pom.xml

@@ -54,11 +54,22 @@
             <artifactId>github-api</artifactId>
             <version>1.93</version>
         </dependency>
-        <!-- SQLite JDBC Driver -->
+        <!-- MySQL JDBC Driver -->
         <dependency>
-            <groupId>org.xerial</groupId>
-            <artifactId>sqlite-jdbc</artifactId>
-            <version>3.23.1</version>
+            <groupId>mysql</groupId>
+            <artifactId>mysql-connector-java</artifactId>
+            <version>8.0.12</version>
+        </dependency>
+        <dependency>
+            <groupId>com.h2database</groupId>
+            <artifactId>h2</artifactId>
+            <version>1.4.197</version>
+        </dependency>
+        <!-- Hibernate Database ORM -->
+        <dependency>
+            <groupId>org.hibernate</groupId>
+            <artifactId>hibernate-core</artifactId>
+            <version>5.3.6.Final</version>
         </dependency>
     </dependencies>
     

src/main/java/nl/andrewlalis/Main.java

@@ -1,10 +1,14 @@
 package nl.andrewlalis;
 
+import nl.andrewlalis.model.Student;
+import nl.andrewlalis.model.database.DbUtil;
 import nl.andrewlalis.ui.control.command.CommandExecutor;
 import nl.andrewlalis.ui.control.command.executables.*;
 import nl.andrewlalis.ui.view.InitializerApp;
 import nl.andrewlalis.util.CommandLine;
 import nl.andrewlalis.util.Logging;
+import org.hibernate.Session;
+import org.hibernate.SessionFactory;
 
 import java.util.Map;
 import java.util.logging.Logger;
@@ -46,6 +50,13 @@ public class Main {
         logger.info("GithubManager for Github Repositories in Educational Organizations.\n" +
                 "© Andrew Lalis (2018), All rights reserved.\n" +
                 "Program initialized.");
+
+        SessionFactory factory = DbUtil.getSessionFactory();
+        Session session = factory.openSession();
+        session.beginTransaction();
+        System.out.println(session.save(new Student(1, "a", "a@e.com", "git", null)));
+        session.getTransaction().commit();
+        session.close();
     }
 
 }

src/main/java/nl/andrewlalis/git_api/GithubManager.java

@@ -177,7 +177,7 @@ public class GithubManager {
         GHRepository repo = this.createRepository(team.generateUniqueName(prefix), taTeam.getGithubTeam(), team.generateRepoDescription(), false, true, true);
 
         if (repo == null) {
-            logger.severe("Repository for student team " + team.getId() + " could not be created.");
+            logger.severe("Repository for student team " + team.getNumber() + " could not be created.");
             return;
         }
 
@@ -254,7 +254,7 @@ public class GithubManager {
      */
     private void inviteStudentsToRepos(StudentTeam team, GHRepository assignmentsRepo) {
         try {
-            logger.finest("Adding students from team: " + team.getId() + " as collaborators.");
+            logger.finest("Adding students from team: " + team.getNumber() + " as collaborators.");
             for (Student student : team.getStudents()) {
                 GHUser user = this.github.getUser(student.getGithubUsername());
 

src/main/java/nl/andrewlalis/model/Person.java

@@ -1,31 +1,53 @@
 package nl.andrewlalis.model;
 
+import nl.andrewlalis.model.database.BaseEntity;
+
+import javax.persistence.Column;
+import javax.persistence.Entity;
+import javax.persistence.Table;
+
 /**
  * A generic object that students, teaching assistants, and professors can extend from. This covers all the basic
  * functionality that applies to anyone in the system.
  */
-public abstract class Person  {
+@Entity(name = "Person")
+@Table(name = "persons")
+public abstract class Person extends BaseEntity {
 
     /**
      * The unique identification number for this person. (P- or S-Number)
      */
+    @Column(name="number")
     protected int number;
 
     /**
      * The person's first and last name.
      */
+    @Column(name="name")
     protected String name;
 
     /**
      * The person's email address.
      */
+    @Column(name="email_address")
     protected String emailAddress;
 
     /**
      * The person's github username.
      */
+    @Column(name="github_username")
     protected String githubUsername;
 
+    /**
+     * Constructs an empty default Person.
+     */
+    public Person() {
+        this.number = -1;
+        this.name = null;
+        this.emailAddress = null;
+        this.githubUsername = null;
+    }
+
     /**
      * Constructs a Person from only a github username, which is, in some cases, enough to perform a lot of actions.
      * @param githubUsername The person's github username.
@@ -58,18 +80,34 @@ public abstract class Person  {
         return this.number;
     }
 
+    public void setNumber(int number) {
+        this.number = number;
+    }
+
     public String getName(){
         return this.name;
     }
 
+    public void setName(String name) {
+        this.name = name;
+    }
+
     public String getEmailAddress(){
         return this.emailAddress;
     }
 
+    public void setEmailAddress(String emailAddress) {
+        this.emailAddress = emailAddress;
+    }
+
     public String getGithubUsername(){
         return this.githubUsername;
     }
 
+    public void setGithubUsername(String githubUsername) {
+        this.githubUsername = githubUsername;
+    }
+
     /**
      * Determines if two persons are the same. This is defined as:
      * Two persons are equal if at least one of their personal data points is identical. Because each of the data points

src/main/java/nl/andrewlalis/model/Student.java

@@ -1,12 +1,15 @@
 package nl.andrewlalis.model;
 
+import javax.persistence.*;
+import java.util.ArrayList;
 import java.util.List;
-import java.util.Map;
 import java.util.logging.Logger;
 
 /**
  * Represents one student's github information.
  */
+@Entity(name = "Student")
+@Table(name="students")
 public class Student extends Person {
 
     private static final Logger logger = Logger.getLogger(Student.class.getName());
@@ -17,7 +20,20 @@ public class Student extends Person {
     /**
      * A list of partners that the student has said that they would like to be partners with.
      */
-    private List<Integer> preferredPartners;
+    @ManyToMany
+    @JoinTable(
+            name = "student_preferred_partners",
+            joinColumns = { @JoinColumn(name = "student_id")},
+            inverseJoinColumns = {@JoinColumn(name = "preferred_partner_id")}
+    )
+    private List<Student> preferredPartners;
+
+    /**
+     * Constructs an empty student object.
+     */
+    public Student() {
+        this.preferredPartners = new ArrayList<>();
+    }
 
     /**
      * Constructs a student similarly to a Person, but with an extra preferredPartners list.
@@ -28,24 +44,31 @@ public class Student extends Person {
      * @param preferredPartners A list of this student's preferred partners, as a list of integers representing the
      * other students' numbers.
      */
-    public Student(int number, String name, String emailAddress, String githubUsername, List<Integer> preferredPartners) {
+    public Student(int number, String name, String emailAddress, String githubUsername, List<Student> preferredPartners) {
         super(number, name, emailAddress, githubUsername);
         this.preferredPartners = preferredPartners;
     }
 
-    public List<Integer> getPreferredPartners() {
+    public List<Student> getPreferredPartners() {
         return this.preferredPartners;
     }
 
+    public void setPreferredPartners(List<Student> preferredPartners) {
+        this.preferredPartners = preferredPartners;
+    }
+
+    public void addPreferredPartner(Student student) {
+        this.preferredPartners.add(student);
+    }
+
     /**
-     * Using a given map of all students, returns a student's preferred team.
-     * @param studentMap A mapping from student number to student for all students who have signed up.
-     * @return A team with unknown id, comprised of this student's preferred partners.
+     * Returns a student's preferred team, including himself.
+     * @return A team with unknown number, comprised of this student's preferred partners.
      */
-    public StudentTeam getPreferredTeam(Map<Integer, Student> studentMap) {
+    public StudentTeam getPreferredTeam() {
         StudentTeam t = new StudentTeam();
-        for (int partnerNumber : this.getPreferredPartners()) {
-            t.addMember(studentMap.get(partnerNumber));
+        for (Student partner : this.getPreferredPartners()) {
+            t.addMember(partner);
         }
         t.addMember(this);
         return t;

src/main/java/nl/andrewlalis/model/StudentTeam.java

@@ -2,21 +2,29 @@ package nl.andrewlalis.model;
 
 import org.kohsuke.github.GHRepository;
 
+import javax.persistence.Entity;
+import javax.persistence.ManyToOne;
+import javax.persistence.Table;
+import javax.persistence.Transient;
 import java.util.Arrays;
 
 /**
  * Represents one or more students' collective information.
  */
-public class StudentTeam extends Team{
+@Entity(name = "StudentTeam")
+@Table(name = "student_teams")
+public class StudentTeam extends Team {
 
     /**
      * The repository belonging to this team.
      */
+    @Transient
     private GHRepository repository;
 
     /**
      * The TATeam responsible for this student team.
      */
+    @ManyToOne
     private TATeam taTeam;
 
     public StudentTeam() {
@@ -62,11 +70,11 @@ public class StudentTeam extends Team{
      * Generates a unique name which is intended to be used for the repository name of this team.
      * @param prefix A prefix to further reduce the chances of duplicate names.
      *               It is suggested to use something like "2018_OOP"
-     * @return A string comprised of the prefix, team id, and student number of each team member.
+     * @return A string comprised of the prefix, team number, and student number of each team member.
      */
     public String generateUniqueName(String prefix) {
         StringBuilder sb = new StringBuilder(prefix);
-        sb.append("_team_").append(this.id);
+        sb.append("_team_").append(this.number);
         for (Student s : this.getStudents()) {
             sb.append('_').append(s.getNumber());
         }
@@ -79,7 +87,7 @@ public class StudentTeam extends Team{
      */
     public String generateRepoDescription() {
         StringBuilder sb = new StringBuilder();
-        sb.append("Group ").append(this.id).append(": ");
+        sb.append("Group ").append(this.number).append(": ");
         for (int i = 0; i < this.memberCount(); i++) {
             sb.append(this.getStudents()[i].getName());
             if (i != this.memberCount()-1) {

src/main/java/nl/andrewlalis/model/TATeam.java

@@ -2,14 +2,19 @@ package nl.andrewlalis.model;
 
 import org.kohsuke.github.GHTeam;
 
+import javax.persistence.Entity;
+import javax.persistence.OneToMany;
+import javax.persistence.Table;
+import javax.persistence.Transient;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.List;
 
 /**
- * Represents a teaching assistant team, which is itself a 'team' in the organization. This class is used for parsing
- * json from requests to github to get a list of all teams in the organization.
+ * Represents a teaching assistant team, which is itself a 'team' in the organization.
  */
+@Entity(name = "TATeam")
+@Table(name = "ta_teams")
 public class TATeam extends Team {
 
     /**
@@ -20,11 +25,13 @@ public class TATeam extends Team {
     /**
      * The Github team associated with this team.
      */
+    @Transient
     private GHTeam githubTeam;
 
     /**
      * A list of all student teams for which this TA team is responsible.
      */
+    @OneToMany
     private List<StudentTeam> studentTeams;
 
     /**

src/main/java/nl/andrewlalis/model/TeachingAssistant.java

@@ -1,8 +1,13 @@
 package nl.andrewlalis.model;
 
+import javax.persistence.Entity;
+import javax.persistence.Table;
+
 /**
  * Represents an administrator in the organization, who manages student teams.
  */
+@Entity(name = "TeachingAssistant")
+@Table(name = "teaching_assistants")
 public class TeachingAssistant extends Person {
 
     /**

src/main/java/nl/andrewlalis/model/Team.java

@@ -1,5 +1,8 @@
 package nl.andrewlalis.model;
 
+import nl.andrewlalis.model.database.BaseEntity;
+
+import javax.persistence.*;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.List;
@@ -8,39 +11,48 @@ import java.util.List;
  * An abstract Team object from which both Teaching Assistant and Student teams can be built. A Team consists of a list
  * of members, and a unique identification number.
  */
-public abstract class Team {
+@Entity(name = "Team")
+@Table(name = "teams")
+public abstract class Team extends BaseEntity {
 
     /**
      * An identification number unique to this team alone.
      */
-    protected int id;
+    @Column(name = "number")
+    protected int number;
 
     /**
      * A list of members of this team.
      */
+    @OneToMany
+    @JoinTable(
+            name = "team_members",
+            joinColumns = {@JoinColumn(name = "team_id")},
+            inverseJoinColumns = {@JoinColumn(name = "person_id")}
+    )
     private List<Person> members;
 
     /**
-     * Constructs this team with the given id.
-     * @param id The id to assign to this team.
+     * Constructs this team with the given number.
+     * @param number The number to assign to this team.
      */
-    public Team(int id) {
-        this.id = id;
+    public Team(int number) {
+        this.number = number;
         this.members = new ArrayList<>();
     }
 
     /**
-     * @param newId The new id number to assign to this team.
+     * @param newId The new number number to assign to this team.
      */
-    public void setId(int newId) {
-        this.id = newId;
+    public void setNumber(int newId) {
+        this.number = newId;
     }
 
     /**
-     * @return This team's id number.
+     * @return This team's number number.
      */
-    public int getId() {
-        return this.id;
+    public int getNumber() {
+        return this.number;
     }
 
     /**
@@ -123,7 +135,7 @@ public abstract class Team {
 
     /**
      * Checks if an object is equal to this team. First checks if the other object is a Team, and then if it has the
-     * same id and team size. If both of those conditions are met, then it will check that all team members are the
+     * same number and team size. If both of those conditions are met, then it will check that all team members are the
      * same.
      * @param obj The object to check for equality.
      * @return True if the two objects represent the same team, or false otherwise.
@@ -132,7 +144,7 @@ public abstract class Team {
     public boolean equals(Object obj) {
         if (obj instanceof Team) {
             Team team = (Team) obj;
-            return team.getId() == this.getId() && this.hasSameMembers(team);
+            return team.getNumber() == this.getNumber() && this.hasSameMembers(team);
         }
         return false;
     }
@@ -143,7 +155,7 @@ public abstract class Team {
     @Override
     public String toString() {
         StringBuilder sb = new StringBuilder();
-        sb.append("Team of ").append(this.memberCount()).append(" members:\tID: ").append(this.id).append('\n');
+        sb.append("Team of ").append(this.memberCount()).append(" members:\tID: ").append(this.number).append('\n');
         for (Person person : this.members) {
             sb.append(person.toString()).append('\n');
         }

src/main/java/nl/andrewlalis/model/database/BaseEntity.java

@@ -0,0 +1,28 @@
+package nl.andrewlalis.model.database;
+
+import javax.persistence.GeneratedValue;
+import javax.persistence.GenerationType;
+import javax.persistence.Id;
+import javax.persistence.MappedSuperclass;
+
+/**
+ * Defines a base entity which all others in the database extend from.
+ */
+@MappedSuperclass
+public abstract class BaseEntity {
+
+    /**
+     * The number for this entity.
+     */
+    @Id
+    @GeneratedValue(strategy = GenerationType.IDENTITY)
+    private Long id;
+
+    public Long getId() {
+        return id;
+    }
+
+    public void setId(Long id) {
+        this.id = id;
+    }
+}

src/main/java/nl/andrewlalis/model/database/Database.java

@@ -1,266 +0,0 @@
-package nl.andrewlalis.model.database;
-
-import nl.andrewlalis.model.*;
-
-import java.sql.*;
-import java.util.ArrayList;
-import java.util.List;
-import java.util.logging.Logger;
-
-/**
- * This class abstracts many of the functions needed for interaction with the application's SQLite database.
- */
-public class Database {
-
-    private static final int PERSON_TYPE_STUDENT = 0;
-    private static final int PERSON_TYPE_TA = 1;
-
-    private static final int TEAM_TYPE_STUDENT = 0;
-    private static final int TEAM_TYPE_TA = 1;
-    private static final int TEAM_TYPE_TA_ALL = 2;
-
-    private static final int TEAM_NONE = 1000000;
-    private static final int TEAM_TA_ALL = 1000001;
-
-    private static final int ERROR_TYPE_TEAM = 0;
-    private static final int ERROR_TYPE_PERSON = 1;
-    private static final int ERROR_TYPE_SYSTEM = 2;
-
-    /**
-     * The connection needed for all queries.
-     */
-    private Connection connection;
-
-    /**
-     * The logger for outputting debug info.
-     */
-    private static final Logger logger = Logger.getLogger(Database.class.getName());
-    static {
-        logger.setParent(Logger.getGlobal());
-    }
-
-    public Database(String databaseFilename) {
-        try {
-            this.connection = DriverManager.getConnection("jdbc:sqlite:" + databaseFilename);
-        } catch (SQLException e) {
-            e.printStackTrace();
-        }
-    }
-
-    /**
-     * Initializes the database from the table_init.sql script, which defines the table schema.
-     * Then, inserts some constant starter data from /sql/insert/types.sql.
-     * @return True if successful, false if not.
-     */
-    public boolean initialize() {
-        List<PreparedStatement> tableStatements = Utils.prepareStatementsFromFile("/sql/table_init.sql", this.connection);
-        for (PreparedStatement statement : tableStatements) {
-            try {
-                statement.execute();
-            } catch (SQLException e) {
-                logger.severe("SQLException while executing prepared statement:\n" + statement.toString() + "\nCode: " + e.getErrorCode());
-                return false;
-            }
-        }
-        logger.fine("Database tables initialized.");
-        List<PreparedStatement> insertStatements = Utils.prepareStatementsFromFile("/sql/insert/types.sql", this.connection);
-        for (PreparedStatement statement : insertStatements) {
-            try {
-                statement.execute();
-            } catch (SQLException e) {
-                logger.severe("SQLException while inserting into table:\n" + statement.toString() + "\nCode: " + e.getErrorCode());
-                return false;
-            }
-        }
-        logger.fine("Initial types inserted.");
-        return true;
-    }
-
-    /**
-     * Stores a person in the database.
-     * @param person The person object to store.
-     * @param personType The type of person to store, using a constant defined above.
-     * @return True if successful, false otherwise.
-     */
-    public boolean insertPerson(Person person, int personType) {
-        try {
-            logger.finest("Storing person: " + person);
-            String sql = "INSERT INTO persons (id, name, email_address, github_username, person_type_id) VALUES (?, ?, ?, ?, ?);";
-            PreparedStatement stmt = this.connection.prepareStatement(sql);
-            stmt.setInt(1, person.getNumber());
-            stmt.setString(2, person.getName());
-            stmt.setString(3, person.getEmailAddress());
-            stmt.setString(4, person.getGithubUsername());
-            stmt.setInt(5, personType);
-            return stmt.execute();
-        } catch (SQLException e) {
-            logger.severe("SQLException while inserting Person: " + person + '\n' + e.getMessage());
-            return false;
-        }
-    }
-
-    /**
-     * Stores a student in the database.
-     * @param student The student to store.
-     * @return True if the operation was successful, false otherwise.
-     */
-    public boolean insertStudent(Student student) {
-        logger.finest("Storing student: " + student);
-        if (!insertPerson(student, PERSON_TYPE_STUDENT)) {
-            return false;
-        }
-        try {
-            String sql = "INSERT INTO students (person_id, chose_partner) VALUES (?, ?);";
-            PreparedStatement stmt = this.connection.prepareStatement(sql);
-            stmt.setInt(1, student.getNumber());
-            stmt.setInt(2, student.getPreferredPartners().size() > 0 ? 1 : 0);
-            if (!stmt.execute()) {
-                return false;
-            }
-            // Storing partners.
-            String sqlPartner = "INSERT INTO student_preferred_partners (student_id, partner_id) VALUES (?, ?);";
-            PreparedStatement stmtPartner = this.connection.prepareStatement(sqlPartner);
-            for (int partnerId : student.getPreferredPartners()) {
-                stmtPartner.setInt(1, student.getNumber());
-                stmtPartner.setInt(2, partnerId);
-                stmtPartner.execute();
-            }
-            return true;
-        } catch (SQLException e) {
-            logger.severe("SQL Exception while inserting Student into database.\n" + e.getMessage());
-            e.printStackTrace();
-            return false;
-        }
-    }
-
-    /**
-     * Stores a teaching assistant in the database.
-     * @param ta The teaching assistant to store.
-     * @return True if successful, false otherwise.
-     */
-    public boolean insertTeachingAssistant(TeachingAssistant ta) {
-        if (!insertPerson(ta, PERSON_TYPE_TA)) {
-            return false;
-        }
-        try {
-            String sql = "INSERT INTO teaching_assistants (person_id) VALUES (?);";
-            PreparedStatement stmt = this.connection.prepareStatement(sql);
-            stmt.setInt(1, ta.getNumber());
-            stmt.execute();
-            return true;
-        } catch (SQLException e) {
-            logger.severe("SQL Exception while inserting TeachingAssistant.\n" + e.getMessage());
-            e.printStackTrace();
-            return false;
-        }
-    }
-
-    /**
-     * Stores a team in the database, and any persons who do not yet exist.
-     * @param team The team to store.
-     * @param type The type of team that this is.
-     * @param personType The type of people that this team is made of.
-     * @return True if successful, false otherwise.
-     */
-    public boolean insertTeam(Team team, int type, int personType) {
-        try {
-            String sql = "INSERT INTO teams (id, team_type_id) VALUES (?, ?);";
-            PreparedStatement stmt = this.connection.prepareStatement(sql);
-            stmt.setInt(1, team.getId());
-            stmt.setInt(2, type);
-            if (stmt.execute()) {
-                for (Person p : team.getMembers()) {
-                    this.insertPerson(p, personType);
-                    String sqlMembers = "INSERT INTO team_members (team_id, person_id) VALUES (?, ?);";
-                    PreparedStatement stmtMembers = this.connection.prepareStatement(sqlMembers);
-                    stmtMembers.setInt(1, team.getId());
-                    stmtMembers.setInt(2, p.getNumber());
-                    stmtMembers.execute();
-                }
-            }
-            return true;
-        } catch (SQLException e) {
-            logger.severe("SQLException while inserting team: " + team + '\n' + e.getMessage());
-            return false;
-        }
-    }
-
-    /**
-     * Stores a student team in the database.
-     * @param team The team to store.
-     * @return True if successful, false otherwise.
-     */
-    public boolean insertStudentTeam(StudentTeam team) {
-        if (!this.insertTeam(team, TEAM_TYPE_STUDENT, PERSON_TYPE_STUDENT)) {
-            return false;
-        }
-        try {
-            String sql = "INSERT INTO student_teams (team_id, repository_name, teaching_assistant_team_id) VALUES (?, ?, ?);";
-            PreparedStatement stmt = this.connection.prepareStatement(sql);
-            stmt.setInt(1, team.getId());
-            stmt.setString(2, (team.getRepository() == null) ? null : team.getRepository().getName());
-            stmt.setInt(3, (team.getTaTeam() == null) ? TEAM_NONE : team.getTaTeam().getId());
-            return stmt.execute();
-        } catch (SQLException e) {
-            logger.severe("SQLException while inserting student team: " + team + '\n' + e.getMessage());
-            e.printStackTrace();
-            return false;
-        }
-    }
-
-    /**
-     * Stores a list of student teams in the database.
-     * @param teams The list of teams to store.
-     * @return True if successful, or false if an error occurred.
-     */
-    public boolean storeStudentTeams(List<StudentTeam> teams) {
-        for (StudentTeam team : teams) {
-            this.insertStudentTeam(team);
-        }
-        return true;
-    }
-
-    /**
-     * Retrieves a list of preferred partners that each student has set.
-     * @param studentId The student id to search by.
-     * @return A list of student id's for all students that the given student wishes to be their partner.
-     */
-    private List<Integer> retrievePreferredPartners(int studentId) {
-        try {
-            logger.finest("Retrieving preferred partners of student: " + studentId);
-            String sql = "SELECT partner_id FROM student_preferred_partners WHERE student_id=?;";
-            PreparedStatement stmt = this.connection.prepareStatement(sql);
-            stmt.setInt(1, studentId);
-            ResultSet results = stmt.executeQuery();
-            List<Integer> partners = new ArrayList<>();
-            while (results.next()) {
-                partners.add(results.getInt(1));
-            }
-            return partners;
-        } catch (SQLException e) {
-            logger.severe("SQL Exception while retrieving preferred partners of student: " + studentId + '\n' + e.getMessage());
-            e.printStackTrace();
-            return new ArrayList<>();
-        }
-    }
-
-    /**
-     * Retrieves a student by their id.
-     * @param id The id of the student (student number)
-     * @return The student corresponding to this number, or null if it could not be found.
-     */
-    public Student retrieveStudent(int id) {
-        try {
-            String sql = "SELECT * FROM persons WHERE id=?";
-            PreparedStatement stmt = this.connection.prepareStatement(sql);
-            stmt.setInt(1, id);
-            ResultSet result = stmt.executeQuery();
-            return new Student(id, result.getString("name"), result.getString("email_address"), result.getString("github_username"), this.retrievePreferredPartners(id));
-        } catch (SQLException e) {
-            logger.severe("SQL Exception while retrieving Student.\n" + e.getMessage());
-            e.printStackTrace();
-            return null;
-        }
-    }
-
-}

src/main/java/nl/andrewlalis/model/database/DbUtil.java

@@ -0,0 +1,51 @@
+package nl.andrewlalis.model.database;
+
+import org.hibernate.SessionFactory;
+import org.hibernate.boot.MetadataSources;
+import org.hibernate.boot.registry.StandardServiceRegistry;
+import org.hibernate.boot.registry.StandardServiceRegistryBuilder;
+
+/**
+ * A utility class for easier interaction with the Hibernate database.
+ */
+public class DbUtil {
+
+    private static SessionFactory sessionFactory;
+
+    /**
+     * Set up the session factory based on hibernate.cfg.xml.
+     */
+    private static void setUp() {
+        final StandardServiceRegistry registry = new StandardServiceRegistryBuilder()
+                .configure()
+                .build();
+        try {
+            sessionFactory = new MetadataSources(registry)
+                    .buildMetadata()
+                    .buildSessionFactory();
+        } catch (Exception e) {
+            e.printStackTrace();
+            StandardServiceRegistryBuilder.destroy(registry);
+        }
+    }
+
+    /**
+     * Close the session factory when it's no longer needed.
+     */
+    public static void tearDown() {
+        if (sessionFactory != null) {
+            sessionFactory.close();
+        }
+    }
+
+    /**
+     * Gets the session factory so that sessions can be made.
+     * @return The session factory.
+     */
+    public static SessionFactory getSessionFactory() {
+        if (sessionFactory == null) {
+            setUp();
+        }
+        return sessionFactory;
+    }
+}

src/main/java/nl/andrewlalis/model/database/Utils.java

@@ -1,52 +0,0 @@
-package nl.andrewlalis.model.database;
-
-import nl.andrewlalis.util.FileUtils;
-
-import java.sql.Connection;
-import java.sql.PreparedStatement;
-import java.sql.SQLException;
-import java.util.ArrayList;
-import java.util.List;
-import java.util.logging.Logger;
-
-/**
- * Contains some methods which make database actions much easier.
- */
-public class Utils {
-
-    /**
-     * The logger for outputting debug info.
-     */
-    private static final Logger logger = Logger.getLogger(Utils.class.getName());
-    static {
-        logger.setParent(Logger.getGlobal());
-    }
-
-    /**
-     * Gets an ordered list of prepared statements from a file which contains multiple statements separated by a
-     * semicolon. This method separates those statements into their own strings, and prepares them individually to be
-     * executed later.
-     * @param filename The name of the file which contains the statements.
-     * @param connection The connection to a database; used to prepare statements.
-     * @return An ordered list of prepared statements which are based on the contents of the file provided.
-     */
-    public static List<PreparedStatement> prepareStatementsFromFile(String filename, Connection connection) {
-        String string = FileUtils.readStringFromFile(filename);
-        if (string == null || string.isEmpty()) {
-            return new ArrayList<>();
-        }
-        String[] splits = string.split(";");
-        List<PreparedStatement> statements = new ArrayList<>();
-        for (String split : splits) {
-            if (split.trim().length() > 1) {
-                try {
-                    statements.add(connection.prepareStatement(split));
-                } catch (SQLException e) {
-                    logger.severe("SQLException while preparing a statement:\n" + split + "\nError Code: " + e.getErrorCode() + '\n' + e.getMessage());
-                }
-            }
-        }
-        return statements;
-    }
-
-}

src/main/java/nl/andrewlalis/util/TeamGenerator.java

@@ -2,9 +2,6 @@ package nl.andrewlalis.util;
 
 import nl.andrewlalis.model.Student;
 import nl.andrewlalis.model.StudentTeam;
-import nl.andrewlalis.model.error.Error;
-import nl.andrewlalis.model.error.Severity;
-import nl.andrewlalis.ui.view.InitializerApp;
 import org.apache.commons.csv.CSVFormat;
 import org.apache.commons.csv.CSVRecord;
 
@@ -45,9 +42,9 @@ public class TeamGenerator {
         Iterable<CSVRecord> records = CSVFormat.DEFAULT.withFirstRecordAsHeader().parse(new FileReader(filename));
 
         logger.fine("Reading all records into map.");
-        Map<Integer, Student> studentMap;
+        List<Student> students;
         try {
-            studentMap = readAllStudents(records, teamSize);
+            students = readAllStudents(records, teamSize);
         } catch (ArrayIndexOutOfBoundsException e) {
             logger.severe("StudentTeam size does not match column count in records.");
             throw new IllegalArgumentException("StudentTeam size does not match column count in records.");
@@ -55,7 +52,7 @@ public class TeamGenerator {
 
 
         logger.fine("Generating all valid teams from student map.");
-        return generateAllValidTeams(studentMap, teamSize);
+        return generateAllValidTeams(students, teamSize);
     }
 
     /**
@@ -71,21 +68,23 @@ public class TeamGenerator {
      * After all students with preferred partners are placed in teams, the single students are merged, and their teams
      * are added afterwards.
      *
-     * @param studentMap A mapping for each student to their student number.
+     * @param students A list of students, each with a list of preferred partners.
      * @param teamSize The preferred maximum size for a team.
      * @return A list of teams, most of which are of teamSize size.
      */
-    private static List<StudentTeam> generateAllValidTeams(Map<Integer, Student> studentMap, int teamSize) {
-        List<Student> singleStudents = new ArrayList<>(studentMap.values());
+    private static List<StudentTeam> generateAllValidTeams(List<Student> students, int teamSize) {
+        List<Student> singleStudents = new ArrayList<>(students);
         List<StudentTeam> studentTeams = new ArrayList<>();
 
+        // An integer which increments for each valid team. Used to create identifiers for each team.
         int teamCount = 1;
+
         // For each student, try to make a team from its preferred partners.
-        for (Map.Entry<Integer, Student> e : studentMap.entrySet()) {
-            StudentTeam newTeam = e.getValue().getPreferredTeam(studentMap);
+        for (Student student : students) {
+            StudentTeam newTeam = student.getPreferredTeam();
             logger.finest("Checking if student's preferred team is valid:\n" + newTeam);
             // Check if the team is of a valid size, and is not a duplicate.
-            // Note that at this stage, singles are treated as studentTeams of 1, and thus not valid for any teamSize > 1.
+            // Note that at this stage, singles are treated as student teams of 1, and thus not valid for any team size > 1.
             if (newTeam.isValid(teamSize)) {
                 // We know that the team is valid on its own, so now we check if it has members identical to any team already created.
                 boolean matchFound = false;
@@ -97,7 +96,7 @@ public class TeamGenerator {
                 }
                 if (!matchFound) {
                     // Once we know this team is completely valid, we remove all the students in it from the list of singles.
-                    newTeam.setId(teamCount++);
+                    newTeam.setNumber(teamCount++);
                     singleStudents.removeAll(Arrays.asList(newTeam.getStudents()));
                     studentTeams.add(newTeam);
                     logger.fine("Created team:\n" + newTeam);
@@ -114,14 +113,14 @@ public class TeamGenerator {
      * size as possible.
      * @param singleStudents A list of students who have no preferred partners.
      * @param teamSize The preferred team size.
-     * @param teamIndex The current number used in assigning an id to the team.
+     * @param teamIndex The current number used in assigning an number to the team.
      * @return A list of teams comprising of single students.
      */
     private static List<StudentTeam> mergeSingleStudents(List<Student> singleStudents, int teamSize, int teamIndex) {
         List<StudentTeam> studentTeams = new ArrayList<>();
         while (!singleStudents.isEmpty()) {
             StudentTeam t = new StudentTeam();
-            t.setId(teamIndex++);
+            t.setNumber(teamIndex++);
             logger.fine("Creating new team of single students:\n" + t);
             while (t.memberCount() < teamSize && !singleStudents.isEmpty()) {
                 Student s = singleStudents.remove(0);
@@ -141,8 +140,10 @@ public class TeamGenerator {
      * @return A map of all students in the file.
      * @throws ArrayIndexOutOfBoundsException if the teamSize does not work with the columns in the record.
      */
-    private static Map<Integer, Student> readAllStudents(Iterable<CSVRecord> records, int teamSize) throws ArrayIndexOutOfBoundsException {
+    private static List<Student> readAllStudents(Iterable<CSVRecord> records, int teamSize) throws ArrayIndexOutOfBoundsException {
         Map<Integer, Student> studentMap = new HashMap<>();
+        Map<Student, List<Integer>> studentPreferredIds = new HashMap<>();
+        // Perform the initial read of the students.
         for (CSVRecord record : records) {
             logger.finest("Read record: " + record);
             List<Integer> preferredIds = new ArrayList<>();
@@ -152,21 +153,38 @@ public class TeamGenerator {
                     preferredIds.add(Integer.parseInt(record.get(columnOffset + i)));
                 }
             }
-            Student s = new Student(Integer.parseInt(record.get(3)), record.get(2), record.get(1), record.get(4), preferredIds);
+            Student s = new Student();
+            s.setNumber(Integer.parseInt(record.get(3)));
+            s.setName(record.get(2));
+            s.setEmailAddress(record.get(1));
+            s.setGithubUsername(record.get(4));
             if (studentMap.containsValue(s)) {
                 logger.warning("Duplicate entry found for student: " + s + "\nOverwriting previous value.");
             }
             studentMap.put(s.getNumber(), s);
+            studentPreferredIds.put(s, preferredIds);
         }
 
-        // Perform a safety check to ensure all preferred partners are valid students.
-        for (Map.Entry<Integer, Student> entry : studentMap.entrySet()) {
-            // Remove any ids that don't exist in the whole list of students.
-            entry.getValue().getPreferredPartners().removeIf(partnerId -> !studentMap.containsKey(partnerId));
+        // The final list of students, with preferred partners set.
+        List<Student> students = new ArrayList<>();
+
+        // Assign students to their preferred students.
+        for (Map.Entry<Student, List<Integer>> entry : studentPreferredIds.entrySet()) {
+            Student s = entry.getKey();
+            for (int partnerNumber : entry.getValue()) {
+                // Check that this preferred partner number exists.
+                if (studentMap.containsKey(partnerNumber)) {
+                    s.addPreferredPartner(studentMap.get(partnerNumber));
+                } else {
+                    logger.warning("Student " + s + " has invalid preferred partner.");
+                }
+            }
+            students.add(s);
         }
+
         // At this point, all students are valid, and all preferred partners are valid.
-        logger.fine("Read " + studentMap.size() + " students from records.");
-        return studentMap;
+        logger.fine("Read " + students.size() + " students from records.");
+        return students;
     }
 
 }

src/main/resources/hibernate.cfg.xml

@@ -0,0 +1,30 @@
+<?xml version="1.0" encoding="UTF-8" ?>
+<!DOCTYPE hibernate-configuration PUBLIC
+        "-//Hibernate/Hibernate Configuration DTD 3.0//EN"
+        "http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd">
+<hibernate-configuration>
+    <session-factory>
+        <!-- Database connection settings -->
+        <property name="hibernate.connection.driver_class">org.h2.Driver</property>
+        <property name="hibernate.connection.url">jdbc:h2:./initializer.h2</property>
+        <property name="hibernate.dialect">org.hibernate.dialect.H2Dialect</property>
+        <property name="hibernate.connection.username">root</property>
+        <property name="hibernate.connection.password">root</property>
+
+        <!-- JDBC connection pool -->
+        <property name="connection.pool_size">1</property>
+
+        <!-- Debugging to show sql queries. -->
+        <property name="show_sql">false</property>
+
+        <!-- Set Hibernate to create tables beforehand. -->
+        <property name="hibernate.hbm2ddl.auto">create-drop</property>
+
+        <!-- Mapping -->
+        <mapping class="nl.andrewlalis.model.Team"/>
+        <mapping class="nl.andrewlalis.model.Student"/>
+        <mapping class="nl.andrewlalis.model.StudentTeam"/>
+        <mapping class="nl.andrewlalis.model.TeachingAssistant"/>
+        <mapping class="nl.andrewlalis.model.TATeam"/>
+    </session-factory>
+</hibernate-configuration>