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Update BackupUtils.java

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pull/2/head
puavjn2x9 11 months ago
parent e2718d4bac
commit a8597d0950
1 changed files with 59 additions and 55 deletions
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114
src/net/micode/notes/tool/BackupUtils.java
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@ -37,13 +37,13 @@ import java.io.PrintStream;
public class BackupUtils {
private static final String TAG = "BackupUtils";
private static final String TAG = "BackupUtils";// 定义了一个私有静态常量字符串TAG，用于在日志中标记该类
// Singleton stuff
private static BackupUtils sInstance;
private static BackupUtils sInstance;// 声明了一个私有静态BackupUtils对象sInstance，用于实现单例模式
public static synchronized BackupUtils getInstance(Context context) {
public static synchronized BackupUtils getInstance(Context context) {//获取BackupUtils类的实例的静态方法
if (sInstance == null) {
sInstance = new BackupUtils(context);
sInstance = new BackupUtils(context);//在第一次调用时，会创建一个新的BackupUtils对象，并将其赋值给静态变量sInstance
}
return sInstance;
}
@ -53,53 +53,53 @@ public class BackupUtils {
* status
*/
// Currently, the sdcard is not mounted
public static final int STATE_SD_CARD_UNMOUONTED = 0;
public static final int STATE_SD_CARD_UNMOUONTED = 0;//表示sd卡未挂载的状态。
// The backup file not exist
public static final int STATE_BACKUP_FILE_NOT_EXIST = 1;
public static final int STATE_BACKUP_FILE_NOT_EXIST = 1;//表示备份文件不存在的状态
// The data is not well formated, may be changed by other programs
public static final int STATE_DATA_DESTROIED = 2;
public static final int STATE_DATA_DESTROIED = 2;//表示数据格式错误，可能被其他程序修改的状态
// Some run-time exception which causes restore or backup fails
public static final int STATE_SYSTEM_ERROR = 3;
public static final int STATE_SYSTEM_ERROR = 3;//表示备份或还原过程中发生运行时异常的状态
// Backup or restore success
public static final int STATE_SUCCESS = 4;
public static final int STATE_SUCCESS = 4;//表示备份或还原成功的状态
private TextExport mTextExport;
private BackupUtils(Context context) {
private BackupUtils(Context context) {//用于初始化BackupUtils对象。在构造函数内部，创建了一个TextExport对象mTextExport。
mTextExport = new TextExport(context);
}
private static boolean externalStorageAvailable() {
private static boolean externalStorageAvailable() {//检查外部存储是否可用
return Environment.MEDIA_MOUNTED.equals(Environment.getExternalStorageState());
}
public int exportToText() {
public int exportToText() {//执行导出到文本的操作
return mTextExport.exportToText();
}
public String getExportedTextFileName() {
public String getExportedTextFileName() {//返回导出的文本文件名
return mTextExport.mFileName;
}
public String getExportedTextFileDir() {
public String getExportedTextFileDir() {//导出的文本文件所在目录
return mTextExport.mFileDirectory;
}
private static class TextExport {
private static final String[] NOTE_PROJECTION = {
private static class TextExport {//处理文本导出的具体实现
private static final String[] NOTE_PROJECTION = {//查询备份数据的列名
NoteColumns.ID,
NoteColumns.MODIFIED_DATE,
NoteColumns.SNIPPET,
NoteColumns.TYPE
};
private static final int NOTE_COLUMN_ID = 0;
private static final int NOTE_COLUMN_ID = 0;//笔记的ID列索引
private static final int NOTE_COLUMN_MODIFIED_DATE = 1;
private static final int NOTE_COLUMN_MODIFIED_DATE = 1;//修改日期列索引
private static final int NOTE_COLUMN_SNIPPET = 2;
private static final int NOTE_COLUMN_SNIPPET = 2;//摘要列索引
private static final String[] DATA_PROJECTION = {
private static final String[] DATA_PROJECTION = {//查询的数据列
DataColumns.CONTENT,
DataColumns.MIME_TYPE,
DataColumns.DATA1,
@ -116,14 +116,14 @@ public class BackupUtils {
private static final int DATA_COLUMN_PHONE_NUMBER = 4;
private final String [] TEXT_FORMAT;
private static final int FORMAT_FOLDER_NAME = 0;
private static final int FORMAT_NOTE_DATE = 1;
private static final int FORMAT_NOTE_CONTENT = 2;
private final String [] TEXT_FORMAT;//存储了用于格式化导出文本的模板字符串
private static final int FORMAT_FOLDER_NAME = 0;//文件夹名称的格式索引
private static final int FORMAT_NOTE_DATE = 1;//笔记日期的格式索引
private static final int FORMAT_NOTE_CONTENT = 2;//笔记内容的格式索引
private Context mContext;
private String mFileName;
private String mFileDirectory;
private Context mContext;//上下文对象
private String mFileName;//文件名
private String mFileDirectory;//文件所在的目录
public TextExport(Context context) {
TEXT_FORMAT = context.getResources().getStringArray(R.array.format_for_exported_note);
@ -139,7 +139,7 @@ public class BackupUtils {
/**
* Export the folder identified by folder id to text
*/
private void exportFolderToText(String folderId, PrintStream ps) {
private void exportFolderToText(String folderId, PrintStream ps) {//将该文件夹中的笔记导出为文本
// Query notes belong to this folder
Cursor notesCursor = mContext.getContentResolver().query(Notes.CONTENT_NOTE_URI,
NOTE_PROJECTION, NoteColumns.PARENT_ID + "=?", new String[] {
@ -148,12 +148,13 @@ public class BackupUtils {
if (notesCursor != null) {
if (notesCursor.moveToFirst()) {
do {
do {// 打印笔记的最后修改日期
// Print note's last modified date
ps.println(String.format(getFormat(FORMAT_NOTE_DATE), DateFormat.format(
mContext.getString(R.string.format_datetime_mdhm),
notesCursor.getLong(NOTE_COLUMN_MODIFIED_DATE))));
// Query data belong to this note
// 查询属于该笔记的数据
String noteId = notesCursor.getString(NOTE_COLUMN_ID);
exportNoteToText(noteId, ps);
} while (notesCursor.moveToNext());
@ -171,17 +172,18 @@ public class BackupUtils {
noteId
}, null);
if (dataCursor != null) {
if (dataCursor != null) {//是否有符合条件的数据行
if (dataCursor.moveToFirst()) {
// 遍历游标以检索每个数据行的MIME类型
do {
String mimeType = dataCursor.getString(DATA_COLUMN_MIME_TYPE);
if (DataConstants.CALL_NOTE.equals(mimeType)) {
if (DataConstants.CALL_NOTE.equals(mimeType)) {// 将电话号码、通话日期和位置信息打印到输出流中
// Print phone number
String phoneNumber = dataCursor.getString(DATA_COLUMN_PHONE_NUMBER);
long callDate = dataCursor.getLong(DATA_COLUMN_CALL_DATE);
String location = dataCursor.getString(DATA_COLUMN_CONTENT);
if (!TextUtils.isEmpty(phoneNumber)) {
if (!TextUtils.isEmpty(phoneNumber)) {//判断是否为空字符
ps.println(String.format(getFormat(FORMAT_NOTE_CONTENT),
phoneNumber));
}
@ -218,43 +220,45 @@ public class BackupUtils {
/**
* Note will be exported as text which is user readable
*/
public int exportToText() {
if (!externalStorageAvailable()) {
Log.d(TAG, "Media was not mounted");
return STATE_SD_CARD_UNMOUONTED;
public int exportToText() { //总函数，调用上面的exportFolder和exportNote
if (!externalStorageAvailable()) {// 检查外部存储是否可用（即 SD 卡是否已挂载）
Log.d(TAG, "Media was not mounted");// 如果外部存储不可用，则在日志中记录错误消息
return STATE_SD_CARD_UNMOUONTED;// 返回常量表示 SD 卡未挂载
}
PrintStream ps = getExportToTextPrintStream();
if (ps == null) {
PrintStream ps = getExportToTextPrintStream();// 获取一个打印流来写入导出的笔记
if (ps == null) {// 如果无法获取打印流，则记录错误消息并返回常量表示系统错误
Log.e(TAG, "get print stream error");
return STATE_SYSTEM_ERROR;
}
// 首先导出文件夹及其下的笔记
// First export folder and its notes
Cursor folderCursor = mContext.getContentResolver().query(
Notes.CONTENT_NOTE_URI,
Notes.CONTENT_NOTE_URI,// 查询内容 URI 表示要访问的数据库表
NOTE_PROJECTION,
"(" + NoteColumns.TYPE + "=" + Notes.TYPE_FOLDER + " AND "
"(" + NoteColumns.TYPE + "=" + Notes.TYPE_FOLDER + " AND "// 查询条件
+ NoteColumns.PARENT_ID + "<>" + Notes.ID_TRASH_FOLER + ") OR "
+ NoteColumns.ID + "=" + Notes.ID_CALL_RECORD_FOLDER, null, null);
+ NoteColumns.ID + "=" + Notes.ID_CALL_RECORD_FOLDER, null, null);//查询中用的可选参数
if (folderCursor != null) {
if (folderCursor != null) {// 如果能够查询到文件夹
if (folderCursor.moveToFirst()) {
do {
// Print folder's name
// 打印文件夹的名称
String folderName = "";
if(folderCursor.getLong(NOTE_COLUMN_ID) == Notes.ID_CALL_RECORD_FOLDER) {
if(folderCursor.getLong(NOTE_COLUMN_ID) == Notes.ID_CALL_RECORD_FOLDER) {// // 如果当前文件夹是来电录音文件夹
folderName = mContext.getString(R.string.call_record_folder_name);
} else {
folderName = folderCursor.getString(NOTE_COLUMN_SNIPPET);
}
if (!TextUtils.isEmpty(folderName)) {
ps.println(String.format(getFormat(FORMAT_FOLDER_NAME), folderName));
if (!TextUtils.isEmpty(folderName)) {// 如果文件夹名称不为空
ps.println(String.format(getFormat(FORMAT_FOLDER_NAME), folderName));// 写入文件夹名称到打印流中
}
String folderId = folderCursor.getString(NOTE_COLUMN_ID);
exportFolderToText(folderId, ps);
exportFolderToText(folderId, ps); // 导出当前文件夹的笔记到打印流中
} while (folderCursor.moveToNext());
}
folderCursor.close();
folderCursor.close();// 关闭查询结果集游标
}
// Export notes in root's folder
@ -264,7 +268,7 @@ public class BackupUtils {
NoteColumns.TYPE + "=" + +Notes.TYPE_NOTE + " AND " + NoteColumns.PARENT_ID
+ "=0", null, null);
if (noteCursor != null) {
if (noteCursor != null) {//导出在根文件夹中的笔记
if (noteCursor.moveToFirst()) {
do {
ps.println(String.format(getFormat(FORMAT_NOTE_DATE), DateFormat.format(
@ -285,15 +289,15 @@ public class BackupUtils {
/**
* Get a print stream pointed to the file {@generateExportedTextFile}
*/
private PrintStream getExportToTextPrintStream() {
File file = generateFileMountedOnSDcard(mContext, R.string.file_path,
private PrintStream getExportToTextPrintStream() {//私有方法，返回一个PrintStream对象，用于导出文本
File file = generateFileMountedOnSDcard(mContext, R.string.file_path,//调用generateFileMountedOnSDcard方法生成一个文件对象，作为导出文件的路径。
R.string.file_name_txt_format);
if (file == null) {
if (file == null) {//如果文件对象为空，表示创建导出文件失败，打印错误消息并返回空
Log.e(TAG, "create file to exported failed");
return null;
}
mFileName = file.getName();
mFileDirectory = mContext.getString(R.string.file_path);
mFileDirectory = mContext.getString(R.string.file_path);//将文件名和文件路径保存到相应的变量中
PrintStream ps = null;
try {
FileOutputStream fos = new FileOutputStream(file);
@ -321,10 +325,10 @@ public class BackupUtils {
fileNameFormatResId,
DateFormat.format(context.getString(R.string.format_date_ymd),
System.currentTimeMillis())));
File file = new File(sb.toString());
File file = new File(sb.toString());//在指定的路径上创建一个新的文件
try {
if (!filedir.exists()) {
if (!filedir.exists()) {//如果文件目录不存在，则尝试创建目录
filedir.mkdir();
}
if (!file.exists()) {
@ -334,7 +338,7 @@ public class BackupUtils {
} catch (SecurityException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
e.printStackTrace();//会打印错误信息并返回空
}
return null;

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