complete

.gitignore

@@ -1,3 +1,4 @@
+Secrets.java
 
 # Created by https://www.gitignore.io/api/intellij
 # Edit at https://www.gitignore.io/?templates=intellij

pom.xml

@@ -14,5 +14,15 @@
         <artifactId>junit</artifactId>
         <version>4.10</version>
     </dependency>
+    <dependency>
+        <groupId>com.h2database</groupId>
+        <artifactId>h2</artifactId>
+        <version>1.4.197</version>
+    </dependency>
+    <dependency>
+        <groupId>mysql</groupId>
+        <artifactId>mysql-connector-java</artifactId>
+        <version>8.0.18</version>
+    </dependency>
 </dependencies>
 </project>

src/main/java/MainApp.java

@@ -0,0 +1,12 @@
+import daos.UserDao;
+import models.User;
+
+public class MainApp {
+    public static void main(String... args) {
+        UserDao userDao = new UserDao();
+//        User user = userDao.findById(3);
+//        userDao.delete(13);
+//        userDao.delete(14);
+//        System.out.println(user.toString());
+    }
+}

src/main/java/daos/ConnectionFactory.java

@@ -0,0 +1,27 @@
+package daos;
+
+import com.mysql.cj.jdbc.Driver;
+import java.sql.Connection;
+import java.sql.DriverManager;
+import java.sql.SQLException;
+
+public class ConnectionFactory {
+    private static final String URL = Secrets.getURL();
+    private static final String USER = Secrets.getUSER();
+    private static final String PASS = Secrets.getPASS();
+
+
+    public static Connection getConnection()
+    {
+        try {
+            DriverManager.registerDriver(new Driver());
+            return DriverManager.getConnection(URL, USER, PASS);
+        } catch (SQLException ex) {
+            throw new RuntimeException("Error connecting to the database", ex);
+        }
+    }
+//    public static void main(String[] args) {
+//        Connection connection = ConnectionFactory.getConnection();
+//    }
+}
+

src/main/java/daos/DAO.java

@@ -0,0 +1,12 @@
+package daos;
+
+
+import java.util.Set;
+
+public interface DAO<E> {
+    E findById(Integer id);
+    Set<E> findAll();
+    Boolean insert(E obj);
+    Boolean update(Integer id, E obj);
+    Boolean delete(Integer id);
+}

src/main/java/daos/DTO.java

@@ -0,0 +1,5 @@
+package daos;
+
+public interface DTO<T> {
+    Integer getId(T obj);
+}

src/main/java/daos/UserDao.java

@@ -0,0 +1,109 @@
+package daos;
+
+import models.User;
+
+import java.sql.*;
+import java.util.HashSet;
+import java.util.Set;
+
+public class UserDao implements DAO<User> {
+
+    public User findById(Integer id) {
+        Connection connection = ConnectionFactory.getConnection();
+
+        try {
+            String query = "SELECT * FROM Users WHERE id = " + id + ";";
+            Statement statement = connection.createStatement();
+            ResultSet resultSet = statement.executeQuery(query);
+
+            if (resultSet.next()) return extractUserFromResultSet(resultSet);
+
+        } catch(SQLException e) {
+            e.printStackTrace();
+        }
+
+        return null;
+    }
+
+    public Set<User> findAll() {
+        Connection connection = ConnectionFactory.getConnection();
+        try {
+            Statement statement = connection.createStatement();
+            ResultSet resultSet = statement.executeQuery("SELECT * FROM Users;");
+            Set users = new HashSet();
+            while(resultSet.next())
+            {
+                User user = extractUserFromResultSet(resultSet);
+                users.add(user);
+            }
+            return users;
+        } catch (SQLException ex) {
+            ex.printStackTrace();
+        }
+        return null;
+    }
+
+    public Boolean insert(User user) {
+        Connection connection = ConnectionFactory.getConnection();
+        try {
+            PreparedStatement ps = connection.prepareStatement("INSERT INTO Users VALUES (NULL, ?, ?, ?, ?, ?);");
+            ps = prepareUserForImport(ps, user);
+
+            int i = ps.executeUpdate();
+            if(i == 1) return true;
+
+        } catch (SQLException ex) {
+            ex.printStackTrace();
+        }
+        return false;
+    }
+
+    public Boolean update(Integer id, User user) {
+        Connection connection = ConnectionFactory.getConnection();
+        try {
+            PreparedStatement ps = connection.prepareStatement("UPDATE Users SET first_name=?, last_name=?, fav_color=?, job=?, birthdate=? WHERE id=?;");
+            ps = prepareUserForImport(ps, user);
+            ps.setInt(6, id);
+
+            int i = ps.executeUpdate();
+            if(i == 1) return true;
+        } catch (SQLException ex) {
+            ex.printStackTrace();
+        }
+        return false;
+    }
+
+    public Boolean delete(Integer id) {
+        Connection connection = ConnectionFactory.getConnection();
+        try {
+            Statement statement = connection.createStatement();
+            int i = statement.executeUpdate("DELETE FROM Users WHERE id=" + id + ";");
+            if(i == 1) {
+                return true;
+            }
+        } catch (SQLException ex) {
+            ex.printStackTrace();
+        }
+        return false;
+    }
+
+    private User extractUserFromResultSet(ResultSet rs) throws SQLException {
+        User user = new User();
+        user.setId( rs.getInt("id") );
+        user.setFirstName( rs.getString("first_name") );
+        user.setLastName( rs.getString("last_name") );
+        user.setFavColor( rs.getString("fav_color") );
+        user.setJob( rs.getString("job") );
+        user.setBirthday( rs.getDate("birthdate") );
+        return user;
+    }
+
+    private PreparedStatement prepareUserForImport(PreparedStatement ps, User user) throws SQLException {
+        ps.setString(1, user.getFirstName());
+        ps.setString(2, user.getLastName());
+        ps.setString(3, user.getFavColor());
+        ps.setString(4, user.getJob());
+        ps.setDate(5, new java.sql.Date(user.getBirthday().getTime()));
+        return ps;
+    }
+}

src/main/java/daos/UserDto.java

@@ -0,0 +1,25 @@
+package daos;
+
+import models.User;
+
+import java.sql.Connection;
+import java.sql.ResultSet;
+import java.sql.SQLException;
+import java.sql.Statement;
+
+public class UserDto implements DTO<User> {
+    public Integer getId(User user) {
+        return user.getId();
+    }
+    public static Integer getLastIdOfLast() {
+        Connection connection = ConnectionFactory.getConnection();
+        try {
+            Statement statement = connection.createStatement();
+            ResultSet resultSet = statement.executeQuery("SELECT id FROM Users ORDER BY id DESC LIMIT 1;");
+            if (resultSet.next()) return resultSet.getInt("id");
+        } catch (SQLException ex) {
+            ex.printStackTrace();
+        }
+        return null;
+    }
+}

src/main/java/models/User.java

@@ -0,0 +1,85 @@
+package models;
+
+import java.util.Date;
+
+public class User {
+    private Integer id;
+    private String firstName;
+    private String lastName;
+    private String favColor;
+    private Date birthday;
+    private String job;
+
+    public User() {}
+
+    public User(String firstName, String lastName, String favColor, Date birthday, String job) {
+        this.firstName = firstName;
+        this.lastName = lastName;
+        this.favColor = favColor;
+        this.birthday = birthday;
+        this.job = job;
+    }
+
+    public User(Integer id, String firstName, String lastName, String favColor, Date birthday, String job) {
+        this.id = id;
+        this.firstName = firstName;
+        this.lastName = lastName;
+        this.favColor = favColor;
+        this.birthday = birthday;
+        this.job = job;
+    }
+
+    public Integer getId() {
+        return id;
+    }
+
+    public void setId(Integer id) {
+        this.id = id;
+    }
+
+    public String getFirstName() {
+        return firstName;
+    }
+
+    public void setFirstName(String firstName) {
+        this.firstName = firstName;
+    }
+
+    public String getLastName() {
+        return lastName;
+    }
+
+    public void setLastName(String lastName) {
+        this.lastName = lastName;
+    }
+
+    public String getFavColor() {
+        return favColor;
+    }
+
+    public void setFavColor(String favColor) {
+        this.favColor = favColor;
+    }
+
+    public Date getBirthday() {
+        return birthday;
+    }
+
+    public void setBirthday(Date birthday) {
+        this.birthday = birthday;
+    }
+
+    public String getJob() {
+        return job;
+    }
+
+    public void setJob(String job) {
+        this.job = job;
+    }
+
+    @Override
+    public String toString() {
+        return String.format("%s %s\t|\t%s\t|\t%s\t|\t%s",
+                this.getFirstName(), this.getLastName(), this.getFavColor(), this.getJob(), this.getBirthday());
+    }
+}

src/test/java/daos/TestConnectionFactory.java

@@ -0,0 +1,17 @@
+package daos;
+
+import org.junit.Test;
+
+import static org.junit.Assert.fail;
+
+public class TestConnectionFactory {
+    @Test
+    public void testGetConnection() {
+        try {
+            ConnectionFactory.getConnection();
+        } catch( RuntimeException rte) {
+            fail("Could not connect to MySQL database");
+        }
+
+    }
+}