#17 taskdb.json changed to the right variable types, JsonTaskDatabase.java fully implemented and documented

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

@@ -1,67 +1,112 @@
 package ch.zhaw.gartenverwaltung.io;
 
-import ch.zhaw.gartenverwaltung.types.HardinessZone;
 import ch.zhaw.gartenverwaltung.types.Task;
 import com.fasterxml.jackson.databind.ObjectMapper;
 import com.fasterxml.jackson.datatype.jsr310.JavaTimeModule;
 import com.fasterxml.jackson.datatype.jsr310.deser.LocalDateDeserializer;
-import com.fasterxml.jackson.datatype.jsr310.deser.YearMonthDeserializer;
 
 import java.io.File;
 import java.io.IOException;
 import java.net.URL;
 import java.time.LocalDate;
-import java.time.YearMonth;
 import java.time.format.DateTimeFormatter;
 import java.util.Collections;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
 
+/**
+ * Implements the {@link TaskDatabase} interface for loading and writing {@link Task} objects
+ * from and to a JSON file.
+ * The reads are cached to minimize file-io operations.
+ */
 public class JsonTaskDatabase implements TaskDatabase{
+    IdProvider idProvider;
     private final URL dataSource = getClass().getResource("taskdb.json");
 
     private Map<Long, Task> taskMap = Collections.emptyMap();
 
+    /**
+     * Creating constant objects required to deserialize the {@link LocalDate} classes
+     */
     private final static JavaTimeModule timeModule = new JavaTimeModule();
     static {
-        DateTimeFormatter dateFormat = DateTimeFormatter.ofPattern("yy-MM");
-        YearMonthDeserializer dateDeserializer = new YearMonthDeserializer(dateFormat);
-        timeModule.addDeserializer(YearMonth.class, dateDeserializer);
+        DateTimeFormatter dateFormat = DateTimeFormatter.ofPattern("yyyy-MM-dd");
+        LocalDateDeserializer dateDeserializer = new LocalDateDeserializer(dateFormat);
+        timeModule.addDeserializer(LocalDate.class, dateDeserializer);
     }
 
+    /**
+     * If no data is currently loaded, data is loaded from {@link #dataSource}.
+     * In any case, the values of {@link #taskMap} are returned.
+     *
+     * @see TaskDatabase#getTaskList(LocalDate, LocalDate)
+     */
     @Override
     public List<Task> getTaskList(LocalDate start, LocalDate end) throws IOException{
-
         if(taskMap.isEmpty()) {
             loadTaskListFromFile();
         }
         return taskMap.values().stream().filter(task -> task.isInTimePeriode(start, end)).toList();
     }
 
+    /**
+     * If no data is currently loaded, data is loaded from {@link #dataSource}.
+     * If the {@link Task} has an id than the task is added to the {@link #taskMap}
+     * otherwise the id is generated with the {@link IdProvider} before adding
+     * it to the {@link #taskMap}. In any case, the {@link #taskMap} is written
+     * to the {@link #dataSource}.
+     *
+     * @see TaskDatabase#saveTask(Task)
+     */
     @Override
     public void saveTask(Task task) throws IOException {
-        ObjectMapper mapper = new ObjectMapper();
-        if(dataSource != null) {
-            mapper.writeValue(new File(dataSource.getFile()), task);
+        if(taskMap.isEmpty()) {
+            loadTaskListFromFile();
         }
+        if(task.getId() == 0) {
+            task.withId(idProvider.incrementAndGet());
+        }
+        writeTaskListToFile();
     }
 
+    /**
+     * If no data is currently loaded, data is loaded from {@link #dataSource}.
+     * If the {@link Task}s id is found in the {@link #taskMap}, the Task is removed
+     * from the  {@link #taskMap}. Then the Task are written to the {@link #dataSource}.
+     *
+     * @see TaskDatabase#removeTask(Task)
+     */
     @Override
     public void removeTask(Task task) throws IOException {
-        if(!taskMap.isEmpty() && taskMap.containsKey(task.getId())){
+        if(taskMap.isEmpty()) {
+            loadTaskListFromFile();
+        }
+        if(taskMap.containsKey(task.getId())){
             taskMap.remove(task.getId());
+            writeTaskListToFile();
         }
     }
 
+    /**
+     * Writes cached data to the {@link #dataSource}.
+     *
+     * @throws IOException If the database cannot be accessed
+     */
     private void writeTaskListToFile() throws IOException {
         ObjectMapper mapper = new ObjectMapper();
         mapper.registerModule(timeModule);
 
-        mapper.writeValue(new File(dataSource.getFile()), taskMap);
+        if(dataSource != null) {
+            mapper.writeValue(new File(dataSource.getFile()), taskMap);
+        }
     }
 
-
+    /**
+     * Loads the database from {@link #dataSource} and updates the cached data.
+     *
+     * @throws IOException If the database cannot be accessed
+     */
     private void loadTaskListFromFile() throws IOException {
         if (dataSource != null) {
             ObjectMapper mapper = new ObjectMapper();
@@ -74,26 +119,6 @@ public class JsonTaskDatabase implements TaskDatabase{
                     .collect(HashMap::new,
                         (res, task) -> res.put(task.getId(), task),
                         (existing, replacement) -> {});
-            System.out.println(taskMap);
-        }
-    }
-
-    //Test main method
-    public static void main(String[] args) {
-        LocalDate date = LocalDate.now();
-        LocalDate yesterday = LocalDate.now();
-        yesterday = yesterday.minusDays(1);
-        Task testTask = new Task("water", "apply water", date);
-        JsonTaskDatabase jsonTaskDatabase = new JsonTaskDatabase();
-        JsonPlantDatabase jsonPlantDatabase = new JsonPlantDatabase();
-
-        try {
-            //test load file
-            jsonPlantDatabase.getPlantList(HardinessZone.ZONE_8A);
-            jsonTaskDatabase.loadTaskListFromFile();
-
-        } catch (Exception e){
-            System.out.println("Task load failed!: " + e.getMessage());
         }
     }
 }

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

@@ -1,5 +1,7 @@
 package ch.zhaw.gartenverwaltung.io;
 
+import ch.zhaw.gartenverwaltung.types.HardinessZone;
+import ch.zhaw.gartenverwaltung.types.Plant;
 import ch.zhaw.gartenverwaltung.types.Task;
 
 import java.io.IOException;
@@ -7,8 +9,34 @@ import java.time.LocalDate;
 import java.util.Date;
 import java.util.List;
 
+/**
+ * A database of {@link Task}s.
+ * The interface specifies the minimal required operations.
+ */
 public interface TaskDatabase {
+    /**
+     * Yields a list of all {@link Task}s in the database with the start and end date of a period of time.
+     *
+     * @param start The start date of the wanted time period
+     * @param end The end date of the wanted time period
+     * @return A list of {@link Task}s planned in the specified time period
+     * @throws IOException If the database cannot be accessed
+     */
     List<Task> getTaskList(LocalDate start, LocalDate end) throws IOException;
+
+    /**
+     * Saves the {@link Task} in the Cache.
+     *
+     * @param task The {@link Task} which is wanted to be saved in the TaskList
+     * @throws IOException If the database cannot be accessed
+     */
     void saveTask(Task task) throws IOException;
+
+    /**
+     * Removes the {@link Task}from the Cache.
+     *
+     * @param task The {@link Task} which has to be removed from the {@link Task} list.
+     * @throws IOException If the database cannot be accessed
+     */
     void removeTask(Task task) throws IOException;
 }

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

@@ -16,6 +16,16 @@ public class Task {
     private Integer interval;
     private LocalDate endDate;
 
+    /**
+     * default constructor
+     * (used by Json deserializer)
+     */
+    public Task(){
+        name= "";
+        description= "";
+        startDate = LocalDate.now();
+    }
+
     public Task(String name, String description, LocalDate startDate) {
         this.name = name;
         this.description = description;

src/main/resources/ch/zhaw/gartenverwaltung/io/taskdb.json

@@ -2,49 +2,49 @@
   {
   "id" : 1,
   "name" : "sow plant",
-  "description": "Plant the seeds/ crops in de bed.",
-  "startDate" : "22-05",
-  "endDate" : "22-05",
+  "description": "Plant the seeds, crops in de bed.",
+  "startDate" : "2022-05-01",
+  "endDate" : "2022-05-01",
   "interval" : 0
   },
   {
     "id" : 2,
     "name" : "water plant",
     "description": "water the plant, so that the soil is wet around the plant.",
-    "startDate" : "22-05",
-    "endDate" : "22-09",
+    "startDate" : "2022-05-01",
+    "endDate" : "2022-09-01",
     "interval" : 2
   },
   {
     "id" : 3,
     "name" : "fertilize plant",
-    "description": "The fertilizer has to be mixed with water. Then fertilize the plant's soil with the mixture",
-    "startDate" : "22-06",
-    "endDate" : "22-08",
+    "description": "The fertilizer has to be mixed with water. Then fertilize the plants soil with the mixture",
+    "startDate" : "2022-06-01",
+    "endDate" : "2022-08-01",
     "interval" : 28
   },
   {
     "id" : 4,
     "name" : "covering plant",
     "description": "Take a big enough coverage for the plants. Cover the whole plant with a bit space between the plant and the coverage",
-    "startDate" : "22-07",
-    "endDate" : "22-07",
+    "startDate" : "2022-07-01",
+    "endDate" : "2022-07-01",
     "interval" : 0
   },
   {
     "id" : 5,
     "name" : "look after plant",
     "description": "Look for pest or illness at the leaves of the plant. Check the soil around the plant, if the roots are enough covered with soil",
-    "startDate" : "22-05",
-    "endDate" : "22-09",
+    "startDate" : "2022-05-01",
+    "endDate" : "2022-09-01",
     "interval" : 5
   },
   {
     "id" : 6,
     "name" : "harvest plant",
     "description": "Pull the ripe vegetables out from the soil. Clean them with clear, fresh water. ",
-    "startDate" : "22-09",
-    "endDate" : "22-09",
+    "startDate" : "2022-09-01",
+    "endDate" : "2022-09-01",
     "interval" : 0
   }
 ]