Got CSV reading to work properly.

pom.xml

@@ -79,6 +79,12 @@
 			<artifactId>mysql-connector-java</artifactId>
 			<version>8.0.15</version>
 		</dependency>
+		<!-- CSV Format dependency -->
+		<dependency>
+			<groupId>org.apache.commons</groupId>
+			<artifactId>commons-csv</artifactId>
+			<version>1.5</version>
+		</dependency>
 	</dependencies>
 
 	<build>

src/main/java/nl/andrewlalis/teaching_assistant_assistant/TeachingAssistantAssistantApplication.java

@@ -27,6 +27,11 @@ public class TeachingAssistantAssistantApplication implements CommandLineRunner
 	@Override
 	public void run(String... args) throws Exception {
 		System.out.println("Running startup...");
-
+//
+//		String exampleDate = "2019/04/15 4:13:41 PM GMT+2 ";
+//		// Parse the timestamp.
+//		DateTimeFormatter formatter = DateTimeFormatter.ofPattern("yyyy/MM/dd h:mm:ss a O ");
+//		ZonedDateTime dateTime = ZonedDateTime.parse(exampleDate, formatter);
+//		System.out.println("Read time: " + dateTime.toString());
 	}
 }

src/main/java/nl/andrewlalis/teaching_assistant_assistant/controllers/Courses.java

@@ -41,7 +41,6 @@ public class Courses {
             consumes = "application/x-www-form-urlencoded"
     )
     public String post(@ModelAttribute Course course) {
-        System.out.println("Object submitted: " + course);
         this.courseRepository.save(course);
         return "courses/entity";
     }

src/main/java/nl/andrewlalis/teaching_assistant_assistant/controllers/courses/ImportStudents.java

@@ -0,0 +1,61 @@
+package nl.andrewlalis.teaching_assistant_assistant.controllers.courses;
+
+import nl.andrewlalis.teaching_assistant_assistant.model.Course;
+import nl.andrewlalis.teaching_assistant_assistant.model.people.teams.StudentTeam;
+import nl.andrewlalis.teaching_assistant_assistant.model.repositories.CourseRepository;
+import nl.andrewlalis.teaching_assistant_assistant.model.repositories.TeamRepository;
+import nl.andrewlalis.teaching_assistant_assistant.util.team_importing.StudentTeamImporter;
+import org.springframework.stereotype.Controller;
+import org.springframework.ui.Model;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.PathVariable;
+import org.springframework.web.bind.annotation.PostMapping;
+import org.springframework.web.bind.annotation.RequestParam;
+import org.springframework.web.multipart.MultipartFile;
+
+import java.io.IOException;
+import java.util.List;
+import java.util.Optional;
+
+/**
+ * Controller for importing students from a CSV sheet.
+ */
+@Controller
+public class ImportStudents {
+
+    private CourseRepository courseRepository;
+
+    private TeamRepository teamRepository;
+
+    protected ImportStudents(CourseRepository courseRepository, TeamRepository teamRepository) {
+        this.courseRepository = courseRepository;
+        this.teamRepository = teamRepository;
+    }
+
+    @GetMapping("/courses/{code}/import_students")
+    public String get(@PathVariable String code, Model model) {
+        Optional<Course> optionalCourse = this.courseRepository.findByCode(code);
+        optionalCourse.ifPresent(course -> model.addAttribute("course", course));
+        return "courses/import_students";
+    }
+
+    @PostMapping(
+            value = "/courses/{code}/import_students"
+    )
+    public String post(@PathVariable String code, @RequestParam MultipartFile file) {
+        Optional<Course> optionalCourse = this.courseRepository.findByCode(code);
+
+        if (!optionalCourse.isPresent()) {
+            System.out.println("No course found.");
+            return "redirect:/courses";
+        }
+
+        try {
+            List<StudentTeam> studentTeams = StudentTeamImporter.importFromCSV(file.getInputStream(), optionalCourse.get());
+        } catch (IOException e) {
+            e.printStackTrace();
+        }
+
+        return "redirect:/courses/{code}";
+    }
+}

src/main/java/nl/andrewlalis/teaching_assistant_assistant/model/Course.java

@@ -77,12 +77,12 @@ public class Course extends BasicEntity {
         this.code = code;
     }
 
-    public void addStudentGroup(StudentTeam group) {
-        this.studentTeams.add(group);
+    public void addStudentTeam(StudentTeam team) {
+        this.studentTeams.add(team);
     }
 
-    public void addTeachingAssistantGroup(TeachingAssistantTeam group) {
-        this.teachingAssistantTeams.add(group);
+    public void addTeachingAssistantTeam(TeachingAssistantTeam team) {
+        this.teachingAssistantTeams.add(team);
     }
 
     /*

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

@@ -26,6 +26,9 @@ public abstract class Person extends BasicEntity {
     @Column
     private String emailAddress;
 
+    @Column
+    private String githubUsername;
+
     /**
      * The list of teams that this person belongs to. Because a person can belong to more than one team, it is implied
      * that each person exists in only one location in the database. Therefore, if one person is enrolled in two courses
@@ -50,12 +53,14 @@ public abstract class Person extends BasicEntity {
      * @param firstName The person's first name.
      * @param lastName The person's last name.
      * @param emailAddress The person's email address.
+     * @param githubUsername The person's github username;
      */
-    public Person(String firstName, String lastName, String emailAddress) {
+    public Person(String firstName, String lastName, String emailAddress, String githubUsername) {
         this();
         this.firstName = firstName;
         this.lastName = lastName;
         this.emailAddress = emailAddress;
+        this.githubUsername = githubUsername;
     }
 
     public void assignToTeam(Team team) {
@@ -82,8 +87,40 @@ public abstract class Person extends BasicEntity {
         return this.emailAddress;
     }
 
+    public String getGithubUsername() {
+        return this.githubUsername;
+    }
+
+    /**
+     * Determines if two Persons are equal. They are considered equal when all of the basic identifying information
+     * about the person is the same, regardless of case.
+     * @param o The other object.
+     * @return True if the other object is the same person, or false if not.
+     */
+    @Override
+    public boolean equals(Object o) {
+        if (o == null) {
+            return false;
+        }
+
+        if (o instanceof Person) {
+            Person p = (Person) o;
+            return (
+                    this.getFirstName().equalsIgnoreCase(p.getFirstName())
+                    && this.getLastName().equalsIgnoreCase(p.getLastName())
+                    && this.getEmailAddress().equalsIgnoreCase(p.getEmailAddress())
+                    && this.getGithubUsername().equalsIgnoreCase(p.getGithubUsername())
+            );
+        }
+
+        return false;
+    }
+
     @Override
     public String toString() {
-        return this.getFirstName() + ' ' + this.getLastName() + '[' + this.getId() + ']';
+        return "First Name: " + this.getFirstName()
+                + ", Last Name: " + this.getLastName()
+                + ", Email: " + this.getEmailAddress()
+                + ", Github Username: " + this.getGithubUsername();
     }
 }

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

@@ -1,5 +1,6 @@
 package nl.andrewlalis.teaching_assistant_assistant.model.people;
 
+import javax.persistence.Column;
 import javax.persistence.Entity;
 
 /**
@@ -8,13 +9,52 @@ import javax.persistence.Entity;
 @Entity
 public class Student extends Person {
 
+    /**
+     * The student's unique student number, as given by the university.
+     */
+    @Column(unique = true, nullable = false)
+    private int studentNumber;
+
     /**
      * Default constructor for JPA.
      */
     protected Student() {}
 
-    public Student(String firstName, String lastName, String emailAddress) {
-        super(firstName, lastName, emailAddress);
+    /**
+     * Constructs a new student with all the properties of a Person, and any extra properties.
+     * @param firstName The student's first name.
+     * @param lastName The student's last name.
+     * @param emailAddress The student's email address.
+     * @param githubUsername The student's Github username.
+     * @param studentNumber The student's unique student number.
+     */
+    public Student(String firstName, String lastName, String emailAddress, String githubUsername, int studentNumber) {
+        super(firstName, lastName, emailAddress, githubUsername);
+
+        this.studentNumber = studentNumber;
     }
 
+    public int getStudentNumber() {
+        return studentNumber;
+    }
+
+    public void setStudentNumber(int studentNumber) {
+        this.studentNumber = studentNumber;
+    }
+
+    /**
+     * Determines if two students are equal. They are considered equal if their person attributes are the same, or
+     * their student-specific attributes are equal.
+     * @param o The other object.
+     * @return True if the other object is the same student.
+     */
+    @Override
+    public boolean equals(Object o) {
+        return super.equals(o) || this.getStudentNumber() == ((Student) o).getStudentNumber();
+    }
+
+    @Override
+    public String toString() {
+        return super.toString() + ", Student Number: " + this.getStudentNumber();
+    }
 }

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

@@ -15,7 +15,7 @@ public class TeachingAssistant extends Person {
 
     }
 
-    public TeachingAssistant(String firstName, String lastName, String emailAddress) {
-        super(firstName, lastName, emailAddress);
+    public TeachingAssistant(String firstName, String lastName, String githubUsername, String emailAddress) {
+        super(firstName, lastName, emailAddress, githubUsername);
     }
 }

src/main/java/nl/andrewlalis/teaching_assistant_assistant/util/sample_data/CourseGenerator.java

@@ -56,11 +56,11 @@ public class CourseGenerator extends TestDataGenerator<Course> {
         List<StudentTeam> studentTeams = this.generateStudentTeams();
         List<TeachingAssistantTeam> teachingAssistantTeams = this.generateTeachingAssistantTeams();
         for (StudentTeam team : studentTeams) {
-            course.addStudentGroup(team);
+            course.addStudentTeam(team);
             team.setCourse(course);
         }
         for (TeachingAssistantTeam team : teachingAssistantTeams) {
-            course.addTeachingAssistantGroup(team);
+            course.addTeachingAssistantTeam(team);
             team.setCourse(course);
         }
         return course;

src/main/java/nl/andrewlalis/teaching_assistant_assistant/util/sample_data/StudentGenerator.java

@@ -12,6 +12,6 @@ public class StudentGenerator extends PersonGenerator<Student> {
     public Student generate() {
         String firstName = this.getRandomFirstName();
         String lastName = this.getRandomLastName();
-        return new Student(firstName, lastName, this.getRandomEmailAddress(firstName, lastName));
+        return new Student(firstName, lastName, this.getRandomEmailAddress(firstName, lastName), null, this.getRandomInteger(0, 100000000));
     }
 }

src/main/java/nl/andrewlalis/teaching_assistant_assistant/util/sample_data/TeachingAssistantGenerator.java

@@ -12,6 +12,6 @@ public class TeachingAssistantGenerator extends PersonGenerator<TeachingAssistan
     public TeachingAssistant generate() {
         String firstName = this.getRandomFirstName();
         String lastName = this.getRandomLastName();
-        return new TeachingAssistant(firstName, lastName, this.getRandomEmailAddress(firstName, lastName));
+        return new TeachingAssistant(firstName, lastName, null, this.getRandomEmailAddress(firstName, lastName));
     }
 }

src/main/java/nl/andrewlalis/teaching_assistant_assistant/util/team_importing/StudentRecordEntry.java

@@ -0,0 +1,44 @@
+package nl.andrewlalis.teaching_assistant_assistant.util.team_importing;
+
+import nl.andrewlalis.teaching_assistant_assistant.model.people.Student;
+
+import java.time.ZonedDateTime;
+
+/**
+ * Represents a pair of students, one of which has indicated that the other is their partner.
+ */
+public class StudentRecordEntry {
+
+    private Student student;
+
+    private Student partnerStudent;
+
+    private ZonedDateTime dateTime;
+
+    public StudentRecordEntry(ZonedDateTime dateTime, Student student, Student partnerStudent) {
+        this.student = student;
+        this.partnerStudent = partnerStudent;
+        this.dateTime = dateTime;
+    }
+
+    public Student getStudent() {
+        return this.student;
+    }
+
+    public Student getPartnerStudent() {
+        return this.partnerStudent;
+    }
+
+    public ZonedDateTime getDateTime() {
+        return this.dateTime;
+    }
+
+    public boolean hasPartner() {
+        return this.partnerStudent != null;
+    }
+
+    @Override
+    public String toString() {
+        return "Entry at: " + this.dateTime.toString() + "\n\tStudent: " + this.getStudent() + "\n\tPreferred partner: " + this.getPartnerStudent();
+    }
+}

src/main/java/nl/andrewlalis/teaching_assistant_assistant/util/team_importing/StudentTeamImporter.java

@@ -0,0 +1,136 @@
+package nl.andrewlalis.teaching_assistant_assistant.util.team_importing;
+
+import nl.andrewlalis.teaching_assistant_assistant.model.Course;
+import nl.andrewlalis.teaching_assistant_assistant.model.people.Student;
+import nl.andrewlalis.teaching_assistant_assistant.model.people.teams.StudentTeam;
+import org.apache.commons.csv.CSVFormat;
+import org.apache.commons.csv.CSVRecord;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.InputStreamReader;
+import java.time.ZonedDateTime;
+import java.time.format.DateTimeFormatter;
+import java.util.*;
+
+/**
+ * Provides some methods to streamline the process of transforming a CSV file of student data into a list of valid teams
+ * which can be used for a course.
+ */
+public class StudentTeamImporter {
+
+    /**
+     * Imports data from the given File Input Stream into the course.
+     * @param fileInputStream An input stream representing the contents of a CSV file.
+     * @param course The course to add the students to.
+     * @return A list of valid teams that the given file describes.
+     */
+    public static List<StudentTeam> importFromCSV(InputStream fileInputStream, Course course) throws IOException {
+        Iterable<CSVRecord> records = CSVFormat.DEFAULT
+                .withSkipHeaderRecord()
+                .withHeader("timestamp", "email", "name", "number", "github_username", "has_partner", "partner_name", "partner_number", "partner_email", "partner_github_username")
+                .parse(new InputStreamReader(fileInputStream));
+
+        List<StudentRecordEntry> studentEntries = extractStudentsFromRecords(records);
+
+        for (StudentRecordEntry entry : studentEntries) {
+            System.out.println(entry.toString());
+        }
+
+        return new ArrayList<>();
+
+    }
+
+    /**
+     * Extracts all student data from a list of records, and automatically discards outdated responses (those where the
+     * same student submitted more than once).
+     * @param records The list of records in the CSV file.
+     * @return A mapping for each timestamp to
+     */
+    private static List<StudentRecordEntry> extractStudentsFromRecords(Iterable<CSVRecord> records) {
+        List<StudentRecordEntry> studentEntries = new ArrayList<>();
+
+        for (CSVRecord record : records) {
+            // Parse the actual student.
+            Student s = parseStudentRecordData(record.get("name"), record.get("email"), record.get("github_username"), record.get("number"));
+
+            // Parse the student's preferred partner, if they exist.
+            Student preferredPartner = null;
+            if (record.get("has_partner").equalsIgnoreCase("yes")) {
+                preferredPartner = parseStudentRecordData(record.get("partner_name"), record.get("partner_email"), record.get("partner_github_username"), record.get("partner_number"));
+            }
+
+            // Parse the timestamp.
+            DateTimeFormatter formatter = DateTimeFormatter.ofPattern("yyyy/MM/dd h:mm:ss a O ");
+            ZonedDateTime dateTime = ZonedDateTime.parse(record.get("timestamp") + ' ', formatter);
+            // A space is added because of a java bug: https://stackoverflow.com/questions/37287103/why-does-gmt8-fail-to-parse-with-pattern-o-despite-being-copied-straight-ou
+
+            studentEntries.add(new StudentRecordEntry(dateTime, s, preferredPartner));
+        }
+
+        studentEntries = removeDuplicateEntries(studentEntries);
+
+        return studentEntries;
+    }
+
+
+    private static List<StudentRecordEntry> removeDuplicateEntries(List<StudentRecordEntry> studentEntries) {
+        List<StudentRecordEntry> uniqueStudentEntries = new ArrayList<>();
+
+        for (StudentRecordEntry entry : studentEntries) {
+            // Check for if the current entry's student already exists.
+            boolean duplicateFound = false;
+            for (StudentRecordEntry existingEntry : uniqueStudentEntries) {
+                if (entry.getStudent().equals(existingEntry.getStudent())) {
+                    duplicateFound = true;
+                    // Check if the existing entry is older than the new one; it should be overwritten.
+                    if (existingEntry.getDateTime().isBefore(entry.getDateTime())) {
+                        uniqueStudentEntries.remove(existingEntry);
+                        uniqueStudentEntries.add(entry);
+                        break;
+                    }
+                }
+            }
+
+            if (!duplicateFound) {
+                uniqueStudentEntries.add(entry);
+            }
+        }
+
+        return uniqueStudentEntries;
+    }
+
+    /**
+     * Creates a student object from given entries in a record obtained from a CSV file.
+     * @param name The name value.
+     * @param email The email value.
+     * @param githubUsername The github_username value.
+     * @param studentNumber The number value.
+     * @return A student object constructed from the given data.
+     */
+    private static Student parseStudentRecordData(String name, String email, String githubUsername, String studentNumber) {
+        // Extract a sensible first and last name.
+        String[] nameSegments = name.split(" ");
+        String firstName = "No First Name Given";
+        String lastName = "No Last Name Given";
+
+        if (nameSegments.length > 0) {
+            firstName = nameSegments[0];
+        }
+
+        if (nameSegments.length > 1) {
+            lastName = String.join(" ", Arrays.copyOfRange(nameSegments, 1, nameSegments.length));
+        }
+
+        // Extract a sensible github username.
+        String githubURL = "https://github.com/";
+
+        if (githubUsername.startsWith(githubURL)) {
+            githubUsername = githubUsername.substring(githubURL.length());
+        }
+
+        // Create the student.
+        return new Student(firstName, lastName, email, githubUsername, Integer.parseInt(studentNumber));
+    }
+
+}

src/main/resources/templates/courses/entity.html

@@ -48,7 +48,7 @@
         <a th:href="@{/courses/{code}/import_students(code=${course.getCode()})}">Import students from CSV</a>
     </div>
     <div class="sidebar_block">
-        <a th:href="@{/courses/{code}/import_teaching_assistants(code=${course.getCode()})}">Import teaching assistants from CSV</a>
+        <a th:disabled="true" th:href="@{/courses/{code}/import_teaching_assistants(code=${course.getCode()})}">Import teaching assistants from CSV</a>
     </div>
 </div>
 

src/main/resources/templates/courses/import_students.html

@@ -0,0 +1,26 @@
+<!DOCTYPE html>
+<html lang="en" xmlns:th="http://www.thymeleaf.org" th:replace="~{layouts/basic_page :: layout (~{::title}, ~{::#content}, ~{::#sidebar_content})}">
+<head>
+    <title>Import Students via CSV</title>
+</head>
+<body>
+
+<div id="content">
+    <p>
+        Please select a CSV file to import.
+    </p>
+
+    <form method="post" action="#" enctype="multipart/form-data" th:action="@{/courses/{code}/import_students(code=${course.getCode()})}">
+        <label for="file_input">File:</label>
+        <input id="file_input" type="file" name="file" accept="text/csv"/>
+        <button type="submit">Submit</button>
+    </form>
+
+</div>
+
+<div id="sidebar_content">
+
+</div>
+
+</body>
+</html>

src/main/resources/templates/courses/import_teaching_assistants.html

@@ -0,0 +1,10 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+    <meta charset="UTF-8">
+    <title></title>
+</head>
+<body>
+
+</body>
+</html>