You could actually use type-safe nested `ConfigurationProperties`.

    @ConfigurationProperties
    public class DatabaseProperties {
        
        private Connection primaryConnection;
        
        private Connection backupConnection;
        
        // getter, setter ...
        
        public static class Connection {

            private String host;

            // getter, setter ...

        }
        
    }

Now you can set the property `primaryConnection.host`.

If you don&#39;t want to use inner classes then you can annotate the fields with `@NestedConfigurationProperty`.

    @ConfigurationProperties
    public class DatabaseProperties {
        
        @NestedConfigurationProperty
        private Connection primaryConnection; // Connection is defined somewhere else
        
        @NestedConfigurationProperty
        private Connection backupConnection;
        
        // getter, setter ...
        
    }

See also the [Reference Guide](http://docs.spring.io/spring-boot/docs/current/reference/htmlsingle/#configuration-metadata-nested-properties) and [Configuration Binding Docs](https://github.com/spring-projects/spring-boot/wiki/Spring-Boot-Configuration-Binding).

UIAlertController with two buttons with styles set:

    UIAlertActionStyle.Cancel
    UIAlertActionStyle.Default

in iOS 8.2, the Cancel button is non-bold and Default is bold.
In iOS 8.3 they have switched round

You can see it Apple&#39;s own apps e.g., Settings &gt; Mail &gt; Add Account &gt; iCloud &gt; enter invalid data, then it shows like this on 8.3:

  Unsupported Apple ID

Learn More (bold)
OK (non-bold)


whereas it was the other way round for 8.2.

Any workaround to make it like 8.2 again. Why has it changed?

iOS UIAlertController bold button changed in 8.3

When I do:

    IO.inspect [:right, :top, :left, ...very_long_list]

I only get the first items (it&#39;s a list of moves to solve a 15-puzzle) like this:

    [:right, :top, :left, :bot, :bot, :left, :top, :top, :right, :right, :bot,
      :left, :bot, :left, :top, :right, :bot, :right, :top, :top, :left, :bot,
      :left, :top, :right, :right, :bot, :bot, :left, :top, :top, :left, :bot,
      :right, :top, :right, :bot, :left, :left, :top, :right, :bot, :right, :top,
      :left, :left, :bot, ...] # =&gt; See the &#39;...&#39;
                                    instead, I would like 
                                    to get the complete list

How can I tell `IO.inspect` to not trim the list? Is there an option or something?

How to use IO.inspect on a long list without trimming it?

Spring boot comes with many cool features. My favourite one is a type-safe configuration mechanism through [`@ConfigurationProperties`][1] and corresponding yml/properties files. I&#39;m writing a library that configures Cassandra connection via Datastax Java driver. I want to allow developers to configure `Cluster` and `Session` objects by simply editing yml file. This is easy in spring-boot. But I want to allow her/him configure multiple connections this way. In PHP framework - Symfony it is as easy as:


    doctrine:
      dbal:
        default_connection: default
        connections:
          default:
            driver:   &quot;%database_driver%&quot;
            host:     &quot;%database_host%&quot;
            port:     &quot;%database_port%&quot;
            dbname:   &quot;%database_name%&quot;
            user:     &quot;%database_user%&quot;
            password: &quot;%database_password%&quot;
            charset:  UTF8
          customer:
            driver:   &quot;%database_driver2%&quot;
            host:     &quot;%database_host2%&quot;
            port:     &quot;%database_port2%&quot;
            dbname:   &quot;%database_name2%&quot;
            user:     &quot;%database_user2%&quot;
            password: &quot;%database_password2%&quot;
            charset:  UTF8

(this snippet comes from [Symfony documentation][2])

Is it possible in spring-boot using ConfigurationProperties? Should I nest them?

  [1]: http://docs.spring.io/spring-boot/docs/current/reference/htmlsingle/#boot-features-external-config-typesafe-configuration-properties
  [2]: http://symfony.com/doc/current/cookbook/doctrine/multiple_entity_managers.html


Spring Boot - nesting ConfigurationProperties

Spring boot comes with many cool features. My favourite one is a type-safe configuration mechanism through <a href="http://docs.spring.io/spring-boot/docs/current/reference/htmlsingle/#boot-features-external-config-typesafe-configuration-properties" target="_blank" rel="noopener noreferrer"><code>@ConfigurationProperties</code></a> and corresponding yml/properties files. I'm writing a library that configures Cassandra connection via Datastax Java driver. I want to allow developers to configure <code>Cluster</code> and <code>Session</code> objects by simply editing yml file. This is easy in spring-boot. But I want to allow her/him configure multiple connections this way. In PHP framework - Symfony it is as easy as:
<pre><code class="hljs language-yaml">doctrine:
 dbal:
 default_connection: default
 connections:
 default:
 driver: "%database_driver%"
 host: "%database_host%"
 port: "%database_port%"
 dbname: "%database_name%"
 user: "%database_user%"
 password: "%database_password%"
 charset: UTF8
 customer:
 driver: "%database_driver2%"
 host: "%database_host2%"
 port: "%database_port2%"
 dbname: "%database_name2%"
 user: "%database_user2%"
 password: "%database_password2%"
 charset: UTF8
</code></pre>
(this snippet comes from <a href="http://symfony.com/doc/current/cookbook/doctrine/multiple_entity_managers.html" target="_blank" rel="noopener noreferrer">Symfony documentation</a>)
Is it possible in spring-boot using ConfigurationProperties? Should I nest them?

I try to run this test:

        @Mock IRoutingObjHttpClient routingClientMock;
        @Mock IRoutingResponseRepository routingResponseRepositoryMock;
    
    
        @Test
        public void testSendRoutingRequest() throws Exception {
            CompleteRoutingResponse completeRoutingResponse = new CompleteRoutingResponse();
            completeRoutingResponse.regression_latencyMillis = 500L;
    
            Mockito.when(routingClientMock.sendRoutingRequest(any(RoutingRequest.class))).thenReturn(completeRoutingResponse);
    
            RoutingObjHttpClientWithReRun routingObjHttpClientWithReRun = new RoutingObjHttpClientWithReRun
                    (routingClientMock, routingResponseRepositoryMock);
    
    ...
        }

but I get NullPointerException for:

`Mockito.when(routingClientMock.`

what am i missing?

mock instance is null after @Mock annotation

Similar problem with https://stackoverflow.com/questions/26582300/how-to-use-sbt-behind-authenticated-proxy. I tried with the given answer and problem still there. 

When I run **sbt** in terminal, it shows and stucks at : 

    Getting org.scala-sbt sbt 0.13.6 ...

additional information: 

     sbt --version
     sbt launcher version 0.13.6

How could I fix it?


stuck at &quot;Getting org.scala-sbt sbt 0.13.6 ...&quot; when running sbt in terminal

I do have a relation between three model object in my project (model and repository snippets in the end of the post. 

When I call `PlaceRepository.findById` it does fire three select queries:

(&quot;sql&quot;)

 1. `SELECT * FROM place p where id = arg`
 2. `SELECT * FROM user u where u.id = place.user.id`
 3. `SELECT * FROM city c LEFT OUTER JOIN state s on c.woj_id = s.id where c.id = place.city.id`

That&#39;s rather unusual behavior (for me). As far as I can tell after reading Hibernate documentation it should always use JOIN queries. There is no difference in the queries when `FetchType.LAZY` changed to  `FetchType.EAGER` in the `Place` class (query with additional SELECT), the same for the `City` class when `FetchType.LAZY` changed to  `FetchType.EAGER` (query with JOIN). 

When I use `CityRepository.findById` suppressing fires two selects: 

 1. `SELECT * FROM city c where id = arg`
 2. `SELECT * FROM state s where id = city.state.id`

My goal is to have a the sam behavior in all situations (either always JOIN or SELECT, JOIN preferred though). 

Model definitions:

Place:

    @Entity
    @Table(name = &quot;place&quot;)
    public class Place extends Identified {

        @Fetch(FetchMode.JOIN)
        @ManyToOne(fetch = FetchType.LAZY)
        @JoinColumn(name = &quot;id_user_author&quot;)
        private User author;

        @Fetch(FetchMode.JOIN)
        @ManyToOne(fetch = FetchType.LAZY)
        @JoinColumn(name = &quot;area_city_id&quot;)
        private City city;
        //getters and setters
    }

City: 

    @Entity
    @Table(name = &quot;area_city&quot;)
    public class City extends Identified {

        @Fetch(FetchMode.JOIN)
        @ManyToOne(fetch = FetchType.LAZY)
        @JoinColumn(name = &quot;area_woj_id&quot;)
        private State state;
        //getters and setters
    }

Repositories: 

PlaceRepository

    public interface PlaceRepository extends JpaRepository&lt;Place, Long&gt;, PlaceRepositoryCustom {
        Place findById(int id);
    }


UserRepository: 

    public interface UserRepository extends JpaRepository&lt;User, Long&gt; {
            List&lt;User&gt; findAll();
        User findById(int id);
    }

CityRepository: 

    public interface CityRepository extends JpaRepository&lt;City, Long&gt;, CityRepositoryCustom {    
        City findById(int id);
    }

How does the FetchMode work in Spring Data JPA

Let consider a hashmap

    Map&lt;Integer, List&gt; id1 = new HashMap&lt;Integer,List&gt;();

I inserted some values into both hashmap.

For Example,
                
    List&lt;String&gt; list1 = new ArrayList&lt;String&gt;();
    
    list1.add(&quot;r1&quot;);
    list1.add(&quot;r4&quot;);
    
    List&lt;String&gt; list2 = new ArrayList&lt;String&gt;();
    list2.add(&quot;r2&quot;);
    list2.add(&quot;r5&quot;);
    
    List&lt;String&gt; list3 = new ArrayList&lt;String&gt;();
    list3.add(&quot;r3&quot;);
    list3.add(&quot;r6&quot;);
    
    id1.put(1,list1);
    id1.put(2,list2);
    id1.put(3,list3);
    id1.put(10,list2);
    id1.put(15,list3);

 Q1)    Now I want to apply a filter condition on the key in hashmap and retrieve the corresponding value(List).

        

Eg: Here My query is key=1, and output should be &#39;list1&#39;

 I wrote 
                
            

    id1.entrySet().stream().filter( e -&gt; e.getKey() == 1);
                
  But I don&#39;t know how to retrieve as a list as output of this stream operation.


Q2)        Again I want to apply a filter condition on the key in hashmap and retrieve the corresponding list of lists.

  Eg:  Here My query is key=1%(i.e key can be 1,10,15), and output should be &#39;list1&#39;,&#39;list2&#39;,&#39;list3&#39;(list of lists).




Hashmap with Streams in Java 8 Streams to collect value of Map

I have been studying apache kafka for a month now. I am however, stuck at a point now. My use case is, I have two or more consumer processes running on different machines. I ran a few tests in which I published 10,000 messages in kafka server. Then while processing these messages I killed one of the consumer processes and restarted it. Consumers were writing processed messages in a file. So after consumption finished, file was showing more than 10k messages. So some messages were duplicated. 

In consumer process I have disabled auto commit. Consumers manually commit offsets batch wise. So for e.g if 100 messages are written to file, consumer commits offsets. When single consumer process is running and it crashes and recovers duplication is avoided in this manner. But when more than one consumers are running and one of them crashes and recovers, it writes duplicate messages to file.

Is there any effective strategy to avoid these duplicate messages? 

Effective strategy to avoid duplicate messages in apache kafka consumer

I am developing a REST API using Spring 4. I would like to secure some of the endpoints using Spring Security, but based on what I&#39;ve read this can be done with either `@EnableGlobalMethodSecurity` or `@EnableWebSecurity`. Unfortunately, the documentation that I have found for these don&#39;t clearly explain what they do (or how they compare). If I want to secure a Spring REST API with authentication and authorization based on data and relationships declared in a standard relational database, what is the recommended method for achieving this in Spring 4?

@EnableGlobalMethodSecurity vs @EnableWebSecurity

I am studying for the Spring Core certification an I have some doubts about how Spring handle the **beans lifecycle** and in particular about the **bean post processor**.

So I have this schema:

![enter image description here][1]


It is pretty clear for me what it means:

The following steps take place in the **Load Bean Definitions** phase:

 - The **@Configuration** classes are processed and/or **@Components** are
   scanned for and/or **XML files** are parsed.

 - Bean definitions added to BeanFactory (each indexed under its id)

 - Special **BeanFactoryPostProcessor** beans invoked, it can modify the definition of any bean (for example for the property-placeholder values replacements).

Then the following steps take place in the **beans creation phase**:

 - Each bean is eagerly instantiated by default (created in right order with its dependencies injected).

 - After dependency injection each bean goes through a post-processing
   phase in which further configuration and initialization may occur.

 - After post processing the bean is fully initialized and ready for use (tracked by its id until the context is destroyed)

Ok, this is pretty clear for me and I also know that **there are two types of bean post processors** which are:

 - **Initializers:** Initialize the bean if instructed (i.e. @PostConstruct).

 - and **All the rest:** that allow for additional configuration and that **may run before or after the initialize step**

And I post this slide:

![enter image description here][2]

So it is very clear for me what does the **initializers** bean post processors (they are the methods annotated with **@PostContruct** annotation and that are automatically called immediately after the setter methods (so after the dependency injection), and I know that I can use to perform some initialization batch (as populate a cache as in the previous example).

But what exactly represents the other bean post processor? What do we mean when we say that these steps are performed **before or after the initialization phase**?

So my beans are instantiated and its dependencies are injected, so then the initialization phase is completed (by the execution of a **@PostContruct** annotated method). What do we mean by saying that a Bean Post Processor is used before the initialization phase? It means that it happens before the **@PostContruct** annotated method execution? Does it means that it could happen before the dependency injection (before that the setter methods are called)?

And what exactly do we mean when we say that it is performed **after the initialization step**. It means that it happens after that the execution of a **@PostContruct** annotated method, or what?

I can easily figure into my head why I need a **@PostContruct** annotated method but I can&#39;t figure some typical example of the other kind of bean post processor, can you show me some typical example of when are used?



  [1]: http://i.stack.imgur.com/gL8Ky.jpg
  [2]: http://i.stack.imgur.com/YKAZH.jpg

How exactly does the Spring BeanPostProcessor work?

I&#39;m trying to add a jsp page in my Spring Boot service. My problem is that every time I try to go to that page I have this:

&gt; Whitelabel Error Page
&gt; 
&gt; This application has no explicit mapping for /error, so you are seeing
&gt; this as a fallback.
&gt; 
&gt; Tue Apr 21 23:16:00 EEST 2015 There was an unexpected error (type=Not
&gt; Found, status=404). No message available

I have added the prefix and sufix into my application.properties:

    spring.view.prefix: /WEB-INF/jsp/
    spring.view.suffix: .jsp

This is my controller class:

    @Controller
    public class MarkerController {
    	@RequestMapping(value=&quot;/map&quot;)
    	public String trafficSpy() {
    		return &quot;index&quot;;
    	}
    }

My Application class:

    @SpringBootApplication
    public class Application extends SpringBootServletInitializer {
    	private static Logger logger = Logger.getLogger(Application.class.getName());
    		
    	public static void main(String[] args) {
    		 	logger.info(&quot;SPRING VERSION: &quot; + SpringVersion.getVersion());
    	        SpringApplication.run(Application.class, args);
    	    }
    }

And the index.jsp:

    &lt;!DOCTYPE html&gt;
    &lt;%@ taglib prefix=&quot;c&quot; uri=&quot;http://java.sun.com/jsp/jstl/core&quot;%&gt;
    &lt;html lang=&quot;en&quot;&gt;
    
    &lt;body&gt;
        &lt;h1&gt;Hello, World!!!&lt;/h1&gt;
    
    
        &lt;p&gt;JSTL URL: ${url}&lt;/p&gt;
    &lt;/body&gt;
    
    &lt;/html&gt;

And this is the src file structure:

    ├── src
    │&#160;&#160; ├── main
    │&#160;&#160; │&#160;&#160; ├── java
    │&#160;&#160; │&#160;&#160; │&#160;&#160; └── com
    │&#160;&#160; │&#160;&#160; │&#160;&#160;     └── example
    │&#160;&#160; │&#160;&#160; │&#160;&#160;         └── internetprogramming
    │&#160;&#160; │&#160;&#160; │&#160;&#160;             └── myserver
    │&#160;&#160; │&#160;&#160; │&#160;&#160;                 └── server
    │&#160;&#160; │&#160;&#160; │&#160;&#160;                     ├── Application.java
    │&#160;&#160; │&#160;&#160; │&#160;&#160;                     ├── config
    │&#160;&#160; │&#160;&#160; │&#160;&#160;                     │&#160;&#160; └── DatabaseConfig.java
    │&#160;&#160; │&#160;&#160; │&#160;&#160;                     ├── controller
    │&#160;&#160; │&#160;&#160; │&#160;&#160;                     │&#160;&#160; └── MarkerController.java
    │&#160;&#160; │&#160;&#160; │&#160;&#160;                     ├── dao
    │&#160;&#160; │&#160;&#160; │&#160;&#160;                     │&#160;&#160; ├── MarkerDaoImplementation.java
    │&#160;&#160; │&#160;&#160; │&#160;&#160;                     │&#160;&#160; └── MarkerDaoInterface.java
    │&#160;&#160; │&#160;&#160; │&#160;&#160;                     ├── Marker.java
    │&#160;&#160; │&#160;&#160; │&#160;&#160;                     └── service
    │&#160;&#160; │&#160;&#160; │&#160;&#160;                         ├── MarkerServiceImplementation.java
    │&#160;&#160; │&#160;&#160; │&#160;&#160;                         └── MarkerServiceInterface.java
    │&#160;&#160; │&#160;&#160; ├── resources
    │&#160;&#160; │&#160;&#160; │&#160;&#160; └── application.properties
    │&#160;&#160; │&#160;&#160; └── webapp
    │&#160;&#160; │&#160;&#160;     └── WEB-INF
    │&#160;&#160; │&#160;&#160;         └── jsp
    │&#160;&#160; │&#160;&#160;             └── index.jsp



Spring Boot JSP 404

I&#39;m using `spring-boot` and `@Scheduled` annotation to execute some tasks.

How can I find out what the default pool size of scheduled tasks is by default in spring-boot?

Reason: the following class does not execute the jobs in parallel, but one after the other. Maybe only a single thread executor is configured by default?

    @Service
    public class ZipFileTesterAsync {
    
        @Scheduled(fixedDelay = 60000, initialDelay = 500)
    	public void run() throws Exception {
        	System.out.println(&quot;import 1&quot;);
    	    TimeUnit.MINUTES.sleep(1);
    	    System.out.println(&quot;import 1 finished&quot;);
        }
        
        @Scheduled(fixedDelay = 60000, initialDelay = 1000)
    	public void run2() throws Exception {
        	System.out.println(&quot;import 2&quot;);
    	    TimeUnit.MINUTES.sleep(1);
        }
    }

Result: the 2nd job is executed after the first finished.


What is the default scheduler pool size in spring-boot?

I have a Spring-Boot application where the default properties are set in an `application.properties` file in the classpath (src/main/resources/application.properties).

I would like to override some default settings in my JUnit test with properties declared in a `test.properties` file (src/test/resources/test.properties)

I usualy have a dedicated Config Class for my Junit Tests, e.g.

    package foo.bar.test;
    
    import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
    import org.springframework.context.annotation.Configuration;
    import org.springframework.context.annotation.Import;
    
    @Configuration
    @Import(CoreConfig.class)
    @EnableAutoConfiguration
    public class TestConfig {
      
    }

I first thought that using `@PropertySource(&quot;classpath:test.properties&quot;)` in  the TestConfig class would do the trick, but these properties will not overwrite the application.properties settings (see Spring-Boot Reference Doc - [23. Externalized Configuration][1]).

Then I tried to use `-Dspring.config.location=classpath:test.properties` when invoking the test. That was successful - but I don&#39;t want to set this system property for each test execution. Thus I put it in the code

    @Configuration
    @Import(CoreConfig.class)
    @EnableAutoConfiguration
    public class TestConfig {
      
      static {
        System.setProperty(&quot;spring.config.location&quot;, &quot;classpath:test.properties&quot;);
      }
    
    }

which unfortunatly was again not successful.

There must be a simple solution on how to override `application.properties` settings in JUnit tests with `test.properties` that I must have overlooked.

  [1]: http://docs.spring.io/spring-boot/docs/1.2.3.RELEASE/reference/htmlsingle/#boot-features-external-config

Override default Spring-Boot application.properties settings in Junit Test

I&#39;ve been working on a Spring/Spring MVC application and I&#39;m looking to add performance metrics. I&#39;ve come across Spring Boot Actuator and it looks like a great solution. However my application is not a Spring Boot application. My application is running in a traditional container Tomcat 8.

I added the following dependencies

    // Spring Actuator
    compile &quot;org.springframework.boot:spring-boot-starter-actuator:1.2.3.RELEASE&quot;

I created the following config class.

    @EnableConfigurationProperties
    @Configuration
    @EnableAutoConfiguration
    @Profile(value = {&quot;dev&quot;, &quot;test&quot;})
    @Import(EndpointAutoConfiguration.class)
    public class SpringActuatorConfig {
    
    }

I even went as far as adding `@EnableConfigurationProperties` on every configuration class as suggested on another post on StackOverflow. However that didn&#39;t do anything. The endpoints are still not being created and return 404s.

Spring Boot Actuator without Spring Boot

I&#39;m having a small problem with formatting a Java 8 LocalDateTime in my Spring Boot Application. With &#39;normal&#39; dates I have no problem, but the LocalDateTime fields are converted to the following:

    &quot;startDate&quot; : {
        &quot;year&quot; : 2010,
        &quot;month&quot; : &quot;JANUARY&quot;,
        &quot;dayOfMonth&quot; : 1,
        &quot;dayOfWeek&quot; : &quot;FRIDAY&quot;,
        &quot;dayOfYear&quot; : 1,
        &quot;monthValue&quot; : 1,
        &quot;hour&quot; : 2,
        &quot;minute&quot; : 2,
        &quot;second&quot; : 0,
        &quot;nano&quot; : 0,
        &quot;chronology&quot; : {
          &quot;id&quot; : &quot;ISO&quot;,
          &quot;calendarType&quot; : &quot;iso8601&quot;
        }
      }

While I would like convert it to something like:

    &quot;startDate&quot;: &quot;2015-01-01&quot;

My code looks like this:

    @JsonFormat(pattern=&quot;yyyy-MM-dd&quot;)
    @DateTimeFormat(iso = DateTimeFormat.ISO.TIME)
    public LocalDateTime getStartDate() {
        return startDate;
    }

But either of the above annotations don&#39;t work, the date keeps getting formatted like above. Suggestions welcome!


Content Type	Original Author	Original Content on Stackoverflow
Question	wikp	View Question on Stackoverflow
Solution 1 - Java	Roland Weisleder	View Answer on Stackoverflow

Spring Boot - nesting ConfigurationProperties

Java Problem Overview

Java Solutions

Solution 1 - Java

How to use IO.inspect on a long list without trimming it?

iOS UIAlertController bold button changed in 8.3

Attributions