First commmit for Spring Multi-tenancy with Hibernate example.

spring-all/src/main/java/org/baeldung/multi-tenancy/java/com/baeldung/multitenancy/entities/Book.java

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+package com.baeldung.multitenancy.entities;
+
+import javax.persistence.*;
+import javax.validation.constraints.NotNull;
+
+@Entity
+public class Book {
+
+    @Id
+    @GeneratedValue(strategy = GenerationType.AUTO)
+    @Column(name = "id")
+    Long id;
+
+    @NotNull
+    @Column(name = "name")
+    String name;
+
+    // standard getters and setters
+}

spring-all/src/main/java/org/baeldung/multi-tenancy/java/com/baeldung/multitenancy/implementation/CurrentSessionTenantIdentifierResolver.java

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+package com.baeldung.multitenancy.implementation;
+
+import org.hibernate.context.spi.CurrentTenantIdentifierResolver;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.beans.factory.annotation.Autowired;
+
+import javax.servlet.http.HttpServletRequest;
+import java.text.MessageFormat;
+
+/**
+ * CurrentSessionTenantIdentifierResolver-- here we fetch the tenantId from the request.
+ * User: baeldung
+ * Date: 9/06/15
+ */
+
+public class CurrentSessionTenantIdentifierResolver implements CurrentTenantIdentifierResolver {
+
+    @Autowired
+    private HttpServletRequest request;
+
+    @Override
+    public String resolveCurrentTenantIdentifier() {
+        String tenantId = request.getHeader("X-TenantId");
+        return tenantId;
+    }
+
+    @Override
+    public boolean validateExistingCurrentSessions() {
+        // Additional logic to ensure appropriate connections are made.
+        return false;
+    }
+}

spring-all/src/main/java/org/baeldung/multi-tenancy/java/com/baeldung/multitenancy/implementation/SessionFactoryBean.java

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+package com.baeldung.multitenancy.implementation;
+
+import org.hibernate.tool.hbm2ddl.SchemaExport;
+
+import javax.sql.DataSource;
+import java.io.IOException;
+import java.sql.Connection;
+import java.sql.SQLException;
+import java.util.Map;
+
+/**
+ * Created with IntelliJ IDEA.
+ * User: vtajzich
+ * Date: 8/21/13
+ */
+public class SessionFactoryBean extends org.springframework.orm.hibernate4.LocalSessionFactoryBean {
+
+    private Map<String, DataSource> dataSourceMap;
+
+    @Override
+    public void afterPropertiesSet() throws IOException {
+        super.afterPropertiesSet();
+
+        for (Map.Entry<String, DataSource> entry : dataSourceMap.entrySet()) {
+
+            Connection connection = null;
+
+            try {
+
+                connection = entry.getValue().getConnection();
+
+                SchemaExport export = new SchemaExport(getConfiguration(), connection);
+
+                export.setOutputFile(entry.getKey() + "-schema.sql");
+                export.setDelimiter(";");
+
+                // define your rules, here.
+                //The below code allows creation, but does not allow dropping entries
+                export.execute(true, true, false, true);
+
+            } catch (SQLException e) {
+                throw new RuntimeException(e);
+            }
+        }
+    }
+
+    public void setDataSourceMap(Map<String, DataSource> dataSourceMap) {
+        this.dataSourceMap = dataSourceMap;
+    }
+}

spring-all/src/main/java/org/baeldung/multi-tenancy/java/com/baeldung/multitenancy/implementation/SimpleMultiTenantConnectionProvider.java

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+package com.baeldung.multitenancy.implementation;
+
+import org.hibernate.service.jdbc.connections.spi.AbstractDataSourceBasedMultiTenantConnectionProviderImpl;
+
+import javax.sql.DataSource;
+import java.util.Map;
+
+/**
+ * CurrentSessionTenantIdentifierResolver-- here we fetch the DB conection for the given tenantIdentifier.
+ * User: baeldung
+ * Date: 9/06/15
+ */
+
+public class SimpleMultiTenantConnectionProvider extends AbstractDataSourceBasedMultiTenantConnectionProviderImpl {
+
+    private Map<String, DataSource> dataSourceMap;
+
+    @Override
+    protected DataSource selectAnyDataSource() {
+        return (DataSource) dataSourceMap.values().toArray()[0];
+    }
+
+    @Override
+    protected DataSource selectDataSource(String tenantIdentifier) {
+        return dataSourceMap.get(tenantIdentifier);
+    }
+
+    public Map<String, DataSource> getDataSourceMap() {
+        return dataSourceMap;
+    }
+
+    public void setDataSourceMap(Map<String, DataSource> dataSourceMap) {
+        this.dataSourceMap = dataSourceMap;
+    }
+}

spring-all/src/main/java/org/baeldung/multi-tenancy/java/com/baeldung/multitenancy/service/MultiTenantService.java

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+package com.baeldung.multitenancy.service;
+
+import com.baeldung.multitenancy.entities.Book;
+import org.hibernate.SessionFactory;
+import org.springframework.stereotype.Service;
+
+import java.util.List;
+
+/**
+ * MultitenantService-- we use the SessionFactory to save and fetch entities.
+ * User: baeldung
+ * Date: 9/06/15
+ */
+
+@Service
+public class MultiTenantService {
+
+    @AutoWired
+    private SessionFactory sessionFactory;
+
+    public void save(Book book) {
+        sessionFactory.getCurrentSession().save(book);
+    }
+
+    public Book findBook(Long id) {
+        return (Book) sessionFactory.
+                getCurrentSession().get(Book.class, id);
+    }
+
+    public List<Book> findAllBooks() {
+        return sessionFactory.
+                getCurrentSession().createQuery("from Books").list();
+    }
+
+    public void setSessionFactory(SessionFactory sessionFactory){
+        this.sessionFactory = sessionFactory;
+    }
+}

spring-all/src/main/java/org/baeldung/multi-tenancy/resources/applicationContext.xml

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+<?xml version="1.0" encoding="UTF-8" standalone="no"?>
+<beans xmlns="http://www.springframework.org/schema/beans"
+    xmlns:context="http://www.springframework.org/schema/context"
+    xmlns:tx="http://www.springframework.org/schema/tx" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.2.xsd         http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.2.xsd                   http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-3.2.xsd">
+
+    <context:property-placeholder location="classpath*:database.properties" />
+    <context:spring-configured />
+
+    <context:component-scan base-package="com.baeldung.multitenancy">
+    </context:component-scan>
+
+    <util:map id="mydatasources">
+        <entry key="tenant1" value-ref="source1" />
+        <entry key="tenant2" value-ref="source2" />
+    </util:map>
+
+    <bean id="source1" parent="mainDataSource">
+        <property name="url" value="jdbc:mysql://localhost/tenant1" />
+        <property name="username" value="baeldung" />
+        <property name="password" value="spring" />
+    </bean>
+
+    <bean id="source2" parent="mainDataSource">
+        <property name="url" value="jdbc:mysql://localhost/tenant2" />
+        <property name="username" value="testuser" />
+        <property name="password" value="password" />
+    </bean>
+
+    <bean class="org.apache.commons.dbcp.BasicDataSource" abstract="true"
+        destroy-method="close" id="mainDataSource">
+        <property name="driverClassName" value="${database.driverClassName}" />
+        <property name="testOnBorrow" value="true" />
+        <property name="testOnReturn" value="true" />
+        <property name="testWhileIdle" value="true" />
+        <property name="numTestsPerEvictionRun" value="2" />
+        <property name="minEvictableIdleTimeMillis" value="1000000" />
+        <property name="timeBetweenEvictionRunsMillis" value="1000000" />
+        <property name="validationQuery" value="SELECT 1" />
+    </bean>
+
+    <bean id="sessionFactory" class="com.baeldung.multitenancy.SessionFactoryBean">
+        <property name="dataSourceMap" ref="mydatasources" />
+        <property name="dataSource" ref="source1" />
+        <property name="hibernateProperties">
+            <map>
+                <entry key="hibernate.dialect" value="org.hibernate.dialect.MySQLDialect" />
+                <entry key="hibernate.show_sql" value="true" />
+                <entry key="hibernate.multiTenancy" value="DATABASE" />
+                <entry key="hibernate.tenant_identifier_resolver"
+                    value-ref="currentSessionTenantIdentifierResolver" />
+                <entry key="hibernate.multi_tenant_connection_provider"
+                    value-ref="simpleMultiTenantConnectionProvider" />
+            </map>
+        </property>
+    </bean>
+
+    <bean id="currentSessionTenantIdentifierResolver"
+        class="com.baeldung.multitenancy.implementation.CurrentSessionTenantIdentifierResolver"
+        scope="request">
+        <aop:scoped-proxy />
+    </bean>
+
+    <bean id="simpleMultiTenantConnectionProvider"
+        class="com.baeldung.multitenancy.implementation.SimpleMultiTenantConnectionProvider">
+        <property name="dataSourceMap" ref="datasources" />
+    </bean>
+
+
+    <bean id="multitenantService" class="com.baeldung.multitenancy.service.MultitenantService">
+        <property name="sessionFactory" ref="sessionFactory" />
+    </bean>
+
+    <tx:annotation-driven mode="aspectj"
+        transaction-manager="transactionManager" />
+
+    <bean id="transactionManager"
+        class="org.springframework.orm.hibernate4.HibernateTransactionManager">
+        <property name="sessionFactory" ref="sessionFactory" />
+        <property name="autodetectDataSource" value="false" />
+    </bean>
+
+    <tx:advice id="transactionServiceDao" transaction-manager="transactionManager">
+        <tx:attributes>
+            <tx:method name="exists" propagation="SUPPORTS"
+                rollback-for="java.lang.Exception" />
+            <tx:method name="find*" propagation="SUPPORTS"
+                rollback-for="java.lang.Exception" />
+            <tx:method name="get*" propagation="SUPPORTS"
+                rollback-for="java.lang.Exception" />
+            <tx:method name="*" propagation="REQUIRED"
+                rollback-for="java.lang.Exception" />
+            <tx:method name="*Commit" propagation="REQUIRES_NEW"
+                rollback-for="java.lang.Exception" />
+        </tx:attributes>
+    </tx:advice>
+
+    <aop:config>
+        <aop:pointcut id="serviceInvocation"
+            expression="execution(public com.baeldung.multitenancy.service.MultitenantService.*(..))" />
+        <aop:advisor pointcut-ref="serviceInvocation"
+            advice-ref="transactionServiceDao" />
+    </aop:config>
+
+</beans>

spring-all/src/main/java/org/baeldung/multi-tenancy/resources/database.properties

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+database.driverClassName=com.mysql.jdbc.Driver