Spring – Hibernate – JAX-RS Putting Hibernate to REST

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns="http://java.sun.com/xml/ns/javaee"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://java.sun.com/xml/ns/javaee
		  http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"
         version="2.5">
    <description>hibernate-rest</description>
    <display-name>hibernate-rest</display-name>
 
    <!-- Spring config  -->
    <context-param>
           <param-name>contextConfigLocation</param-name>
           <param-value>
               /WEB-INF/conf/applicationContext.xml
           </param-value>
       </context-param>
 
    <context-param>
        <param-name>log4jConfigLocation</param-name>
        <param-value>/WEB-INF/conf/log4j.properties</param-value>
    </context-param>
 
 
    <!-- Spring Listeners -->
    <listener>
        <listener-class>org.springframework.web.util.Log4jConfigListener</listener-class>
    </listener>
    <listener>
        <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
    </listener>
    <listener>
        <listener-class>org.springframework.web.context.request.RequestContextListener</listener-class>
    </listener>
 
    <filter>
        <filter-name>openSessionInViewFilter</filter-name>
        <filter-class>
            org.springframework.orm.hibernate3.support.OpenSessionInViewFilter
        </filter-class>
    </filter>
 
    <filter-mapping>
        <filter-name>openSessionInViewFilter</filter-name>
        <url-pattern>/*</url-pattern>
    </filter-mapping>
 
    <!-- Remote web services -->
       <servlet>
           <servlet-name>CXFServlet</servlet-name>
           <servlet-class>
               org.apache.cxf.transport.servlet.CXFServlet
           </servlet-class>
       </servlet>
 
       <servlet>
           <servlet-name>remoteApiBasicHttpHandlerImpl</servlet-name>
           <servlet-class>org.springframework.web.context.support.HttpRequestHandlerServlet</servlet-class>
       </servlet>
 
 
       <!-- Remote web services mapping -->
       <servlet-mapping>
           <servlet-name>CXFServlet</servlet-name>
           <url-pattern>/api/*</url-pattern>
       </servlet-mapping>
 
 
</web-app>

<!DOCTYPE hibernate-configuration PUBLIC "-//Hibernate/Hibernate Configuration DTD//EN" "http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd">
<hibernate-configuration>
	<session-factory name="com.raulraja.tutorials">
        <!-- Persistent entities -->
        <mapping class="com.raulraja.model.domain.Person"/>  
    </session-factory>
</hibernate-configuration>

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
        xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
        xmlns:aop="http://www.springframework.org/schema/aop"
        xmlns:tx="http://www.springframework.org/schema/tx"
        xmlns:cxf="http://cxf.apache.org/core"
        xmlns:jaxws="http://cxf.apache.org/jaxws"
        xmlns:jaxrs="http://cxf.apache.org/jaxrs" xmlns:util="http://www.springframework.org/schema/util"
        xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-2.0.xsd
       http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-2.0.xsd
       http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-2.0.xsd
       http://cxf.apache.org/core
       http://cxf.apache.org/schemas/core.xsd
       http://cxf.apache.org/jaxws
       http://cxf.apache.org/schemas/jaxws.xsd
       http://cxf.apache.org/jaxrs
       http://cxf.apache.org/schemas/jaxrs.xsd http://www.springframework.org/schema/util http://www.springframework.org/schema/util/spring-util.xsd"
        default-autowire="byName">
 
    <!-- Load CXF modules from cxf.jar -->
    <import resource="classpath:META-INF/cxf/cxf.xml"/>
    <import resource="classpath:META-INF/cxf/cxf-extension-soap.xml"/>
    <import resource="classpath:META-INF/cxf/cxf-servlet.xml"/>
    <import resource="classpath:META-INF/cxf/cxf-extension-jaxrs-binding.xml"/>
 
 
    <cxf:bus>
        <cxf:features>
            <cxf:logging/>
        </cxf:features>
    </cxf:bus>
 
    <!-- A template instance to expose as the service -->
    <bean id="person" class="com.raulraja.model.domain.Person"/>
 
    <!-- The rest server configuration -->
    <jaxrs:server id="restServer" address="/rest/">
        <jaxrs:serviceBeans>
            <ref bean="person"/>
        </jaxrs:serviceBeans>
        <jaxrs:extensionMappings>
            <entry key="feed" value="application/atom+xml"/>
            <entry key="json" value="application/json"/>
            <entry key="xml" value="application/xml"/>
            <entry key="html" value="text/html"/>
        </jaxrs:extensionMappings>
    </jaxrs:server>
 
    <!-- The datasource -->
    <bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource" destroy-method="close">
        <property name="driverClass" value="org.postgresql.Driver"/>
        <property name="jdbcUrl" value="jdbc:postgresql://localhost:5432/tutorials?autoReconnect=true"/>
        <property name="user" value="tutorials"/>
        <property name="password" value="tutorials"/>
    </bean>
 
    <!-- The hibernate session factory -->
    <bean id="sessionFactory" class="org.springframework.orm.hibernate3.LocalSessionFactoryBean">
        <property name="configLocations">
            <list>
                <value>WEB-INF/conf/hibernate.cfg.xml</value>
            </list>
        </property>
        <property name="configurationClass">
            <value>org.hibernate.cfg.AnnotationConfiguration</value>
        </property>
        <property name="hibernateProperties">
            <props>
                <prop key="hibernate.dialect">org.hibernate.dialect.PostgreSQLDialect</prop>
                <prop key="hibernate.hbm2ddl.auto">update</prop>
            </props>
        </property>
        <property name="dataSource">
            <ref bean="dataSource"/>
        </property>
    </bean>
 
    <!-- A persistence adapter implementation that acts as a data access service -->
    <bean id="persistenceAdapter" class="com.raulraja.model.persistence.impl.HibernatePersistenceAdapterImpl" autowire="autodetect">
        <property name="defaultResultSize" value="10"/>
        <property name="hibernateTemplate">
            <ref bean="hibernateTemplate"/>
        </property>
    </bean>
 
    <!-- The transaction manager -->
    <bean id="transactionManager" class="org.springframework.orm.hibernate3.HibernateTransactionManager">
        <property name="sessionFactory">
            <ref bean="sessionFactory"/>
        </property>
    </bean>
 
    <!-- enable the configuration of transactional behavior based on annotations -->
    <tx:annotation-driven transaction-manager="transactionManager"/>
 
    <!-- The hibernate template -->
    <bean id="hibernateTemplate" class="org.springframework.orm.hibernate3.HibernateTemplate">
        <property name="sessionFactory">
            <ref bean="sessionFactory"/>
        </property>
    </bean>
 
    <!-- statically injects the persistence service in the entities base class -->
    <bean class="org.springframework.beans.factory.config.MethodInvokingFactoryBean">
        <property name="staticMethod" value="com.raulraja.model.domain.PersistentEntity.setPersistenceAdapter"/>
        <property name="arguments">
            <ref bean="persistenceAdapter"/>
        </property>
    </bean>
 
 
</beans>

package com.raulraja.model.domain;
 
import javax.xml.bind.annotation.*;
import java.util.ArrayList;
import java.util.List;
 
/**
 * An object that encapsualtes pagination over list of records
 */
@XmlRootElement(namespace = PersistentEntity.NAMESPACE)
@XmlType(name = "paginatedList", namespace = PersistentEntity.NAMESPACE)
public class PaginatedList<Entity> {
 
	/**
	 * the total amount of items available in the data store
	 */
	private long count;
 
	/**
	 * the starting record displayed on the list
	 */
	private long start;
 
	/**
	 * the size of this list
	 */
	private long size;
 
	/**
	 * the records contained on the list
	 */
	private List<Entity> items = new ArrayList<Entity>();
 
	/**
	 * default constructor
	 */
	public PaginatedList() {
		super();
	}
 
	/**
	 * Constructor that takes the data
	 * @param count the total amount of items available in the data store
	 * @param start the starting record displayed on the list
	 * @param items the records contained on the list
	 */
	public PaginatedList(long count, long start, List<Entity> items) {
		this();
		setCount(count);
		setStart(start);
		setItems(items);
		setSize(items.size());
	}
 
	/**
	 * @return the total amount of items available in the data store
	 */
	public long getCount() {
		return count;
	}
 
	public void setCount(long count) {
		this.count = count;
	}
 
	/**
	 * @return the starting record displayed on the list
	 */
	public long getStart() {
		return start;
	}
 
	public void setStart(long start) {
		this.start = start;
	}
 
	/**
	 * @return the size of this list
	 */
	public long getSize() {
		return size;
	}
 
	public void setSize(long size) {
		this.size = size;
	}
 
	/**
	 * @return the records contained on the list
	 */
	@XmlElementWrapper(name = "items")
	@XmlElements({
            @XmlElement(name="person", type=Person.class, namespace = PersistentEntity.NAMESPACE),
			@XmlElement(name="property", type=Object.class, namespace = PersistentEntity.NAMESPACE)
    })
	public List<Entity> getItems() {
		return items;
	}
 
	public void setItems(List<Entity> items) {
		this.items = items;
	}
}

package com.raulraja.model.domain;
 
import com.raulraja.model.persistence.PersistenceAdapter;
import org.apache.commons.beanutils.BeanUtils;
import org.apache.commons.beanutils.PropertyUtils;
import org.springframework.transaction.annotation.Transactional;
 
import javax.ws.rs.*;
import java.lang.reflect.InvocationTargetException;
 
/**
 * Base class for entities with static access to the persistent context
 */
public abstract class PersistentEntity<Entity extends PersistentEntity> {
 
	public static final String NAMESPACE = "https://apps.raulraja.org/api";
 
	private static PersistenceAdapter<PersistentEntity> persistenceAdapter;
 
	public static void setPersistenceAdapter(PersistenceAdapter<PersistentEntity> persistenceAdapter) {
		PersistentEntity.persistenceAdapter = persistenceAdapter;
	}
 
	public abstract Long getId();
 
	public abstract Class<Entity> getMappedClass();
 
	@Override
	@SuppressWarnings("unchecked")
	public boolean equals(Object o) {
		if (this == o) {
			return true;
		}
		if (o == null || getClass() != o.getClass()) {
			return false;
		}
 
		PersistentEntity<?> entity = (PersistentEntity<?>) o;
 
		if (getId() != null ? !getId().equals(entity.getId()) : entity.getId() != null) {
			return false;
		}
 
		return true;
	}
 
	@Override
	public int hashCode() {
		return getId() != null ? getId().hashCode() : 0;
	}
 
 
	/**
	 * Returns a paginated list of all entities for this class
	 * @param start the start record
	 * @param size the limit
	 * @return the list of matches
	 */
	@GET @Path("list")
	@SuppressWarnings("unchecked")
    public PaginatedList<Entity> list(@QueryParam("start") int start, @QueryParam("size") int size) {
		Class mappedClass = getMappedClass();
		PaginatedList<Entity> list = (PaginatedList<Entity>) persistenceAdapter.list(mappedClass, start, size);
		return list;
	}
 
	/**
	 * Returns a paginated list of all entities for this class
	 * @param start the start record
	 * @param size the limit
	 * @return the list of matches
	 */
	@GET @Path("{property}/list")
	@SuppressWarnings("unchecked")
    public PaginatedList<Object> list(@PathParam("property") String property, @QueryParam("start") int start, @QueryParam("size") int size) {
		Class mappedClass = getMappedClass();
		PaginatedList<Object> list = (PaginatedList<Object>) persistenceAdapter.list(mappedClass, property, start, size);
		return list;
	}
 
 
	@GET @Path("{id}")
    public PersistentEntity get(@PathParam("id") Long id) {
		Class mappedClass = getMappedClass();
		PersistentEntity entity = persistenceAdapter.get(mappedClass, id);
		return entity;
	}
 
	@GET @Path("{id}/{property}")
    public Object getProperty(@PathParam("id") Long id, @PathParam("property") String property) throws NoSuchMethodException, IllegalAccessException, InvocationTargetException {
		Class mappedClass = getMappedClass();
		PersistentEntity entity = persistenceAdapter.get(mappedClass, id);
		return PropertyUtils.getProperty(entity, property);
	}
 
	@POST @Path("{id}/{property}")
	@Transactional
    public Object updateProperty(@PathParam("id") Long id, @PathParam("property") String property, String value) throws NoSuchMethodException, IllegalAccessException, InvocationTargetException {
		Class mappedClass = getMappedClass();
		PersistentEntity entity = persistenceAdapter.get(mappedClass, id);
		BeanUtils.setProperty(entity, property, value);
		return persistenceAdapter.save(entity);	
	}
 
	@POST @Path("create")
	@Transactional
    public PersistentEntity create(Entity entity) {
		PersistentEntity persistentEntity = get(entity.getId());
		if (persistentEntity != null) {
			throw new IllegalStateException("There is already a " + getMappedClass() + " with id = " + entity.getId());
		}
		persistenceAdapter.save(entity);
		return entity;
	}
 
	@POST @Path("update")
	@Transactional
    public PersistentEntity update(Entity entity) {
		PersistentEntity<Entity> persistentEntity = get(entity.getId());
		if (persistentEntity == null) {
			throw new IllegalStateException("There is no" + getMappedClass() + " with id = " + entity.getId());
		}
		persistentEntity.updateFromRequest(entity);
		persistenceAdapter.save(persistentEntity);
		return persistentEntity;
	}
 
	public abstract Entity updateFromRequest(Entity entity);
 
	@POST @Path("delete")
    public Entity delete(Entity entity) {
		persistenceAdapter.delete(entity);
		return entity;
	}
 
}

package com.raulraja.model.domain;
 
import javax.persistence.Entity;
import javax.persistence.Id;
import javax.persistence.ManyToOne;
import javax.persistence.OneToMany;
import javax.ws.rs.Path;
import javax.xml.bind.annotation.*;
import java.util.ArrayList;
import java.util.List;
 
@Entity
@Path("/person/")
@XmlRootElement
@XmlType(name = "person", namespace = PersistentEntity.NAMESPACE)
public class Person extends PersistentEntity<Person> {
 
	@Id
	private Long id;
 
	private String name;
 
	private String email;
 
	@ManyToOne
	private Person parent;
 
	@OneToMany(mappedBy = "parent")
	private List<Person> children = new ArrayList<Person>();
 
	@XmlElement(type = Long.class)
	public Long getId() {
		return id;
	}
 
	public void setId(Long id) {
		this.id = id;
	}
 
	@XmlElement(type = String.class)
	public String getName() {
		return name;
	}
 
	public void setName(String name) {
		this.name = name;
	}
 
	@XmlElement(type = String.class)
	public String getEmail() {
		return email;
	}
 
	public void setEmail(String email) {
		this.email = email;
	}
 
	@XmlElement(type = Person.class)
	public Person getParent() {
		return parent;
	}
 
	public void setParent(Person parent) {
		this.parent = parent;
	}
 
	@XmlElement(type = Person.class, name = "person", namespace = PersistentEntity.NAMESPACE)
	@XmlElementWrapper(name = "children")
	public List<Person> getChildren() {
		return children;
	}
 
	public void setChildren(List<Person> children) {
		this.children = children;
	}
 
	public Class<Person> getMappedClass() {
		return Person.class;
	}
 
	public Person updateFromRequest(Person person) {
		setName(person.getName());
		setEmail(person.getEmail());
		return this;
	}
 
 
}

package com.raulraja.model.persistence;
 
import com.raulraja.model.domain.PaginatedList;
 
import java.io.Serializable;
 
 
public interface PersistenceAdapter<Entity> {
 
	/**
	 * Returns a paginated list of all entities for this class
	 * @param entityClass the entity class
	 * @param start the start record
	 * @param limit the limit
	 * @return the list of matches
	 */
	PaginatedList<Entity> list(Class<Entity> entityClass, int start, int limit);
 
	/**
	 * Returns a paginated list of the selected property for this class
	 * @param entityClass the entity class
	 * @param start the start record
	 * @param limit the limit
	 * @return the list of matches
	 */
	PaginatedList<?> list(Class<Entity> entityClass, String property, int start, int limit);
 
    /**
     * Find a persistent object based on its unique id
     * @param entityClass the entity's class
     * @param id unique identifier
     * @return returns a persistent object
     */
    public Entity get(Class<Entity> entityClass, Serializable id);
 
    /**
     * Persists an object
     * @param entity to be persisted
	 * @return the saved entity
     */
    public Entity save(Entity entity);
 
    /**
     * Removes an entity from the data store
     * @param entity to be removed
	 * @return the deleted entity
     */
    public Entity delete(Entity entity);
 
 
}

package com.raulraja.model.persistence.impl;
 
import com.raulraja.model.domain.PaginatedList;
import com.raulraja.model.persistence.PersistenceAdapter;
import org.apache.log4j.Logger;
import org.hibernate.*;
import org.hibernate.criterion.DetachedCriteria;
import org.hibernate.criterion.Projections;
import org.hibernate.metadata.ClassMetadata;
import org.springframework.orm.hibernate3.HibernateAccessor;
import org.springframework.orm.hibernate3.HibernateCallback;
import org.springframework.orm.hibernate3.HibernateTemplate;
import org.springframework.orm.hibernate3.support.HibernateDaoSupport;
 
import java.io.Serializable;
import java.sql.SQLException;
import java.util.List;
 
/**
 * Hibernate spring based impl of the persistence adapter
 */
public class HibernatePersistenceAdapterImpl<Entity> extends HibernateDaoSupport implements PersistenceAdapter<Entity> {
 
	private final static Logger log = Logger.getLogger(HibernatePersistenceAdapterImpl.class);
 
	private Integer defaultResultSize = 10;
 
	public void setDefaultResultSize(Integer defaultResultSize) {
		this.defaultResultSize = defaultResultSize;
	}
 
	/**
	 * Returns a paginated list of all entities for this class
	 *
	 * @param entityClass the entity class
	 * @param start	   the start record
	 * @param limit	   the limit
	 * @return the list of matches
	 */
	@SuppressWarnings("unchecked")
	public PaginatedList<Entity> list(Class<Entity> entityClass, int start, int limit) {
		limit = limit > 0 ? limit : defaultResultSize;
		if (entityClass == null)
            return null;
 
        List<Entity> entities;
		PaginatedList<Entity> page = new PaginatedList<Entity>();
 
		int total;
		try {
			DetachedCriteria criteria = DetachedCriteria.forClass(entityClass);
			entities = (List<Entity>) getPreparedHibernateTemplate().findByCriteria(criteria, start, limit);
			total = count(entityClass);
			page = new PaginatedList<Entity>(total, start, entities);
        }
        catch (Throwable e) {
            log.error(e, e);
        }
        return page;
	}
 
	/**
	 * Returns a paginated list of the selected property for this class
	 *
	 * @param entityClass the entity class
	 * @param start	   the start record
	 * @param limit	   the limit
	 * @return the list of matches
	 */
	public PaginatedList<?> list(Class<Entity> entityClass, String property, int start, int limit) {
		limit = limit > 0 ? limit : defaultResultSize;
		if (entityClass == null)
            return null;
 
        List<Object> properties;
		PaginatedList<Object> page = new PaginatedList<Object>();
 
		int total;
		try {
			DetachedCriteria criteria = DetachedCriteria.forClass(entityClass);
			criteria.setProjection(Projections.property(property));
			properties = (List<Object>) getPreparedHibernateTemplate().findByCriteria(criteria, start, limit);
			total = count(entityClass);
			page = new PaginatedList<Object>(total, start, properties);
        }
        catch (Throwable e) {
            log.error(e, e);
        }
        return page;
	}
 
	private Integer count(final Class<Entity> entityClass) {
		return (Integer) getPreparedHibernateTemplate().execute(new HibernateCallback(){
			public Object doInHibernate(Session session) throws HibernateException, SQLException {
				Criteria criteria = session.createCriteria(entityClass);
				criteria.setProjection(Projections.rowCount());
				return criteria.list().get(0);
			}
		});
	}
 
	/**
	 * Find a persistent object based on its unique id
	 *
	 * @param entityClass the entity's class
	 * @param id		  unique identifier
	 * @return returns a persistent object
	 */
	@SuppressWarnings("unchecked")
	public Entity get(Class<Entity> entityClass, Serializable id) {
		Entity entity = (Entity) getHibernateTemplate().get(entityClass, id);
		return initializeProxy(entity);
	}
 
	/**
	 * Persists an object
	 *
	 * @param entity to be persisted
	 */
	@SuppressWarnings("unchecked")
	public Entity save(Entity entity) {
		getHibernateTemplate().saveOrUpdate(entity);
		return initializeProxy(entity);
	}
 
	/**
	 * Removes an entity from the data store
	 *
	 * @param entity to be removed
	 */
	@SuppressWarnings("unchecked")
	public Entity delete(Entity entity) {
		getHibernateTemplate().delete(entity);
		return initializeProxy(entity);
	}
 
 
	private HibernateTemplate getPreparedHibernateTemplate() {
        HibernateTemplate template = getHibernateTemplate();
        template.setCacheQueries(true);
        template.setFlushMode(HibernateAccessor.FLUSH_AUTO);
        return template;
    }
 
	private Entity initializeProxy(Entity entity) {
		getPreparedHibernateTemplate().initialize(entity);
		return entity;
	}
 
	/**
	 * Finds a class associated with this path name
	 *
	 * @param name the name
	 * @return the found class if any
	 */
	@SuppressWarnings("unchecked")
	public Class<Entity> getClassForName(String name) {
		final String normalizedName = name.length() > 0 ? name.substring(name.lastIndexOf("."),1).toUpperCase() + name.substring(0) : name;
		return (Class<Entity>) getPreparedHibernateTemplate().execute(new HibernateCallback(){
			public Object doInHibernate(Session session) throws HibernateException, SQLException {
				SessionFactory factory = session.getSessionFactory();
				ClassMetadata classMetadata = factory.getClassMetadata(normalizedName);
				return classMetadata != null ? classMetadata.getMappedClass(EntityMode.POJO) : null;
			}
		});
	}
}