feat: TaskDB types and interfaces

Created the types and interfaces relating to the TaskDatabase

src/main/java/ch/zhaw/gartenverwaltung/io/TaskDatabase.java

@@ -0,0 +1,13 @@
+package ch.zhaw.gartenverwaltung.io;
+
+import ch.zhaw.gartenverwaltung.types.Task;
+
+import java.io.IOException;
+import java.util.Date;
+import java.util.List;
+
+public interface TaskDatabase {
+    List<Task> getTaskList(Date start, Date end);
+    void saveTask(Task task) throws IOException;
+    void removeTask(Task task) throws IOException;
+}

src/main/java/ch/zhaw/gartenverwaltung/types/Task.java

@@ -0,0 +1,50 @@
+package ch.zhaw.gartenverwaltung.types;
+
+import java.util.Date;
+import java.util.Optional;
+
+/**
+ * Models a Task
+ * May be created using the builder pattern.
+ */
+public class Task {
+    private long id;
+    private final String name;
+    private final String description;
+    private final Date startDate;
+    private Integer interval;
+    private Date endDate;
+
+    public Task(String name, String description, Date startDate) {
+        this.name = name;
+        this.description = description;
+        this.startDate = endDate;
+    }
+
+    // Builder-pattern-style setters
+    public Task withId(long id) {
+        this.id = id;
+        return this;
+    }
+    public Task withInterval(int interval) {
+        this.interval = interval;
+        return this;
+    }
+    public Task withEndDate(Date endDate) {
+        this.endDate = endDate;
+        return this;
+    }
+
+    // Getters
+    public long getId() { return id; }
+    public String getName() { return name; }
+    public String getDescription() { return description; }
+    public Date getStartDate() { return startDate; }
+
+    public Optional<Integer> getInterval() {
+        return Optional.ofNullable(interval);
+    }
+    public Optional<Date> getEndDate() {
+        return Optional.ofNullable(endDate);
+    }
+}