Developers Needs SDKMAN Not Super-Man

Every developer has pain for setup development environment to his/her machine with lots of the setups. Sometimes, the pain goes beyond while we need to test same application on multiple versions of sdks or virtual machines.

If you are a Mac user, you have the best option called brew installer.

But if you are Linux user, your pain is unpredictable. 

We are Java developers and Linux users and have the same pain for setting development environment with lots of configuration and different versions virtual machines.

For the sake of innocent developers, for the sake of time, we are going to introduce our superhero called SDKMAN. Which saves us from the cruel world of setup developments tools.

Technical Introduction:  

SDKMAN! is a tool for managing parallel versions of multiple Software Development Kits on most Unix based systems. It provides a convenient Command Line Interface (CLI) and API for installing, switching, removing and listing Candidates. SDKMAN is primary used for JVM based languages and framework. In future, they were plan to move SDKMAN for other environments as well. Currently SDKMAN have a huge list of sdks, which we get from here. 

Install SDKMAN

$ curl -s "https://get.sdkman.io" | bash

$ source "$HOME/.sdkman/bin/sdkman-init.sh"

$ sdk version

Install Java

For installing java, SDK provide simple and easy command as below:

$ sdk install java

Downloading: java 8u152-zulu

In progress...

######################################################################## 100.0%

Repackaging Java 8u152-zulu...

Done repackaging...

Installing: java 8u152-zulu
Done installing!


Setting java 8u152-zulu as default.
root@a33316a976d9:~/.sdkman# java -version
openjdk version "1.8.0_152"
OpenJDK Runtime Environment (Zulu 8.25.0.1-linux64) (build 1.8.0_152-b16)
OpenJDK 64-Bit Server VM (Zulu 8.25.0.1-linux64) (build 25.152-b16, mixed mode)

By default, sdkman download the zulu or open source JDK of java. But if we require installing some specific version of JDK or Specific Oracle JDK, what can we do???

SDKMAN gave us the way to download sdk's with specific versions as well. We can easily list out the existing SDK's which SDKMAN support and install it as per requirements.

$ sdk list

================================================================================
Available Candidates
================================================================================
q-quit                                  /-search down
j-down                                  ?-search up
k-up                                    h-help

--------------------------------------------------------------------------------
Ant (1.10.1)                                             https://ant.apache.org/

Apache Ant is a Java library and command-line tool whose mission is to drive
processes described in build files as targets and extension points dependent
upon each other. The main known usage of Ant is the build of Java applications.
Ant supplies a number of built-in tasks allowing to compile, assemble, test and
run Java applications. Ant can also be used effectively to build non Java

So on ...................

$ sdk list java

================================================================================
Available Java Versions
================================================================================
     9.0.1-zulu                                                                    
     9.0.1-oracle                                                                  
     9.0.0-zulu                                                                    
 > * 8u152-zulu                                                                    
     8u151-oracle                                                                  
     8u144-zulu                                                                    
     8u131-zulu                                                                    
     7u141-zulu                                                                    
     6u93-zulu                              
	 
$ sdk install java 8u151-oracle

Oracle requires that you agree with the Oracle Binary Code License Agreement
prior to installation. The license agreement can be found at:

  http://www.oracle.com/technetwork/java/javase/terms/license/index.html

Do you agree to the terms of this agreement? (Y/n): y


Downloading: java 8u151-oracle

In progress...

######################################################################## 100.0%

Repackaging Java 8u151-oracle...

Done repackaging...

Installing: java 8u151-oracle
Done installing!

Do you want java 8u151-oracle to be set as default? (Y/n): y

Setting java 8u151-oracle as default.

$ java -version
java version "1.8.0_151"
Java(TM) SE Runtime Environment (build 1.8.0_151-b12)
Java HotSpot(TM) 64-Bit Server VM (build 25.151-b12, mixed mode)

As it shows, we can install oracle java successfully. But, at the start of this blog, as we discussed we can install multiple version of the same SDK easily and manage easily. If we go through the blog again, first we install OpenJDK after we are installing OracleJDK, single machine multiple JDKS and we also set OracleJDK as default, so how can we use OpenJDK as per our requirements??

Below are powerfull and ease commands of SDKMAN which help us to achieve this functionality.

$ sdk list java

================================================================================
Available Java Versions
================================================================================
     9.0.1-zulu                                                                    
     9.0.1-oracle                                                                  
     9.0.0-zulu                                                                    
   * 8u152-zulu                                                                    
 > * 8u151-oracle                                                                  
     8u144-zulu                                                                    
     8u131-zulu                                                                    
     7u141-zulu                                                                    
     6u93-zulu                                                                     
                                                                                   
                                                                                   
                                                                                   
                                                                                   
                                                                                   
                                                                                   

================================================================================
+ - local version
* - installed
> - currently in use
================================================================================


$ java -version
java version "1.8.0_151"
Java(TM) SE Runtime Environment (build 1.8.0_151-b12)
Java HotSpot(TM) 64-Bit Server VM (build 25.151-b12, mixed mode)

$ sdk use java 8u152-zulu

$ java -version
openjdk version "1.8.0_152"
OpenJDK Runtime Environment (Zulu 8.25.0.1-linux64) (build 1.8.0_152-b16)
OpenJDK 64-Bit Server VM (Zulu 8.25.0.1-linux64) (build 25.152-b16, mixed mode)

I am sure, now you can feel the power of SDKMAN and how easy is using this tool. This makes developers life happy and safe.

References: 

1. http://sdkman.io/index.html
2. Thanks to google funny images.

Cinnamon: Way For Monitoring & Metrics Generation for Akka ActorSystem.

We are developing huge applications and deployed on multiple virtual machines and clusters. For monitoring applications, we need to enable logs into our application and analysis that logs with help of some tools like elastic stack.
But !! what if we need to check health of our application on virtual machines and clusters? For that, we are using several Metrics for system health check like Gauges, Histograms and more.

Lightbend Telemetry gives us one of the way for metrics generation and monitoring systems (application) by using Cinnamon plugins. Today's we look into Cinnamon for monitoring akka ActorSytem. Configuring cinnamon is not a rocket science, there are simple steps, which, we are going to define here.

The first step for using cinnamon is, we need to create and account on lightbend, from where we can download credentials and paste into our home directory(for linux users). All instructions are define in this link.

Note: For today's example, we are using sbt project, but we can easily integrate with maven and gradle as well.

>>> We need to add cinnamon plugin in our plugin.sbt file as below:


>>> Now, require to add some dependencies to add in our build.sbt:


>>> Add cinnamon configuration on application.conf as below:


There are lots of option for configure monitoring to actor system, for more information please click on this link.

Example: 

My example is a simple hello world actor application, but when we run that example, in console we are seeing cinnamon metrics. The example as below:

For running the application we need to execute sbt run command as below:


As in logs, we have seeing, 4 types of metrics are there. Every metrics have its own befits and analysis. These metrics gives us a report on akka actor systems like actors count, threads count, mailbox capacity and more.

For more examples, you can check github repo.

References:

• http://developer.lightbend.com/docs/monitoring/latest/getting-started/sbt.html

Integrate JOOQ With Spring and Perform CRUD Operations.

Introduction:

In the last POST we discuss about  generate Java classes using JOOQ maven generator. These java files are represent table in database. Like hibernate Jboss tools are used to generate entities corresponding to the table. Today we perform CRUD Operations with the help of JOOQ. For Generating java classes, refer to my previous POST. In this we Integrate  JOOQ with SPRING framework. There are may blog post that help me to create this example and also the JOOQ website, which share lots of example. 

Step 1:

The Dependencies that we need : 

Step 2:

Create the class to handle JOOQ exception in standard exception. Mostly the framework follow the standard SQLException framework, in which the framework specific exception are wrap into standard SQL exception so it can maintain easily. Now we create the class for handle JOOQ exception and wrap into Standard Exception. 

import org.jooq.ExecuteContext;
import org.jooq.SQLDialect;
import org.jooq.impl.DefaultExecuteListener;
import org.springframework.jdbc.support.SQLErrorCodeSQLExceptionTranslator;
import org.springframework.jdbc.support.SQLExceptionTranslator;
import org.springframework.jdbc.support.SQLStateSQLExceptionTranslator;

public class JOOQToSpringExceptionTransformer extends DefaultExecuteListener {
  private static final long serialVersionUID = -5749466061513426635L;
  @Override
  public void exception(ExecuteContext ctx) {
 SQLDialect dialect = ctx.configuration().dialect();
 SQLExceptionTranslator sqlExceptionTranslator = null;
 if(dialect != null){
  sqlExceptionTranslator = new SQLErrorCodeSQLExceptionTranslator(dialect.getName());
 }else{
  sqlExceptionTranslator = new SQLStateSQLExceptionTranslator();
 }
 
 ctx.exception(sqlExceptionTranslator.translate("JOOQ", ctx.sql(), ctx.sqlException()));
  }
}

In this :
DefaultExecuteListener : The DefaultExecuteListener class is the public default implementation of the ExecuteListener interface which provides listener methods for different life cycle events of a single query execution.

Step 3: 

In this we Cover Database Java Based Configuration: 

Properties File : application.properties

#Database Configuration
db.driver=com.mysql.jdbc.Driver
db.url=jdbc:mysql://localhost:3306/jooq_test
db.username=test
db.password=root

#jOOQ Configuration
jooq.sql.dialect=MYSQL

Database Configuration file: PersistenceConfiguration.java

import javax.sql.DataSource;

import org.apache.commons.dbcp2.BasicDataSource;
import org.jooq.DSLContext;
import org.jooq.SQLDialect;
import org.jooq.impl.DataSourceConnectionProvider;
import org.jooq.impl.DefaultConfiguration;
import org.jooq.impl.DefaultDSLContext;
import org.jooq.impl.DefaultExecuteListenerProvider;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.PropertySource;
import org.springframework.core.env.Environment;
import org.springframework.jdbc.datasource.DataSourceTransactionManager;
import org.springframework.jdbc.datasource.LazyConnectionDataSourceProxy;
import org.springframework.jdbc.datasource.TransactionAwareDataSourceProxy;
import org.springframework.transaction.annotation.EnableTransactionManagement;

/**
 * @author Programmers
 *
 */
@Configuration
@ComponentScan({"com.the13star.service.test", "com.the13star.service.impl", "com.the13star.dao.impl" })
@EnableTransactionManagement
@PropertySource("classpath:application.properties")
public class PersistenceContext {

 @Autowired
 private Environment environment;

 @Bean(destroyMethod = "close") // destroyMethod attribute is used to close the bean
 public DataSource dataSource() {
  BasicDataSource dataSource = new BasicDataSource();
  dataSource.setDriverClassName(environment.getRequiredProperty("db.driver").trim());
  dataSource.setUrl(environment.getRequiredProperty("db.url").trim());
  dataSource.setUsername(environment.getRequiredProperty("db.username").trim());
  dataSource.setPassword(environment.getRequiredProperty("db.password").trim());
  dataSource.setInitialSize(5);
  dataSource.setMaxTotal(5);
  return dataSource;
 }

 // To delay opening a jdbc connection until the first actual sql statement
 // happens use LazyConnectionDataSourceProxy
 @Bean
 public LazyConnectionDataSourceProxy lazyConnectionDataSource() {
  return new LazyConnectionDataSourceProxy(dataSource());
 }

 // Configure jOOQ's ConnectionProvider to use Spring's
 // TransactionAwareDataSourceProxy,
 // which can dynamically discover the transaction context
 /**
  * Configure the TransactionAwareDataSourceProxy bean. This bean ensures
  * that all JDBC connection are aware of Spring-managed transactions. In
  * other words, JDBC connections participates in thread-bound transactions
  */
 @Bean
 public TransactionAwareDataSourceProxy transactionAwareDataSource() {
  return new TransactionAwareDataSourceProxy(lazyConnectionDataSource());
 }

 /**
  * Configure the DataSourceTransactionManager bean. We must pass the
  * LazyConnectionDataSourceProxy bean as as constructor argument when we
  * create a new DataSourceTransactionManager object.
  */
 @Bean
 public DataSourceTransactionManager dataSourceTransactionManager() {
  return new DataSourceTransactionManager(lazyConnectionDataSource());
 }

 /**
  * Configure the DataSourceConnectionProvider bean. jOOQ will get the used
  * connections from the DataSource given as a constructor argument. We must
  * pass the TransactionAwareDataSourceProxy bean as a constructor argument
  * when we create a new DataSourceConnectionProvider object. This ensures
  * that the queries created jOOQ participate in Spring-managed transactions.
  */
 @Bean
 public DataSourceConnectionProvider connectionProvider() {
  return new DataSourceConnectionProvider(transactionAwareDataSource());
 }

 @Bean
 public JOOQToSpringExceptionTransformer jooqToSpringExceptionTranslator() {
  return new JOOQToSpringExceptionTransformer();
 }

 /**
  * Invoking an internal, package-private constructor for the example
  * Implement your own Configuration for more reliable behaviour
  */
 @Bean
 public DefaultConfiguration configuration() {
  DefaultConfiguration configuration = new DefaultConfiguration();
  configuration.set(connectionProvider());
  configuration.set(new DefaultExecuteListenerProvider(
    jooqToSpringExceptionTranslator()));

  String sqlDialect = environment.getRequiredProperty("jooq.sql.dialect");
  SQLDialect dialect = SQLDialect.valueOf(sqlDialect);
  configuration.set(dialect);

  return configuration;

 }

 /**
  * Configure the DSL object, optionally overriding jOOQ Exceptions with
  * Spring Exceptions. We use this bean when we are creating database queries
  * with jOOQ.
  */
 @Bean
 public DSLContext dslContext() {
  return new DefaultDSLContext(configuration());
 }

 /**
  * We use this bean to create the database schema for database when our
  * application is started (If you don’t use an embedded database, you don’t
  * have to configure this bean).
  */
 /*
 @Bean
 public DataSourceInitializer dataSourceInitializer() {
  DataSourceInitializer dataSourceInitializer = new DataSourceInitializer();
  dataSourceInitializer.setDataSource(dataSource());
  
  ResourceDatabasePopulator databasePopulator = new ResourceDatabasePopulator();
  databasePopulator.addScript(new ClassPathResource(environment.getRequiredProperty("")));
  
  dataSourceInitializer.setDatabasePopulator(databasePopulator);
  return dataSourceInitializer;
 }*/
}

Step 4: 

Create Service layer : 

import java.util.List;

import com.the13star.dbmetadata.tables.records.UserDetailRecord;

public interface UserDetailService {
 public void saveUserDetail(int id, String name, int age);

 public List getAllUsers();

 public UserDetailRecord getUserByID(int i);

 public int updateUserById(UserDetailRecord userDetailRecord);

 public int deleteUserById(int id);
}

import java.util.List;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import com.the13star.dao.UserDetailDao;
import com.the13star.dbmetadata.tables.records.UserDetailRecord;
import com.the13star.service.UserDetailService;

/**
 * @author Programmers
 *
 */
@Service
public class UserDetailServiceImpl implements UserDetailService {
 
 @Autowired
 private UserDetailDao userDetailDao;

 /* (non-Javadoc)
  * @see com.the13star.service.UserDetailService#saveUserDetail(int, java.lang.String, int)
  */
 @Override
 public void saveUserDetail(int id, String name, int age) {
  UserDetailRecord record = new UserDetailRecord();
  record.setId(id);
  record.setName(name);
  record.setAge(age);
  
  userDetailDao.insertNewUser(record);
 }

 @Override
 public List getAllUsers() {
  return userDetailDao.getAllUsers();
 }

 @Override
 public UserDetailRecord getUserByID(int id) {
  return userDetailDao.getUserByID(id);
 }

 @Override
 public int updateUserById(UserDetailRecord userDetailRecord) {
  return userDetailDao.updateUserById(userDetailRecord);
 }

 @Override
 public int deleteUserById(int id) {
  return userDetailDao.deleteUserById(id);
 }

}

Step 5:

Create Dao Layer : 

import java.util.List;

import com.the13star.dbmetadata.tables.records.UserDetailRecord;


/**
 * @author Programmers
 *
 */
public interface UserDetailDao {

 public void insertNewUser(UserDetailRecord userDetailRecord);

 public List getAllUsers();

 public UserDetailRecord getUserByID(int id);

 public int updateUserById(UserDetailRecord userDetailRecord);

 public int deleteUserById(int id);
}

import java.util.ArrayList;
import java.util.List;

import org.jooq.DSLContext;
import org.jooq.DeleteConditionStep;
import org.jooq.DeleteWhereStep;
import org.jooq.InsertValuesStep3;
import org.jooq.Result;
import org.jooq.UpdateConditionStep;
import org.jooq.UpdateSetFirstStep;
import org.jooq.UpdateSetMoreStep;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Repository;

import com.the13star.dao.UserDetailDao;
import com.the13star.dbmetadata.tables.UserDetail;
import com.the13star.dbmetadata.tables.records.UserDetailRecord;

/**
 * @author Programmers
 *
 */
@Repository
public class UserDetailDaoImpl implements UserDetailDao {

 @Autowired
 DSLContext dslContext;

 public void insertNewUser(UserDetailRecord userDetailRecord) {
  InsertValuesStep3 userdetails = dslContext
    .insertInto(UserDetail.USER_DETAIL, UserDetail.USER_DETAIL.ID,
      UserDetail.USER_DETAIL.NAME, UserDetail.USER_DETAIL.AGE);
  userdetails.values(userDetailRecord.getId(),
    userDetailRecord.getName(), userDetailRecord.getAge());
  userdetails.execute();
 }

 @Override
 public List getAllUsers() {
  Result userDetails = dslContext
    .fetch(UserDetail.USER_DETAIL);
  return new ArrayList<>(userDetails);
 }

 @Override
 public UserDetailRecord getUserByID(int id) {
  return dslContext.fetchOne(UserDetail.USER_DETAIL,
    UserDetail.USER_DETAIL.ID.equal(id));
 }

 @Override
 public int updateUserById(UserDetailRecord userDetailRecord) {
  UpdateSetFirstStep updateSetFirstStep = dslContext
    .update(UserDetail.USER_DETAIL);
  UpdateSetMoreStep updateSetMoreStep = updateSetFirstStep
    .set(UserDetail.USER_DETAIL.NAME, userDetailRecord.getName())
    .set(UserDetail.USER_DETAIL.AGE, userDetailRecord.getAge());
  UpdateConditionStep updateConditionStep = updateSetMoreStep
    .where(UserDetail.USER_DETAIL.ID.equal(userDetailRecord.getId()));
  return updateConditionStep.execute();
 }

 @Override
 public int deleteUserById(int id) {
  DeleteWhereStep deleteWhereStep = dslContext.delete(UserDetail.USER_DETAIL);
  DeleteConditionStep deleteConditionStep = deleteWhereStep.where(UserDetail.USER_DETAIL.ID.equal(id));
  return deleteConditionStep.execute();
 }

}

Step 6: 

Launch Our Code:

import java.util.List;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.annotation.AnnotationConfigApplicationContext;
import org.springframework.stereotype.Component;

import com.the13star.configurations.PersistenceContext;
import com.the13star.dbmetadata.tables.records.UserDetailRecord;
import com.the13star.service.UserDetailService;

/**
 * @author Programmers
 *
 */
@Component
public class UserDetailTest {
 
 @Autowired
 private UserDetailService userDetailService;
 /**
  * @param args
  */ 
 
 private void start() {
  //userDetailService.saveUserDetail(3, "MICKY", 21);
  List userDetails = userDetailService.getAllUsers();
  for(UserDetailRecord record : userDetails){
   System.out.println(record);
  }
  /*
  UserDetailRecord record = userDetailService.getUserByID(1);
  System.out.println(record);*/
  /*
  UserDetailRecord userDetailRecord = new UserDetailRecord();
  userDetailRecord.setId(3);
  userDetailRecord.setName("Micky");
  userDetailRecord.setAge(26);
  int result = userDetailService.updateUserById(userDetailRecord);*/
  /*
  int result = userDetailService.deleteUserById(2);
  System.out.println("Result : "+result);*/
 }
 
 public static void main(String[] args) {
  AnnotationConfigApplicationContext applicationContext = new AnnotationConfigApplicationContext(PersistenceContext.class);
  UserDetailTest userDetailTest = applicationContext.getBean(UserDetailTest.class);
  userDetailTest.start();
  applicationContext.close();
 }

}

For downloading the example code, go to the this link: 

JOOQ Reverse Engineering Using Maven Generator

Introduction : 

JOOQ is used to write type safe SQL queries using JAVA. Some time it is difficult to write SQL queries for Java Developer, because Java Developer is familiar with Object Oriented World and with its own language syntax. SQL is a different language and developers need to learn new language for deal with data base using queries. For the sake of learning new language syntax and new structure, The JOOQ provide a way to use queries using Java Programming Syntax. There are lots of rich ORM tools which also provide the way to implement queries using Java Programming Syntax, these queries called CRITERIA queries. But these ORM tools have some Limitations , so if the programmer only need to apply types safety queries, the JOOQ is the best way to do this. There are lots of things that JOOQ provide. For JOOQ detail go to JOOQ Home Page. JOOQ also provide some classes or function that are familiar for SQL developer like for select query JOOQ provide select method in class. 

JOOQ also provide the reverse engineering for generate Java POJO's or Entities from existing table in database. They provide several approaches to use generator to generate Entities. In this POST we discuss about Maven Generator for generate Entities.  

Step 1:

Add the Generator plugin in Maven pom.xml. 

 3.3.1



 
  org.jooq
  jooq
  ${jooq-version}
 

 
  org.jooq
  jooq-meta
  ${jooq-version}
 

 
  org.jooq
  jooq-codegen
  ${jooq-version}
 




 
 org.jooq
 jooq-codegen-maven
 ${jooq-version}

 
 
   
   
   generate
  
  
 

 
  
   mysql
   mysql-connector-java
   5.1.30
  
 

 
 
  
  
   com.mysql.jdbc.Driver
   jdbc:mysql://localhost/jooq_test
   root
   root
  

  

  
   org.jooq.util.DefaultGenerator
   
    org.jooq.util.mysql.MySQLDatabase
    .*
    
    jooq_test
   
   
    com.the13star.entities
    src/main/java
   
  

For JOOQ we need some dependencies to add in the pom.xml file. But the generator plugin also need some dependencies for plugin use only. That dependencies are declare in the generator plugin. If we already declare dependencies in dependency block and not declare in plugin the generator will not run. We again need to declare dependencies in the generator plugin, because plugin use its individual dependencies for run like MySQL dependency in the above code. If maven provide the way to use dependencies of dependency block in plugin please discuss.
In this we use DefaultGenerator for generate Entities, you can also use your custom generator.

Step 2

For run the generator use Maven install command from eclipse or command line, after generator run, there are three packages structures are automatically create in your project. 

The three pakcages are 

1. com.the13star.dbmetadata: According to its name it is used to represent meta information of database table. Like Kyes.java contain information regarding primary key's etc. 

2.  com.the13star.dbmetadata.tables: This package contain the information of db tables like. Field in table, types of column etc. One java file represent one table. according to above example there is only one table in DB. 

3.  com.the13star.dbmetadata.tables.records: This package represent the record of table or represent the one row in table. We will also said that, this is our Java POJO or Entity file.