MentaContainer

package org.mentacontainer.example;

import java.util.Date;

import org.mentacontainer.Container;

import org.mentacontainer.Scope;

import org.mentacontainer.impl.MentaContainer;

public class BasicOperations {

        public static void main(String[] args) {

                case1();

                case2();

                case3();

                case4();

                case5();

                case6();

                case7();

                case8();

                case9();

                case10();

        }

        public static class Connection {

        }

        public static interface UserDAO {

                public String getUsername(int id);

        }

        public static class JdbcUserDAO implements UserDAO {

                private Connection conn;

                public void setConnection(Connection conn) {

                        this.conn = conn;

                }

                @Override

                public String getUsername(int id) {

                        // connection will be injected by the container...

                        if (conn == null) throw new IllegalStateException("conn is null!");

                        // use the connection to get the username...

                        return "saoj";

                }

        }

        public static interface AccountDAO {

                public double getBalance(int id);

        }

        public static class JdbcAccountDAO implements AccountDAO {

                private final Connection conn;

                public JdbcAccountDAO(Connection conn) {

                        this.conn = conn;

                }

                @Override

                public double getBalance(int id) {

                        assert conn != null;

                        // use the connection to get the balance...

                        return 1000000D;

                }

        }

        private static void case9() {

                Container c = new MentaContainer();

                c.ioc("connection", Connection.class); // in real life this will be a connection pool factory...

                c.ioc("accountDAO", JdbcAccountDAO.class);

                c.ioc("userDAO", JdbcUserDAO.class);

                c.autowire("connection"); // all beans that need a connection in the constructor or setter will receive one...

                AccountDAO accountDAO = c.get("accountDAO");

                UserDAO userDAO = c.get("userDAO");

                System.out.println(accountDAO.getBalance(25)); // => 1000000

                System.out.println(userDAO.getUsername(45)); // => "saoj"

        }

        private static void case1() {

                Container c = new MentaContainer();

                c.ioc("myString1", String.class);

                String myString1 = c.get("myString1");

                System.out.println(myString1); // ==> "" ==> default constructor new String() was used

                c.ioc("myString2", String.class).addInitValue("saoj");

                String myString2 = c.get("myString2");

                System.out.println(myString2); // ==> "saoj" ==> constructor new String("saoj") was used

                c.ioc("myDate1", Date.class).addPropertyValue("hours", 15) // setHours(15)

                        .addPropertyValue("minutes", 10) // setMinutes(10)

                        .addPropertyValue("seconds", 45); // setSeconds(45)

                Date myDate1 = c.get("myDate1");

                System.out.println(myDate1); // ==> a date with time 15:10:45

        }

        private static void case5() {

                Container c = new MentaContainer();

                c.ioc("connection", Connection.class); // in real life this will be a connection pool factory...

                c.ioc("accountDAO", JdbcAccountDAO.class).addInitDependency("connection");

                AccountDAO accountDAO = c.get("accountDAO");

                System.out.println(accountDAO.getBalance(25)); // => 1000000

        }

        private static void case7() {

                Container c = new MentaContainer();

                c.ioc("connection", Connection.class); // in real life this will be a connection pool factory...

                c.ioc("accountDAO", JdbcAccountDAO.class);

                c.autowire("connection"); // all beans that need a connection in the constructor will get one...

                AccountDAO accountDAO = c.get("accountDAO");

                System.out.println(accountDAO.getBalance(25)); // => 1000000

        }

        private static void case6() {

                Container c = new MentaContainer();

                c.ioc("connection", Connection.class); // in real life this will be a connection pool factory...

                c.ioc("userDAO", JdbcUserDAO.class).addPropertyDependency("connection");

                UserDAO userDAO = c.get("userDAO");

                System.out.println(userDAO.getUsername(54)); // => "saoj"

        }

        private static void case8() {

                Container c = new MentaContainer();

                c.ioc("connection", Connection.class); // in real life this will be a connection pool factory...

                c.ioc("userDAO", JdbcUserDAO.class);

                c.autowire("connection");

                UserDAO userDAO = c.get("userDAO");

                System.out.println(userDAO.getUsername(54)); // => "saoj"

        }

        private static void case2() {

                Container c = new MentaContainer();

                c.ioc("myString", String.class, Scope.SINGLETON).addInitValue("saoj");

                String s1 = c.get("myString");

                String s2 = c.get("myString");

                System.out.println(s1 == s2); // ==> true ==> same instance

                System.out.println(s1.equals(s2)); // ==> true => of course

        }

        private static void case3() {

                Container c = new MentaContainer();

                c.ioc("userDAO", JdbcUserDAO.class);

                c.ioc("connection", Connection.class); // in real life this would be a connection pool

                                                       // or the hibernate SessionFactory

                // "conn" = the name of the property

                // Connection.class = the type of the property

                // "connection" = the source from where the dependency will come from

                c.autowire("connection");

                UserDAO userDAO = c.get("userDAO");

                // the container detects that userDAO has a dependency: name = "conn" and type = "Connection.class"

                // where does it go to get the dependency to insert?

                // In itself: it does a Container.get("connection") => "connection" => the source

                System.out.println(userDAO.getUsername(11)); // ==> "saoj" ==> connection is not null as expected...

        }

        public static class SomeService {

                private UserDAO userDAO;

                public void setUserDAO(UserDAO userDAO) {

                        this.userDAO = userDAO;

                }

                public void doSomething() {

                        System.out.println(userDAO.getUsername(11));

                }

        }

        private static void case4() {

                Container c = new MentaContainer();

                c.ioc("userDAO", JdbcUserDAO.class);

                c.ioc("connection", Connection.class);

                c.autowire("connection");

                SomeService service = new SomeService();

                c.inject(service); // populate (inject) all properties of SomeService with

                                     // beans from the container

                service.doSomething(); // ==> "saoj"

        }

        public static class SomeService2 {

                private final UserDAO userDAO;

                public SomeService2(UserDAO userDAO) {

                        this.userDAO = userDAO;

                }

                public void doSomething() {

                        System.out.println(userDAO.getUsername(11));

                }

        }

        private static void case10() {

                Container c = new MentaContainer();

                c.ioc("userDAO", JdbcUserDAO.class);

                c.ioc("connection", Connection.class);

                c.autowire("connection");

                SomeService2 service = c.construct(SomeService2.class);

                service.doSomething(); // ==> "saoj"

        }      

}