Spring Boot and AngularJS quick start

In this post I am going to show very simple and quick example of web application using Spring Boot with AngularJS. This app contains simple functionality of sending and storing imaginary messages. I've also used gradle for build management. All code is public and it is available on my github: https://github.com/rafalnowak/spring-boot-fun

Introduction to Spring Boot

Spring Boot is quite new project created under Spring Source umbrella. It was very few months ago when it reached version 1.0 and status of general availability.
Most important and prominent goals of this projects are:
  • providing ability to create simple web apps very quickly
  • minimizing amount of XML codebloat which is usually necessary to configure every Spring application
  • most of app configuration is automatical
  • simplify running and deployment process by using embedded Tomcat or Jetty servers that can run our applications without special effort and deploy process
  • there are lot of so called spring boot starters which are packages containing default configuration for various fields of Spring like database access by JPA, aspect oriented programming or security
As we can see, it looks promising. In this post I'll show few basic steps necessary to create and boot simple Spring Boot web application.

First steps

Although Spring Boot can be used with special command line interface tools, I've decided to use it with very popular gradle build system.
Spring Boot comes with plugins to integrate with maven or gradle. They allow us to easily run application in embedded server. Necessary instructions to include these plugin are shown on snippet below:
buildscript {
    repositories {
        mavenCentral()
    }

    dependencies {
        classpath("org.springframework.boot:spring-boot-gradle-plugin:1.0.1.RELEASE")
    }
}
With this basic config we can proceed to next steps. In my sample project I've divided application into two modules: one contains persistence layer with domain object and JPA repositories and another contains presentation layer with controllers. Of course this completely optional and in such simple project it does not add any benefits. But it can show how to create multi module project in gradle. Next code fragment contains common configuration for all modules in our gradle build:
allprojects {
    apply plugin: "java"

    version = '1.0-SNAPSHOT'
    group = "info.rnowak.springBootFun"

    repositories {
        mavenLocal()
        mavenCentral()
    }

    dependencies {
        compile "org.springframework.boot:spring-boot-starter-test:1.0.1.RELEASE"
        compile "com.google.guava:guava:16.0.1"
        compile "com.h2database:h2:1.3.175"

        testCompile "junit:junit:4.11"
        testCompile "org.mockito:mockito-all:1.9.5"
        testCompile "org.assertj:assertj-core:1.5.0"
    }
}
Now when we have common configuration, we can declare basic modules of application:
project(":persistence") {
    dependencies {
        compile "org.springframework.boot:spring-boot-starter-data-jpa:1.0.1.RELEASE"

        testCompile project(":webapp")
    }
}

project(":webapp") {
    apply plugin: "spring-boot"

    dependencies {
        compile project(":persistence")
        compile "org.springframework.boot:spring-boot-starter-web:1.0.1.RELEASE"
    }
}
Most important parts are including special Spring Boot Starter packages and declaring usage of spring-boot plugin in one of subprojects.
Every starter packet contains dependencies for all necessary libraries used on given feature. For example, JPA starter has Hibernate dependencies and AOP starter contains spring-aop and AspectJ libraries. What is more, with this libraries Spring Boot provides also default configuration.
It is simple quick start configuration but it is enough for some starter applications.

Let's start fun with Spring!

Our next step should be creating of starting point of application. With Spring Boot it can be done by writing regular main method in some class. Now you only need to annotate this class with special Spring Boot auto configuration annotations and application is ready to run! Example of start class is shown below:
package info.rnowak.springFun;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
import org.springframework.context.annotation.ComponentScan;

@ComponentScan
@EnableAutoConfiguration
public class SpringFun {
    public static void main(String[] args) {
        SpringApplication app = new SpringApplication(SpringFun.class);
        app.setShowBanner(false);
        app.run(args);
    }
}
Well, this step look simple but it has few interesting implications for all application.
Firstly, this class enables component scan for Spring managed beans with root package info.rnowak.springFun because it is placed in this package.
Another thing is that this main method allows to run application using command gradle run. By default it uses embedded Tomcat running on port 8080. Of course this behaviour can be changed and it is very well described in project documentation. It is also possible to create runnable jar from our application.
With main class defined we can create all other classes in our application like controllers, repositories, domain classes or services. But I won't show exact examples of such classes because they do not differ in any way from the same classes in old classic Spring. If you are interesed in my example, please take a look at the repository Spring Boot Fun repo.

Add some AngularJS

One of another "side effect" of Spring Boot main configuration class is that we get few default view resolvers. View resolver, in short version, is Spring feature, which maps names of view to specific view files.
Spring Boot with its default configuration sets lookup path for index.html file which will be served by default controller. Framework looks for this file in public/, webapp/ or resources/ directory on classpath. So you can just put index.html file in one of these locations and Spring Boot will create controller serving this view. And this is the way we can use AngularJS in our project. Of course it's not the only way but it is the simplest method for using AngularJS with Spring Boot application.
In our example application index.html file was placed in webapp/ directory and it looks like this:
<!DOCTYPE html>

<html ng-app="springFun">

<head>
    <link rel="stylesheet" href="//netdna.bootstrapcdn.com/bootstrap/3.1.1/css/bootstrap.min.css">

    <script src="//ajax.googleapis.com/ajax/libs/jquery/2.1.0/jquery.min.js"></script>
    <script src="//netdna.bootstrapcdn.com/bootstrap/3.1.1/js/bootstrap.min.js"></script>

    <script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.3.0-beta.4/angular.min.js"></script>
    <script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.3.0-beta.4/angular-route.min.js"></script>
    <script src="js/application.js"></script>
    <script src="js/controllers.js"></script>
</head>

<body>

    <nav class="navbar navbar-default" role="navigation">
        <div class="container-fluid">
            <div class="navbar-header">
                <a class="navbar-brand" href="#/index">Spring Boot Fun</a>
            </div>
            <div class="collapse navbar-collapse">
                <ul class="nav navbar-nav">
                    <li><a href="#/list">Messages list</a></li>
                    <li><a href="#/about">About</a></li>
                </ul>
            </div>
        </div>
    </nav>

    <div ng-view></div>

    <footer class="text-center">
        Spring Boot Fun
    </footer>

</body>

</html>
This file includes all angular libraries used in project, controllers definition and main application module with routing defined.
The rest of files is available in repository mentioned earlier in post so I will not provide all listings here as it would be just waste of virtual space in post :)

Summary

As we can see, Spring Boot greatly decreases time needed to write and run simple Java web application. It reduces amount of XML configuration and provieds a lot of default values and conventions. But if we want to precisely set some settings, Spring Boot does not forbid it and programmer can manually set all the settings.
Also deploy of application is simplified because Spring Boot with gradle or maven plugin allows to run application in place with these tools. We can also create runnable jar that contains embedded Tomcat or Jetty. And if it is not desired by us, we can always use war plugin and create regular, traditional war and deploy it in classical way.
Spring Boot has also great documentation and I strongly encourage to read it by everybody interested in this tool: Spring Boot Docs

Custom SonarQube rules for Unit Tests

I need a new rule

In our project we use (formely Sonar) to manage our code quality. It is a great tool and I recommend everyone to set it up and read its reports.

Recently, we've agreed that it's better to use assertj assertions in our unit tests than JUnit's. So I've decided to write a simple rule that checks if some of JUnit asserts assertTrue, assertFalse, assertNull and others are used. Then, I've discovered it's not so easy to do it with Sonar:

  • only 10 code quality rules are applied to unit tests - they are in special repository PMD Unit Tests (source)
  • these 10 rules are disabled by default, you have to enable them by hand
  • you cannot add new rules to this group

However, it turned out it is doable with a small tricks.

Custom PMD Unit Tests rule tutorial

Create your XPath expression by following this tutorial on how to create custom PMD rule. There is a visual editor to test your rules as you develop them - that's great. My XPath expression to avoid all JUnit assertions looks like this:

//PrimaryPrefix/Name[@Image='assertEquals' or @Image='assertNull' or @Image='assertNotNull' or @Image='assertSame' or @Image='assertNotSame' or @Image='assertArrayEquals' or @Image='assertTrue' or @Image='assertFalse']

Go to your Sonar installation, log in as an Administrator, head to Quality Profiles and select a profile that you use. Search for "xpath" and change Activation to Any. You should see two results like this:

Expand XPath rule template (dont' worry that it says it's deprecated) and then click Copy rule. Fill a form with message and XPath and save it. Then take a look at the bottom - you need an identifier of this rule:

You have created a PMD rule, now you need to move it to PMD Unit Tests group. Connect to Sonar's MySQL database. Search for your rule by key:

mysql> select id, plugin_rule_key, plugin_name, parent_id, status from rules where plugin_rule_key='XPathRule_1385721910';
+-----+----------------------+----------------+-----------+-------------+
| id | plugin_rule_key | plugin_name | parent_id | status |
+-----+----------------------+----------------+-----------+-------------+
| 903 | XPathRule_1385721910 | pmd | NULL | DEPRECATED |
+-----+----------------------+----------------+-----------+-------------+
1 row in set (0.00 sec)

Update plugin_name and status (remember to use appropiate primary key for id column):

mysql> update rules set plugin_name='pmd-unit-tests', status='READY' where id=903;
Query OK, 1 row affected (0.00 sec)
Rows matched: 1 Changed: 1 Warnings: 0

There is one step left. Sonar will change this rule's status to REMOVED on restart due to his boot checks. You need to trick him and change parent_id to other's PMD Unit Tests rule. List all these rules and choose one's identifier.

mysql> select id, plugin_name, status from rules where plugin_name='pmd-unit-tests';
+-----+----------------+---------+
| id | plugin_name | status |
+-----+----------------+---------+
| 775 | pmd-unit-tests | READY |
| 776 | pmd-unit-tests | READY |
| 777 | pmd-unit-tests | READY |
| 778 | pmd-unit-tests | READY |
| 779 | pmd-unit-tests | READY |
| 780 | pmd-unit-tests | READY |
| 781 | pmd-unit-tests | READY |
| 782 | pmd-unit-tests | READY |
| 783 | pmd-unit-tests | READY |
| 784 | pmd-unit-tests | READY |
| 903 | pmd-unit-tests | READY |
+-----+----------------+---------+
11 rows in set (0.00 sec)

Choose any id you like, let's say 775 and apply it as parent_id to your newly created rule:

mysql> update rules set parent_id=775 where id=903;
Query OK, 1 row affected (0.00 sec)
Rows matched: 1 Changed: 1 Warnings: 0

Go to your Quality profile and make sure your rule is active! Check it twice, it's easy to forget that step. It's all set up, enjoy your analysis!

Custom SonarQube rules for Unit Tests

I need a new rule

In our project we use (formely Sonar) to manage our code quality. It is a great tool and I recommend everyone to set it up and read its reports.

Recently, we've agreed that it's better to use assertj assertions in our unit tests than JUnit's. So I've decided to write a simple rule that checks if some of JUnit asserts assertTrue, assertFalse, assertNull and others are used. Then, I've discovered it's not so easy to do it with Sonar:

  • only 10 code quality rules are applied to unit tests - they are in special repository PMD Unit Tests (source)
  • these 10 rules are disabled by default, you have to enable them by hand
  • you cannot add new rules to this group

However, it turned out it is doable with a small tricks.

Custom PMD Unit Tests rule tutorial

Create your XPath expression by following this tutorial on how to create custom PMD rule. There is a visual editor to test your rules as you develop them - that's great. My XPath expression to avoid all JUnit assertions looks like this:

//PrimaryPrefix/Name[@Image='assertEquals' or @Image='assertNull' or @Image='assertNotNull' or @Image='assertSame' or @Image='assertNotSame' or @Image='assertArrayEquals' or @Image='assertTrue' or @Image='assertFalse']

Go to your Sonar installation, log in as an Administrator, head to Quality Profiles and select a profile that you use. Search for "xpath" and change Activation to Any. You should see two results like this:

Expand XPath rule template (dont' worry that it says it's deprecated) and then click Copy rule. Fill a form with message and XPath and save it. Then take a look at the bottom - you need an identifier of this rule:

You have created a PMD rule, now you need to move it to PMD Unit Tests group. Connect to Sonar's MySQL database. Search for your rule by key:

mysql> select id, plugin_rule_key, plugin_name, parent_id, status from rules where plugin_rule_key='XPathRule_1385721910';
+-----+----------------------+----------------+-----------+-------------+
| id | plugin_rule_key | plugin_name | parent_id | status |
+-----+----------------------+----------------+-----------+-------------+
| 903 | XPathRule_1385721910 | pmd | NULL | DEPRECATED |
+-----+----------------------+----------------+-----------+-------------+
1 row in set (0.00 sec)

Update plugin_name and status (remember to use appropiate primary key for id column):

mysql> update rules set plugin_name='pmd-unit-tests', status='READY' where id=903;
Query OK, 1 row affected (0.00 sec)
Rows matched: 1 Changed: 1 Warnings: 0

There is one step left. Sonar will change this rule's status to REMOVED on restart due to his boot checks. You need to trick him and change parent_id to other's PMD Unit Tests rule. List all these rules and choose one's identifier.

mysql> select id, plugin_name, status from rules where plugin_name='pmd-unit-tests';
+-----+----------------+---------+
| id | plugin_name | status |
+-----+----------------+---------+
| 775 | pmd-unit-tests | READY |
| 776 | pmd-unit-tests | READY |
| 777 | pmd-unit-tests | READY |
| 778 | pmd-unit-tests | READY |
| 779 | pmd-unit-tests | READY |
| 780 | pmd-unit-tests | READY |
| 781 | pmd-unit-tests | READY |
| 782 | pmd-unit-tests | READY |
| 783 | pmd-unit-tests | READY |
| 784 | pmd-unit-tests | READY |
| 903 | pmd-unit-tests | READY |
+-----+----------------+---------+
11 rows in set (0.00 sec)

Choose any id you like, let's say 775 and apply it as parent_id to your newly created rule:

mysql> update rules set parent_id=775 where id=903;
Query OK, 1 row affected (0.00 sec)
Rows matched: 1 Changed: 1 Warnings: 0

Go to your Quality profile and make sure your rule is active! Check it twice, it's easy to forget that step. It's all set up, enjoy your analysis!

Integration tests with Maven and JUnit

There is no doubt that integration tests phase is crucial in modern applications development. We need to test behaviour of our subsystems and how they interact with other modules. Using JUnit and Maven it's quite easy to create integration tests and run them in separate phase than unit test. It is very important, because integration tests tend to take much more time than unit ones because they work with database, network connections, other subsystems etc. Therefore, we want to run them more rarely. With JUnit in version >= 4.8 there are two approaches for creating and running integration test:
  • using naming conventions and specifying separate executions for maven-surefire plugin
  • create marking interface and mark integration tests with @Category annotation and run test from failsafe-plugin (although it is possible to use surefire in both cases)
 

Separate executions

First method needs naming convention like naming all unit tests with "..Test.java" postfix (or "..Spec.groovy" ;) and integration tests with "..IntegrationTest.java". Then we need to change maven surefire configuration:
<plugin>
    <groupId>org.apache.maven.plugins</groupId>
    <artifactId>maven-surefire-plugin</artifactId>
    <version>2.15</version>
    <configuration>
        <skip>true</skip>    
    </configuration>
</plugin>
What I did here is forcing maven to skip default test phase. Instead of that, I will configure two separate executions (just below the <configuration> section):
<executions>
    <execution>
        <id>unit-tests</id>
        <phase>test</phase>
        <goals>
            <goal>test</goal>
        </goals>
        <configuration>
            <skip>false</skip>
            <includes>
                <include>**/*Test.class</include>
                <include>**/*Spec.class</include>
            </includes>
            <excludes>
                <exclude>**/*IntegrationTest.class</exclude>
            </excludes>
        </configuration>
    </execution>
    <execution>
        <id>integration-tests</id>
        <phase>integration-test</phase>
        <goals>
            <goal>test</goal>
        </goals>
        <configuration>
            <skip>false</skip>
            <includes>
                <include>**/*IntegrationTest.class</include>
            </includes>
        </configuration>
    </execution>
</executions>
In unit test execution I include all test that match naming convention for unit tests (both JUnit and spock ones) and exclude files matching integration test pattern and in integration test execution I did something opposite ;)

Annotations

Another method requires defining of marking interface like this:
package info.rnowak.webtex.common.test;

public interface IntegrationTest {

}
Then we can mark our integration test class with:
@Category(IntegrationTest.class)
Next thing is changing of surefire plugin configuration to omit integration test:
<plugin>
    <groupId>org.apache.maven.plugins</groupId>
    <artifactId>maven-surefire-plugin</artifactId>
    <version>2.15</version>
    <configuration>
        <includes>
            <include>**/*Test.class</include>
            <include>**/*Spec.class</include>
        </includes>  
        <excludedGroups>info.rnowak.webtex.common.test.IntegrationTest</excludedGroups> 
    </configuration>
</plugin>
What has changed here is new <excludedGroups> tag with name of interface which marks our integration tests. Next, we need to add and configure maven-failsafe plugin in order to run test from out integration test group:
<plugin><plugin>
    <groupId>org.apache.maven.plugins</groupId>
    <artifactId>maven-failsafe-plugin</artifactId>
    <version>2.15</version>
    <executions>
        <execution>
            <goals>
                <goal>integration-test</goal>
            </goals>
            <configuration>
                <groups>info.rnowak.webtex.common.test.IntegrationTest</groups>
                <includes>
                    <include>**/*.class</include>
                </includes>
            </configuration>
        </execution>
    </executions>
</plugin>
With this configuration failsafe will run only test marked with @Category(IntegrationTest.class) annotation, no matter what their names are.

What is better?

Well, in my opinion it's just a matter of taste and style. Annotating each integration class may be a little cumbersome but we are not limited to naming classes within specified convention. On the other hand, unit test and integration test usually are named with some convention, so annotations are not a big deal.

Spock, Java and Maven

Few months ago I've came across Groovy - powerful language for JVM platform which combines the power of Java with abilities typical for scripting languages (dynamic typing, metaprogramming).
Together with Groovy I've discovered spock framework (https://code.google.com/p/spock/) - specification framework for Groovy (of course you can test Java classes too!). But spock is not only test/specification framework - it also contains powerful mocking tools.
Even though spock is dedicated for Groovy there is no problem with using it for Java classes tests. In this post I'm going to describe how to configure Maven project to build and run spock specifications together with traditional JUnit tests.
Firstly, we need to prepare pom.xml and add necessary dependencies and plugins.
Two obligatory libraries are:
<dependency>
    <groupid>org.spockframework</groupId>
    <artifactid>spock-core</artifactId>
    <version>0.7-groovy-2.0</version>
    <scope>test</scope>
</dependency>
<dependency>
    <groupid>org.codehaus.groovy</groupId>
    <artifactid>groovy-all</artifactId>
    <version>${groovy.version}</version>
    <scope>test</scope>
</dependency>
Where groovy.version is property defined in pom.xml for more convenient use and easy version change, just like this:
<properties>
    <gmaven-plugin.version>1.4</gmaven-plugin.version>
    <groovy.version>2.1.5</groovy.version>
</properties>
 
I've added property for gmaven-plugin version for the same reason ;)
Besides these two dependencies, we can use few additional ones providing extra functionality:
  • cglib - for class mocking
  • objenesis - enables mocking classes without default constructor
To add them to the project put these lines in <dependencies> section of pom.xml:
<dependency>
    <groupid>cglib</groupId>
    <artifactid>cglib-nodep</artifactId>
    <version>3.0</version>
    <scope>test</scope>
</dependency>
<dependency>
    <groupid>org.objenesis</groupId>
    <artifactid>objenesis</artifactId>
    <version>1.3</version>
    <scope>test</scope>
</dependency>
 
And that's all for dependencies section. Now we will focus on plugins necessary to compile Groovy classes. We need to add gmaven-plugin with gmaven-runtime-2.0 dependency in plugins section:
<plugin>
    <groupid>org.codehaus.gmaven</groupId>
    <artifactid>gmaven-plugin</artifactId>
    <version>${gmaven-plugin.version}</version>
    <configuration>
        <providerselection>2.0</providerSelection>
    </configuration>
    <executions>
        <execution>
            <goals>
                <goal>compile</goal>
                <goal>testCompile</goal>
            </goals>
        </execution>
    </executions>
    <dependencies>
        <dependency>
            <groupid>org.codehaus.gmaven.runtime</groupId>
            <artifactid>gmaven-runtime-2.0</artifactId>
            <version>${gmaven-plugin.version}</version>
            <exclusions>
                <exclusion>
                    <groupid>org.codehaus.groovy</groupId>
                    <artifactid>groovy-all</artifactId>
                </exclusion>
            </exclusions>
        </dependency>
        <dependency>
            <groupid>org.codehaus.groovy</groupId>
            <artifactid>groovy-all</artifactId>
            <version>${groovy.version}</version>
        </dependency>
    </dependencies>
</plugin>
 
With these configuration we can use spock and write our first specifications. But there is one issue: default settings for maven-surefire plugin demand that test classes must end with "..Test" postfix, which is ok when we want to use such naming scheme for our spock tests. But if we want to name them like CommentSpec.groovy or whatever with "..Spec" ending (what in my opinion is much more readable) we need to make little change in surefire plugin configuration:
<plugin>
    <groupid>org.apache.maven.plugins</groupId>
    <artifactid>maven-surefire-plugin</artifactId>
    <version>2.15</version>
    <configuration>
        <includes>
            <include>**/*Test.java</include>
            <include>**/*Spec.java</include>
        </includes>
    </configuration>
</plugin>
 
As you can see there is a little trick ;) We add include directive for standard Java JUnit test ending with "..Test" postfix, but there is also an entry for spock test ending with "..Spec". And there is a trick: we must write "**/*Spec.java", not "**/*Spec.groovy", otherwise Maven will not run spock tests (which is strange and I've spent some time to figure out why Maven can't run my specs). Little update: instead of "*.java" postfix for both types of tests we can write "*.class" what is in my opinion more readable and clean:
<include>**/*Test.class</include>
<include>**/*Spec.class</include>
(thanks to Tomek Pęksa for pointing this out!)
With such configuration, we can write either traditional JUnit test and put them in src/test/java directory or groovy spock specifications and place them in src/test/groovy. And both will work together just fine :) In one of my next posts I'll write something about using spock and its mocking abilities in practice, so stay in tune.
 

Journal.IO 1.3 released

About


Just a moment ago (in February 17th) Journal.IO 1.3 has been released. Journal.IO (https://github.com/sbtourist/Journal.IO) is a lightweight, zero-dependency journal storage implementation written in Java. We use it in our project for storing application events (Event Sourcing pattern). It is a good, stable solution if you want to have simple in use event storage e.g. if you want to implement lightweight queuing mechanism and JMS is overhead for you.

New version resolves some bugs and improves delete operation performance. Unfortunately new version uses new log format which isn't backward compatible. Therefore we decide to write a simple migrating tool for migrate 1.2 version compatible logs to 1.3 version.

Migrator


Migrator was written in groovy. It is available on github (https://github.com/arkadius/journalioMigration). Also link to the tool is available from official Journal.IO homepage. To use it simply run:



oldLogsRoot is recursively scanned for logs which are migrated parallel in 5 threads (used ASYNC read mode additionally speed up this process). Migrated logs are written in the same hierarchy in newLogsRoot.