Java tutorial
/* 50AH-code ========= 50 Android Hacks (http://manning.com/sessa/) book source code Copyright (c) 2012 Manning Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions: The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software. THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. */ /******************************************************************************* * Copyright (c) 2012 Manning * See the file license.txt for copying permission. ******************************************************************************/ package com.manning.androidhacks.hack023.dao; import java.util.ArrayList; import java.util.List; import android.content.ContentResolver; import android.content.ContentValues; import android.database.Cursor; import com.manning.androidhacks.hack023.model.Todo; import com.manning.androidhacks.hack023.provider.StatusFlag; import com.manning.androidhacks.hack023.provider.TodoContentProvider; public class TodoDAO { private static final TodoDAO instance = new TodoDAO(); private TodoDAO() { } public static TodoDAO getInstance() { return instance; } public void addNewTodo(ContentResolver contentResolver, Todo item) { addNewTodo(contentResolver, item, StatusFlag.ADD); } public void addNewTodo(ContentResolver contentResolver, Todo list, int flag) { ContentValues contentValue = getTodoContentValues(list, flag); contentResolver.insert(TodoContentProvider.CONTENT_URI, contentValue); } private ContentValues getTodoContentValues(Todo todo, int flag) { ContentValues cv = new ContentValues(); cv.put(TodoContentProvider.COLUMN_SERVER_ID, todo.getId()); cv.put(TodoContentProvider.COLUMN_TITLE, todo.getTitle()); cv.put(TodoContentProvider.COLUMN_STATUS_FLAG, flag); return cv; } public List<Todo> getCleanTodos(ContentResolver contentResolver) { return getTodosWithSelection(contentResolver, TodoContentProvider.COLUMN_STATUS_FLAG + " = " + StatusFlag.CLEAN); } private List<Todo> getTodosWithSelection(ContentResolver contentResolver, String selection) { Cursor cursor = contentResolver.query(TodoContentProvider.CONTENT_URI, null, selection, null, null); List<Todo> list = new ArrayList<Todo>(); while (cursor.moveToNext()) { int localId = cursor.getInt(cursor.getColumnIndexOrThrow(TodoContentProvider.COLUMN_ID)); int serverId = cursor.getInt(cursor.getColumnIndexOrThrow(TodoContentProvider.COLUMN_SERVER_ID)); String name = cursor.getString(cursor.getColumnIndexOrThrow(TodoContentProvider.COLUMN_TITLE)); int status = cursor.getInt(cursor.getColumnIndexOrThrow(TodoContentProvider.COLUMN_STATUS_FLAG)); Todo currentTodo = new Todo(); if (status == StatusFlag.ADD) { currentTodo.setId((long) localId); } else { currentTodo.setId((long) serverId); } currentTodo.setTitle(name); currentTodo.setStatus(status); list.add(currentTodo); } cursor.close(); return list; } public int deleteTodo(ContentResolver contentResolver, Long id) { int ret = 0; /* Using the local id */ int status = getTodoStatus(contentResolver, id); switch (status) { case StatusFlag.ADD: ret = contentResolver.delete(TodoContentProvider.CONTENT_URI, TodoContentProvider.COLUMN_ID + "=" + id, null); break; case StatusFlag.MOD: case StatusFlag.CLEAN: ContentValues cv = new ContentValues(); cv.put(TodoContentProvider.COLUMN_STATUS_FLAG, StatusFlag.DELETE); contentResolver.update(TodoContentProvider.CONTENT_URI, cv, TodoContentProvider.COLUMN_ID + "=" + id, null); break; default: throw new RuntimeException("Tried to delete a todo with invalid status"); } return ret; } public int getTodoStatus(ContentResolver contentResolver, Long id) { Cursor c = contentResolver.query(TodoContentProvider.CONTENT_URI, null, TodoContentProvider.COLUMN_ID + "=" + id, null, null); int status = 0; try { if (c.moveToNext()) { status = c.getInt(c.getColumnIndexOrThrow(TodoContentProvider.COLUMN_STATUS_FLAG)); } else { throw new RuntimeException("Tried to delete a non existent todo"); } } finally { c.close(); } return status; } public int forcedDeleteTodo(ContentResolver contentResolver, Long id) { return contentResolver.delete(TodoContentProvider.CONTENT_URI, TodoContentProvider.COLUMN_SERVER_ID + "=" + id, null); } public Todo isTodoInDb(ContentResolver contentResolver, Long serverId) { Todo todo = null; Cursor cursor = contentResolver.query(TodoContentProvider.CONTENT_URI, null, TodoContentProvider.COLUMN_SERVER_ID + "=" + serverId, null, null); if (cursor.moveToNext()) { String name = cursor.getString(cursor.getColumnIndexOrThrow(TodoContentProvider.COLUMN_TITLE)); int status = cursor.getInt(cursor.getColumnIndexOrThrow(TodoContentProvider.COLUMN_STATUS_FLAG)); todo = new Todo(); todo.setId(serverId); todo.setTitle(name); todo.setStatus(status); } cursor.close(); return todo; } public void modifyTodoFromServer(ContentResolver contentResolver, Todo list) { ContentValues cv = new ContentValues(); cv.put(TodoContentProvider.COLUMN_TITLE, list.getTitle()); cv.put(TodoContentProvider.COLUMN_STATUS_FLAG, StatusFlag.CLEAN); contentResolver.update(TodoContentProvider.CONTENT_URI, cv, TodoContentProvider.COLUMN_SERVER_ID + "=" + list.getId(), null); } public List<Todo> getDirtyList(ContentResolver mContentResolver) { return getTodosWithSelection(mContentResolver, TodoContentProvider.COLUMN_STATUS_FLAG + " != " + StatusFlag.CLEAN); } public void clearAdd(ContentResolver contentResolver, long id, Todo serverTodo) { ContentValues cv = getTodoContentValues(serverTodo, StatusFlag.CLEAN); contentResolver.update(TodoContentProvider.CONTENT_URI, cv, TodoContentProvider.COLUMN_ID + "=" + id, null); } public int deleteTodoForced(ContentResolver contentResolver, long id) { return contentResolver.delete(TodoContentProvider.CONTENT_URI, TodoContentProvider.COLUMN_SERVER_ID + "=" + id, null); } }