Spring Profile pattern , part 4

Phase 3: using the pattern

As you can recall, in previous steps we defined an interface for configuration data.
Now we will use the interface in a class which needs different data per environment.

Please note that this example is the key differentiator from the example given in  the Spring blog, since now we don't need to create a class for each profile, since in this case we use the same method across profiles and only the data changes.


Step 3.1 - example for using the pattern

@Configuration
@EnableTransactionManagement
//DB connection configuration class 
//(don't tell me you're still using xml... ;-)
public class PersistenceConfig {

 @Autowired
 private SystemStrings systemStrings; //Spring will wire by active profile

 @Bean
 public LocalContainerEntityManagerFactoryBean entityManagerFactoryNg(){
  LocalContainerEntityManagerFactoryBean factoryBean
  = new LocalContainerEntityManagerFactoryBean();
  factoryBean.setDataSource( dataSource() );
  factoryBean.setPersistenceUnitName("my_pu");       
  JpaVendorAdapter vendorAdapter = new HibernateJpaVendorAdapter(){
   {
    // JPA properties
    this.setDatabase( Database.MYSQL);
this.setDatabasePlatform("org.hibernate.dialect.MySQLDialect");
    this.setShowSql(systemStrings.getShowSqlMngHibernate());//is set per environemnt..           
   
   }
  };       
  factoryBean.setJpaVendorAdapter( vendorAdapter );
  factoryBean.setJpaProperties( additionalProperties() );

  return factoryBean;
 }
//...
@Bean
 public ComboPooledDataSource dataSource(){
  ComboPooledDataSource poolDataSource = new ComboPooledDataSource();
  try {
   poolDataSource.setDriverClass( systemStrings.getDriverClassNameMngHibernate() );
  } catch (PropertyVetoException e) {
   e.printStackTrace();
  }       
                 //is set per environemnt..
  poolDataSource.setJdbcUrl(systemStrings.getJdbcUrl());
  poolDataSource.setUser( systemStrings.getDBUsername() );
  poolDataSource.setPassword( systemStrings.getDBPassword() );
  //.. more properties...       
  return poolDataSource;
 }
}

I would appreciate comments and improvements.
Enjoy!

part 1, part 2 , part 3, part 4

Spring Profile pattern , part 3

Phase 2: implementing the profile pattern
This phase utilizes the infra we built before and implements the profile pattern.



Step 2.1 - create a properties interface
Create an interface for the configuration data you have.
In our case, the interface will provide access to the four configuration data  items.
so it would look something like:

public interface SystemStrings {

String getJdbcUrl();
String getDBUsername();
String getDBPassword();
Boolean getHibernateShowSQL();
//..... 

Step 2.2 - create a class for each profile
Example for a development profile:

@Dev //Notice the dev annotation
@Component("systemStrings")
public class SystemStringsDevImpl extends AbstractSystemStrings implements SystemStrings{
      
 public SystemStringsDevImpl() throws IOException {
                //indication on the relevant properties file
  super("/properties/my_company_dev.properties");
 } 
}

Example for a production profile:

@Prouction //Notice the production annotation
@Component("systemStrings")
public class SystemStringsProductionImpl extends AbstractSystemStrings implements SystemStrings{
      
 public SystemStringsProductionImpl() throws IOException {
                //indication on the relevant properties file
  super("/properties/my_company_production.properties");
 } 
}

The two classes above are where the binding between the properties file and the related environment occur.

You've probably noticed that the classes extend an abstract class. This technique is useful so we won't need to define each getter for each Profile, this would not be manageable in the long run, and really, there is no point of doing it.

The sweet and honey lies in the next step, where the abstract class is defined.

Step 2.3 - create an abstract file which holds the entire data

public abstract class AbstractSystemStrings implements SystemStrings{

 //Variables as in configuration properties file
private String jdbcUrl;
private String dBUsername;
private String dBPassword;
private boolean hibernateShowSQL;

public AbstractSystemStrings(String activePropertiesFile) throws IOException {
  //option to override project configuration from externalFile
  loadConfigurationFromExternalFile();//optional..
                //load relevant properties
  loadProjectConfigurationPerEnvironment(activePropertiesFile);  
 }

private void loadProjectConfigurationPerEnvironment(String activePropertiesFile) throws IOException {
  Resource[] resources = new ClassPathResource[ ]  {  new ClassPathResource( activePropertiesFile ) };
  Properties props = null;
  props = PropertiesLoaderUtils.loadProperties(resources[0]);
                jdbcUrl = props.getProperty("jdbc.url");
                dBUsername = props.getProperty("db.username"); 
                dBPassword = props.getProperty("db.password");
                hibernateShowSQL = new Boolean(props.getProperty("hibernate.show_sql"));  
}

//here should come the interface getters....

part 1, part 2 , part 3, part 4, next >>

Spring Profile pattern ,part 2

Spring Profile pattern -  phase 1: infra preparation


This phase will establish the initial infra for using Spring Profile and the configuration files.

Step 1.1  - create a properties file which contains all configuration data
Assuming you have a maven style project, create a file in src/main/resources/properties for each environment, e.g:
my_company_dev.properties
my_company_test.properties
my_company_production.properties

example for my_company_dev.properties content:

jdbc.url=jdbc:mysql://localhost:3306/my_project_db
db.username=dev1
db.password=dev1
hibernate.show_sql=true

example for my_company_production.properties content:


jdbc.url=jdbc:mysql://10.26.26.26:3306/my_project_db
db.username=prod1
db.password=fdasjkladsof8aualwnlulw344uwj9l34
hibernate.show_sql=false


Step 1.2  - create an annotation for each profile
In src.main.java.com.mycompany.annotation create annotation for each Profile, e.g :

@Target(ElementType.TYPE)
@Retention(RetentionPolicy.RUNTIME)
@Profile("DEV")
public @interface Dev {
}

@Target(ElementType.TYPE)
@Retention(RetentionPolicy.RUNTIME)
@Profile("PRODUCTION")
public @interface Production {
}

Create an enum for each profile:
public interface MyEnums {

public enum Profile{
DEV,
TEST,
PRODUCTION
}

Step 1.3  - make sure the profile is loaded during context loading

• Define a system variable to indicate on which environment the code is running.
  In Tomcat, go to ${tomcat.di}/conf/catalina.properties and insert a line:
  profile=DEV  (according to your environment)
• Define a class to set the active profile
  

  public class ConfigurableApplicationContextInitializer implements
    ApplicationContextInitializer {
  
   @Override
   public void initialize(ConfigurableApplicationContext applicationContext) {
        
    String profile = System.getProperty("profile");
      
    if (profile==null || profile.equalsIgnoreCase(Profile.DEV.name())){
     applicationContext.getEnvironment().setActiveProfiles(Profile.DEV.name());   
    }else if(profile.equalsIgnoreCase(Profile.PRODUCTION.name())){
     applicationContext.getEnvironment().setActiveProfiles(Profile.PRODUCTION.name()); 
    }else if(profile.equalsIgnoreCase(Profile.TEST.name())){
     applicationContext.getEnvironment().setActiveProfiles(Profile.TEST.name()); 
          }
   }
  }
  

• Make sure the class is loaded during context loading
  in the project web.xml, insert the following:

  
       contextInitializerClasses
       com.matomy.conf.ConfigurableApplicationContextInitializer
   
  

part 1, part 2 , part 3, part 4 , next >>

Spring Profile pattern , part 1

Recently we were introduced with the concept of Spring Profiles.
This concept is an easy configuration differentiator  for different deployment environments.
The straight forward use case (which was presented) was to annotate the relevant classes so Spring would load the appropriate class according to the active profile.

However, this approach might not always serve the common use case... often, the configuration keys would be the same and only the values will change per environment.

In this post, I would like to present a pattern to support loading configuration data per environment, without the need to create/maintain multiple classes for each profile (i.e. for each environment).

Throughout the post I would take the DB connection configuration as a sample, assuming we have different DB definitions (e.g. username or connection URL) for each deployment environment.

The main idea is to use one class for loading the configuration (i.e.. one class for DB connection definition) and inject into it the appropriate instance which holds the correct profile configuration data.

For convenience and clarity, the process was divided into 3 phases:

Phase 1: infra preparation
Step 1.1  - create a properties file which contains all configuration data
Step 1.2  - create an annotation for each profile
step 1.3  - make sure the profile is loaded during context loading

Phase 2: implementing the profile pattern
Step 2.1 - create a properties interface
Step 2.2 - create a class for each profile
Step 2.3 - create an abstract file which holds the entire data

Phase 3: using the pattern
Step 3.1 - example for using the pattern

next part >>

JPA 2.0 Metamodel generation using Eclipse Maven build

Update:
Please see this updated post in that manner which simplifies the process a bit better.


In order to write JPA2.0 queries using the criteria API in a type safe manner, one can use the corresponding @Entity generated metamodel.

This post is for developers who are familiar with this concept, and feel their current metamodel files generation process need improvement.

Over the web there are some guidelines regarding the best way to generate these static metamodel classes.
However, maybe it's just me, but I could not run them in a proper way.
Some methods generated the metamodel classes in the target directory and some simply did not work.
When running the metamodel generation tool, I had to set the pom file with the proc parameter manually with the "only" value and revert it when I wanted to generate the other java files.
(Very tedious when rapid model changes  are needed)

I would like to suggest a way to create the static metamodel files in the source directory (right beside the @Entities they refer)  AND run the build without modifying the pom/maven file.

The process is set from two steps:
1) Configure the POM.xml
2) Configure eclipse to run the build

So, first thing first - lets configure the pom file:

            org.hibernate

            hibernate-jpamodelgen

            1.1.1.Final

        

    

    

        

            

                maven-clean-plugin

                2.4.1

                

                  

                       

                     ../your_project_name/src/main/java/com/your_path/model/                     

                      

                        **/*_.java                       

                                           

                      false

                    

                  

                

              

           

            

                org.apache.maven.plugins

                maven-compiler-plugin

                2.3.2

                

                    1.7

                    1.7                                           

                    

                        org.hibernate.jpamodelgen.JPAMetaModelEntityProcessor

                    

                    

                        ../your_project_name/src/main/java/

                    

                

            

        

    

The artifact is needed for the @Entity classes analysis and static Metamodel generation.
The maven-clean section is to clean the previous metamodel files (pattern: *_.java ) before generation (useful since the metamodel generation raise an error if any previous file already exist).
The maven-compileer section refer to the class with the metamodel generation class and set the target directory as the source directory (not the target!).

Next step is to define the eclipse maven build.
You can follow the below screenshots (sample build for project called "management"):


Configure the metamodel build:

Configure the project build:

• For every "regular" build simply run the project build.
• For any change in the @Entity files, run the compile metamodel build.

That's it..

Important note:
If you know how to run the two builds automatically one after the other, kindly leave a comment.