Yes, you can expect this even if you are using parallel stream as long as you did not explicitly convert it into [`unordered()`](https://docs.oracle.com/javase/8/docs/api/java/util/stream/BaseStream.html#unordered--) mode. 

The ordering never changes in sequential mode, but may change in parallel mode. The stream becomes unordered either:

* If you explicitly turn it into unordered mode via `unordered()` call
* If the stream source reports that it&#39;s unordered (for example, `HashSet` stream is unordered as order is implementation dependent and you cannot rely on it)
* If you are using unordered terminal operation (for example, `forEach()` operation or collecting to unordered collector like `toSet()`)

In your case none of these conditions met, thus your stream is ordered.

I have a simple app that displays text.

The app starts with a main screen with a few options (ex. an info button that leads to info about the app, a browse button that allows the user to see all the individual pieces of text that can be displayed).  The main button leads to another screen where text is displayed.  By swiping left and right he can see different passages of text.  This is the main purpose of the app.

Currently I have an ActionBar implemented.  My MainActivity.Java extends AppCompatActivity.  Everything in the app is in this activity. 

Now I want to make it so the ActionBar appears only in &quot;Display&quot; mode, not in the start up screen, or &quot;info&quot; / &quot;browse&quot; mode.

**Is it possible to have an ActionBar in one part of the app, and *no* ActionBar in another part of the app? (And keep it all in the same activity?)**

I&#39;ve been trying to accomplish this without avail.  If this is possible, what should I try next?

So far, I&#39;ve attempted the following:

1)  Create this theme

    &lt;style name=&quot;Theme.AppCompat.NoActionBar&quot; parent=&quot;Theme.AppCompat.Light&quot;&gt;
        &lt;item name=&quot;android:windowActionBar&quot;&gt;false&lt;/item&gt;  
        &lt;item name=&quot;android:windowNoTitle&quot;&gt;true&lt;/item&gt;
    &lt;/style&gt;  

And apply it to MainActivity ...  

    &lt;activity
            android:name=&quot;.MainActivity&quot;
            android:label=&quot;@string/app_name&quot;
            android:theme=&quot;@style/Theme.AppCompat.NoActionBar&quot; &gt; 
   ....
After doing this, the ActionBar was still there.  (This comes from this S.O. post (https://stackoverflow.com/questions/26878386)

2)  Another attempt was to add this to onCreate.   

    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        getWindow().requestFeature(Window.FEATURE_ACTION_BAR);
        getActionBar().hide();

        setContentView(R.layout.activity_main);

This came from studying this S.O. post:  (https://stackoverflow.com/questions/8500283)

Any suggestions?



How To Show and hide ActionBar with AppCompat v.7

I&#39;m using Spring 4 MVC with Jackson 2 for my service. For one of the operations I have a request object that has an attribute where the leading camel case word this is only one letter in length:

    private String aLogId;

This class has the appropriately named getters and setters:

    public String getALogId() { return aLogId; }
    public void setALogId(String aLogId) { this.aLogId = aLogId; }

However, when I attempt to post a request to this service using the corresponding JSON property:

    {&quot;aLogId&quot;:&quot;This is a log id&quot;}

I&#39;m receiving a 500 response from the Spring framework saying the field is not recognized and my controller class is never called:

&gt; Could not read JSON: Unrecognized field &quot;aLogId&quot; (class

However, when I change the &quot;L&quot; to lower case, the request is deserialized as expected and my controller class is hit:

    {&quot;alogId&quot;:&quot;This is a log id&quot;}

Why does Jackson expect the &quot;L&quot; to be lower case when it is obviously the second word in the camel case convention for the attribute and intended to be in upper case? Is it because the first word is only a single letter long?

There are other attributes in the request object where the first word is more than one letter and those attributed don&#39;t face this same issue with the mismatch in case.

Why does Jackson 2 not recognize the first capital letter if the leading camel case word is only a single letter long?

    List&lt;MyObject&gt; myList = new ArrayList&lt;&gt;(); 
    //populate myList here
    
    List&lt;String&gt; nameList = myList.stream()
            .map(MyObject::getName)
            .collect(Collectors.toList());

In above code, can I expect that order of `MyObject` names in `nameList` is always the same as the order of `myList`?

Java stream map and collect - order of resulting container

<pre><code class="hljs language-ini">List&#x3C;MyObject> myList = new ArrayList&#x3C;>(); 
//populate myList here

List&#x3C;String> nameList = myList.stream()
 .map(MyObject::getName)
 .collect(Collectors.toList());
</code></pre>
In above code, can I expect that order of <code>MyObject</code> names in <code>nameList</code> is always the same as the order of <code>myList</code>?

The problem I&#39;m facing is that `Matchers.anyObject()` returns `null`. When used to mock method that only accepts non-nullable types it causes a &quot;Should not be null&quot; exception to be thrown. 

    `when`(mockedBackend.login(anyObject())).thenAnswer { invocationOnMock -&gt; someResponse }

Mocked method:

    public open fun login(userCredentials: UserCredentials): Response

Is it possible to use Mockito in Kotlin?

How can I configure and use two data sources?

For example here is what I have for the first data source:

**application.properties**

    #first db
    spring.datasource.url = [url]
    spring.datasource.username = [username]
    spring.datasource.password = [password]
    spring.datasource.driverClassName = oracle.jdbc.OracleDriver

    #second db ...

**Application class**

    @SpringBootApplication
    public class SampleApplication
    {
        public static void main(String[] args) {
            SpringApplication.run(SampleApplication.class, args);
        }
    }

How do I modify `application.properties` to add another data source? How do I autowire it to be used by a different repository?



Spring Boot Configure and Use Two DataSources

There is a lot of information about adding libraries and dependencies, but I haven&#39;t been able to find any useful information on being able to actually edit a library.

I have added https://github.com/jdamcd/android-crop as a dependency in my project, but I would like to edit some of its features, mostly layout related stuff. However, when I go into browse the files Android Studio says 
&quot;files under the build folder are generated and should not be edited&quot; and when I edit them they are returned back to their pre-edited state once the system builds. 

I also tried editing the files in notepad++ and the same problem occurs (they are returned to their pre-edited state on build). 

Can someone tell me either how to edit the library or a workaround whereby I can change the layouts/some java without having to copy and paste the entire library into my project to make it editable? 

Thanks in advance, 

God speed. 

**Edit: The answer is instead of simply adding the library as a dependency in the build.gradle file using this code:  compile &#39;com.soundcloud.android:android-crop:0.9.10@aar&#39;**

**You have to add it as a module instead of just an external dependency, then you can edit the files.**

**If anyone is wondering how follows these steps:**

1.	Create library folder (call it whatever you want) in the root directory, i.e. the first folder you go into to get to the app and its contents. 
2.	Download the library, unzip it.
3.	Put the folder from step 2 in the folder you created in step 1. 
4.	Add the module to the `settings.gradle` like so: 
`include &#39;:LibraryContainingFolder:ActualLibFolder&#39;`
5.	Sync and clean
6.	Go to project structure in Android Studio, click on the main module, normally called app, click on dependencies tab, then click the green plus, then click &quot;Module dependency&quot;.
The module should appear written as the containing folder and the library folder in it separated by colons &#39;something:somethingElse&#39;. Add the module. 
7.  Sync, clean, buid etc.



 

How do you edit a dependency/external library in android studio?

I need to convert mutable list object to immutable list. What is the possible way in java?

    	
    public void action() {
        List&lt;MutableClass&gt; mutableList = Arrays.asList(new MutableClass(&quot;san&quot;, &quot;UK&quot;, 21), new MutableClass(&quot;peter&quot;, &quot;US&quot;, 34));
        List&lt;MutableClass&gt; immutableList = immutateList(mutableList);
    }

    public List&lt;MutableClass&gt; immutateList(List&lt;MutableClass&gt; mutableList){
        //some code here to make this beanList immutable
        //ie. objects and size of beanList should not be change.
        //ie. we cant add new object here.
        //ie. we cant remove or change existing one.
    }

###`MutableClass`
    
    final class MutableClass {
        final String name;    
        final String address;
        final int age;
        MutableClass(String name, String address, int age) {
        	this.name = name;
        	this.address = address;
        	this.age = age;
        }
    }


How to create Immutable List in java?

I am attempting to work through a tutorial from Programmer Bruce that is supposed to allow the deserialization of polymorphic JSON. 

The complete list can be found here
[Programmer Bruce tutorials][1] (Great stuff btw)

  [1]: http://programmerbruce.blogspot.ca/2011/05/deserialize-json-with-jackson-into.html

I have worked through the first five with no problems but I have hit a snag on the last one (Example 6), which of course is the one I really need to get working.

I am getting the following error at compile time

&gt; The method readValue(JsonParser, Class&lt;T&gt;) in the type ObjectMapper is not applicable for the arguments (ObjectNode, Class&lt;capture#6-of ? extends Animal&gt;)

and it&#39;s being caused by the chunk of code

      public Animal deserialize(  
          JsonParser jp, DeserializationContext ctxt)   
          throws IOException, JsonProcessingException  
      {  
        ObjectMapper mapper = (ObjectMapper) jp.getCodec();  
        ObjectNode root = (ObjectNode) mapper.readTree(jp);  
        Class&lt;? extends Animal&gt; animalClass = null;  
        Iterator&lt;Entry&lt;String, JsonNode&gt;&gt; elementsIterator =   
            root.getFields();  
        while (elementsIterator.hasNext())  
        {  
          Entry&lt;String, JsonNode&gt; element=elementsIterator.next();  
          String name = element.getKey();  
          if (registry.containsKey(name))  
          {  
            animalClass = registry.get(name);  
            break;  
          }  
        }  
        if (animalClass == null) return null;  
        return mapper.readValue(root, animalClass);
      }  
    } 

Specifically by the line 

&gt; return mapper.readValue(root, animalClass);

Has anyone run into this before and if so, was there a solution?

I&#39;d appreciate any help anyone can give
Thanks in advance
Jon D.

Deserialize JSON with Jackson into Polymorphic Types - A Complete Example is giving me a compile error

I am a Python beginner and have a puzzle.
When I write code like this:
    
    lst = [1, 2, 3, 4]

Pycharm give me a prompt that is &quot;this list creation could be rewritten as a list literal&quot;.
But if it&#39;s replaced by
    
    lst = list([1, 2, 3, 4])

Pycharm doesn&#39;t say anything. Who could tell me why?

Is this code like `lst = [1, 2, 3, 4]` legal in Python? Can I ignore prompt?




When I assign a list to variable why Pycharm give me a prompt that is &quot;this list creation could be rewritten as a list literal&quot;?

I am novice to Python and following a tutorial. There is an example of `list` in the tutorial :

    example = list(&#39;easyhoss&#39;)
Now, In tutorial, `example= [&#39;e&#39;,&#39;a&#39;,...,&#39;s&#39;]`. But in my case I am getting following error:

    &gt;&gt;&gt; example = list(&#39;easyhoss&#39;)
    Traceback (most recent call last):
      File &quot;&lt;stdin&gt;&quot;, line 1, in &lt;module&gt;
    TypeError: &#39;list&#39; object is not callable

Please tell me where I am wrong. I searched SO [this][1] but it is different.


  [1]: https://stackoverflow.com/questions/5735841/python-typeerror-list-object-is-not-callable

TypeError: &#39;list&#39; object is not callable in python

How to return `False` if all elements are in a list are `False`?

The given list is:

    data = [False, False, False]


Test if all elements of a python list are False

I wrote my first &quot;Hello World&quot; 4 months ago. Since then, I have been following a Coursera Python course provided by Rice University. I recently worked on a mini-project involving tuples and lists. There is something strange about adding a tuple into a list for me:

    a_list = []
    a_list.append((1, 2))       # Succeed! Tuple (1, 2) is appended to a_list
    a_list.append(tuple(3, 4))  # Error message: ValueError: expecting Array or iterable

It&#39;s quite confusing for me. Why specifying the tuple to be appended by using &quot;tuple(...)&quot; instead of simple &quot;(...)&quot; will cause a `ValueError`?

BTW: I used `CodeSkulptor` [coding tool used in the course][1]


  [1]: http://www.codeskulptor.org/

Append a tuple to a list - what&#39;s the difference between two ways?

I have a list of namedtuples named `Books` and am trying to increase the `price` field by 20% which does change the value of `Books`. I tried to do:

    from collections import namedtuple
    Book = namedtuple(&#39;Book&#39;, &#39;author title genre year price instock&#39;)
    BSI = [
           Book(&#39;Suzane Collins&#39;,&#39;The Hunger Games&#39;, &#39;Fiction&#39;, 2008, 6.96, 20),
           Book(&#39;J.K. Rowling&#39;, &quot;Harry Potter and the Sorcerer&#39;s Stone&quot;, &#39;Fantasy&#39;, 1997, 4.78, 12)]
    for item in BSI:
        item = item.price*1.10
    print(item.price)

But I keep getting :

     Traceback (most recent call last):
     print(item.price)
     AttributeError: &#39;float&#39; object has no attribute &#39;price&#39;

 I understand that I cannot set the fields in a namedtuple. How do I go about updating `price`?


I tried to make it into a function:

    def restaurant_change_price(rest, newprice):
        rest.price = rest._replace(price = rest.price + newprice)
        return rest.price
    
    print(restaurant_change_price(Restaurant(&quot;Taillevent&quot;, &quot;French&quot;, &quot;343-3434&quot;, &quot;Escargots&quot;, 24.50), 25))

but I get an error with replace saying:

     rest.price = rest._replace(price = rest.price + newprice)
     AttributeError: can&#39;t set attribute

Can someone let me know why this is happening?

Changing values of a list of namedtuples

I have map `Map&lt;Type, Long&gt; countByType` and I want to have a list which has sorted (min to max) keys by their corresponding values. My try is:


    countByType.entrySet().stream().sorted().collect(Collectors.toList());

however this just gives me a list of entries, how can I get a list of types, without losing the order?

Java 8 stream map to list of keys sorted by values

To better understand the new stream API I&#39;m trying to convert some old code, but I&#39;m stuck on this one.


     public Collection&lt;? extends File&gt; asDestSet() {
        HashMap&lt;IFileSourceInfo, Set&lt;File&gt;&gt; map = new HashMap&lt;IFileSourceInfo, Set&lt;File&gt;&gt;();
        //...
        Set&lt;File&gt; result = new HashSet&lt;File&gt;();
        for (Set&lt;File&gt; v : map.values()) {
            result.addAll(v);
        }
        return result;
    }

I can&#39;t seem to create a valid Collector for it:

     public Collection&lt;? extends File&gt; asDestSet() {
        HashMap&lt;IFileSourceInfo, Set&lt;File&gt;&gt; map = new HashMap&lt;IFileSourceInfo, Set&lt;File&gt;&gt;();
        //...
    	return map.values().stream().collect(/* what? */);
    }

Java 8 Stream Collecting Set

I can convert a [`java.util.Date`][1] to a [`java.time.Instant`][2] (Java 8 and later) this way:  

    Calendar cal = Calendar.getInstance();
    cal.set(Calendar.HOUR_OF_DAY, 8);
    cal.set(Calendar.MINUTE, 30);
    Date startTime = cal.getTime();
    Instant i = startTime.toInstant();

Can anybody let me know about the convert that instant to date with a specific date &amp; time format? i.e 2015-06-02 8:30:00

I have gone through api but could not find a satisfactory answer.


  [1]: http://docs.oracle.com/javase/8/docs/api/java/util/Date.html
  [2]: http://docs.oracle.com/javase/8/docs/api/java/time/Instant.html

How to convert an Instant to a date format?

I have a `List&lt;Person&gt;`. I need to get a `List` from a property of `Person`.

For example, I have a `Person` class:

    class Person
    {
        private String name;
        private String birthDate;
        public String getName() {
            return name;
        }
        public String getBirthDate() {
            return birthDate; 
        }
        Person(String name) {
            this.name = name;
        }
    }

    List&lt;Person&gt; personList = new ArrayList&lt;&gt;();
    personList.add(new Person(&quot;David&quot;));
    personList.add(new Person(&quot;Joe&quot;));
    personList.add(new Person(&quot;Michel&quot;));
    personList.add(new Person(&quot;Barak&quot;));

I want to get a list of names with the `Stream` API, like this:

    List&lt;String&gt; names = personList.stream().somecode().collect(Collectors.toList());
    names.stream().forEach(System.out::println);

    #David
    #Joe
    #Michel
    #Barak

This code doesn&#39;t work:

    public class Main 
    {
        public static void main(String[] args) 
        {
	        List&lt;Person&gt; personList = new ArrayList&lt;&gt;();
            Person person = new Person(&quot;Иван&quot;);
            person.getFriends().addAll(Arrays.asList(&quot;Друг 1&quot;, &quot;Друг 2&quot;, &quot;Друг 3&quot;));
            personList.add(person);
            person = new Person(&quot;Федор&quot;);
            person.getFriends().addAll(Arrays.asList(&quot;Друг 4&quot;, &quot;Друг 5&quot;, &quot;Друг 6&quot;));
            personList.add(person);
            person = new Person(&quot;Алексей&quot;);
            person.getFriends().addAll(Arrays.asList(&quot;Друг 7&quot;, &quot;Друг 8&quot;, &quot;Друг 9&quot;));
            personList.add(person);
            person = new Person(&quot;Константин&quot;);
            person.getFriends().addAll(Arrays.asList(&quot;Друг 10&quot;, &quot;Друг 11&quot;, &quot;Друг 12&quot;));

            List&lt;String&gt; friens = personList.stream().map(e-&gt;e.getFriends()).collect(Collectors.toList());

            friends.stream().forEach(System.out::println);
            //Друг 1
            //Друг 2
            //Друг 3
            //Друг 4
            //...

        }
    }

    class Person
    {
        String name;
        List&lt;String&gt; friends;

        Person(String name) {
            this.name = name;
        }
        public String getName() {
            return name;
        }

        public List&lt;String&gt; getFriends() {
            return friends;
        }
    }

&lt;br&gt;
How can I get a `List` of a property with `Stream` API? 

How can I get a List from some class properties with Java 8 Stream?

I have a large file that contains a list of items.

I would like to create a batch of items, make an HTTP request with this batch  (all of the items are needed as parameters in the HTTP request). I can do it very easily with a `for` loop, but as Java 8 lover, I want to try writing this with Java 8&#39;s Stream framework (and reap the benefits of lazy processing).

Example:

    List&lt;String&gt; batch = new ArrayList&lt;&gt;(BATCH_SIZE);
    for (int i = 0; i &lt; data.size(); i++) {
      batch.add(data.get(i));
      if (batch.size() == BATCH_SIZE) process(batch);
    }
    
    if (batch.size() &gt; 0) process(batch);

I want to do something a long the line of
`lazyFileStream.group(500).map(processBatch).collect(toList())`

What would be the best way to do this?

Java 8 Stream with batch processing

I have the following `Stream`:

    Stream&lt;T&gt; stream = stream();

    T result = stream.filter(t -&gt; {
        double x = getX(t);
        double y = getY(t);
        return (x == tx &amp;&amp; y == ty);
    }).findFirst().get();

    return result;

However, there is not always a result which gives me the following error:

&gt;NoSuchElementException: No value present

So how can I return a `null` if there is no value present?



Content Type	Original Author	Original Content on Stackoverflow
Question	Lahiru Chandima	View Question on Stackoverflow
Solution 1 - Java	Tagir Valeev	View Answer on Stackoverflow

Java stream map and collect - order of resulting container

Java Problem Overview

Java Solutions

Solution 1 - Java

Why does Jackson 2 not recognize the first capital letter if the leading camel case word is only a single letter long?

How To Show and hide ActionBar with AppCompat v.7

Attributions