or UTF-8?

<p>I would like to know what is the value of the Java Virtual Machine (JVM) property to set my file encoding to UTF-8.</p>
<p>Do I put <code>-Dfile.encoding=UTF8</code> or <code>-Dfile.encoding=UTF-8</code>?</p>


&gt; **Possible Duplicate:**  
&gt; [File to byte\[\] in Java](https://stackoverflow.com/questions/858980/file-to-byte-in-java)  

&lt;!-- End of automatically inserted text --&gt;

I want to read data from file and unmarshal it to Parcel.
In documentation it is not clear, that FileInputStream has method to read all its content. To implement this, I do folowing:

    FileInputStream filein = context.openFileInput(FILENAME);
    

    int read = 0;
    int offset = 0;
    int chunk_size = 1024;
    int total_size = 0;

    ArrayList&lt;byte[]&gt; chunks = new ArrayList&lt;byte[]&gt;();
    chunks.add(new byte[chunk_size]);
    //first I read data from file chunk by chunk
    while ( (read = filein.read(chunks.get(chunks.size()-1), offset, buffer_size)) != -1) {
        total_size+=read;
        if (read == buffer_size) {
             chunks.add(new byte[buffer_size]);
        }
    }
    int index = 0;
    
    // then I create big buffer        
    byte[] rawdata = new byte[total_size];
    
    // then I copy data from every chunk in this buffer
    for (byte [] chunk: chunks) {
        for (byte bt : chunk) {
             index += 0;
             rawdata[index] = bt;
             if (index &gt;= total_size) break;
        }
        if (index&gt;= total_size) break;
    }

    // and clear chunks array
    chunks.clear();

    // finally I can unmarshall this data to Parcel
    Parcel parcel = Parcel.obtain();
    parcel.unmarshall(rawdata,0,rawdata.length);

I think this code looks ugly, and my question is:
How to do read data from file into byte[] beautifully? :)


Elegant way to read file into byte[] array in Java

Is there a way to convert this:

    /C:/Users/David/Dropbox/My%20Programs/Java/Test/bin/myJar.jar
into this?:

    C:\Users\David\Dropbox\My Programs\Java\Test\bin\myJar.jar

I am using the following code, which will return the full path of the .JAR archive, or the /bin directory.

    fullPath = new String(MainInterface.class.getProtectionDomain()
    			.getCodeSource().getLocation().getPath());

The problem is, `getLocation()` returns a `URL` and I need a normal windows filename.
I have tried adding the following after `getLocation()`:

`toString()` and `toExternalForm()` both return:
	
    file:/C:/Users/David/Dropbox/My%20Programs/Java/Test/bin/

`getPath()` returns:
	
    /C:/Users/David/Dropbox/My%20Programs/Java/Test/bin/

Note the `%20` which should be converted to space.
  
Is there a quick and easy way of doing this? 

Convert URL to normal windows filename Java

I am sure this is an easy one; I just couldn&#39;t find the answer *immediately* from Google.

I know I could do this (right?):

	text = &quot;&quot;
	File.open(path).each_line do |line|
		text += line
	end

	# Do something with text

But that seems a bit excessive, doesn&#39;t it? Or is that the way one would do it in Ruby?

What&#39;s a reasonable way to read an entire text file as a single string?

The following questions are meant for bash and linux only: 

1. Is there a limit on the number of characters in the absolute path name of a file?  
2. Is there a limit on the number of characters for the filename (without extension) only?  

If so, what might these limits be? How can I access them in case they are system specific? 

Limit on file name length in bash

I&#39;d like to read numbers from file into two dimensional array. 

File contents:

 - line containing w, h
 - h lines containing w integers separated with space

For example:

    4 3
    1 2 3 4
    2 3 4 5
    6 7 8 9


How to read numbers from file in Python?

Does Node.js have built-in Base64 encoding yet?

The reason why I ask this is that `final()` from `crypto` can only output hexadecimal, binary or ASCII data. For example:

    var cipher = crypto.createCipheriv(&#39;des-ede3-cbc&#39;, encryption_key, iv);
    var ciph = cipher.update(plaintext, &#39;utf8&#39;, &#39;hex&#39;);
    ciph += cipher.final(&#39;hex&#39;);

    var decipher = crypto.createDecipheriv(&#39;des-ede3-cbc&#39;, encryption_key, iv);
    var txt = decipher.update(ciph, &#39;hex&#39;, &#39;utf8&#39;);
    txt += decipher.final(&#39;utf8&#39;);

According to the documentation, `update()` can output Base64-encoded data. However, `final()` doesn&#39;t support Base64. I tried and it will break.

If I do this:

    var ciph = cipher.update(plaintext, &#39;utf8&#39;, &#39;base64&#39;);
        ciph += cipher.final(&#39;hex&#39;);

Then what should I use for decryption? Hexadecimal or Base64?

Therefore, I&#39;m looking for a function to Base64-encode my encrypted hexadecimal output.




How can I do Base64 encoding in Node.js?

Consider:

    $ cat bla.py 
    u = unicode(&#39;d…&#39;)
    s = u.encode(&#39;utf-8&#39;)
    print s
    $ python bla.py 
      File &quot;bla.py&quot;, line 1
    SyntaxError: Non-ASCII character &#39;\xe2&#39; in file bla.py on line 1, but no encoding declared; see http://www.python.org/peps/pep-0263.html for details

How can I declare UTF-8 strings in source code?


Working with UTF-8 encoding in Python source

I found that in `123 `, `\d` matches `1` and `3` but not `2`. I was wondering if `\d` matches a digit satisfying what kind of requirement? I am talking about Python style regex. 

Regular expression plugin in Gedit is using Python style regex. I created a text file with its content being 

    123

Only `1` and `3` are matched by the regex `\d`; `2` is not.

Generally for a sequence of digit numbers without other characters in between, only the odd order digits are matches, and the even order digits are not. For example in `12345`, the matches are `1`, `3` and `5`. 


Does &quot;\d&quot; in regex mean a digit?

With Python 3 I am requesting a json document from a URL.

    response = urllib.request.urlopen(request)

The `response` object is a file-like object with `read` and `readline` methods. Normally a JSON object can be created with a file opened in text mode.

    obj = json.load(fp)

What I would like to do is:

    obj = json.load(response)

This however does not work as urlopen returns a file object in binary mode.

A work around is of course:

    str_response = response.read().decode(&#39;utf-8&#39;)
    obj = json.loads(str_response)

but this feels bad...

Is there a better way that I can transform a bytes file object to a string file object? Or am I missing any parameters for either `urlopen` or `json.load` to give an encoding?

Let JSON object accept bytes or let urlopen output strings

I know what `base64` encoding is and how to calculate `base64` encoding in C#, however I have seen several times that when I convert a string into base64, there is an `=` at the end.

A few questions came up:

 1. Does a `base64` string always end with `=`?
 2. Why does an `=` get appended at the end?

Why does a base64 encoded string have an = sign at the end

I wonder why most modern solutions built using Perl don&#39;t enable [UTF-8][1] by default.

I understand there are many legacy problems for core Perl scripts, where it may break things. But, from my point of view, in the 21&lt;sup&gt;st&lt;/sup&gt; century, big new projects (or projects with a big perspective) should make their software UTF-8 proof from scratch. Still I don&#39;t see it happening. For example, [Moose][2] enables strict and warnings, but not [Unicode][3]. [Modern::Perl][4] reduces boilerplate too, but no UTF-8 handling.

Why? Are there some reasons to avoid UTF-8 in modern Perl projects in the year 2011?

---

Commenting @tchrist got too long, so I&#39;m adding it here.

It seems that I did not make myself clear. Let me try to add some things.

**tchrist** and I see situation pretty similarly, but our conclusions are completely in opposite ends. I agree, the situation with Unicode is complicated, but this is why we (Perl users and coders) need some layer (or pragma) which makes UTF-8 handling as easy as it must be nowadays.

**tchrist** pointed to many aspects to cover, I will read and think about them for days or even weeks. Still, this is not my point. **tchrist** tries to prove that there is not one single way &quot;to enable UTF-8&quot;. I have not so much knowledge to argue with that. So, I stick to live examples.

I played around with [Rakudo][5] and UTF-8 was just there **as I needed**. I didn&#39;t have any problems, it just worked. Maybe there are some limitation somewhere deeper, but at start, all I tested worked as I expected.

Shouldn&#39;t that be a goal in modern Perl&amp;nbsp;5 too? I stress it more: I&#39;m not suggesting UTF-8 as the default character set for core Perl, I suggest the possibility to trigger it **with a snap** for those who develop **new** projects.

Another example, but with a more negative tone. Frameworks should make development easier. Some years ago, I tried web frameworks, but just threw them away because &quot;enabling UTF-8&quot; was so obscure. I did not find how and where to hook Unicode support. It was so time-consuming that I found it easier to go the old way. Now I saw here there was a bounty to deal with the same problem with [Mason][6] 2: *[How to make Mason2 UTF-8 clean?][7]*. So, it is pretty new framework, but using it with UTF-8 needs deep knowledge of its internals. It is like a big red sign: STOP, don&#39;t use me!

I really like Perl. But dealing with Unicode is painful. I still find myself running against walls. Some way **tchrist** is right and answers my questions: new projects don&#39;t attract UTF-8 because it is too complicated in Perl&amp;nbsp;5.

  [1]: http://en.wikipedia.org/wiki/UTF-8
  [2]: http://en.wikipedia.org/wiki/Moose_%28Perl%29
  [3]: http://en.wikipedia.org/wiki/Unicode
  [4]: http://search.cpan.org/~chromatic/Modern-Perl-1.03/lib/Modern/Perl.pm
  [5]: http://en.wikipedia.org/wiki/Rakudo_Perl
  [6]: http://en.wikipedia.org/wiki/Mason_%28Perl%29
  [7]: https://stackoverflow.com/questions/5858596/how-to-make-mason2-utf8-clean


Why does modern Perl avoid UTF-8 by default?

Does anybody know how to set the encoding in FPDF package to UTF-8? Or at least to ISO-8859-7 (Greek) that supports Greek characters?

Basically I want to create a PDF file containing Greek characters.

Any suggestions would help.
George

FPDF utf-8 encoding (HOW-TO)

I have a database table that contains Swedish/Norwegian strings.

When I query some data, I get output like this:

## Output with `set names latin1;`

	+-----------------------------------+
	| name                              |
	+-----------------------------------+
	| Kid Interi#####                   | 
	| Bwg Homes                         | 
	| If Skadef####kring                | 
	| Jangaard Export                   | 
	| Nordisk Film                      | 
	+-----------------------------------+

Now if I `set names utf8;` in order to see the characters with their proper encoding, then the formatting of the tabular output of the MySQL command line breaks.

## Output with `set names utf8;`

	+-----------------------------------+
	| name                              |
	+-----------------------------------+
	| Kid Interi&#248;r                     | 
	| Bwg Homes                         | 
	| If Skadef&#246;rs&#228;kring              | 
	| Jangaard Export                   | 
	| Nordisk Film                      | 
	+-----------------------------------+

## Question:
This is not a big issue but it makes the output a bit harder to read. Does anybody know how to keep the tabular formatting intact?





MySQL command line formatting with UTF8

I&#39;m using ruby 1.9.2

I&#39;m trying to **parse a CSV file** that contains some French words (e.g. sp&#233;cifi&#233;) and place the contents in a MySQL database.


When I read the lines from the CSV file,

    file_contents = CSV.read(&quot;csvfile.csv&quot;, col_sep: &quot;$&quot;)

The elements come back as Strings that are **ASCII-8BIT** encoded (sp&#233;cifi&#233; becomes sp\xE9cifi\xE9), and strings like &quot;sp&#233;cifi&#233;&quot; are then NOT properly saved into my MySQL database. 

[Yehuda Katz][1] says that ASCII-8BIT is really &quot;binary&quot; data meaning that CSV has no idea how to read the appropriate encoding.

So, if I try to make CSV force the encoding like this:

`file_contents = CSV.read(&quot;csvfile.csv&quot;, col_sep: &quot;$&quot;, encoding: &quot;UTF-8&quot;)` 

I get the following error

    ArgumentError: invalid byte sequence in UTF-8: 

If I go back to my original ASCII-8BIT encoded Strings and examine the String that my CSV read as ASCII-8BIT, it looks like this &quot;Non sp\xE9cifi\xE9&quot; instead of &quot;Non sp&#233;cifi&#233;&quot;.

I can&#39;t convert &quot;Non sp\xE9cifi\xE9&quot; to &quot;Non sp&#233;cifi&#233;&quot; by doing this 
`&quot;Non sp\xE9cifi\xE9&quot;.encode(&quot;UTF-8&quot;)` 

because I get this error: 

`Encoding::UndefinedConversionError: &quot;\xE9&quot; from ASCII-8BIT to UTF-8`, 

which Katz indicated would happen because ASCII-8BIT isn&#39;t really a proper String &quot;encoding&quot;.

**Questions:**

 1. **Can I get CSV to read my file in the appropriate encoding?  If so, how?**
 2. **How do I convert an ASCII-8BIT string to UTF-8 for proper storage in MySQL?** 

  [1]: http://yehudakatz.com/2010/05/05/ruby-1-9-encodings-a-primer-and-the-solution-for-rails/

Ruby read CSV file as UTF-8 and/or convert ASCII-8Bit encoding to UTF-8

What are the roots in garbage collection?

I have read the definition of root as &quot;any reference that you program can access to&quot; and definition of live is that an object that is being used, which can be a local variable, static variable.

I m little confused with discriminating the difference between root and live objects.

What is path to root? How does root and live objects work?

Can someone elaborate ? 



What are the roots?

Given this program:

    class Test {
        public static void main(String[] args) {
            try {
                throw new NullPointerException();
            } catch (NullPointerException npe) {
                System.out.println(&quot;In catch&quot;);
            } finally {
                System.out.println(&quot;In finally&quot;);
            }
        }
    }

Sun&#39;s `javac` (v 1.6.0_24) produces the following bytecode:

    public static void main(java.lang.String[]);

            // Instantiate / throw NPE
       0:   new     #2;         // class NullPointerException
       3:   dup
       4:   invokespecial   #3; // Method NullPointerException.&quot;&lt;init&gt;&quot;:()V
       7:   athrow
    
            // Start of catch clause
       8:   astore_1
       9:   getstatic       #4; // Field System.out
       12:  ldc     #5;         // &quot;In catch&quot;
       14:  invokevirtual   #6; // Method PrintStream.println
       17:  getstatic       #4; // Field System.out
    
            // Inlined finally block
       20:  ldc     #7;         // String In finally
       22:  invokevirtual   #6; // Method PrintStream.println
       25:  goto    39
    
            // Finally block
            // store &quot;incomming&quot; exception(?)
       28:  astore_2
       29:  getstatic       #4; // Field System.out
       32:  ldc     #7;         // &quot;In finally&quot;
       34:  invokevirtual   #6; // Method PrintStream.println
    
            // rethrow &quot;incomming&quot; exception
       37:  aload_2
       38:  athrow
    
       39:  return

With the following exception table:

      Exception table:
       from   to  target type
         0     8     8   Class NullPointerException
         0    17    28   any
        28    29    28   any

&lt;br/&gt;
My question is: **Why on earth does it include that last entry in the exception table?!** 
&lt;br/&gt;&lt;br/&gt;
As I understand it, it basically says &quot;*if the `astore_2` throws an exception, catch it, and retry the same instruction*&quot;.

Such entry is produced even with empty try / catch / finally clauses such as

    try {} catch (NullPointerException npe) {} finally {}


----------

**Some observations**

- Eclipse compiler does not produce any such exception table entry
- The JVM spec does not document any runtime exceptions for [the `astore` instruction](http://java.sun.com/docs/books/jvms/second_edition/html/Instructions2.doc.html#astore).
- I know that it is legal for the JVM to throw `VirtualMachineError` for any instruction. I guess the peculiar entry prevents any such errors from propagating out from that instruction.

Strange exception table entry produced by Sun&#39;s javac

Why is the name of the language, &quot;Clojure&quot;? 

I googled a bit, asked in #clojure. So far, no luck.

Why is Clojure named Clojure

I keep hearing about all the new cool features that are being added to the JVM and one of those cool features is invokedynamic. I would like to know what it is and how does it make reflective programming in Java easier or better?

What&#39;s invokedynamic and how do I use it?

If I have multiple files of the same name on classpath (e.g. I have multiple `.jar` with `log4j.properties`), what are the rules JVM follows to chose one?


Content Type	Original Author	Original Content on Stackoverflow
Question	astrotouf	View Question on Stackoverflow
Solution 1 - File	planetjones	View Answer on Stackoverflow
Solution 2 - File	javabrett	View Answer on Stackoverflow
Solution 3 - File	Pedro Madrid	View Answer on Stackoverflow
Solution 4 - File	Milimetric	View Answer on Stackoverflow
Solution 5 - File	livejq	View Answer on Stackoverflow

JVM property -Dfile.encoding=UTF8 or UTF-8?

File Problem Overview

File Solutions

Solution 1 - File

Solution 2 - File

Solution 3 - File

Solution 4 - File

Solution 5 - File

Difference between multitasking, multithreading and multiprocessing?

Calling a base class' method

Attributions