Lesson 4: Working with Data

livelessons-data/README.adoc

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+:compat-mode:
+= Lesson 4: Working With Data
+
+_How to design microservices that store and consume data in traditional
+relational databases and newer NoSQL stores._
+
+- link:livelessons-data-jpa[Relational Database with JPA]
+- link:livelessons-data-jdbc[Relational Database with JDBC]
+- link:livelessons-data-flyway[Flyway Migration]
+- link:livelessons-data-redis[Redis]
+- link:livelessons-data-mongodb[MongoDB]
+- link:livelessons-data-elasticsearch[Elasticsearch]
+- link:livelessons-data-rest[Spring Data REST]

livelessons-data/livelessons-data-elasticsearch/.gitignore

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+data

livelessons-data/livelessons-data-elasticsearch/README.adoc

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+:compat-mode:
+= Lesson 4: Working With Data (Elasticsearch)
+
+== Introduction
+This example shows how you can connect your microservce to Elasticsearch.
+
+== Building and running the sample
+Use the following commands to build run the application:
+
+```
+$ mvn clean package
+$ java -jar target/livelessons-data-elasticsearch-1.0.0-SNAPSHOT.jar
+```
+
+The example uses an embedded elasticsearch server to store data. If you want to talk
+to a real server you can set `spring.data.elasticsearch.cluster-name` and
+`spring.data.elasticsearch.cluster-nodes` properties.
+
+== Understanding the code
+The familiar Car domain is used again in this example. This time `Car` is a elasticsearch
+document (signified with the Spring Data `@Document` annotation). The same `Repository`
+logic is used as before providing a `findByMakeIgnoringCase` method.
+
+The `DataElasticsearchApplication` class also shows how you can use the
+`ElasticsearchTemplate` to make native elasticsearch queries. In this case we are
+performing a fuzzy search for manufacturers like `ronda`.

livelessons-data/livelessons-data-elasticsearch/pom.xml

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+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+	<modelVersion>4.0.0</modelVersion>
+	<parent>
+		<groupId>livelessons</groupId>
+		<artifactId>livelessons-data</artifactId>
+		<version>1.0.0-SNAPSHOT</version>
+	</parent>
+	<artifactId>livelessons-data-elasticsearch</artifactId>
+	<properties>
+		<main.basedir>../..</main.basedir>
+	</properties>
+	<dependencies>
+		<dependency>
+			<groupId>org.springframework.boot</groupId>
+			<artifactId>spring-boot-starter-data-elasticsearch</artifactId>
+		</dependency>
+	</dependencies>
+</project>

livelessons-data/livelessons-data-elasticsearch/src/main/java/demo/Car.java

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+package demo;
+
+import org.springframework.data.annotation.Id;
+import org.springframework.data.elasticsearch.annotations.Document;
+
+@Document(indexName = "car", type = "car", shards = 1, replicas = 0, refreshInterval = "-1")
+public class Car {
+
+	@Id
+	private Long id;
+
+	private String make;
+
+	private String model;
+
+	private int year;
+
+	Car() {
+	}
+
+	public Car(String make, String model, int year) {
+		super();
+		this.make = make;
+		this.model = model;
+		this.year = year;
+	}
+
+	public String getMake() {
+		return make;
+	}
+
+	public String getModel() {
+		return model;
+	}
+
+	public int getYear() {
+		return year;
+	}
+
+	@Override
+	public String toString() {
+		return make + " " + model + " " + year;
+	}
+
+}

livelessons-data/livelessons-data-elasticsearch/src/main/java/demo/CarRepository.java

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+package demo;
+
+import org.springframework.data.elasticsearch.repository.ElasticsearchRepository;
+
+public interface CarRepository extends ElasticsearchRepository<Car, Long> {
+
+	Iterable<Car> findByMakeIgnoringCase(String make);
+
+}

livelessons-data/livelessons-data-elasticsearch/src/main/java/demo/DataElasticsearchApplication.java

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+package demo;
+
+import org.springframework.beans.factory.InitializingBean;
+import org.springframework.boot.CommandLineRunner;
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+import org.springframework.context.annotation.Bean;
+import org.springframework.data.elasticsearch.core.ElasticsearchTemplate;
+import org.springframework.data.elasticsearch.core.query.NativeSearchQueryBuilder;
+import org.springframework.data.elasticsearch.core.query.SearchQuery;
+
+import static org.elasticsearch.index.query.QueryBuilders.fuzzyLikeThisFieldQuery;
+
+@SpringBootApplication
+public class DataElasticsearchApplication {
+
+	@Bean
+	public InitializingBean seedDatabase(CarRepository repository) {
+		return () -> {
+			repository.deleteAll();
+			repository.save(new Car("Honda", "Civic", 1997));
+			repository.save(new Car("Honda", "Accord", 2003));
+			repository.save(new Car("Ford", "Escort", 1985));
+		};
+	}
+
+	@Bean
+	public CommandLineRunner example(CarRepository repository,
+			ElasticsearchTemplate template) {
+		return (args) -> {
+			System.err.println("From the repository...");
+			repository.findByMakeIgnoringCase("fOrD").forEach(System.err::println);
+
+			System.err.println("\nFrom the template...");
+			SearchQuery query = new NativeSearchQueryBuilder()
+					.withQuery(fuzzyLikeThisFieldQuery("make").likeText("Ronda")).build();
+			template.queryForList(query, Car.class).forEach(System.err::println);
+		};
+	}
+
+	public static void main(String[] args) {
+		SpringApplication.run(DataElasticsearchApplication.class, args);
+		System.exit(0);
+	}
+
+}

livelessons-data/livelessons-data-flyway/README.adoc

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+:compat-mode:
+= Lesson 4: Working With Data (Flyway Migration)
+
+== Introduction
+This example shows how you can use flyway to upgrade a live database.
+
+== Building and running the sample
+Use the following commands to build run the application:
+
+```
+$ mvn clean package
+$ java -jar target/livelessons-flyway-1.0.0-SNAPSHOT.jar
+```
+
+== Understanding the code
+Building on the earlier JPA example this demo shows how a new `color` column could be
+added to the database. The additional `flyway` dependency in the `pom.xml` along with
+scripts in `src/main/db/migration` is all that's needed.
+
+Two scripts are provided. The first creates the initial structure and the second upgrades
+it. Flyway adds an additional meta-table that tracks when an update has been applied and
+prevents it from running multiple times.

livelessons-data/livelessons-data-flyway/pom.xml

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+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+	<modelVersion>4.0.0</modelVersion>
+	<parent>
+		<groupId>livelessons</groupId>
+		<artifactId>livelessons-data</artifactId>
+		<version>1.0.0-SNAPSHOT</version>
+	</parent>
+	<artifactId>livelessons-data-flyway</artifactId>
+	<properties>
+		<main.basedir>../..</main.basedir>
+	</properties>
+	<dependencies>
+		<dependency>
+			<groupId>org.springframework.boot</groupId>
+			<artifactId>spring-boot-starter-data-jpa</artifactId>
+		</dependency>
+		<dependency>
+			<groupId>org.flywaydb</groupId>
+			<artifactId>flyway-core</artifactId>
+		</dependency>
+		<dependency>
+			<groupId>com.h2database</groupId>
+			<artifactId>h2</artifactId>
+		</dependency>
+	</dependencies>
+</project>

livelessons-data/livelessons-data-flyway/src/main/java/demo/Car.java

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+package demo;
+
+import javax.persistence.Entity;
+import javax.persistence.GeneratedValue;
+import javax.persistence.Id;
+
+@Entity
+public class Car {
+
+	@Id
+	@GeneratedValue
+	private long id;
+
+	private String make;
+
+	private String model;
+
+	private int year;
+
+	private String color;
+
+	Car() {
+	}
+
+	public Car(String make, String model, int year, String color) {
+		super();
+		this.make = make;
+		this.model = model;
+		this.year = year;
+		this.color = color;
+	}
+
+	public String getMake() {
+		return make;
+	}
+
+	public String getModel() {
+		return model;
+	}
+
+	public int getYear() {
+		return year;
+	}
+
+	public String getColor() {
+		return color;
+	}
+
+	@Override
+	public String toString() {
+		return make + " " + model + " " + year + " " + this.color;
+	}
+
+}

livelessons-data/livelessons-data-flyway/src/main/java/demo/CarRepository.java

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+package demo;
+
+import org.springframework.data.repository.CrudRepository;
+
+public interface CarRepository extends CrudRepository<Car, Long> {
+
+	Iterable<Car> findByMakeIgnoringCase(String make);
+
+}

livelessons-data/livelessons-data-flyway/src/main/java/demo/DataFlywayApplication.java

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+package demo;
+
+import org.springframework.boot.CommandLineRunner;
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+import org.springframework.context.annotation.Bean;
+
+@SpringBootApplication
+public class DataFlywayApplication {
+
+	@Bean
+	public CommandLineRunner exampleQuery(CarRepository repository) {
+		return args -> repository.findByMakeIgnoringCase("HONDA")
+				.forEach(System.err::println);
+	}
+
+	public static void main(String[] args) {
+		SpringApplication.run(DataFlywayApplication.class, args);
+	}
+
+}

livelessons-data/livelessons-data-flyway/src/main/resources/application.properties

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+spring.jpa.hibernate.ddl-auto=validate

livelessons-data/livelessons-data-flyway/src/main/resources/db/migration/V1__init.sql

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+CREATE TABLE car (
+	id bigint NOT NULL,
+	make varchar(100),
+	model varchar(100),
+	year int,
+	PRIMARY KEY (id)
+);
+
+INSERT INTO car VALUES (0, 'Honda', 'Civic',  1997);
+INSERT INTO car VALUES (1, 'Honda', 'Accord', 2003);
+INSERT INTO car VALUES (2, 'Ford',  'Escort', 1985);

livelessons-data/livelessons-data-flyway/src/main/resources/db/migration/V2__add-color.sql

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+ALTER TABLE car ADD COLUMN (color varchar(200));
+
+UPDATE car SET COLOR = 'Red' WHERE color is null;

livelessons-data/livelessons-data-jdbc/README.adoc

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+:compat-mode:
+= Lesson 4: Working With Data (Relational Database with JDBC)
+
+== Introduction
+This example shows how you can access a classic relational database using Spring JDBC.
+
+== Building and running the sample
+Use the following commands to build run the application:
+
+```
+$ mvn clean package
+$ java -jar target/livelessons-data-jdbc-1.0.0-SNAPSHOT.jar
+```
+
+== Understanding the code
+This demo provides the same domain as the JPA sample but this time the `Car` class is
+a POJO and isn't managed by JPA. The `CarRepository` implements the access logic and
+maps returned rows to the actual object.
+
+This sample also uses `src/main/resources/schema.sql` and `src/main/resources/data.sql`
+scripts (picked up by convention) to create and populate the database.
+
+If you want to try the application with a real MySQL server rather than an in-memory
+database you can uncomment the entries in `src/main/resources/application.properties`.

livelessons-data/livelessons-data-jdbc/pom.xml

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+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+	<modelVersion>4.0.0</modelVersion>
+	<parent>
+		<groupId>livelessons</groupId>
+		<artifactId>livelessons-data</artifactId>
+		<version>1.0.0-SNAPSHOT</version>
+	</parent>
+	<artifactId>livelessons-data-jdbc</artifactId>
+	<properties>
+		<main.basedir>../..</main.basedir>
+	</properties>
+	<dependencies>
+		<dependency>
+			<groupId>org.springframework.boot</groupId>
+			<artifactId>spring-boot-starter-jdbc</artifactId>
+		</dependency>
+		<dependency>
+			<groupId>com.h2database</groupId>
+			<artifactId>h2</artifactId>
+		</dependency>
+		<dependency>
+			<groupId>mysql</groupId>
+			<artifactId>mysql-connector-java</artifactId>
+			<scope>runtime</scope>
+		</dependency>
+	</dependencies>
+</project>