&lt;kbd&gt;F3&lt;/kbd&gt; is the typical &quot;go to implementation&quot;.  For interfaces that go to the _interface_ definition.

Instead use &lt;kbd&gt;Ctrl&lt;/kbd&gt; + &lt;kbd&gt;T&lt;/kbd&gt; to see all implementations of the interface definition.  You can then easily go to the one you want with the arrow keys and Enter.  I believe that the first one is automatically selected so that &lt;kbd&gt;Ctrl-T&lt;/kbd&gt; + &lt;kbd&gt;Enter&lt;/kbd&gt; will do what you need. 

I just checked this on my Eclipse 3.6 install: Hold control (command on Mac), hover over the method name and select &quot;Open Implementation&quot;. 

You may assign a keyboard shortcut to this action by using Window &gt; Preferences &gt; General &gt; Keys and searching for &quot;Open Implementation&quot;.

In the keymap (General &gt; Keys) search for &quot;open implementation&quot; and map it to whatever you want.  I chose &lt;kbd&gt;Ctrl&lt;/kbd&gt; + &lt;kbd&gt;Shift&lt;/kbd&gt; + &lt;kbd&gt;I&lt;/kbd&gt;.  Make sure you select &quot;Editing Java Source&quot; in the When box.  I tested it, and having the cursor over the method name and pressing &lt;kbd&gt;Ctrl&lt;/kbd&gt; + &lt;kbd&gt;Shift&lt;/kbd&gt; + &lt;kbd&gt;I&lt;/kbd&gt; took me directly to the implementation instead of showing the hierarchy that you get with &lt;kbd&gt;Ctrl&lt;/kbd&gt; + &lt;kbd&gt;T&lt;/kbd&gt;.

![enter image description here][1]

Also you can see an answer to a nearly identical question for other options:

* https://stackoverflow.com/questions/2105979/in-eclipse-ctrl-click-goes-to-the-declaration-of-the-method-i-clicked-for-inter


  [1]: http://i.stack.imgur.com/2Fu8z.png

I&#39;ve noticed recently that there are a great many algorithms out there based in part or in whole on clever uses of numbers in creative bases.  For example:

- Binomial heaps are based on binary numbers, and the more complex skew binomial heaps are based on skew binary numbers.
- Some algorithms for generating lexicographically ordered permutations are based on the factoradic number system.
- Tries can be thought of as trees that look at one digit of the string at a time, for an appropriate base.
- Huffman encoding trees are designed to have each edge in the tree encode a zero or one in some binary representation.
- Fibonacci coding is used in Fibonacci search and to invert certain types of logarithms.

My question is: **what other algorithms are out there that use a clever number system as a key step of their intuition or proof?**. I&#39;m thinking about putting together a talk on the subject, so the more examples I have to draw from, the better.

Algorithms based on number base systems?

I&#39;m trying to read an embedded text file with `System.Reflection.Assembly.GetExecutingAssembly().GetManifestResourceStream(resource);` but it gives me a `Stream`. The embedded resource is a text file so, how can I turn this `Stream` into a `TextReader`?

Get a TextReader from a Stream?

If I&#39;m in an interface and pointing to a method name, what can I do to quickly go to the ONLY implementation of that method ?

using eclipse 3.6.x

shortcut : how to get eclipse to go to the ONLY implementation of an interface&#39;s method

<p>If I'm in an interface and pointing to a method name, what can I do to quickly go to the ONLY implementation of that method ?</p>
<p>using eclipse 3.6.x</p>


My program saves encrypted product key data to the computer with the `java.util.Preferences` class (system preferences, not user).  The problem is, on both Windows and Linux (haven&#39;t tested on OSX, but it&#39;s probably the same), if I don&#39;t run the program with `sudo` or with Administrator privileges, it emits an exception or warning whenever it tries to read or save the data.

Obviously requiring the user to run the program with Admin privileges would be impractical.  Optimally, I&#39;d like the operating system to ask the user for permission.

This is quite silly, and removes half the purpose of `Preferences`.  How can this be fixed?

**Here&#39;s a summary what I need**: I need my program to ask for permission from the operating system to save system settings.

----
### Here is the error information ###

Here&#39;s the error when the when I try to read a node (because the node doesn&#39;t exist):

    Mar 18, 2011 9:41:15 AM java.util.prefs.WindowsPreferences &lt;init&gt;
    WARNING: Could not create windows registry node Software\JavaSoft\Prefs\myapp at root 0x80000002. Windows RegCreateKeyEx(...) returned error code 5.
    Mar 18, 2011 9:41:15 AM java.util.prefs.WindowsPreferences WindowsRegOpenKey1
    WARNING: Trying to recreate Windows registry node Software\JavaSoft\Prefs\myapp at root 0x80000002.
    Mar 18, 2011 9:41:15 AM java.util.prefs.WindowsPreferences openKey
    WARNING: Could not open windows registry node Software\JavaSoft\Prefs\myapp at root 0x80000002. Windows RegOpenKey(...) returned error code 2.
    Mar 18, 2011 9:41:15 AM java.util.prefs.WindowsPreferences WindowsRegOpenKey1
    WARNING: Trying to recreate Windows registry node Software\JavaSoft\Prefs\myapp\subpackage at root 0x80000002.
    Mar 18, 2011 9:41:15 AM java.util.prefs.WindowsPreferences openKey
    WARNING: Could not open windows registry node Software\JavaSoft\Prefs\myapp\subpackage at root 0x80000002. Windows RegOpenKey(...) returned error code 2.

And this is what happens when I try to write to a node:

    Mar 18, 2011 9:43:11 AM java.util.prefs.WindowsPreferences WindowsRegOpenKey1
    WARNING: Trying to recreate Windows registry node Software\JavaSoft\Prefs\myapp\subpackage at root 0x80000002.
    Mar 18, 2011 9:43:11 AM java.util.prefs.WindowsPreferences openKey
    WARNING: Could not open windows registry node Software\JavaSoft\Prefs\myapp\subpackage at root 0x80000002. Windows RegOpenKey(...) returned error code 2.

Java: java.util.Preferences Failing

I am generating a key and need to store it in DB, so I convert it into a String, but to get back the key from the String. What are the possible ways of accomplishing this?

My code is,

    SecretKey key = KeyGenerator.getInstance(&quot;AES&quot;).generateKey();
    String stringKey=key.toString();
    System.out.println(stringKey);

How can I get the key back from the String?


Converting Secret Key into a String and Vice Versa

I&#39;m trying to write an app that helps you manage your finances.  I&#39;m using an `EditText` Field where the user can specify an amount of money.

I set the `inputType` to `numberDecimal` which works fine, except that this allows people to enter numbers such as `123.122` which is not perfect for money.

Is there a way to limit the number of characters after the decimal point to two?

Limit Decimal Places in Android EditText

What is the difference between Unidirectional and Bidirectional associations?

Since the table generated in the db are all the same,so the only difference I found is that each side of the bidiretional assocations will have a refer to the other,and the unidirectional not.


**This is a Unidirectional association**

    public class User {
    	private int		id;
    	private String	name;
    	@ManyToOne
    	@JoinColumn(
    			name = &quot;groupId&quot;)
    	private Group	group;
    }
    
    public class Group {
    	private int		id;
    	private String	name;
    }
    
**The Bidirectional association**
    
    public class User {
    	private int		id;
    	private String	name;
    	@ManyToOne
    	@JoinColumn(
    			name = &quot;groupId&quot;)
    	private Group	group;
    }
    public class Group {
    	private int			id;
    	private String		name;
    	@OneToMany(mappedBy=&quot;group&quot;)
    	private List&lt;User&gt;	users;
    }


The difference is whether the group holds a reference of the user.

So I wonder if this is the only difference? which is recommended?

What is the difference between Unidirectional and Bidirectional JPA and Hibernate associations?

I am retrieving data from a database, where the field contains a String with HTML data. I want to replace all of the double quotes such that it can be used for `parseJSON` of *jQuery*.

Using Java, I am trying to replace the quotes using..

    details.replaceAll(&quot;\&quot;&quot;,&quot;\\\&quot;&quot;);
      //details.replaceAll(&quot;\&quot;&quot;,&quot;&amp;quote;&quot;); details.replaceAll(&quot;\&quot;&quot;,&quot;&amp;#34&quot;);


The resultant string doesn&#39;t show the desired change. 
An O&#39;Reilly [article][1] prescribes using Apache string utils. Is there any other way??

Is there a regex or something that I could use?


  [1]: http://oreilly.com/pub/h/1515

Replace all double quotes within String

What is the difference between the menu items rollback, backout and strip in the Mercurial Eclipse plugin?

Can I delete the commit in the local repository without modify the files in my workspace with one of this 3 commands?

Or is there another solution how I can commit and push a fix on another part of the project? My current work is not finish and I can not push it. But I must checkin a quick fix for another part of the project.

The only solution that I see is to create a second workspace. But this look like a overkill for me.

What is the difference between rollback, backout and strip in the Mercurial Eclipse plugin?

In a method I am debugging, I am spawning a new thread. I need to debug the execution of this new thread rather than the parent thread. How can I do this in eclipse?

Debugging multiple threads in eclipse

Our company is using eclipse since several years now (we are using WTP since release 0.7)

I am currently evaluating **eclipse 3.6.2 with WTP 3.2.3** which should replace eclipse 3.4.2 with WTP 3.0.4 as being our main IDE.

And I have to say that once again I am quite disappointed in concerns of performance:&lt;br&gt;
***WTP 3.2.3 seems to be much slower than 3.0.4.***&lt;br&gt;
In fact I am really wondering why WTP gets slower with each release.

One of our applications (dynamic web project) contain about **4000 java classes and 700 jsps/jsp fragments**. We only need basic WTP functionality for developing jsps, xmls and xsd. We don&#39;t need high sophistic features like [Dali][1] (should JPA tools really covered by a *webtools project*?), [Libra][2] or a [visual xml editor][3] in the first place.&lt;br&gt;

Another interesting point is that WTP seems to **slow down the whole IDE**.
SWT is non-reponsive for some fraction of seconds, cpu usage is very high (especially after a built took place - if you look at the system jobs, several jsp/javascript indexers are doing work for some minutes, even if all WTP build validators have been disabled), opening new files are slower, navigating through the project etc.

This can be especially seen on older machines which do contains only a single core cpu.

**The worst thing is that I&#39;ve got the feeling that the WTP dev team does not care much about performance**
(e.g. have a look at the http://wiki.eclipse.org/WTP_Performance_Tests page - last update took place in 2008).

Bug reports and Newsgroup posts regarding to performance of basic features (e.g. jsp editing/validating) are often ignored or closed after some time, some examples: [here][4], [here][5], [and here][6].


[Quo vadis, WTP?][7]


----------


**Please don&#39;t get me wrong:**

I don&#39;t want to blame WTP.&lt;br&gt;
In fact I believe that WTP is a good open-source project developed by a talented team.&lt;br&gt;
But obviously the **project has a problem with its quality assurance**, especially in terms of performance which affects usability and user acceptance.

I just want to point out that the team should focus on the things which are **essential to most of the users** in the first place and afterwards work on implementing super-duper-features.

**My Questions**

- What are your experiences with WTP, especially the most recent releases?
- Can you confirm or disprove my observations?
- Are there better alternatives?
- Did you switch from or to WTP and why?
- Do you have some best practices to speed it up, especially for upper-mid-sized like ours?


----------


**UPDATE**

I&#39;d like to make an update on this question to reflect the current answers and 
to sum up the current results:

- Many users complain about more or less on the same issues so I see those issues as confirmed.&lt;br&gt;
BTW, this question is also mentioned on **a news post on [theserverside.com][8]** with additional comments.

- The responsible WTP project lead, nitind, made a notable post on the current situation of WTP, which I like to cite:&lt;br&gt;
***&quot;The simple fact is that we don&#39;t spend much time on performance tests because we lack resources for doing that.&quot;***&lt;br&gt;
***&quot;Of course we&#39;d like to be proactive about it rather than reactive, but we tend to allocate our time to functional problems first.&quot;***&lt;br&gt;

So this question turns a little bit into some kind of an open letter from the community to the WTP team:

    Dear WTP team,
    
    it&#39;s obvious that WTP is suffering from major quality/performance issues 
    which you try to play down or to ignore.
    Please invest some time to improve the current situation 
    at the cost of new features and do everything what&#39;s required 
    to solve the current problems.
    E.g. revive the performance team, do some regression tests between 
    previous releases or ask the community for (precise defined) help.
    
    I am sure that they are enough people willing and able to help here.
    
    If you like, do some kind of poll to get a feeling what should be 
    the most important scopes of future&#39;s WTP releases.
    
    Please, please, listen to your community.


  [1]: http://www.eclipse.org/webtools/dali/
  [2]: http://www.eclipse.org/libra/
  [3]: http://www.eclipse.org/webtools/incubator/
  [4]: https://bugs.eclipse.org/bugs/show_bug.cgi?id=170640
  [5]: https://bugs.eclipse.org/bugs/show_bug.cgi?id=170646
  [6]: https://bugs.eclipse.org/bugs/show_bug.cgi?id=136935
  [7]: http://www.google.de/trends?q=eclipse%20WTP&amp;ctab=0&amp;geo=all&amp;date=all&amp;sort=1
  [8]: http://www.theserverside.com/news/thread.tss?thread_id=62120

Eclipse webtools project (WTP) and its performance / quality

I have a java project written using eclipse ide and I want to run it through ssh on a different machine, but I have to do this using the command line and I don&#39;t know exactly how.

I am a beginner at both shell commands and java.

Could you please give me a useful link with answers regarding this question, or perhaps a set instructions of how to do this?

Java - Build and run eclipse project from command line

I am building a Java Google App Engine server project and a Java desktop client. I would like to run them both at once, but I&#39;m not sure if this is possible using Eclipse/GAE plugin. Is there some way? I&#39;d like to be able to step through them both at the same time.

I tried opening a new instance of Eclipse, but it complained that the workspace is already in use, both projects are in the same workspace. (Perhaps I could just move them to different workspaces.)

Run two Java programs from Eclipse at once?

I&#39;m a Ruby programming trying to switch from Textmate to MacVim, and I&#39;m having trouble wading through the gargantuan lists of things you can do in VIM and all of the keypresses for them. I&#39;m tired of hearing &quot;You can use &#39;I&#39; for inserting text, or &#39;a&#39; for appending text after the character, or &#39;A&#39; for appending text at the end of the line, or…&quot; I can&#39;t imagine everyone uses all 20 different keypresses to navigate text, 10 or so keys to start adding text, and 18 ways to visually select an inner block. Or do you!?

My ideal cheat sheet would be the 30-40 most-used keypresses or commands that everyone uses for writing code on a daily basis, along with the absolute essential plugins that rubyists use daily and the 10 most-used commands for them. In theory, once I have that and start becoming as proficient in VIM as I am in Textmate, *then* I can start learning the thousands of other VIM commands that will make me **more** efficient.

Or, am I learning VIM the wrong way altogether?



What are the most-used vim commands/keypresses?

I thought this would be easy to achieve, but so far I haven&#39;t found solutions for comment/uncomment shortcut on both `Java class editor` and `jsf faceted webapp XHTML file editor` :

 1. to quickly comment/uncomment a line (like &lt;kbd&gt;ctrl&lt;/kbd&gt; + &lt;kbd&gt;d&lt;/kbd&gt; is for removing single line)
 2. being able to choose multiple lines and comment/uncomment it

---

**For example :**

**single line java code**, from :

    private String name;

into

    //private String name;

---

**multiple line java code**, from :

    private String name;
    private int age;

into

    /*private String name;
    private int age;*/

---

**single line xhtml code**, from :

    &lt;h:inputText ... /&gt;

into

    &lt;!-- h:inputText ... / --&gt;

---

**multiple line xhtml code**, from :

    &lt;h:inputTextarea
      rows=&quot;xx&quot;
      cols=&quot;yy&quot;
      ...
    /&gt;

into

    &lt;!-- h:inputTextarea
      rows=&quot;xx&quot;
      cols=&quot;yy&quot;
      ...
    / --&gt;

---


Eclipse comment/uncomment shortcut?

I&#39;m using IntelliJ IDEA, but I think this applies to any IDE.

In IDEA, some [very useful keyboard shortcuts][1] conflict with Ubuntu keyboard shortcuts. Some examples:

 - **&lt;kbd&gt;Ctrl&lt;/kbd&gt;+&lt;kbd&gt;Alt&lt;/kbd&gt;+&lt;kbd&gt;L&lt;/kbd&gt;** : formats the source code (mapped to &quot;Lock Screen&quot; in Ubuntu)
 - **&lt;kbd&gt;Ctrl&lt;/kbd&gt;+&lt;kbd&gt;Alt&lt;/kbd&gt;+&lt;kbd&gt;Left&lt;/kbd&gt;** : navigates backward (mapped to &quot;switch to workspace on the left of the current workspace&quot; in Ubuntu)
 - ...

I&#39;ve been using Ubuntu for a long time, and I&#39;m used to these shortcuts. I use them all the time to switch between workspaces, lock my session... At the same time, I know how useful the IntelliJ shortcuts can be, and I want to avoid using the mouse as much as possible.

Currently, my workaround for &quot;format source code&quot; is &lt;kbd&gt;Alt&lt;/kbd&gt;+&lt;kbd&gt;D&lt;/kbd&gt; (opens the &quot;Code&quot; menu), followed by &quot;R&quot; (&quot;Reformat Code&quot;). It works okay, since I don&#39;t format code that often, but it could be better. There is no real alternative for **&lt;kbd&gt;Ctrl&lt;/kbd&gt;+&lt;kbd&gt;Alt&lt;/kbd&gt;+&lt;kbd&gt;Left&lt;/kbd&gt;**, though.

How do you manage these conflicts in your IDE?

Do you simply remap all the conflicting IDE keyboard shortcuts to something else (and then get lost when you are pair programming with a colleague with different shortcuts...)?

Do you remap the Linux keyboard shortcuts (even though you are &quot;used&quot; to them)?

Is there a way to make keyboard shortcuts &quot;contextual&quot;? By this, I mean: hit a key to go into &quot;IDEA mode&quot; when coding (all conflicting Ubuntu shortcuts are temporarily deactivated), hit the key again to go back to &quot;Standard mode&quot; (Ubuntu shortcuts are reactived).

Do you have any other ideas / tips on how to manage this problem?

  [1]: https://stackoverflow.com/questions/294167/what-are-the-most-useful-intellij-idea-keyboard-shortcuts

Managing keyboard shortcut conflicts between IDE and OS (Ubuntu)

In previous versions of `Xcode` it was possible to create a key binding to delete the current line. There were different solutions and they are described for example here:

https://stackoverflow.com/questions/476953/xcode-delete-line-hot-key

https://stackoverflow.com/questions/551383/xcode-duplicate-delete-line

&lt;http://bigdiver.wordpress.com/2009/09/11/configure-homeend-key-bidings-on-mac-os-x/&gt;

&lt;http://www.betadesigns.co.uk/Blog/2010/02/03/custom-xcode-shortcuts/&gt;

All solutions include modifying one of these files:

&gt; ~/Library/Application Support/Xcode/Key Bindings/*.pbxkeys  
&gt; ~/Library/KeyBindings/DefaultKeyBinding.dict  
&gt; ~/Library/KeyBindings/PBKeyBinding.dict

A good resource for the existing shortcuts in `Xcode 4` is http://cocoasamurai.blogspot.com/2011/03/xcode-4-keyboard-shortcuts-now.html . There are many listed regarding deletion, but none for &quot;delete line&quot;.


BUT, these solutions do **NOT** work since `Xcode 4`. 

**Update**:
Issue is still the same as of `Xcode 5.1.1`

**Update**:
Issue is still the same as of `Xcode 6.1 GM Seed 2`

**Update**:
Still applies to Xcode Version 7.3 (7D175) as of 26th April 2016

**Update**:
Six years later Xcode 8.3 has a built-in solution. See answer below.

How do I create a Delete-Line Keyboard shortcut in Xcode 8? The Xcode 3 solutions do not work anymore

Is there a keyboard shortcut in Visual Studio (aside from &lt;kbd&gt;CTRL&lt;/kbd&gt;+&lt;kbd&gt;TAB&lt;/kbd&gt; and selection) that would take me from inside a document directly into the solution explorer? I don&#39;t want to customize any shortcuts or change any default behavior. 

Content Type	Original Author	Original Content on Stackoverflow
Question	anjanb	View Question on Stackoverflow
Solution 1 - Java	Thorbjørn Ravn Andersen	View Answer on Stackoverflow
Solution 2 - Java	Zoe	View Answer on Stackoverflow
Solution 3 - Java	digitaljoel	View Answer on Stackoverflow

shortcut : how to get eclipse to go to the ONLY implementation of an interface's method

Java Problem Overview

Java Solutions

Solution 1 - Java

Solution 2 - Java

Solution 3 - Java

Get a TextReader from a Stream?

Algorithms based on number base systems?

Attributions