wip

Author: thombergs

spring-boot/zero-downtime/pom.xml

@@ -42,6 +42,13 @@
 			<artifactId>h2</artifactId>
 		</dependency>
 
+		<!-- LAUNCHDARKLY -->
+		<dependency>
+			<groupId>com.launchdarkly</groupId>
+			<artifactId>launchdarkly-java-server-sdk</artifactId>
+			<version>5.3.0</version>
+		</dependency>
+
 	</dependencies>
 
 	<build>

spring-boot/zero-downtime/src/main/java/io/reflectoring/zerodowntime/CustomerController.java

@@ -6,26 +6,43 @@
 @RestController
 public class CustomerController {
 
-    private final CustomerRepository customerRepository;
+    private final CustomerRepository oldCustomerRepository;
+    private final NewCustomerRepository newCustomerRepository;
+    private final FeatureFlagService featureFlagService;
 
-    public CustomerController(CustomerRepository customerRepository) {
-        this.customerRepository = customerRepository;
+    public CustomerController(CustomerRepository oldCustomerRepository, NewCustomerRepository newCustomerRepository, FeatureFlagService featureFlagService) {
+        this.oldCustomerRepository = oldCustomerRepository;
+        this.newCustomerRepository = newCustomerRepository;
+        this.featureFlagService = featureFlagService;
     }
 
     @GetMapping("/customers/create")
     String createUser() {
-        Customer customer = new Customer("Bob", "Builder", "21 Build Street");
-        customerRepository.save(customer);
+        if (featureFlagService.writeToNewCustomerSchema()) {
+            NewCustomer customer = new NewCustomer("Bob", "Builder", "Build Street", "21");
+            newCustomerRepository.save(customer);
+        } else {
+            OldCustomer customer = new OldCustomer("Bob", "Builder", "21 Build Street");
+            oldCustomerRepository.save(customer);
+        }
         return "customer created";
     }
 
     @GetMapping("/customers/list")
     String showUser() {
-        Iterable<Customer> customers = customerRepository.findAll();
         StringBuffer buffer = new StringBuffer();
-        for (Customer customer : customers) {
-            buffer.append("\n");
-            buffer.append(customer.toString());
+        if (featureFlagService.readFromNewCustomerSchema()) {
+            Iterable<NewCustomer> customers = newCustomerRepository.findAll();
+            for (NewCustomer customer : customers) {
+                buffer.append("\n");
+                buffer.append(customer.toString());
+            }
+        } else {
+            Iterable<OldCustomer> customers = oldCustomerRepository.findAll();
+            for (OldCustomer customer : customers) {
+                buffer.append("\n");
+                buffer.append(customer.toString());
+            }
         }
         return buffer.toString();
     }

spring-boot/zero-downtime/src/main/java/io/reflectoring/zerodowntime/CustomerRepository.java

@@ -2,5 +2,5 @@
 
 import org.springframework.data.repository.CrudRepository;
 
-public interface CustomerRepository extends CrudRepository<Customer, Long> {
+public interface CustomerRepository extends CrudRepository<OldCustomer, Long> {
 }

spring-boot/zero-downtime/src/main/java/io/reflectoring/zerodowntime/FeatureFlagService.java

@@ -0,0 +1,24 @@
+package io.reflectoring.zerodowntime;
+
+import com.launchdarkly.sdk.LDUser;
+import com.launchdarkly.sdk.server.LDClient;
+import org.springframework.stereotype.Component;
+
+@Component
+public class FeatureFlagService {
+
+    private final LDClient launchdarklyClient;
+
+    public FeatureFlagService(LDClient launchdarklyClient) {
+        this.launchdarklyClient = launchdarklyClient;
+    }
+
+    public Boolean writeToNewCustomerSchema() {
+        return true;
+    }
+
+    public Boolean readFromNewCustomerSchema() {
+        return false;
+    }
+
+}

spring-boot/zero-downtime/src/main/java/io/reflectoring/zerodowntime/LaunchDarklyConfiguration.java

@@ -0,0 +1,27 @@
+package io.reflectoring.zerodowntime;
+
+import com.launchdarkly.sdk.server.LDClient;
+import org.springframework.beans.factory.annotation.Value;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+
+import javax.annotation.PreDestroy;
+import java.io.IOException;
+
+@Configuration
+public class LaunchDarklyConfiguration {
+
+    private LDClient launchdarklyClient;
+
+    @Bean
+    public LDClient launchdarklyClient(@Value("${launchdarkly.sdkKey}") String sdkKey) {
+        this.launchdarklyClient = new LDClient(sdkKey);
+        return this.launchdarklyClient;
+    }
+
+    @PreDestroy
+    public void destroy() throws IOException {
+        this.launchdarklyClient.close();
+    }
+
+}

spring-boot/zero-downtime/src/main/java/io/reflectoring/zerodowntime/NewCustomer.java

@@ -0,0 +1,34 @@
+package io.reflectoring.zerodowntime;
+
+
+import org.springframework.data.annotation.Id;
+import org.springframework.data.relational.core.mapping.Table;
+
+@Table("CUSTOMER")
+public class NewCustomer {
+
+    @Id
+    private long id;
+    private String firstName;
+    private String lastName;
+    private String addressStreet;
+    private String addressStreetNumber;
+
+    public NewCustomer(String firstName, String lastName, String addressStreet, String addressStreetNumber) {
+        this.firstName = firstName;
+        this.lastName = lastName;
+        this.addressStreet = addressStreet;
+        this.addressStreetNumber = addressStreetNumber;
+    }
+
+    @Override
+    public String toString() {
+        return "NewCustomer{" +
+                "id=" + id +
+                ", firstName='" + firstName + '\'' +
+                ", lastName='" + lastName + '\'' +
+                ", addressStreet='" + addressStreet + '\'' +
+                ", addressStreetNumber='" + addressStreetNumber + '\'' +
+                '}';
+    }
+}

spring-boot/zero-downtime/src/main/java/io/reflectoring/zerodowntime/NewCustomerRepository.java

@@ -0,0 +1,6 @@
+package io.reflectoring.zerodowntime;
+
+import org.springframework.data.repository.CrudRepository;
+
+public interface NewCustomerRepository extends CrudRepository<NewCustomer, Long> {
+}

spring-boot/zero-downtime/src/main/java/io/reflectoring/zerodowntime/Customer.java renamed to spring-boot/zero-downtime/src/main/java/io/reflectoring/zerodowntime/OldCustomer.java

@@ -5,23 +5,23 @@
 import org.springframework.data.relational.core.mapping.Table;
 
 @Table("CUSTOMER")
-public class Customer {
+public class OldCustomer {
 
     @Id
     private long id;
     private String firstName;
     private String lastName;
     private String address;
 
-    public Customer(String firstName, String lastName, String address) {
+    public OldCustomer(String firstName, String lastName, String address) {
         this.firstName = firstName;
         this.lastName = lastName;
         this.address = address;
     }
 
     @Override
     public String toString() {
-        return "Customer{" +
+        return "OldCustomer{" +
                 "id=" + id +
                 ", firstName='" + firstName + '\'' +
                 ", lastName='" + lastName + '\'' +

spring-boot/zero-downtime/src/main/resources/application.yml

@@ -6,4 +6,7 @@ spring.jpa.database-platform: org.hibernate.dialect.H2Dialect
 spring:
   h2:
     console:
-      enabled: true
+      enabled: true
+
+launchdarkly:
+  sdkKey: <YOUR-SDK-KEY>

spring-boot/zero-downtime/src/main/resources/db/migration/V002__add_address_columns.sql

@@ -0,0 +1,2 @@
+alter table customer add column address_street varchar(100) null;
+alter table customer add column address_street_number varchar(100) null;