Rework which entity properties are optional/mandatory

gradle/wrapper/gradle-wrapper.properties

@@ -1,5 +1,6 @@
+#Thu Mar 28 13:00:59 CET 2019
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-5.2.1-bin.zip
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists
+distributionUrl=https\://services.gradle.org/distributions/gradle-5.2.1-all.zip

src/main/kotlin/de/code_freak/codefreak/entity/Assignment.kt

@@ -13,20 +13,20 @@ class Assignment(
    * e.g. "Java Threads and Runnable"
    */
   @Column(nullable = false)
-  var title: String? = null,
+  var title: String,
 
   /**
    * The lecturer who created this assignment
    */
   @ManyToOne
-  var owner: User? = null,
+  var owner: User,
 
   /**
    * The classroom this assignment belongs to
    * This can be null for assignments that are shared via link
    */
   @ManyToOne(optional = true)
-  var classroom: Classroom? = null,
+  var classroom: Classroom?,
 
   /**
    * A list of tasks in this assignment ordered by their position

src/main/kotlin/de/code_freak/codefreak/entity/AssignmentTask.kt

@@ -12,50 +12,47 @@ class AssignmentTask(
    * Related assignment this task belongs to
    */
   @ManyToOne
-  var assignment: Assignment? = null,
+  var assignment: Assignment,
 
   /**
    * Position/Index in the assignment (zero-based)
    */
   @Column(nullable = false)
-  var position: Long? = null,
+  var position: Long,
 
   /**
    * Title of the task
    */
   @Column(nullable = false)
-  var title: String? = null,
+  var title: String,
 
   /**
    * The task body/description of what to do
    */
   @Lob
-  @Column(nullable = false)
-  var body: String? = null,
+  var body: String?,
 
   /**
    * A tar archive of files that act as boilerplate code
    */
-  @Column(nullable = false)
   @Lob
-  var files: ByteArray? = null,
+  var files: ByteArray?,
 
   /**
    * A weight >=0, <=100 how the task is weighted
    * The total weight of all tasks should not be > 100
    */
-  @Column(nullable = false)
-  var weight: Int? = null,
+  var weight: Int?,
 
   /**
    * Evaluations that will be applied to this task
    */
   @OneToMany(mappedBy = "task")
-  var evaluation: List<TaskEvaluation>? = ArrayList()
+  var evaluation: List<TaskEvaluation> = ArrayList()
 ) : JpaPersistable() {
 
   /**
    * Same like position but one-based index
    */
-  val number get() = this.position?.plus(1L)
+  val number get() = this.position.plus(1L)
 }

src/main/kotlin/de/code_freak/codefreak/entity/Classroom.kt

@@ -10,7 +10,7 @@ class Classroom(
    * Name of this course
    */
   @Column(nullable = false)
-  var name: String? = null,
+  var name: String,
 
   /**
    * Assignments in this course

src/main/kotlin/de/code_freak/codefreak/entity/Submission.kt

@@ -9,11 +9,11 @@ class Submission(
    * The user that handed in this submissions
    */
   @ManyToOne
-  var user: User? = null,
+  var user: User,
 
   /**
    * The assignment this submission belongs to
    */
   @ManyToOne
-  var assignment: Assignment? = null
+  var assignment: Assignment
 ) : JpaPersistable()

src/main/kotlin/de/code_freak/codefreak/entity/SubmissionTask.kt

@@ -10,11 +10,11 @@ class SubmissionTask(
    * The submission of which this task is part of
    */
   @ManyToOne
-  var submission: Submission? = null,
+  var submission: Submission,
 
   /**
    * A tar archive of files that have been submitted
    */
   @Lob
-  var files: ByteArray? = null
+  var files: ByteArray
 ) : JpaPersistable()

src/main/kotlin/de/code_freak/codefreak/entity/TaskEvaluation.kt

@@ -12,14 +12,14 @@ class TaskEvaluation(
    * The task that should be evaluated
    */
   @ManyToOne
-  var task: AssignmentTask? = null,
+  var task: AssignmentTask,
 
   /**
    * The adapter that is responsible for evaluation
    *
    * TODO: Create a enum/registry that holds all possible evaluators – see #12
    */
-  var adapter: String? = null,
+  var adapter: String,
 
   /**
    * Configuration for the adapter as key-value pairs

src/main/kotlin/de/code_freak/codefreak/entity/TaskEvaluationResult.kt

@@ -9,16 +9,16 @@ class TaskEvaluationResult(
    * The submission of which this task is part of
    */
   @ManyToOne
-  var submissionTask: SubmissionTask? = null,
+  var submissionTask: SubmissionTask,
 
   /**
    * Link to the evaluation that has been used to create the result
    */
   @ManyToOne
-  var evaluation: TaskEvaluation? = null,
+  var evaluation: TaskEvaluation,
 
   /**
-   * A tar archive of files that have been submitted
+   * The result value that was determined by the evaluation
    */
-  var result: Long? = null
+  var result: Long
 ) : JpaPersistable()

src/main/resources/application.properties

@@ -10,7 +10,6 @@
 # spring.datasource.password=postgres
 # spring.datasource.driver-class-name=org.postgresql.Driver
 # spring.jpa.database-platform=org.hibernate.dialect.PostgreSQLDialect
-# spring.jpa.properties.hibernate.globally_quoted_identifiers=true
 #
 # or in-memory (DO NOT USE IN PRODUCTION)
 #
@@ -27,3 +26,6 @@ spring.profiles.active=dev
 
 # Hides HHH000424: Disabling contextual LOB creation as createClob() method threw error
 logging.level.org.hibernate.engine.jdbc.env.internal.LobCreatorBuilderImpl = WARN
+
+# Escape all table names to avoid issues with reserved keywords like "user"
+spring.jpa.properties.hibernate.globally_quoted_identifiers=true