Android doesn&#39;t use Oracle&#39;s Java SE versions, [it&#39;s based on parts of the Apache Harmony project][1] so it doesn&#39;t even support Java 7. Harmony is not actively developed any more and won&#39;t support 1.7.

Unless Google decides to upgrade Harmony and the Android SDK to a newer Java version, there won&#39;t be any Java 7 or Java 8 features in Android - even if new features are just syntactical. They could use an alternative implementation like the _OpenJDK_, though I don&#39;t know of any plans for this. Some people think the use of OpenJDK is unlikely because of lawsuits between Google and Oracle.

--- 

[*Some* features of Java 7][2], most notable: diamond operators, multi-catch, string switch and in Android N also [some Java 8 features][3] like lambda expressions have been implemented in Android since this answer was written. (Thanks to [Ross][4] and [Stefan][5] for mentioning it in the comments). 

Google has to implement those features by their own effort and it seems that the choose to do so mostly for more popular features.

  [1]: https://stackoverflow.com/questions/7535385/how-does-androids-java-version-relate-to-a-java-se-version
  [2]: https://stackoverflow.com/a/13550632/897024
  [3]: https://developer.android.com/preview/j8-jack.htm
  [4]: https://stackoverflow.com/users/150474/
  [5]: https://stackoverflow.com/users/1439733/

An update SQL query was executed on the server, which caused many problems later.

How can I get the list of update queries executed in last 2 months, so that I can trace the exact problematic SQL query?

Find out the history of SQL queries

I&#39;m trying to ajax-update a conditionally rendered component.

	&lt;h:form&gt;
        ...
		&lt;h:commandButton value=&quot;Login&quot; action=&quot;#{login.submit}&quot;&gt;
			&lt;f:ajax execute=&quot;@form&quot; render=&quot;:text&quot; /&gt;
		&lt;/h:commandButton&gt;
	&lt;/h:form&gt;
	&lt;h:outputText id=&quot;text&quot; value=&quot;You&#39;re logged in!&quot; rendered=&quot;#{not empty user}&quot; /&gt;

However, that does not work. I can assure that `#{user}` is actually available. How is this caused and how can I solve it?


Ajax update/render does not work on a component which has rendered attribute

I understand that the &quot;java&quot; in a dalvik vm is different from Java se in terms of API and architecture etc. But the syntax has always been the same. (Please correct me if I am wrong)

Now the support of [lambda expression in java 8][1] is about to be released, will android java follow it? did google or aosp promise on making dalvik consistent with java se?


UPDATE: Now as in Android 4.4 Kit Kat (API 19), Java 7 syntax has been OFFICIALLY supported.[Source from android.com][2]


  [1]: http://openjdk.java.net/projects/lambda/
  [2]: http://tools.android.com/tech-docs/new-build-system/user-guide#TOC-Using-sourceCompatibility-1.7

will android java support lambda expression in java 8?

I understand that the "java" in a dalvik vm is different from Java se in terms of API and architecture etc. But the syntax has always been the same. (Please correct me if I am wrong)
Now the support of <a href="http://openjdk.java.net/projects/lambda/" target="_blank" rel="noopener noreferrer">lambda expression in java 8</a> is about to be released, will android java follow it? did google or aosp promise on making dalvik consistent with java se?
UPDATE: Now as in Android 4.4 Kit Kat (API 19), Java 7 syntax has been OFFICIALLY supported.<a href="http://tools.android.com/tech-docs/new-build-system/user-guide#TOC-Using-sourceCompatibility-1.7" target="_blank" rel="noopener noreferrer">Source from android.com</a>

I&#39;m using [Travis-CI][1] to provide continuous integration builds for a few Java open source projects I&#39;m working on.

Normally this works smoothly, but I have a problem when the POM specifies GPG signing, e.g. 

    &lt;plugin&gt;
      &lt;groupId&gt;org.apache.maven.plugins&lt;/groupId&gt;
      &lt;artifactId&gt;maven-gpg-plugin&lt;/artifactId&gt;
      &lt;version&gt;1.4&lt;/version&gt;
      &lt;executions&gt;
        &lt;execution&gt;
          &lt;id&gt;sign-artifacts&lt;/id&gt;
          &lt;phase&gt;verify&lt;/phase&gt;
          &lt;goals&gt;
            &lt;goal&gt;sign&lt;/goal&gt;
          &lt;/goals&gt;
        &lt;/execution&gt;
      &lt;/executions&gt;
    &lt;/plugin&gt;

This causes the Travis build to fail - apparently because it does not have a passphrase available while running `mvn install`. See [this build][2] for an example.

What is the best way to configure Maven and/or Travis to skip GPG signing for CI test builds, but still perform GPG signing when I do a proper release build?


  [1]: https://travis-ci.org/
  [2]: https://travis-ci.org/nuroko/nurokore/jobs/4683227

Suppressing GPG signing for Maven-based continuous integration builds (Travis CI)

I was playing around with Java 8 lambdas to easily filter collections. But I did not find a concise way to retrieve the result as a new list within the same statement. Here is my most concise approach so far:

    List&lt;Long&gt; sourceLongList = Arrays.asList(1L, 10L, 50L, 80L, 100L, 120L, 133L, 333L);
    List&lt;Long&gt; targetLongList = new ArrayList&lt;&gt;();
    sourceLongList.stream().filter(l -&gt; l &gt; 100).forEach(targetLongList::add);

Examples on the net did not answer my question because they stop without generating a new result list. There must be a more concise way. I would have expected, that the `Stream` class has methods as `toList()`, `toSet()`, …

Is there a way that the variables `targetLongList` can be directly be assigned by the third line?

Retrieving a List from a java.util.stream.Stream in Java 8

Is there a oneliner to get the name of the month when we know: 

```lang-java
int monthNumber  = calendar.get(Calendar.MONTH)
``` 

Or what is the easiest way?

How can I get Month Name from Calendar?

Why does the second line of this code throw `ArrayIndexOutOfBoundsException`?

    String filename = &quot;D:/some folder/001.docx&quot;;
    String extensionRemoved = filename.split(&quot;.&quot;)[0];

While this works:

    String driveLetter = filename.split(&quot;/&quot;)[0];

I use Java 7.

Java string split with &quot;.&quot; (dot)

I have a command line tool that performs a DNS check. If the DNS check succeeds, the command proceeds with further tasks. I am trying to write unit tests for this using Mockito. Here&#39;s my code:

    public class Command() {
        // ....
        void runCommand() {
            // ..
            dnsCheck(hostname, new InetAddressFactory());
            // ..
            // do other stuff after dnsCheck
        }
         
        void dnsCheck(String hostname, InetAddressFactory factory) {
            // calls to verify hostname
        }
    }

I am using InetAddressFactory to mock a static implementation of the `InetAddress` class. Here&#39;s the code for the factory:

    public class InetAddressFactory {
        public InetAddress getByName(String host) throws UnknownHostException {
            return InetAddress.getByName(host);
        }
    }

Here&#39;s my unit test case:

    @RunWith(MockitoJUnitRunner.class)
    public class CmdTest {
        
        // many functional tests for dnsCheck

        // here&#39;s the piece of code that is failing
        // in this test I want to test the rest of the code (i.e. after dnsCheck)
        @Test
        void testPostDnsCheck() {
            final Cmd cmd = spy(new Cmd());

            // this line does not work, and it throws the exception below:
            // tried using (InetAddressFactory) anyObject()
            doNothing().when(cmd).dnsCheck(HOST, any(InetAddressFactory.class));
            cmd.runCommand();
        }
    }

Exception on running `testPostDnsCheck()` test:

    org.mockito.exceptions.misusing.InvalidUseOfMatchersException: 
    Invalid use of argument matchers!
    2 matchers expected, 1 recorded.
    This exception may occur if matchers are combined with raw values:
        //incorrect:
        someMethod(anyObject(), &quot;raw String&quot;);
    When using matchers, all arguments have to be provided by matchers.
    For example:
        //correct:
        someMethod(anyObject(), eq(&quot;String by matcher&quot;));

Any input on how to solve this? 

Mockito: InvalidUseOfMatchersException

I&#39;m very new to programming and I have some doubts. 

I have a `AsyncTask` which is I call as `RunInBackGround`. 

and I start this process like:

    new RunInBackGround().execute();

But I wish to wait until this call is finish its executing, before proceeding to the other statements of code.

How can I do that?

Are there any way for it?



Waiting till the async task finish its work

I have 10 markers in the `GoogleMap`. I want to zoom in as much as possible and keep all markers in view? In the earlier version this can be achieved from `zoomToSpan()` but in v2 I have no idea how about doing that. Further, I know the radius of the circle that needs to be visible.

Android map v2 zoom to show all the markers

Following

[How to draw a path between two markers][1]


I had to add lot of polylines between two markers, to make a path.

One of the markers is draggable, lets say source is draggable.

So, when user starts dragging the marker, the path previously drawn must be erased and a new path between new source and destination must be draw.

I am able to draw the new path, but how can i erase the previous path?

This is how the path is drawn:

		for (int z = 0; z &lt; list.size() - 1; z++) {
			LatLng src = list.get(z);
			LatLng dest = list.get(z + 1);
			Polyline line = map.addPolyline(new PolylineOptions()
					.add(new LatLng(src.latitude, src.longitude),
							new LatLng(dest.latitude, dest.longitude))
					.width(2).color(Color.RED).geodesic(true));
		}

One solution i can get is

&gt; map.clear();

To clear all the polylines, markers etc.. and add the markers again, then drawn the path.

But as soon as I start dragging, the marker is cleared, hence not visible on the map :(

Thank You

  [1]: https://stackoverflow.com/questions/14702621/answer-draw-path-between-two-points-using-google-maps-android-api-v2

How to remove all the polylines from a map

I need to convert the UTC time stamp that I get from the server to local device time. Currently, I get 5 hrs difference in my time. For example, when I post to the server, the post time says 5 hours ago instead of a second ago. How could I fix this issue?

Below is the code that I do:

    long timestamp = cursor.getLong(columnIndex);
				CharSequence relTime = DateUtils
						.getRelativeTimeSpanString(timestamp * 1000
								+ TimeZone.getDefault().getRawOffset(),
								System.currentTimeMillis(),
								DateUtils.MINUTE_IN_MILLIS);
				((TextView) view).setText(relTime);

How to convert UTC timestamp to device local time in android

I want to Update my Android SDK Tool from 22.0.1 to  22.0.4

I also Have ADT installed, but could not update the SDK Tool to  22.0.4

I am facing the following issue :

    Download interrupted: Read timed out issue.

Below is the screen shot while updating SDK :


![enter image description here][2]
Can anyone help me :

Thanks in Advance.

&gt; **EDITED :** I Found the Solution For above problem and have added the Solution as an answer. If anyone has the same problem, he/she can also solve
&gt; this issue as explained.


  [1]: http://i.stack.imgur.com/E9MFV.png
  [2]: http://i.stack.imgur.com/uqOvP.png

Update Android SDK Tool to 22.0.4(Latest Version) from 22.0.1

I am going to learn a little bit about Dalvik VM, dex and Smali.
  
I have read about smali, but still cannot clearly understand where its place in chain of compilers. And what its purpose.    
Here some questions:

1. As I know, dalvik as other Virtual Machines run bytecode, in case of Android it is dex byte code.    
2. What is smali? Does Android OS or Dalvik Vm work with it directly, or it is just the same dex bytecode but more readable for the human?   
3. Is it something like dissasembler for Windows (like OllyDbg) program executable consist of different machines code (D3 , 5F for example) and there is appropriate assembly command to each machine code, but Dalvik Vm also is software, so smali is readable representation of bytecodes 
4. There is new ART enviroment. Is it still use bytecodes or it executes directly native code? 

Thank you in advance.

What is Smali Code Android

While hunting through some code I came across the arrow operator, what exactly does it do? I thought Java did not have an arrow operator.

    return (Collection&lt;Car&gt;) CollectionUtils.select(listOfCars, (arg0) -&gt; {
            return Car.SEDAN == ((Car)arg0).getStyle();
    });

***Details**: Java 6, Apache Commons Collection, IntelliJ 12* 

***Update/Answer:** It turns out that IntelliJ 12 supports Java 8, which supports lambdas, and is &quot;folding&quot; Predicates and displaying them as lambdas. Below is the &quot;un-folded&quot; code.*

    return (Collection&lt;Car&gt;) CollectionUtils.select(listOfCars, new Predicate() {
        public boolean evaluate(Object arg0) {
            return Car.SEDAN == ((Car)arg0).getStyle();
        }
    });





What does the arrow operator, &#39;-&gt;&#39;, do in Java?

Since I use Maven I have been able to build and install in my local repository projects that have incomplete Javadoc tags (for example, a missing parameter). 

However, since I migrated to Java 8 (1.8.0-ea-b90) Maven is absolutely strict about missing documentation tags and show me lots of Javadoc errors related to Javadoc problems when I try to build or install a project where the Javadoc is not &quot;perfect&quot;. Some of the projects I am trying to compile and install in my local repository are third party projects from which I do not have control. So the workaround of just fixing all the Javadocs in all these projects does not seem to be feasable in my scenario.

This is a small part of the output I see when I execute `mvn clean package install` in my project:

&lt;!-- language: lang-none --&gt;

    [INFO] ------------------------------------------------------------------------
    [INFO] BUILD FAILURE
    [INFO] ------------------------------------------------------------------------
    [INFO] Total time: 9.026s
    [INFO] Finished at: Mon Apr 08 21:06:17 CEST 2013
    [INFO] Final Memory: 27M/437M
    [INFO] ------------------------------------------------------------------------
    [ERROR] Failed to execute goal org.apache.maven.plugins:maven-javadoc-plugin:2.9:jar (attach-javadocs) on project jpc: MavenReportException: Error while creating archive:
    [ERROR] Exit code: 1 - /Users/sergioc/Documents/workspaces/heal/jpc/src/main/java/org/jpc/engine/prolog/PrologDatabase.java:10: error: @param name not found
    [ERROR] * @param terms the terms to assert
    [ERROR] ^
    [ERROR] /Users/sergioc/Documents/workspaces/heal/jpc/src/main/java/org/jpc/engine/prolog/PrologDatabase.java:11: warning: no description for @return
    [ERROR] * @return
    [ERROR] ^



The Javadoc Maven plugin is configured like this in my POM:

&lt;!-- language: xml --&gt;

    &lt;plugin&gt;
        &lt;groupId&gt;org.apache.maven.plugins&lt;/groupId&gt;
        &lt;artifactId&gt;maven-javadoc-plugin&lt;/artifactId&gt;
        &lt;version&gt;2.9&lt;/version&gt;
        &lt;executions&gt;
            &lt;execution&gt;
                &lt;id&gt;attach-javadocs&lt;/id&gt;
                &lt;goals&gt;
                    &lt;goal&gt;jar&lt;/goal&gt;
                &lt;/goals&gt;
            &lt;/execution&gt;
        &lt;/executions&gt;
    &lt;/plugin&gt;

As I said before, everything is working fine if I go back to Java 7. 
Maybe is this a bug related to Maven running in Java 8?
How could I make it work (i.e., being able to build the Javadoc of the project and install its code in my local repository) with Java 8?
I have tested with both Maven 3.0.3 and 3.0.5 in OSX.

**UPDATE:**

If I change my Javadoc plugin configuration with `&lt;failOnError&gt;false&lt;/failOnError&gt;` (thanks Martin):

&lt;!-- language: xml --&gt;

    &lt;plugin&gt;
        &lt;groupId&gt;org.apache.maven.plugins&lt;/groupId&gt;
        &lt;artifactId&gt;maven-javadoc-plugin&lt;/artifactId&gt;
        &lt;version&gt;2.9&lt;/version&gt;
        &lt;executions&gt;
            &lt;execution&gt;
                &lt;id&gt;attach-javadocs&lt;/id&gt;
                &lt;goals&gt;
                    &lt;goal&gt;jar&lt;/goal&gt;
                &lt;/goals&gt;
            &lt;/execution&gt;
        &lt;/executions&gt;
    &lt;/plugin&gt;

Then the project is installed in my local repository. However, the Javadoc JAR is still not generated.

A fragment of the output I see in the console with this new configuration is:

&gt; [ERROR] MavenReportException: Error while creating archive:  Exit
&gt; code: 1 - /Users/....java:18: warning: no @param  ... Command line
&gt; was: /Library/Java/Home/bin/javadoc @options @packages
&gt; 
&gt; Refer to the generated Javadoc files in
&gt; &#39;/Users/sergioc/Documents/workspaces/heal/minitoolbox/target/apidocs&#39;
&gt; dir.
&gt; 
&gt; 	at
&gt; org.apache.maven.plugin.javadoc.AbstractJavadocMojo.executeJavadocCommandLine(AbstractJavadocMojo.java:5043)
&gt; 	at
&gt; org.apache.maven.plugin.javadoc.AbstractJavadocMojo.executeReport(AbstractJavadocMojo.java:1990)
&gt; 	at
&gt; org.apache.maven.plugin.javadoc.JavadocJar.execute(JavadocJar.java:181)
&gt; 	at
&gt; org.apache.maven.plugin.DefaultBuildPluginManager.executeMojo(DefaultBuildPluginManager.java:101)
&gt; 	at
&gt; org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:209)
&gt; 	at
&gt; org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:153)
&gt; 	at
&gt; org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:145)
&gt; 	at
&gt; org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject(LifecycleModuleBuilder.java:84)
&gt; 	at
&gt; org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject(LifecycleModuleBuilder.java:59)
&gt; 	at
&gt; org.apache.maven.lifecycle.internal.LifecycleStarter.singleThreadedBuild(LifecycleStarter.java:183)
&gt; 	at
&gt; org.apache.maven.lifecycle.internal.LifecycleStarter.execute(LifecycleStarter.java:161)
&gt; 	at org.apache.maven.DefaultMaven.doExecute(DefaultMaven.java:320) 	at
&gt; org.apache.maven.DefaultMaven.execute(DefaultMaven.java:156) 	at
&gt; org.apache.maven.cli.MavenCli.execute(MavenCli.java:537) 	at
&gt; org.apache.maven.cli.MavenCli.doMain(MavenCli.java:196) 	at
&gt; org.apache.maven.cli.MavenCli.main(MavenCli.java:141) 	at
&gt; sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) 	at
&gt; sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
&gt; 	at
&gt; sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
&gt; 	at java.lang.reflect.Method.invoke(Method.java:491) 	at
&gt; org.codehaus.plexus.classworlds.launcher.Launcher.launchEnhanced(Launcher.java:290)
&gt; 	at
&gt; org.codehaus.plexus.classworlds.launcher.Launcher.launch(Launcher.java:230)
&gt; 	at
&gt; org.codehaus.plexus.classworlds.launcher.Launcher.mainWithExitCode(Launcher.java:409)
&gt; 	at
&gt; org.codehaus.plexus.classworlds.launcher.Launcher.main(Launcher.java:352)

Any workaround about how to build the sources, install the project and generate the Javadoc JAR in one step as it was working with Java 7?

Maven is not working in Java 8 when Javadoc tags are incomplete

Java 8 introduces important new language features such as lambda expressions.

Are these changes in the language accompanied by such significant changes in the compiled bytecode that would prevent it from being run on a Java 7 virtual machine without using some retrotranslator?

Can Java 8 code be compiled to run on Java 7 JVM?

Which of the following is better practice in Java 8?

Java 8:

    joins.forEach(join -&gt; mIrc.join(mSession, join));


Java 7:

    for (String join : joins) {
        mIrc.join(mSession, join);
    }


I have lots of for loops that could be &quot;simplified&quot; with lambdas, but is there really any advantage of using them? Would it improve their performance and readability?

**EDIT**

I&#39;ll also extend this question to longer methods. I know that you can&#39;t return or break the parent function from a lambda and this should also be taken into consideration when comparing them, but is there anything else to be considered?

Content Type	Original Author	Original Content on Stackoverflow
Question	Fermat's Little Student	View Question on Stackoverflow
Solution 1 - Java	kapex	View Answer on Stackoverflow

will android java support lambda expression in java 8?

Java Problem Overview

Java Solutions

Solution 1 - Java

Ajax update/render does not work on a component which has rendered attribute

Find out the history of SQL queries

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