diff --git a/Note.java b/Note.java
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+/*
+ * Copyright (c) 2010-2011, The MiCode Open Source Community (www.micode.net)
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package net.micode.notes.model;
+import android.content.ContentProviderOperation;//批量的更新、插入、删除数据
+import android.content.ContentProviderResult;//操作后的结果
+import android.content.ContentUris;//用于添加和获取uri后面的id
+import android.content.ContentValues;//一种用于存储基本数据类型数据的存储机制
+import android.content.Context;//需要用该类来弄清楚调用者的实例
+import android.content.OperationApplicationException;//操作应用程序容错
+import android.net.Uri;//表示待操作的数据
+import android.os.RemoteException;//远程容错
+import android.util.Log;//输出日志，比如说出错、警告等
+
+import net.micode.notes.data.Notes;
+import net.micode.notes.data.Notes.CallNote;
+import net.micode.notes.data.Notes.DataColumns;
+import net.micode.notes.data.Notes.NoteColumns;
+import net.micode.notes.data.Notes.TextNote;
+
+import java.util.ArrayList;
+
+
+public class Note {
+    private ContentValues mNoteDiffValues;
+    private NoteData mNoteData;
+    private static final String TAG = "Note";
+    /**
+     * Create a new note id for adding a new note to databases
+     */
+    public static synchronized long getNewNoteId(Context context, long folderId) {
+        // Create a new note in the database
+        ContentValues values = new ContentValues();
+        long createdTime = System.currentTimeMillis();
+        values.put(NoteColumns.CREATED_DATE, createdTime);
+        values.put(NoteColumns.MODIFIED_DATE, createdTime);
+        values.put(NoteColumns.TYPE, Notes.TYPE_NOTE);
+        values.put(NoteColumns.LOCAL_MODIFIED, 1);
+        values.put(NoteColumns.PARENT_ID, folderId);//将数据写入数据库表格
+        Uri uri = context.getContentResolver().insert(Notes.CONTENT_NOTE_URI, values);
+//ContentResolver()主要是实现外部应用对ContentProvider中的数据
+//进行添加、删除、修改和查询操作
+        long noteId = 0;
+        try {
+            noteId = Long.valueOf(uri.getPathSegments().get(1));
+        } catch (NumberFormatException e) {
+            Log.e(TAG, "Get note id error :" + e.toString());
+            noteId = 0;
+        }//try-catch异常处理
+        if (noteId == -1) {
+            throw new IllegalStateException("Wrong note id:" + noteId);
+        }
+        return noteId;
+    }
+
+    public Note() {
+        mNoteDiffValues = new ContentValues();
+        mNoteData = new NoteData();
+    }//定义两个变量用来存储便签的数据，一个是存储便签属性，一个是存储便签内容
+
+    public void setNoteValue(String key, String value) {
+        mNoteDiffValues.put(key, value);
+        mNoteDiffValues.put(NoteColumns.LOCAL_MODIFIED, 1);
+        mNoteDiffValues.put(NoteColumns.MODIFIED_DATE, System.currentTimeMillis());
+    }//设置数据库表格的标签属性数据
+
+    public void setTextData(String key, String value) {
+        mNoteData.setTextData(key, value);
+    }//设置数据库表格的标签文本内容的数据
+
+    public void setTextDataId(long id) {
+       mNoteData.setTextDataId(id);
+    }//设置文本数据的id
+    public long getTextDataId() {
+        return mNoteData.mTextDataId;
+    }//得到文本数据的id
+
+    public void setCallDataId(long id) {
+        mNoteData.setCallDataId(id);
+    }//设置电话号码数据的id
+
+    public void setCallData(String key, String value) {
+        mNoteData.setCallData(key, value);
+    }//得到电话号码数据的id
+
+    public boolean isLocalModified() {
+        return mNoteDiffValues.size() > 0 || mNoteData.isLocalModified();
+    }//判断是否是本地修改
+
+    public boolean syncNote(Context context, long noteId) {
+        if (noteId <= 0) {
+            throw new IllegalArgumentException("Wrong note id:" + noteId);
+        }
+
+        if (!isLocalModified()) {
+            return true;
+        }
+
+        /**
+         * In theory, once data changed, the note should be updated on {@link NoteColumns#LOCAL_MODIFIED} and
+         * {@link NoteColumns#MODIFIED_DATE}. For data safety, though update note fails, we also update the
+         * note data info
+         */
+        if (context.getContentResolver().update(
+                ContentUris.withAppendedId(Notes.CONTENT_NOTE_URI, noteId), mNoteDiffValues, null,
+                null) == 0) {
+            Log.e(TAG, "Update note error, should not happen");
+            // Do not return, fall through
+        }
+        mNoteDiffValues.clear();
+
+        if (mNoteData.isLocalModified()
+                && (mNoteData.pushIntoContentResolver(context, noteId) == null)) {
+            return false;
+        }
+
+        return true;
+    }//判断数据是否同步
+
+    private class NoteData {//定义一个基本的便签内容的数据类，主要包含文本数据和电话号码数据
+        private long mTextDataId;
+
+        private ContentValues mTextDataValues;//文本数据
+
+        private long mCallDataId;
+
+        private ContentValues mCallDataValues;//电话号码数据
+
+        private static final String TAG = "NoteData";
+
+        public NoteData() {
+            mTextDataValues = new ContentValues();
+            mCallDataValues = new ContentValues();
+            mTextDataId = 0;
+            mCallDataId = 0;
+        }
+//下面是上述几个函数的具体实现
+        boolean isLocalModified() {
+            return mTextDataValues.size() > 0 || mCallDataValues.size() > 0;
+        }
+
+        void setTextDataId(long id) {
+            if(id <= 0) {
+                throw new IllegalArgumentException("Text data id should larger than 0");
+            }
+            mTextDataId = id;
+        }
+
+        void setCallDataId(long id) {
+            if (id <= 0) {
+                throw new IllegalArgumentException("Call data id should larger than 0");
+            }
+            mCallDataId = id;
+        }
+
+        void setCallData(String key, String value) {
+            mCallDataValues.put(key, value);
+            mNoteDiffValues.put(NoteColumns.LOCAL_MODIFIED, 1);
+            mNoteDiffValues.put(NoteColumns.MODIFIED_DATE, System.currentTimeMillis());
+        }
+
+        void setTextData(String key, String value) {
+            mTextDataValues.put(key, value);
+            mNoteDiffValues.put(NoteColumns.LOCAL_MODIFIED, 1);
+            mNoteDiffValues.put(NoteColumns.MODIFIED_DATE, System.currentTimeMillis());
+        }
+//下面函数的作用是将新的数据通过uri的操作存储到数据库
+        Uri pushIntoContentResolver(Context context, long noteId) {
+            /**
+             * Check for safety
+             */
+            if (noteId <= 0) {
+                throw new IllegalArgumentException("Wrong note id:" + noteId);
+            }//判断数据是否合法
+
+            ArrayList<ContentProviderOperation> operationList = new ArrayList<ContentProviderOperation>();
+            ContentProviderOperation.Builder builder = null;//数据库的操作列表
+
+            if(mTextDataValues.size() > 0) {
+                mTextDataValues.put(DataColumns.NOTE_ID, noteId);
+                if (mTextDataId == 0) {
+                    mTextDataValues.put(DataColumns.MIME_TYPE, TextNote.CONTENT_ITEM_TYPE);
+                    Uri uri = context.getContentResolver().insert(Notes.CONTENT_DATA_URI,
+                            mTextDataValues);
+                    try {
+                        setTextDataId(Long.valueOf(uri.getPathSegments().get(1)));
+                    } catch (NumberFormatException e) {
+                        Log.e(TAG, "Insert new text data fail with noteId" + noteId);
+                        mTextDataValues.clear();
+                        return null;
+                    }
+                } else {
+                    builder = ContentProviderOperation.newUpdate(ContentUris.withAppendedId(
+                            Notes.CONTENT_DATA_URI, mTextDataId));
+                    builder.withValues(mTextDataValues);
+                    operationList.add(builder.build());
+                }
+                mTextDataValues.clear();
+            }//把文本数据存入DataColumns
+
+            if(mCallDataValues.size() > 0) {
+                mCallDataValues.put(DataColumns.NOTE_ID, noteId);
+                if (mCallDataId == 0) {
+                    mCallDataValues.put(DataColumns.MIME_TYPE, CallNote.CONTENT_ITEM_TYPE);
+                    Uri uri = context.getContentResolver().insert(Notes.CONTENT_DATA_URI,
+                            mCallDataValues);
+                    try {
+                        setCallDataId(Long.valueOf(uri.getPathSegments().get(1)));
+                    } catch (NumberFormatException e) {
+                        Log.e(TAG, "Insert new call data fail with noteId" + noteId);
+                        mCallDataValues.clear();
+                        return null;
+                    }
+                } else {
+                    builder = ContentProviderOperation.newUpdate(ContentUris.withAppendedId(
+                            Notes.CONTENT_DATA_URI, mCallDataId));
+                    builder.withValues(mCallDataValues);
+                    operationList.add(builder.build());
+                }
+                mCallDataValues.clear();
+            }//吧电话号码数据存入DataColumns
+
+            if (operationList.size() > 0) {
+                try {
+                    ContentProviderResult[] results = context.getContentResolver().applyBatch(
+                            Notes.AUTHORITY, operationList);
+                    return (results == null || results.length == 0 || results[0] == null) ? null
+                            : ContentUris.withAppendedId(Notes.CONTENT_NOTE_URI, noteId);
+                } catch (RemoteException e) {
+                    Log.e(TAG, String.format("%s: %s", e.toString(), e.getMessage()));
+                    return null;
+                } catch (OperationApplicationException e) {
+                    Log.e(TAG, String.format("%s: %s", e.toString(), e.getMessage()));
+                    return null;
+                }
+            }//存储过程中的异常处理
+            return null;
+        }
+    }
+}