diff --git a/exercise1/EJB.java b/exercise1/EJB.java
new file mode 100644
index 0000000..48f3c78
--- /dev/null
+++ b/exercise1/EJB.java
@@ -0,0 +1,55 @@
+package exercise1;
+
+import javax.ejb.Local;
+import javax.ejb.LocalBean;
+import javax.ejb.Stateless;
+import javax.inject.Inject;
+import javax.persistence.EntityManager;
+import javax.persistence.PersistenceContext;
+import javax.persistence.Query;
+import javax.validation.constraints.NotNull;
+import java.util.List;
+
+/**
+ * Created by Giovanni on 24/05/2015.
+ */
+@Stateless
+@LocalBean
+public class EJB implements RemoteInterface {
+
+    @PersistenceContext(unitName = "exercise1")
+    EntityManager em ;
+
+
+    public void create_student (@NotNull Student s) {
+        em.persist(s);
+    }
+    public void update_student (@NotNull Student s) {
+        em.merge(s);
+        em.persist(s);
+    }
+    public void delete_student (@NotNull Student s) {
+        em.merge(s);
+        em.remove(s);
+    }
+
+    public @NotNull List<Student> findname (@NotNull String name) {
+        Query Q = em.createNamedQuery("findname");
+        Q.setParameter(1, name);
+        return (List<Student>)Q.getResultList();
+    }
+
+    public @NotNull List<Student> findsurname (@NotNull String name) {
+        Query Q = em.createNamedQuery("findsurname");
+        Q.setParameter(1,name);
+        return (List<Student>)Q.getResultList();
+    }
+
+    public @NotNull List<Student> findyear (@NotNull String name) {
+        Query Q = em.createNamedQuery("findyear");
+        Q.setParameter(1,name);
+        return (List<Student>)Q.getResultList();
+    }
+
+
+}
diff --git a/exercise1/InitializeDB.java b/exercise1/InitializeDB.java
new file mode 100644
index 0000000..9a04e42
--- /dev/null
+++ b/exercise1/InitializeDB.java
@@ -0,0 +1,40 @@
+package exercise1;
+
+import javax.annotation.PostConstruct;
+import javax.annotation.PreDestroy;
+import javax.ejb.*;
+import javax.inject.Inject;
+
+/**
+ * Created by Giovanni on 24/05/2015.
+ */
+
+@Singleton
+@Startup
+public class InitializeDB {
+
+    private Student s1,s2;
+
+    @Inject
+    private EJB e;
+
+    @PostConstruct
+    void pupulate (){
+            s1 = new Student("mario","marra","1");
+            s2 = new Student("mario","maria","2");
+            e.create_student(s1);
+            e.create_student(s2);
+    }
+
+    @PreDestroy
+    void delete () {
+        e.delete_student(s1);
+        e.delete_student(s2);
+    }
+
+
+
+
+
+
+}
diff --git a/exercise1/RemoteInterface.java b/exercise1/RemoteInterface.java
new file mode 100644
index 0000000..809a841
--- /dev/null
+++ b/exercise1/RemoteInterface.java
@@ -0,0 +1,18 @@
+package exercise1;
+
+import javax.ejb.Remote;
+import javax.persistence.Query;
+import javax.validation.constraints.NotNull;
+import java.util.List;
+
+/**
+ * Created by Giovanni on 24/05/2015.
+ */
+@Remote
+public interface RemoteInterface {
+
+    @NotNull List<Student> findname (@NotNull String name);
+    @NotNull List<Student> findsurname (@NotNull String name) ;
+    @NotNull List<Student> findyear (@NotNull String name) ;
+
+}
diff --git a/exercise1/Student.java b/exercise1/Student.java
new file mode 100644
index 0000000..8aa6dfa
--- /dev/null
+++ b/exercise1/Student.java
@@ -0,0 +1,52 @@
+package exercise1;
+
+import javax.ejb.Local;
+import javax.persistence.*;
+import javax.validation.constraints.NotNull;
+import java.io.Serializable;
+
+/**
+ * Created by Giovanni on 24/05/2015.
+ */
+@Entity
+@NamedQueries({
+        @NamedQuery(name = "findname", query = "SELECT s FROM Student s WHERE s.name =?1"),
+        @NamedQuery(name = "findsurname", query = "SELECT s FROM Student s WHERE s.surname =?1"),
+        @NamedQuery(name = "findyear", query = "SELECT s FROM Student s WHERE s.years =?1")
+})
+public class Student implements Serializable {
+
+    @Id
+    @GeneratedValue
+    private Long id;
+
+    @NotNull
+    private String name;
+    @NotNull
+    private String surname;
+    @NotNull
+    private String years;
+
+
+    public Student(){}
+
+    public Student (@NotNull String in_name, @NotNull String in_surname, @NotNull String in_year){
+
+        name = in_name;
+        surname = in_surname;
+        years = in_year;
+
+    }
+
+    public @NotNull String getName() {
+        return name;
+    }
+
+    public @NotNull String getSurname() {
+        return surname;
+    }
+
+    public @NotNull String getYears() {
+        return years;
+    }
+}
diff --git a/exercise1_client/client.java b/exercise1_client/client.java
new file mode 100644
index 0000000..4412c04
--- /dev/null
+++ b/exercise1_client/client.java
@@ -0,0 +1,43 @@
+package exercise1_client;
+
+import exercise1.RemoteInterface;
+import exercise1.Student;
+
+import javax.naming.Context;
+import javax.naming.InitialContext;
+import javax.naming.NamingException;
+import java.util.Iterator;
+import java.util.List;
+
+/**
+ * Created by Giovanni on 24/05/2015.
+ */
+public class client {
+
+    public static void main (String[] args) {
+
+
+        Context ctx = null;
+        try {
+            ctx =new InitialContext();
+        } catch (NamingException e) {
+            e.printStackTrace();
+        }
+
+        RemoteInterface r = null;
+        try {
+            r =(RemoteInterface) ctx.lookup("java:global/web/EJB!exercise1.RemoteInterface");
+            List<Student>l =  r.findname("mario");
+            Iterator<Student> it = l.iterator();
+            System.out.println(it.next().getSurname());
+            System.out.println(it.next().getSurname());
+
+
+        } catch (NamingException e) {
+            e.printStackTrace();
+        }
+
+
+
+    }
+}
diff --git a/servlet/Servletexercise1.java b/servlet/Servletexercise1.java
new file mode 100644
index 0000000..8e8d926
--- /dev/null
+++ b/servlet/Servletexercise1.java
@@ -0,0 +1,57 @@
+package servlet;
+
+import test3_persistence.store_class;
+import test3_persistence.test_class;
+
+import javax.ejb.EJB;
+import javax.servlet.ServletException;
+import javax.servlet.annotation.WebServlet;
+import javax.servlet.http.HttpServlet;
+import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.HttpServletResponse;
+import java.io.IOException;
+import java.io.PrintWriter;
+import java.util.HashMap;
+import java.util.Iterator;
+import java.util.List;
+
+/**
+ * Created by Giovanni on 25/04/2015.
+ */
+
+@WebServlet(name = "Servletexercise1")
+public class Servletexercise1 extends HttpServlet {
+
+
+    protected void processRequest(HttpServletRequest request,  HttpServletResponse response)   throws ServletException, IOException {
+        response.setContentType("text/html;charset=UTF-8");
+        try (PrintWriter out = response.getWriter()) {
+/* TODO output your page here. */
+
+            out.println("<!DOCTYPE html>");
+            out.println("<html>");
+            out.println("<head>");
+            out.println("<title>Servlet xg</title>");
+            out.println("</head>");
+            out.println("<body>");
+            out.println("<h1>Servlet xg at " + request.getContextPath() + "</h1>");
+
+
+
+            out.println("</body>");
+            out.println("</html>");
+        }
+    }
+
+
+
+    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
+        processRequest(request, response);
+
+    }
+
+    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
+        processRequest(request, response);
+
+    }
+}
diff --git a/servlet/Servlettest2.java b/servlet/Servlettest2.java
index ece0c5b..bc042d7 100644
--- a/servlet/Servlettest2.java
+++ b/servlet/Servlettest2.java
@@ -47,6 +47,10 @@ public class Servlettest2 extends HttpServlet {
     class_with_builtin_constraints class_with_builtin_constraints;
 
 
+    @Inject
+    class_test_method class_test_method;
+
+
     protected void processRequest(HttpServletRequest request,  HttpServletResponse response)   throws ServletException, IOException {
         response.setContentType("text/html;charset=UTF-8");
         try (PrintWriter out = response.getWriter()) {
@@ -61,6 +65,10 @@ public class Servlettest2 extends HttpServlet {
             out.println("<h1>Servlet xg at " + request.getContextPath() + "</h1>");
 
 
+            ///////////////// check null return
+            //class_test_method.test_method();
+            //out.println("Test Null without validator");
+            //out.println("<br>");
 
 
             ///////////////// entire class validation
@@ -123,7 +131,7 @@ public class Servlettest2 extends HttpServlet {
 
 
             out.println("<br>");
-            //////////////// check single property
+            //////////////// check single property without make an instance of the object
             Set<ConstraintViolation<class_with_builtin_constraints>> violations7 = validator.validateValue(class_with_builtin_constraints.class, "title", "aabb");
             if (violations7.size() > 0) out.println("error"); else out.println("tutto ok");
 
diff --git a/test2_constraints_validation/class_test_method.java b/test2_constraints_validation/class_test_method.java
new file mode 100644
index 0000000..d83622e
--- /dev/null
+++ b/test2_constraints_validation/class_test_method.java
@@ -0,0 +1,14 @@
+package test2_constraints_validation;
+
+import javax.validation.constraints.NotNull;
+
+/**
+ * Created by Giovanni on 24/05/2015.
+ */
+public class class_test_method {
+
+    public @NotNull Object test_method(){
+        return null;
+    }
+
+}