You should be able to do this via the `Instant` class, which can represent a moment given the epoch time. If you have epoch seconds, you might create something via something like

    Instant i = Instant.ofEpochSecond(t);
    ZonedDateTime z = ZonedDateTime.ofInstant(i, zoneId);



I have done a fair amount of googling about this question and most of the threads I&#39;ve found are 2+ years old, so I am wondering if anything has changed, or if there is a new method to solve the issue pertaining to this topic.

As you might know when using IntelliJ (I use 14.0.2), it often autosaves files. For me, when making a change in Java or JavaScript files, its about 2 seconds before the changes are saved.  There are options that one would think should have an effect on this, such as Settings &gt; Appearance &amp; Behavior &gt; System Settings &gt; Synchronization &gt; Save files automatically if application is idle for X sec.  These settings seem to have no effect for me though, and IntelliJ still autosaves, for example if I need to scroll up to remember how a method I am referencing does something.

This is really frustrating when I have auto-makes, which mess up TomCat, or watches on files via Grunt, Karma, etc when doing JS development.  Is there a magic setting that they&#39;ve put in recently?  Has anyone figured out how to turn off auto-save, or *actually* delay it?  

Turning off IntelliJ Auto-save

Xcode 6.3.  Within a class implementing UITextFieldDelegate protocol, I would like to override touchesBegan() method to possibly hide the keyboard.  If I avoid a compiler error in the function spec, then there is a complier error trying to read the &quot;touch&quot; from the Set or NSSet, or else the   super.touchesBegan(touches , withEvent:event) throws an error.  One of these combinations compiled in Xcode 6.2!  (So where is documentation to Swift &quot;Set&quot; and how to get an element from one?)

     override func touchesBegan(touches: NSSet, withEvent event: UIEvent) { 
        // Hiding the Keyboard when the User Taps the Background
            if let touch =  touches.anyObject() as? UITouch {
                if nameTF.isFirstResponder() &amp;&amp; touch.view != nameTF {
                    nameTF.resignFirstResponder();
                }
            }
            super.touchesBegan(touches , withEvent:event)
        }

Try:

    override func touchesBegan(touches: NSSet, withEvent event: UIEvent) or
    override func touchesBegan(touches: Set&lt;UITouch&gt;, withEvent event: UIEvent) 

Compiler error:
Overriding method with selector &#39;touchesBegan:withEvent:&#39; has incompatible type &#39;(NSSet, UIEvent) -&gt; ()&#39;
and

    super.touchesBegan(touches , withEvent:event)
also complains

&#39;NSSet&#39; is not implicitly convertible to &#39;Set&lt;NSObject&gt;&#39;; did you mean to use &#39;as&#39; to explicitly convert?


Try:

    override func touchesBegan(touches: Set&lt;AnyObject&gt;, withEvent event: UIEvent) 

Compiler error:
 Type &#39;AnyObject&#39; does not conform to protocol &#39;Hashable&#39;


Try:

    override func touchesBegan(touches: Set&lt;NSObject&gt;, withEvent event: UIEvent) 

Compiler error at 

    if let touch = touches.anyObject() as? UITouch 

 &#39;Set&lt;NSObject&gt;&#39; does not have a member named &#39;anyObject&#39; BUT the function spec and call to super() are OK!

Try:

    override func touchesBegan(touches: NSSet&lt;AnyObject&gt;, withEvent event: UIEvent) -&gt; () or
    override func touchesBegan(touches: NSSet&lt;NSObject&gt;, withEvent event: UIEvent) 


Compiler error:
Cannot specialize non-generic type &#39;NSSet&#39;






Overriding method with selector &#39;touchesBegan:withEvent:&#39; has incompatible type &#39;(NSSet, UIEvent) -&gt; ()&#39;

Java 8&#39;s `LocalDateTime` has an `ofEpochSecond` method. Unfortunately, there is no such method in the `ZonedDateTime`. Now, I have an Epoch value and an explicit `ZoneId` given. How do I get a `ZonedDateTime` out of these?

Java 8: How to create a ZonedDateTime from an Epoch value?

<p>Java 8's <code>LocalDateTime</code> has an <code>ofEpochSecond</code> method. Unfortunately, there is no such method in the <code>ZonedDateTime</code>. Now, I have an Epoch value and an explicit <code>ZoneId</code> given. How do I get a <code>ZonedDateTime</code> out of these?</p>


![enter image description here][1]I have imported the jenkins jobs from existing jenkins server from another machine. But the problem is, it has the JDK referenced as per the old machines and I want to change it to use the JDK configured in my new jenkins. But I am unable to find any way of doing this. So, please if you have come across this situation and found a way then please help me too.

Thanks.


  [1]: http://i.stack.imgur.com/4oSiR.png

How to change the JDK for a Jenkins job?

I&#39;ve been working with the new [Optional type in Java 8](https://docs.oracle.com/javase/8/docs/api/java/util/Optional.html), and I&#39;ve come across what seems like a common operation that isn&#39;t supported functionally: an &quot;orElseOptional&quot;

Consider the following pattern:

    Optional&lt;Result&gt; resultFromServiceA = serviceA(args);
    if (resultFromServiceA.isPresent) return result;
    else {
        Optional&lt;Result&gt; resultFromServiceB = serviceB(args);
        if (resultFromServiceB.isPresent) return resultFromServiceB;
        else return serviceC(args);
    }

There are many forms of this pattern, but it boils down to wanting an &quot;orElse&quot; on an optional that takes a function producing a new optional, called only if the current one does not exist.

It&#39;s implementation would look like this:

    public Optional&lt;T&gt; orElse(Supplier&lt;Optional&lt;? extends T&gt;&gt; otherSupplier) {
        return value != null ? this : other.get();
    }

I&#39;m curious if there&#39;s a reason such a method doesn&#39;t exist, if I&#39;m just using Optional in an unintended way, and what other ways people have come up with to deal with this case.

I should say that I think that solutions involving custom utility classes/methods aren&#39;t elegant because people working with my code won&#39;t necessarily know they exist.

Also, if anyone knows, will such a method be included in JDK 9, and where might I propose such a method? This seems like a pretty glaring omission to the API to me.

Optional orElse Optional in Java

With Spring Boot I can instantiate a `JdbcTemplate` with the following:

Code:

    @Autowired
    private JdbcTemplate jdbcTemplate;

Properties:

    spring.datasource.url=jdbc:postgresql://my_url:my_port/my_other_stuff
    spring.datasource.username=my_user_name
    spring.datasource.password=my_password
    spring.datasource.driver-class-name=org.postgresql.Driver

This create a DataSource of class: `org.apache.tomcat.jdbc.pool.DataSource`

How do I set the DataSource username/password programmatically? 

We have a policy not to store credentials in plain text and I have to use a specific credential provider where I work.

Configure DataSource programmatically in Spring Boot

I&#39;m getting below error:

    java.lang.ClassCastException: java.util.LinkedHashMap cannot be cast to com.testing.models.Account

with below code

    final int expectedId = 1;

    Test newTest = create();

    int expectedResponseCode = Response.SC_OK;

    ArrayList&lt;Account&gt; account = given().when().expect().statusCode(expectedResponseCode)
        .get(&quot;accounts/&quot; + newTest.id() + &quot;/users&quot;)
        .as(ArrayList.class);
    assertThat(account.get(0).getId()).isEqualTo(expectedId);

Is there a reason why I cannot do `get(0)`?


java.lang.ClassCastException: java.util.LinkedHashMap cannot be cast to com.testing.models.Account

I want to execute a simple native query, but it does not work:

    @Autowired
    private EntityManager em;
    
    Query q = em.createNativeQuery(&quot;SELECT count(*) FROM mytable where username = :username&quot;);
    em.setProperty(&quot;username&quot;, &quot;test&quot;);
    (int) q.getSingleResult();

Why am I getting this exception?

    org.hibernate.QueryException: Not all named parameters have been set: [username]

Native query with named parameter fails with &quot;Not all named parameters have been set&quot;

Some time ago, [I&#39;ve blogged about a Java 8 functional way of calculating fibonacci numbers recursively][1], with a `ConcurrentHashMap` cache and the new, useful `computeIfAbsent()` method:

    import java.util.Map;
    import java.util.concurrent.ConcurrentHashMap;
    
    public class Test {
        static Map&lt;Integer, Integer&gt; cache = new ConcurrentHashMap&lt;&gt;();
    
        public static void main(String[] args) {
            System.out.println(
                &quot;f(&quot; + 8 + &quot;) = &quot; + fibonacci(8));
        }
    
        static int fibonacci(int i) {
            if (i == 0)
                return i;
    
            if (i == 1)
                return 1;
    
            return cache.computeIfAbsent(i, (key) -&gt; {
                System.out.println(
                    &quot;Slow calculation of &quot; + key);
    
                return fibonacci(i - 2) + fibonacci(i - 1);
            });
        }
    }

I chose `ConcurrentHashMap` because I was thinking of making this example even more sophisticated by introducing parallelism (which I didn&#39;t in the end).

Now, let&#39;s increase the number from `8` to `25` and observe what happens:

            System.out.println(
                &quot;f(&quot; + 25 + &quot;) = &quot; + fibonacci(25));

The program never halts. Inside the method, there&#39;s a loop that just runs forever:

    for (Node&lt;K,V&gt;[] tab = table;;) {
        // ...
    }

I&#39;m using:

&lt;!-- language: lang-none --&gt;

    C:\Users\Lukas&gt;java -version
    java version &quot;1.8.0_40-ea&quot;
    Java(TM) SE Runtime Environment (build 1.8.0_40-ea-b23)
    Java HotSpot(TM) 64-Bit Server VM (build 25.40-b25, mixed mode)

[Matthias, a reader of that blog post also confirmed the issue (he actually found it)][3].

This is weird. I would have expected any of the following two:

- It works
- It throws a `ConcurrentModificationException`

But just never halting? That seems dangerous. Is it a bug? Or did I misunderstand some contract?


  [1]: http://blog.jooq.org/2014/02/28/java-8-friday-goodies-easy-as-pie-local-caching
  [3]: http://blog.jooq.org/2014/02/28/java-8-friday-goodies-easy-as-pie-local-caching/#comment-121821

Recursive ConcurrentHashMap.computeIfAbsent() call never terminates. Bug or &quot;feature&quot;?

I would like to do the following:

    List&lt;Integer&gt; list = IntStream.range(0, 7).collect(Collectors.toList());

but in a way that the resulting list is an implementation of Guava&#39;s `ImmutableList`.

I know I could do

    List&lt;Integer&gt; list = IntStream.range(0, 7).collect(Collectors.toList());
    List&lt;Integer&gt; immutableList = ImmutableList.copyOf(list);

but I would like to collect to it directly. I&#39;ve tried

    List&lt;Integer&gt; list = IntStream.range(0, 7)
        .collect(Collectors.toCollection(ImmutableList::of));

but it threw an exception:

&gt; java.lang.UnsupportedOperationException
	at com.google.common.collect.ImmutableCollection.add(ImmutableCollection.java:96)


How can I collect a Java 8 stream into a Guava ImmutableCollection?

The `DateTimeFormatter` class documentation defines separate symbols `u` for year and `y` year-of-era: https://docs.oracle.com/javase/8/docs/api/java/time/format/DateTimeFormatter.html#patterns

What is the difference between year and year-of-era?

What is the difference between year and year-of-era?

This code works (taken in the Javadoc):

	List&lt;Integer&gt; numbers = Arrays.asList(1, 2, 3, 4);
	String commaSeparatedNumbers = numbers.stream()
		.map(i -&gt; i.toString())
		.collect(Collectors.joining(&quot;, &quot;));

This one can&#39;t be compiled:

	int[] numbers = {1, 2, 3, 4};
	String commaSeparatedNumbers = Arrays.stream(numbers)
		.map((Integer i) -&gt; i.toString())
		.collect(Collectors.joining(&quot;, &quot;));

IDEA tells me I have an &quot;incompatible return type String in lambda expression&quot;.

Why ? And how to fix that ?

Why can&#39;t I map integers to strings when streaming from an array?

I have a sheet with a column of unix epoch times (in seconds): 1500598288

How can I convert these into normal dates?

Convert Unix Epoch Time to Date in Google Sheets

I am trying to set a server agnostic date time in my database and I believe the best practice to do so is to set a UTC DateTime. My db server is Cassandra and the db driver for Java understands only the Date type.

So assuming that in my code I am using the new Java 8 ZonedDateTime to get the UTC now (`ZonedDateTime.now(ZoneOffset.UTC)`), how can I convert this ZonedDateTime instance to the &quot;legacy&quot; Date class?

How to convert ZonedDateTime to Date?

I have an epoch second and a *zoneId* (see `method1` below). 

It can be convert to `LocalDateTime` with system default zoneId, but I don&#39;t find the way to convert epoch second to `LocalDateTime` (see  `method2` below), because there is no `ZoneOffset.systemDefault`. I think it&#39;s obscure.

    import java.time.{Instant, LocalDateTime, ZoneId, ZoneOffset}
    
    val epochSecond = System.currentTimeMillis() / 1000
    
    // method1
    LocalDateTime.ofInstant(Instant.ofEpochSecond(epochSecond), ZoneId.systemDefault())
    
    // method2
    LocalDateTime.ofEpochSecond(epochSecond, 0, ZoneOffset.MAX)
---
## NOTE
The source code presented above is [Scala][1].


  [1]: https://www.scala-lang.org/

Is there any way to convert ZoneId to ZoneOffset in Java 8?

I want to convert a `ZonedDateTime` to a `String` in the format of `(&quot;dd/MM/yyyy - hh:mm&quot;)`. I know this is possible in Joda-Time other types, just using their `toString(&quot;dd/MM/yyyy - hh:mm&quot;)`....But this doesn&#39;t work with `ZonedDateTime.toString()`.

# **How can I format a `ZonedDateTime` to a `String`?**

____

EDIT:

I tried to print the time in another timezone and the result appears to be the same always: 

    ZonedDateTime date = ZonedDateTime.now();
    ZoneId la = ZoneId.of(&quot;America/Los_Angeles&quot;);
    ZonedDateTime date2 = date.of(date.toLocalDateTime(), la);
    
    // 24/02/2017 - 04:53
    System.out.println(DateTimeFormatter.ofPattern(&quot;dd/MM/yyyy - hh:mm&quot;).format(date));
    // same result as the previous one
    // 24/02/2017 - 04:53
    System.out.println(DateTimeFormatter.ofPattern(&quot;dd/MM/yyyy - hh:mm&quot;).format(date2));

And I am not in the same timezone as Los Angeles.

_____
EDIT 2:

Found how to change the timezones:

    // Change this:
    ZonedDateTime date2 = date.of(date.toLocalDateTime(), la); // incorrect!
    // To this:
    ZonedDateTime date2 = date.withZoneSameInstant(la);

Content Type	Original Author	Original Content on Stackoverflow
Question	rabejens	View Question on Stackoverflow
Solution 1 - Java	Prisoner	View Answer on Stackoverflow

Java 8: How to create a ZonedDateTime from an Epoch value?

Java Problem Overview

Java Solutions

Solution 1 - Java

Overriding method with selector 'touchesBegan:withEvent:' has incompatible type '(NSSet, UIEvent) -> ()'

Turning off IntelliJ Auto-save

Attributions