JAVA-2592: Update article on AbstractRoutingDatasource (#11320)

Co-authored-by: Dhawal Kapil <dhawalkapil@gmail.com>

persistence-modules/spring-boot-persistence/README.md

@@ -7,4 +7,5 @@
 - [Resolving “Failed to Configure a DataSource” Error](https://www.baeldung.com/spring-boot-failed-to-configure-data-source)
 - [Hibernate Field Naming with Spring Boot](https://www.baeldung.com/hibernate-field-naming-spring-boot)
 - [Spring Boot with Hibernate](https://www.baeldung.com/spring-boot-hibernate)
+- [A Guide to Spring AbstractRoutingDatasource](https://www.baeldung.com/spring-abstract-routing-data-source)
 - More articles: [[more -->]](../spring-boot-persistence-2)

persistence-modules/spring-boot-persistence/src/main/java/com/baeldung/dsrouting/ClientDataSourceRouter.java

@@ -0,0 +1,27 @@
+package com.baeldung.dsrouting;
+
+import org.springframework.jdbc.datasource.lookup.AbstractRoutingDataSource;
+
+import javax.sql.DataSource;
+import java.util.HashMap;
+import java.util.Map;
+
+/**
+ * Returns thread bound client lookup key for current context.
+ */
+public class ClientDataSourceRouter extends AbstractRoutingDataSource {
+
+    @Override
+    protected Object determineCurrentLookupKey() {
+        return ClientDatabaseContextHolder.getClientDatabase();
+    }
+
+    public void initDatasource(DataSource clientADataSource,
+                               DataSource clientBDataSource) {
+        Map<Object, Object> dataSourceMap = new HashMap<>();
+        dataSourceMap.put(ClientDatabase.CLIENT_A, clientADataSource);
+        dataSourceMap.put(ClientDatabase.CLIENT_A, clientBDataSource);
+        this.setTargetDataSources(dataSourceMap);
+        this.setDefaultTargetDataSource(clientADataSource);
+    }
+}

persistence-modules/spring-boot-persistence/src/main/java/com/baeldung/dsrouting/model/ClientADetails.java

@@ -0,0 +1,28 @@
+package com.baeldung.dsrouting.model;
+
+import org.springframework.boot.context.properties.ConfigurationProperties;
+import org.springframework.stereotype.Component;
+
+@Component
+@ConfigurationProperties(prefix = "client-a.datasource")
+public class ClientADetails {
+
+    private String name;
+    private String script;
+
+    public String getName() {
+        return name;
+    }
+
+    public void setName(String name) {
+        this.name = name;
+    }
+
+    public String getScript() {
+        return script;
+    }
+
+    public void setScript(String script) {
+        this.script = script;
+    }
+}

persistence-modules/spring-boot-persistence/src/main/java/com/baeldung/dsrouting/model/ClientBDetails.java

@@ -0,0 +1,28 @@
+package com.baeldung.dsrouting.model;
+
+import org.springframework.boot.context.properties.ConfigurationProperties;
+import org.springframework.stereotype.Component;
+
+@Component
+@ConfigurationProperties(prefix = "client-b.datasource")
+public class ClientBDetails {
+
+    private String name;
+    private String script;
+
+    public String getName() {
+        return name;
+    }
+
+    public void setName(String name) {
+        this.name = name;
+    }
+
+    public String getScript() {
+        return script;
+    }
+
+    public void setScript(String script) {
+        this.script = script;
+    }
+}

persistence-modules/spring-boot-persistence/src/test/java/com/baeldung/dsrouting/DataSourceRoutingTestConfiguration.java

@@ -34,11 +34,11 @@ public class DataSourceRoutingTestConfiguration {
 
     private DataSource clientADatasource() {
         EmbeddedDatabaseBuilder dbBuilder = new EmbeddedDatabaseBuilder();
-        return dbBuilder.setType(EmbeddedDatabaseType.H2).setName("CLIENT_A").addScript("classpath:dsrouting-db.sql").build();
+        return dbBuilder.setType(EmbeddedDatabaseType.H2).setName("CLIENT_A").addScript("dsrouting-db.sql").build();
     }
 
     private DataSource clientBDatasource() {
         EmbeddedDatabaseBuilder dbBuilder = new EmbeddedDatabaseBuilder();
-        return dbBuilder.setType(EmbeddedDatabaseType.H2).setName("CLIENT_B").addScript("classpath:dsrouting-db.sql").build();
+        return dbBuilder.setType(EmbeddedDatabaseType.H2).setName("CLIENT_B").addScript("dsrouting-db.sql").build();
     }
 }

persistence-modules/spring-boot-persistence/src/test/java/com/baeldung/dsrouting/SpringBootDataSourceRoutingIntegrationTest.java

@@ -0,0 +1,62 @@
+package com.baeldung.dsrouting;
+
+import static org.junit.Assert.assertEquals;
+
+import javax.sql.DataSource;
+
+import com.baeldung.dsrouting.model.ClientADetails;
+import com.baeldung.dsrouting.model.ClientBDetails;
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.context.properties.EnableConfigurationProperties;
+import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.jdbc.core.JdbcTemplate;
+import org.springframework.test.annotation.DirtiesContext;
+import org.springframework.test.context.ContextConfiguration;
+import org.springframework.test.context.junit4.SpringRunner;
+
+@RunWith(SpringRunner.class)
+@SpringBootTest(
+        classes = {ClientADetails.class, ClientBDetails.class})
+@ContextConfiguration(classes = SpringBootDataSourceRoutingTestConfiguration.class)
+@DirtiesContext
+@EnableConfigurationProperties(ClientBDetails.class)
+public class SpringBootDataSourceRoutingIntegrationTest {
+
+    @Autowired
+    DataSource routingDatasource;
+
+    @Autowired
+    ClientService clientService;
+
+    @Before
+    public void setup() {
+        final String SQL_CLIENT_A = "insert into client (id, name) values (1, 'CLIENT A')";
+        final String SQL_CLIENT_B = "insert into client (id, name) values (2, 'CLIENT B')";
+
+        JdbcTemplate jdbcTemplate = new JdbcTemplate();
+        jdbcTemplate.setDataSource(routingDatasource);
+
+        ClientDatabaseContextHolder.set(ClientDatabase.CLIENT_A);
+        jdbcTemplate.execute(SQL_CLIENT_A);
+        ClientDatabaseContextHolder.clear();
+
+        ClientDatabaseContextHolder.set(ClientDatabase.CLIENT_B);
+        jdbcTemplate.execute(SQL_CLIENT_B);
+        ClientDatabaseContextHolder.clear();
+    }
+
+    @Test
+    public void givenClientDbs_whenContextsSwitch_thenRouteToCorrectDatabase() throws Exception {
+
+        // test ACME WIDGETS
+        String clientName = clientService.getClientName(ClientDatabase.CLIENT_A);
+        assertEquals(clientName, "CLIENT A");
+
+        // test WIDGETS_ARE_US
+        clientName = clientService.getClientName(ClientDatabase.CLIENT_B);
+        assertEquals(clientName, "CLIENT B");
+    }
+}

persistence-modules/spring-boot-persistence/src/test/java/com/baeldung/dsrouting/SpringBootDataSourceRoutingTestConfiguration.java

@@ -0,0 +1,55 @@
+package com.baeldung.dsrouting;
+
+import com.baeldung.dsrouting.model.ClientADetails;
+import com.baeldung.dsrouting.model.ClientBDetails;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.context.annotation.*;
+import org.springframework.jdbc.datasource.embedded.EmbeddedDatabaseBuilder;
+import org.springframework.jdbc.datasource.embedded.EmbeddedDatabaseType;
+
+import javax.sql.DataSource;
+import java.util.HashMap;
+import java.util.Map;
+
+@Configuration
+public class SpringBootDataSourceRoutingTestConfiguration {
+    @Autowired
+    private ClientADetails clientADetails;
+    @Autowired
+    private ClientBDetails clientBDetails;
+
+    @Bean
+    public ClientService clientService() {
+        return new ClientService(new ClientDao(clientDatasource()));
+    }
+
+    @Bean
+    public DataSource clientDatasource() {
+        Map<Object, Object> targetDataSources = new HashMap<>();
+        DataSource clientADatasource = clientADatasource();
+        DataSource clientBDatasource = clientBDatasource();
+        targetDataSources.put(ClientDatabase.CLIENT_A, clientADatasource);
+        targetDataSources.put(ClientDatabase.CLIENT_B, clientBDatasource);
+
+        ClientDataSourceRouter clientRoutingDatasource = new ClientDataSourceRouter();
+        clientRoutingDatasource.setTargetDataSources(targetDataSources);
+        clientRoutingDatasource.setDefaultTargetDataSource(clientADatasource);
+        return clientRoutingDatasource;
+    }
+
+    private DataSource clientADatasource() {
+        EmbeddedDatabaseBuilder dbBuilder = new EmbeddedDatabaseBuilder();
+        return dbBuilder.setType(EmbeddedDatabaseType.H2)
+                .setName(clientADetails.getName())
+                .addScript(clientADetails.getScript())
+                .build();
+    }
+
+    private DataSource clientBDatasource() {
+        EmbeddedDatabaseBuilder dbBuilder = new EmbeddedDatabaseBuilder();
+        return dbBuilder.setType(EmbeddedDatabaseType.H2)
+                .setName(clientBDetails.getName())
+                .addScript(clientBDetails.getScript())
+                .build();
+    }
+}

persistence-modules/spring-boot-persistence/src/test/resources/application.properties

@@ -4,6 +4,14 @@ spring.datasource.url=jdbc:h2:mem:db;DB_CLOSE_DELAY=-1
 spring.datasource.username=sa
 spring.datasource.password=sa
 
+#database details for CLIENT_A
+client-a.datasource.name=CLIENT_A
+client-a.datasource.script=dsrouting-db.sql
+
+#database details for CLIENT_B
+client-b.datasource.name=CLIENT_B
+client-b.datasource.script=dsrouting-db.sql
+
 # hibernate.X
 hibernate.dialect=org.hibernate.dialect.H2Dialect
 hibernate.show_sql=true

persistence-modules/spring-boot-persistence/src/test/resources/dsrouting-db.sql

@@ -0,0 +1,5 @@
+create table client (
+  id numeric,
+  name  varchar(50),
+  constraint pk_client primary key (id)
+);

persistence-modules/spring-jpa/README.md

@@ -5,7 +5,7 @@
 - [JPA Pagination](https://www.baeldung.com/jpa-pagination)
 - [Sorting with JPA](https://www.baeldung.com/jpa-sort)
 - [Self-Contained Testing Using an In-Memory Database](https://www.baeldung.com/spring-jpa-test-in-memory-database)
-- [A Guide to Spring AbstractRoutingDatasource](https://www.baeldung.com/spring-abstract-routing-data-source)
+- [Obtaining Auto-generated Keys in Spring JDBC](https://www.baeldung.com/spring-jdbc-autogenerated-keys)
 - [Spring Data Annotations](http://www.baeldung.com/spring-data-annotations)
 - More articles: [[next -->]](/spring-jpa-2)
 

persistence-modules/spring-jpa/src/main/java/com/baeldung/dsrouting/ClientDataSourceRouter.java

@@ -1,14 +0,0 @@
-package com.baeldung.dsrouting;
-
-import org.springframework.jdbc.datasource.lookup.AbstractRoutingDataSource;
-
-/**
- * Returns thread bound client lookup key for current context.
- */
-public class ClientDataSourceRouter extends AbstractRoutingDataSource {
-
-    @Override
-    protected Object determineCurrentLookupKey() {
-        return ClientDatabaseContextHolder.getClientDatabase();
-    }
-}