Сринт 7. Добавить функцию чтения и записи задач в CSV файл

src/ru/alexgur/kanban/exceptions/ManageLoadException.java

@@ -0,0 +1,7 @@
+package ru.alexgur.kanban.exceptions;
+
+public class ManageLoadException extends RuntimeException {
+    public ManageLoadException(final String message) {
+        super(message);
+    }
+}

src/ru/alexgur/kanban/exceptions/ManagerSaveException.java

@@ -0,0 +1,7 @@
+package ru.alexgur.kanban.exceptions;
+
+public class ManagerSaveException extends RuntimeException {
+    public ManagerSaveException(final String message) {
+        super(message);
+    }
+}

src/ru/alexgur/kanban/model/Epic.java

@@ -1,12 +1,22 @@
 package ru.alexgur.kanban.model;
 
 import java.util.List;
+
+import ru.alexgur.kanban.service.TaskType;
+
 import java.util.ArrayList;
 
 public class Epic extends Task {
-
     private List<Integer> subTasksIds = new ArrayList<>();
 
+    public Epic() {
+        super();
+    }
+
+    public Epic(int id) {
+        super(id);
+    }
+
     public List<Integer> getSubTasksIds() {
         return subTasksIds;
     }
@@ -29,6 +39,11 @@ public void deleteSubTask(Integer subTasksId) {
         subTasksIds.remove(subTasksId);
     }
 
+    @Override
+    public TaskType getType() {
+        return TaskType.EPIC;
+    }
+
     @Override
     public String toString() {
         return "Task [id=" + id + ", name=" + getName() + ", text=" + getText() + ", status=" + getStatus()

src/ru/alexgur/kanban/model/SubTask.java

@@ -1,9 +1,18 @@
 package ru.alexgur.kanban.model;
 
-public class SubTask extends Task {
+import ru.alexgur.kanban.service.TaskType;
 
+public class SubTask extends Task {
     private int epicId = -1;
 
+    public SubTask() {
+        super();
+    }
+
+    public SubTask(int id) {
+        super(id);
+    }
+
     public SubTask setEpicId(int epicId) {
         if (this.epicId == -1 && this.id != epicId) {
             this.epicId = epicId;
@@ -15,6 +24,11 @@ public int getEpicId() {
         return this.epicId;
     }
 
+    @Override
+    public TaskType getType() {
+        return TaskType.SUBTASK;
+    }
+
     @Override
     public String toString() {
         return "Task [id=" + id + ", name=" + getName() + ", text=" + getText() + ", status=" + getStatus()

src/ru/alexgur/kanban/model/Task.java

@@ -1,6 +1,7 @@
 package ru.alexgur.kanban.model;
 
 import ru.alexgur.kanban.service.Status;
+import ru.alexgur.kanban.service.TaskType;
 
 public class Task {
     private static int globalId = 0; // значение для генерации id экземпляров
@@ -14,6 +15,18 @@ public Task() {
         id = ++globalId;
     }
 
+    public Task(int id) {
+        this.status = Status.NEW;
+        if (globalId < id) {
+            globalId = id;
+        }
+        this.id = id;
+    }
+
+    public TaskType getType() {
+        return TaskType.TASK;
+    }
+
     public int getId() {
         return id;
     }

src/ru/alexgur/kanban/service/FileBackedTaskManager.java

@@ -0,0 +1,216 @@
+package ru.alexgur.kanban.service;
+
+import java.util.List;
+
+import ru.alexgur.kanban.exceptions.ManageLoadException;
+import ru.alexgur.kanban.exceptions.ManagerSaveException;
+import ru.alexgur.kanban.model.Epic;
+import ru.alexgur.kanban.model.SubTask;
+import ru.alexgur.kanban.model.Task;
+import java.io.BufferedReader;
+import java.io.File;
+import java.io.FileReader;
+import java.io.FileWriter;
+import java.io.IOException;
+
+public class FileBackedTaskManager extends InMemoryTaskManager {
+    private File fileToSave;
+    private String eol = "\n";
+    private String csvSplitter = ";";
+
+    @Override
+    public int addTask(Task task) {
+        int newId = super.addTask(task);
+        save();
+        return newId;
+    }
+
+    @Override
+    public int addEpic(Epic epic) {
+        int newId = super.addEpic(epic);
+        save();
+        return newId;
+    }
+
+    @Override
+    public int addSubTask(SubTask subTask) {
+        int newId = super.addSubTask(subTask);
+        save();
+        return newId;
+    }
+
+    @Override
+    public void updateTask(Task task) {
+        super.updateTask(task);
+        save();
+    }
+
+    @Override
+    public void updateSubTask(SubTask subtask) {
+        super.updateSubTask(subtask);
+        save();
+    }
+
+    @Override
+    public void updateEpic(Epic epic) {
+        super.updateEpic(epic);
+        save();
+    }
+
+    @Override
+    public void deleteTask(int id) {
+        super.deleteTask(id);
+        save();
+    }
+
+    @Override
+    public void deleteTasks() {
+        super.deleteTasks();
+        save();
+    }
+
+    @Override
+    public void deleteSubTask(int id) {
+        super.deleteSubTask(id);
+        save();
+    }
+
+    @Override
+    public void deleteSubTasks() {
+        super.deleteSubTasks();
+        save();
+    }
+
+    @Override
+    public void deleteEpic(int id) {
+        super.deleteEpic(id);
+        save();
+    }
+
+    @Override
+    public void deleteEpics() {
+        super.deleteEpics();
+        save();
+    }
+
+    public File getFile() {
+        return fileToSave;
+    }
+
+    public void setFile(File fileToSave) {
+        this.fileToSave = fileToSave;
+    }
+
+    public String getEol() {
+        return eol;
+    }
+
+    public void setEol(String eol) {
+        this.eol = eol;
+    }
+
+    public String getCsvSplitter() {
+        return csvSplitter;
+    }
+
+    public void setCsvSplitter(String csvSplitter) {
+        this.csvSplitter = csvSplitter;
+    }
+
+    public static FileBackedTaskManager loadFromFile(File file) {
+        FileBackedTaskManager taskManager = new FileBackedTaskManager();
+        try (BufferedReader reader = new BufferedReader(new FileReader(file))) {
+            String line;
+            while ((line = reader.readLine()) != null) {
+                line = line.trim();
+                if (line.startsWith("id") || line.isEmpty()) {
+                    continue;
+                }
+
+                Task task = (Task) taskManager.fromString(line);
+
+                if (task.getType() == TaskType.TASK) {
+                    taskManager.addTask(task);
+                } else if (task.getType() == TaskType.SUBTASK) {
+                    taskManager.addSubTask((SubTask) task);
+                } else if (task.getType() == TaskType.EPIC) {
+                    taskManager.addEpic((Epic) task);
+                }
+            }
+        } catch (IOException e) {
+            throw new ManageLoadException("Произошла ошибка во время загрузки файла.");
+        }
+
+        taskManager.updateEpicsSubTasksIds();
+        taskManager.setFile(file);
+        return taskManager;
+    }
+
+    private void save() {
+        if (fileToSave == null) {
+            return;
+        }
+
+        try (FileWriter fileWriter = new FileWriter(fileToSave)) {
+            String csvHeader = "id,type,name,status,description,epic";
+            fileWriter.write(csvHeader + eol);
+
+            for (List<? extends Task> target : List.of(getTasks(), getSubTasks(), getEpics())) {
+                for (Task task : target) {
+                    fileWriter.write(toString(task));
+                }
+            }
+        } catch (IOException e) {
+            throw new ManagerSaveException("Произошла ошибка во время записи файла.");
+        }
+    }
+
+    private <T extends Task> String toString(T task) {
+        String epicId = "";
+        if (task instanceof SubTask) {
+            epicId = String.valueOf(((SubTask) task).getEpicId());
+        }
+        return task.id
+                + csvSplitter
+                + task.getType()
+                + csvSplitter
+                + task.getName()
+                + csvSplitter
+                + task.getStatus()
+                + csvSplitter
+                + task.getText()
+                + csvSplitter
+                + epicId
+                + csvSplitter
+                + eol;
+    }
+
+    private Object fromString(String line) {
+        String[] args = line.trim().split(csvSplitter);
+
+        int id = Integer.valueOf(args[0]);
+        TaskType type = TaskType.valueOf(args[1]);
+        Status status = Status.valueOf(args[3]);
+        String name = args[2];
+        String text = args[4];
+
+        switch (type) {
+            case TASK:
+                Task task = new Task(id);
+                task.setName(name).setText(text).setStatus(status);
+                return task;
+            case SUBTASK:
+                int epicId = Integer.valueOf(args[5]);
+
+                SubTask subTask = new SubTask(id);
+                subTask.setName(name).setText(text).setStatus(status);
+                subTask.setEpicId(epicId);
+                return subTask;
+            case EPIC:
+                Epic epic = new Epic(id);
+                epic.setName(name).setText(text);
+                return epic;
+        }
+        return null;
+    }
+}