Specify offline mode via `-o`/`--offline`:

    mvn -o install

[Maven book reference][1]

  [1]: http://books.sonatype.com/mvnref-book/reference/running-sect-options.html#running-sect-offline-option

Just a simple:

    mvn --offline

In the future, I recommend referring to `mvn --help`.

Maven&#39;s offline mode is invoked using `mvn -o`.

However, that alone may not be enough, because sometimes the current project refers to artifacts which are not yet present in the Maven local repository cache (`~/.m2/repository`). Attempting to build that project in offline mode will fail, because needed dependencies are missing and cannot be downloaded.

So there is another useful goal:

    mvn dependency:go-offline

This is a great command to run before hopping on a plane, which will improve your chances of `BUILD SUCCESS`. See the [go-offline documentation](http://maven.apache.org/plugins/maven-dependency-plugin/go-offline-mojo.html) for details.

`mvn -o` works in most of cases but in some cases it will not enough as from Maven 3 a downloaded  artifact from a remote/central repository creates a `_remote.repositories` file in your local repository with a reference about where the dependency was downloaded.     
It may causes some issues if later you don&#39;t have access to this remote repository during your builds.     
A  workaround that may work is using `mvn -o -llr yourGoal`.   

From the help documentation :
&lt;pre&gt;
 -llr,--legacy-local-repository         Use Maven 2 Legacy Local
                                        Repository behaviour, ie no use of
                                        _remote.repositories. Can also be
                                        activated by using
                                        -Dmaven.legacyLocalRepo=true

 -o,--offline                           Work offline
&lt;/pre&gt;

Another way to execute mvn in an offline way is deleting these `_remote.repositories` meta data stored in the directory of the downloaded dependencies.   

Try -o, or even --help to get help with all options

Im facing an issue which I believe to be VAO-dependant, but Im not sure..

I am not sure about the correct usage of a VAO, what I used to do during GL initialization was a simple

    glGenVertexArrays(1,&amp;vao)

followed by a

    glBindVertexArray(vao)

and later, in my drawing pipeline, I just called **glBindBuffer(), glVertexAttribPointer(), glEnableVertexAttribArray()** and so on.. without caring about the initally bound VAO

is this a correct practice?

OpenGL VAO best practices

I am having trouble using a calculated column in postgres. A similar code which works in SQL is given below, is it possible to recreate this in `PostgreSQL`?

    select cost_1, quantity_1, cost_2, quantity_2, 
          (cost_1 * quantity_1) as total_1,
          (cost_2 * quantity_2) as total_2,
          (calculated total_1 + calculated total_2) as total_3
    from data;

In `PostgreSQL` a similar code returns the error that:
&gt; the column total_1 and total_2 do not exist.


PostgreSQL: using a calculated column in the same query

You can specify in your maven [settings][1] file that you want to run in offline mode, but is there an equivalent command line option? 

I would imagine something like e.g.

    mvn install -Dmaven.offline.true



 [1]: http://maven.apache.org/settings.html

Is there a maven command line option for offline mode?

You can specify in your maven <a href="http://maven.apache.org/settings.html" target="_blank" rel="noopener noreferrer">settings</a> file that you want to run in offline mode, but is there an equivalent command line option?
I would imagine something like e.g.
<pre><code class="hljs language-arduino">mvn install -Dmaven.offline.true
</code></pre>

In an application I have been building we rely on SharedPreferences quite a bit, this got me thinking about what is best practice when it comes to accessing SharedPreferences.  For instance many people say the appropriate way to access it is via this call:

    PreferenceManager.getDefaultSharedPreferences(Context context)

However it seems like this could be dangerous.  If you have a large application that is relying on SharedPreferences you could have key duplication, especially in the case of using some third party library that relies on SharedPreferences as well.  It seems to me that the better call to use would be:

    Context.getSharedPreferences(String name, int mode)

This way if you have a class that heavily relies on SharedPreferences you can create a preference file that is used only by your class.  You could use the fully qualified name of the class to ensure that the file will most likely not be duplicated by someone else.

Also based on this SO question: https://stackoverflow.com/questions/4371273/should-accessing-sharedpreferences-be-done-off-the-ui-thread, it seems that accesses SharedPreferences should be done off the UI thread which makes sense.

Are there any other best practices Android developers should be aware of when using SharedPreferences in their applications?

Android SharedPreferences Best Practices

Code: 
&gt;     public class SMH extends Activity {  
&gt;
&gt;         public void onCreate(Bundle b) {  
&gt;             super.onCreate(b);  
&gt;             setContentView(R.layout.main);  
&gt; 
&gt;             TextView tv = (TextView) findViewById(R.id.tv);  
&gt; 
&gt;             new CountDownTimer(10000, 2000) {  
&gt;                 public void onTick(long m) {  
&gt;                    long sec = m/1000+1;  
&gt;                    tv.append(sec+&quot; seconds remain\n&quot;);  
&gt;                 }  
&gt;                 public void onFinish() {  
&gt;                    tv.append(&quot;Done!&quot;);  
&gt;                 }  
&gt;             }.start();  
&gt;        }

Output:  
    10 seconds remain  
    8 seconds remain  
    6 seconds remain  
    4 seconds remain  
    Done! 



Problem:  

How do I get it to show &quot;_2 seconds remain_&quot;? The time elapsed is indeed 10 seconds, but the last onTick() never happens. If I change the second parameter from 2000 to 1000, then this is the output:  
  
10 seconds remain  
9 seconds remain  
8 seconds remain  
7 seconds remain  
6 seconds remain  
5 seconds remain  
4 seconds remain  
3 seconds remain  
2 seconds remain  
Done!  
  


So you see, it seems to be skipping that last onTick() call. And btw, the XML file is basically the default main.xml with the TextView assigned the id _tv_ and the text set to &quot;&quot;.


Android: CountDownTimer skips last onTick()!

I am starting to configure my development environment and I am using Spring Tool Suite 2.8.1 along with m2E 1.01.

As far as I can tell, since this is a Maven Project (my first), my Maven POM is dictating (along with m2E smarts) my project build configuration and dependencies.

What I would like to know is why my IDE is displaying Java Build Problems that read &quot;Archive required for library *library/path/somejar.jar* cannot be read or is not a valid zip file&quot; when I can see the jars in my .m2 repository?

All the errors pertained to commons-logging:1.1.1 which I excluded in my parent-pom. This was a transistive dependancy via spring-context-support:3.0.5. I excluded that library from my build and now the errors pertain to the spring-context-support library.

I have attached a screenshot to illustrate.

![Markers][1]

  [1]: http://i.stack.imgur.com/0QfjQ.png



Compiler error &quot;archive for required library could not be read&quot; - Spring Tool Suite

I&#39;m reading a JSON response with [Gson](http://code.google.com/p/google-gson/), which returns somtimes a &lt;code&gt;NumberFormatException&lt;/code&gt; because an expected &lt;code&gt;int&lt;/code&gt; value is set to an empty string. Now I&#39;m wondering what&#39;s the best way to handle this kind of exception. If the value is an empty string, the deserialization should be 0.

Expected JSON response:

    {
       &quot;name&quot; : &quot;Test1&quot;,
       &quot;runtime&quot; : 90
    }

But sometimes the runtime is an empty string:

    {
       &quot;name&quot; : &quot;Test2&quot;,
       &quot;runtime&quot; : &quot;&quot;
    }

The java class looks like this:

    public class Foo
    {
        private String name;
        private int runtime;
    }

And the deserialization is this:

    String input = &quot;{\n&quot; +
                   &quot;   \&quot;name\&quot; : \&quot;Test\&quot;,\n&quot; +
                   &quot;   \&quot;runtime\&quot; : \&quot;\&quot;\n&quot; +
                   &quot;}&quot;;

    Gson gson = new Gson();
    Foo foo = gson.fromJson(input, Foo.class);

Which throws a &lt;code&gt;com.google.gson.JsonSyntaxException: java.lang.NumberFormatException: empty String&lt;/code&gt; because an empty String is returned instead of an int value. 

Is there a way to tell Gson, &quot;*if you deserialize the field &lt;code&gt;runtime&lt;/code&gt; of the Type &lt;code&gt;Foo&lt;/code&gt; and there is a NumberFormatException, just return the default value 0*&quot;?

My workaround is to use a &lt;code&gt;String&lt;/code&gt; as the Type of the &lt;code&gt;runtime&lt;/code&gt; field instead of &lt;code&gt;int&lt;/code&gt;, but maybe there is a better way to handle such errors.

How to handle a NumberFormatException with Gson in deserialization a JSON response

While developing a camera app I&#39;ve encountered an exception that only happened when I switch to other app (`onPause()` for my app).

    01-15 17:22:15.017: E/AndroidRuntime(14336): FATAL EXCEPTION: main
    01-15 17:22:15.017: E/AndroidRuntime(14336): java.lang.RuntimeException: Method called after release()
    01-15 17:22:15.017: E/AndroidRuntime(14336): 	at android.hardware.Camera.setPreviewDisplay(Native Method)
    01-15 17:22:15.017: E/AndroidRuntime(14336): 	at android.hardware.Camera.setPreviewDisplay(Camera.java:357)
    01-15 17:22:15.017: E/AndroidRuntime(14336): 	at com.sora.cbir.yuki.image.leaf.CameraPreview.surfaceCreated(CameraPreview.java:32)
    01-15 17:22:15.017: E/AndroidRuntime(14336): 	at android.view.SurfaceView.updateWindow(SurfaceView.java:551)
    01-15 17:22:15.017: E/AndroidRuntime(14336): 	at android.view.SurfaceView.onWindowVisibilityChanged(SurfaceView.java:213)
    01-15 17:22:15.017: E/AndroidRuntime(14336): 	at android.view.View.dispatchWindowVisibilityChanged(View.java:4075)
    01-15 17:22:15.017: E/AndroidRuntime(14336): 	at android.view.ViewGroup.dispatchWindowVisibilityChanged(ViewGroup.java:742)
    01-15 17:22:15.017: E/AndroidRuntime(14336): 	at android.view.ViewGroup.dispatchWindowVisibilityChanged(ViewGroup.java:742)
    01-15 17:22:15.017: E/AndroidRuntime(14336): 	at android.view.ViewGroup.dispatchWindowVisibilityChanged(ViewGroup.java:742)
    01-15 17:22:15.017: E/AndroidRuntime(14336): 	at android.view.ViewGroup.dispatchWindowVisibilityChanged(ViewGroup.java:742)
    01-15 17:22:15.017: E/AndroidRuntime(14336): 	at android.view.ViewRoot.performTraversals(ViewRoot.java:858)
    01-15 17:22:15.017: E/AndroidRuntime(14336): 	at android.view.ViewRoot.handleMessage(ViewRoot.java:1995)
    01-15 17:22:15.017: E/AndroidRuntime(14336): 	at android.os.Handler.dispatchMessage(Handler.java:99)
    01-15 17:22:15.017: E/AndroidRuntime(14336): 	at android.os.Looper.loop(Looper.java:150)
    01-15 17:22:15.017: E/AndroidRuntime(14336): 	at android.app.ActivityThread.main(ActivityThread.java:4389)
    01-15 17:22:15.017: E/AndroidRuntime(14336): 	at java.lang.reflect.Method.invokeNative(Native Method)
    01-15 17:22:15.017: E/AndroidRuntime(14336): 	at java.lang.reflect.Method.invoke(Method.java:507)
    01-15 17:22:15.017: E/AndroidRuntime(14336): 	at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:849)
    01-15 17:22:15.017: E/AndroidRuntime(14336): 	at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:607)
    01-15 17:22:15.017: E/AndroidRuntime(14336): 	at dalvik.system.NativeStart.main(Native Method)



I did some research and found out that I need to add

    mCamera.setPreviewCallback(null);

as a workaround for Android&#39;s camera stack

my `onPause()` now looks like this:
    
    @Override
    protected void onPause() {
        super.onPause();
	    try
	    {    
	    	// release the camera immediately on pause event   
	    	//releaseCamera();
	    	 mCamera.stopPreview(); 
	    	 mCamera.setPreviewCallback(null);
	    	 mCamera.release();
	    	 mCamera = null;

	    }
	    catch(Exception e)
	    {
	    	e.printStackTrace();
	    }
    }

and my `onResume()`:

    @Override
    protected void onResume()
    {
    	super.onResume();
    	try
    	{
    		mCamera.setPreviewCallback(null);
    		mCamera = getCameraInstance();
    		//mCamera.setPreviewCallback(null);
            mPreview = new CameraPreview(Imageupload.this, mCamera);//set preview
            preview.addView(mPreview);
        } catch (Exception e){
            Log.d(TAG, &quot;Error starting camera preview: &quot; + e.getMessage());
        }
    }	
    }

and finally my `getCameraInstance()` method:

	public Camera getCameraInstance(){
	    Camera camera = null;
	    try {
	        camera = Camera.open(); // attempt to get a Camera instance
	    }
	    catch (Exception e){
	        // Camera is not available (in use or does not exist)
	    }
	    Camera.Parameters parameters = camera.getParameters();
        //mPreviewSize = getBestPreviewSize(parameters, wt, ht);
        //mPictureSize = getBestPictureSize(parameters, wt, ht);
	    //Shift W &amp; H =&gt; if camera rotates 90 deg
	    
        mPreviewSize = getOptimalPreviewSize(parameters, wt, ht); //original =&gt; wt,ht
        mPictureSize = getOptimalPictureSize(parameters, wt, ht); //original =&gt; wt,ht
        
        Log.d(&quot;CAMERA&quot;, &quot;SCREEN RESOLUTION H: &quot;+ht);
        Log.d(&quot;CAMERA&quot;, &quot;SCREEN RESOLUTION W: &quot;+wt);
        
        Log.d(&quot;CAMERA&quot;, &quot;PREVIEW RESOLUTION H: &quot;+mPreviewSize.height);
        Log.d(&quot;CAMERA&quot;, &quot;PREVIEW RESOLUTION W: &quot;+mPreviewSize.width);
        
        Log.d(&quot;CAMERA&quot;, &quot;PICTURE RESOLUTION H: &quot;+mPictureSize.height);
        Log.d(&quot;CAMERA&quot;, &quot;PICTURE RESOLUTION W: &quot;+mPictureSize.width);
        //set preview size based on device screen
        parameters.setPreviewSize(mPreviewSize.width, mPreviewSize.height);
        //set picture size based on device screen
        parameters.setPictureSize(mPictureSize.width, mPictureSize.height);
        //set output camera mode
        parameters.setPictureFormat(PixelFormat.JPEG);
        //set focous mode
        parameters.setFocusMode(FOCUS_MODE_AUTO);
        //set flash mode
        parameters.setFlashMode(&quot;auto&quot;);
        List&lt;int[]&gt; fps = parameters.getSupportedPreviewFpsRange();
        //System.out.println(&quot;FPS size: &quot; +fps.size());
        //System.out.println(&quot;MAX FPS:&quot;+(fps.get(fps.size()-1)[1])/1000);
        //log min and max camera supported fps
        Log.d(&quot;CAMERA&quot;, &quot;CAMERA MAX FPS: &quot;+(fps.get(fps.size()-1)[1])/1000);
        Log.d(&quot;CAMERA&quot;, &quot;CAMERA MIN FPS: &quot;+(fps.get(fps.size()-1)[0])/1000);
        if(camera_fps)
        {
        	parameters.setPreviewFpsRange(fps.get(fps.size()-1)[1], fps.get(fps.size()-1)[1]);
        }
        //set camera parameters
        camera.setParameters(parameters);
        
        Toast.makeText(getApplicationContext(), &quot;Your device are capable of previewing @&quot; + fps.get(fps.size()-1)[1]/1000+&quot;fps!&quot;,Toast.LENGTH_SHORT).show();
	    return camera; // returns null if camera is unavailable
	}

any ideas on how to fix this?

method called after release() exception unable to resume with android camera

I am interested in using a &lt;a href=&quot;https://github.com/toelen/spymemcached-jcache&quot;&gt;project on GitHub&lt;/a&gt; as a dependency in my project. The GitHub project has a `pom` file. Can I modify my `pom` file to use this project? If so, how? If not, what is my best course of action?

Can I use a GitHub project directly in Maven?

How does one use Maven to support incremental builds? Is there a guide somewhere? (top Google results are disappointing)

Does Maven support incremental builds?

i was wondering if it&#39;s possible to configure run as maven install in eclipse to skip unit tests, if such thing is doable, then please tell me how to do it, thanks in advance.

How to configure maven install to skip tests in eclipse?

I am compiling a package using maven and it says build failure with following compilation error:

SpanishTest.java[31, 81] unmappable character for encoding UTF8

I searched online and for many people, changing source encoding from UTF-8 to ISO-8859-1 seems to work but I am still getting same compilation error. I am using 32-bit Ubuntu. Here is how that tag looks in my pom.xml

    &lt;project.build.sourceEncoding&gt;ISO-8859-1&lt;/project.build.sourceEncoding&gt;

Even if I change `&lt;project.build.outputEncoding&gt;` tag to ISO-8859-1, I still get the error.Could it be because of java version? I have both-sun java and openjdk installed on my system.

Can anyone please let me know what to do.

Thanks  

Content Type	Original Author	Original Content on Stackoverflow
Question	Joel	View Question on Stackoverflow
Solution 1 - Java	Dave Newton	View Answer on Stackoverflow
Solution 2 - Java	khmarbaise	View Answer on Stackoverflow
Solution 3 - Java	ctrueden	View Answer on Stackoverflow
Solution 4 - Java	davidxxx	View Answer on Stackoverflow
Solution 5 - Java	vickirk	View Answer on Stackoverflow

Is there a maven command line option for offline mode?

Java Problem Overview

Java Solutions

Solution 1 - Java

Solution 2 - Java

Solution 3 - Java

Solution 4 - Java

Solution 5 - Java

PostgreSQL: using a calculated column in the same query

OpenGL VAO best practices

Attributions