jdbc connection with postgresql NullPointerException

Question

I tried for a day to configure a connection to a postgresql database with spring framework. I'm beginner on this techno and i supposed i missed something in my config ...

Here are my code :

ApplicationContext-dao-psql xml file :

<bean id="PsqlConfiguration" class="org.springframework.jdbc.datasource.DriverManagerDataSource">
    <property name="driverClassName" value="org.postgresql.Driver" />
    <property name="url" value="${jdbc.url}" />
    <property name="username" value="${jdbc.user}" />
    <property name="password" value="${jdbc.password}" />
</bean>

<bean id="PhotoDao" class="path.to.class.PhotoDaoImpl">
    <property name="psqlConfiguration" ref="PsqlConfiguration" />
</bean>

the properties (url, username, passwd) are stored in another properties file

applicationContext-service xml file :

<jaxrs:server id="PhotoService" address="/">
    <jaxrs:serviceBeans>
        <ref bean="PhotoServiceImpl" />
    </jaxrs:serviceBeans>
    <jaxrs:extensionMappings>
        <entry key="json" value="application/json" />
    </jaxrs:extensionMappings>
</jaxrs:server>

<bean id="PhotoServiceImpl" class="path.to.class.PhotoServiceImpl">
    <property name="PhotoDao" ref="PhotoDao" />
</bean>

PhotoServiceImpl :

   public class PhotoServiceImpl implements PhotoService {
        public Response getFile(String id){
            byte[] img = null;
            PhotoDaoImpl photo = new PhotoDaoImpl();
            img = photo.getPhoto(id);
            return Response.ok(img).header("Content-disposition","attachment; filename=photo.jpg").build(); 
            }
        }

PhotoDaoImpl :

public class PhotoDaoImpl implements PhotoDao {

    public DataSource psqlConfiguration;

    public DataSource getPsqlConfiguration() {
        return psqlConfiguration;
    }

    public void setPsqlConfiguration(DataSource psqlConfiguration) {
        this.psqlConfiguration = psqlConfiguration;
    }
    Connection conn;

    public byte[] getPhoto(String id){
        byte[] imgData = null;
        try {
        conn = psqlConfiguration.getConnection(); // Here is my Null error
        ...
    }
}

My error is referenced in the line with getConnection().

Stacktrace

juil. 27, 2017 2:37:43 PM org.apache.cxf.phase.PhaseInterceptorChain doDefaultLogging
AVERTISSEMENT: Application {http://path/to/class/}PhotoServiceImpl has thrown exception, unwinding now
org.apache.cxf.interceptor.Fault
    at org.apache.cxf.service.invoker.AbstractInvoker.createFault(AbstractInvoker.java:170)
    at org.apache.cxf.service.invoker.AbstractInvoker.invoke(AbstractInvoker.java:136)
    at org.apache.cxf.jaxrs.JAXRSInvoker.invoke(JAXRSInvoker.java:204)
    at org.apache.cxf.jaxrs.JAXRSInvoker.invoke(JAXRSInvoker.java:101)
    at org.apache.cxf.interceptor.ServiceInvokerInterceptor$1.run(ServiceInvokerInterceptor.java:58)
    at org.apache.cxf.interceptor.ServiceInvokerInterceptor.handleMessage(ServiceInvokerInterceptor.java:94)
    at org.apache.cxf.phase.PhaseInterceptorChain.doIntercept(PhaseInterceptorChain.java:272)
    at org.apache.cxf.transport.ChainInitiationObserver.onMessage(ChainInitiationObserver.java:121)
    at org.apache.cxf.transport.http.AbstractHTTPDestination.invoke(AbstractHTTPDestination.java:241)
    at org.apache.cxf.transport.servlet.ServletController.invokeDestination(ServletController.java:248)
    at org.apache.cxf.transport.servlet.ServletController.invoke(ServletController.java:222)
    at org.apache.cxf.transport.servlet.ServletController.invoke(ServletController.java:153)
    at org.apache.cxf.transport.servlet.CXFNonSpringServlet.invoke(CXFNonSpringServlet.java:171)
    at org.apache.cxf.transport.servlet.AbstractHTTPServlet.handleRequest(AbstractHTTPServlet.java:286)
    at org.apache.cxf.transport.servlet.AbstractHTTPServlet.doGet(AbstractHTTPServlet.java:211)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:622)
    at org.apache.cxf.transport.servlet.AbstractHTTPServlet.service(AbstractHTTPServlet.java:262)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:292)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:207)
    at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:240)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:207)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:212)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:106)
    at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:502)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:141)
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:79)
    at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:616)
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:88)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:528)
    at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1100)
    at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:687)
    at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1520)
    at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.run(NioEndpoint.java:1476)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
    at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
    at java.lang.Thread.run(Thread.java:745)
Caused by: java.lang.NullPointerException
    at path.to.class.PhotoDaoImpl.getPhoto(PhotoDaoImpl.java:38)
    at path.to.class.PhotoServiceImpl.getFile(PhotoServiceImpl.java:23)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:606)
    at org.apache.cxf.service.invoker.AbstractInvoker.performInvocation(AbstractInvoker.java:188)
    at org.apache.cxf.service.invoker.AbstractInvoker.invoke(AbstractInvoker.java:104)
    ... 36 more

I supposed my problem is due to psqlConfiguration which is empty, but i don't understand why ..

Thank you very much for helping me !

Regards

Edit :

i fixed my problem with adding annotations and with creating (and not instancing) my PhotoDao var:

@Component
public class PhotoServiceImpl implements PhotoService {
    public PhotoDao getPhotoDao() {
        return PhotoDao;
    }
    public void setPhotoDao(PhotoDao photoDao) {
        this.PhotoDao = photoDao;
    }

    @Autowired
    private PhotoDao PhotoDao;
    public Response getFile(String id){
        byte[] img = null;
        img = PhotoDao.getPhoto(id);
        return Response.ok(img).header("Content-disposition","attachment; filename=photo.jpg").build(); 
   }    
}