18myx/tools--BackupUtils.txt

package net.micode.notes.tool;

// 导入必要的类
import android.content.Context;
import android.database.Cursor;
import android.os.Environment;
import android.text.TextUtils;
import android.text.format.DateFormat;
import android.util.Log;

import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.PrintStream;

// 备份工具类
public class BackupUtils {
    private static final String TAG = "BackupUtils";

    // 单例实例
    private static BackupUtils sInstance;

    // 获取实例的静态方法，确保在整个应用程序中只有一个实例存在
    public static synchronized BackupUtils getInstance(Context context) {
        if (sInstance == null) {
            sInstance = new BackupUtils(context);
        }
        return sInstance;
    }

    // 数据导出类
    private TextExport mTextExport;

    // 私有构造函数
    private BackupUtils(Context context) {
        mTextExport = new TextExport(context);
    }

    // 检查外部存储是否可用
    private static boolean externalStorageAvailable() {
        return Environment.MEDIA_MOUNTED.equals(Environment.getExternalStorageState());
    }

    // 导出数据到文本文件
    public int exportToText() {
        return mTextExport.exportToText();
    }

    // 获取导出的文本文件名
    public String getExportedTextFileName() {
        return mTextExport.mFileName;
    }

    // 获取导出的文本文件目录
    public String getExportedTextFileDir() {
        return mTextExport.mFileDirectory;
    }

    // 内部私有类，负责文本导出功能
    private static class TextExport {
        // 笔记和数据表的投影
        private static final String[] NOTE_PROJECTION = {
                NoteColumns.ID,
                NoteColumns.MODIFIED_DATE,
                NoteColumns.SNIPPET,
                NoteColumns.TYPE
        };

        private static final String[] DATA_PROJECTION = {
                DataColumns.CONTENT,
                DataColumns.MIME_TYPE,
                DataColumns.DATA1,
                DataColumns.DATA2,
                DataColumns.DATA3,
                DataColumns.DATA4,
        };

        // 笔记和数据表的列索引
        private static final int NOTE_COLUMN_ID = 0;
        private static final int NOTE_COLUMN_MODIFIED_DATE = 1;
        private static final int NOTE_COLUMN_SNIPPET = 2;
        private static final int DATA_COLUMN_CONTENT = 0;
        private static final int DATA_COLUMN_MIME_TYPE = 1;
        private static final int DATA_COLUMN_CALL_DATE = 2;
        private static final int DATA_COLUMN_PHONE_NUMBER = 4;

        // 文本格式数组
        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;

        // 上下文和文件名变量
        private Context mContext;
        private String mFileName;
        private String mFileDirectory;

        // 构造函数
        public TextExport(Context context) {
            TEXT_FORMAT = context.getResources().getStringArray(R.array.format_for_exported_note);
            mContext = context;
            mFileName = "";
            mFileDirectory = "";
        }

        // 获取文本格式字符串
        private String getFormat(int id) {
            return TEXT_FORMAT[id];
        }

        // 导出文件夹到文本
        private void exportFolderToText(String folderId, PrintStream ps) {
            // 查询文件夹下的笔记
            Cursor notesCursor = mContext.getContentResolver().query(Notes.CONTENT_NOTE_URI,
                    NOTE_PROJECTION, NoteColumns.PARENT_ID + "=?", new String[] {
                        folderId
                    }, null);

            // 如果存在笔记，则导出
            if (notesCursor != null) {
                if (notesCursor.moveToFirst()) {
                    do {
                        ps.println(String.format(getFormat(FORMAT_NOTE_DATE), DateFormat.format(
                                mContext.getString(R.string.format_datetime_mdhm),
                                notesCursor.getLong(NOTE_COLUMN_MODIFIED_DATE))));
                        String noteId = notesCursor.getString(NOTE_COLUMN_ID);
                        exportNoteToText(noteId, ps);
                    } while (notesCursor.moveToNext());
                }
                notesCursor.close();
            }
        }

        // 导出笔记到文本
        private void exportNoteToText(String noteId, PrintStream ps) {
            Cursor dataCursor = mContext.getContentResolver().query(Notes.CONTENT_DATA_URI,
                    DATA_PROJECTION, DataColumns.NOTE_ID + "=?", new String[] {
                        noteId
                    }, null);

            if (dataCursor != null) {
                if (dataCursor.moveToFirst()) {
                    do {
                        // 导出笔记内容
                        String mimeType = dataCursor.getString(DATA_COLUMN_MIME_TYPE);
                        if (DataConstants.CALL_NOTE.equals(mimeType)) {
                            // 导出电话笔记内容
                            // ...
                        } else if (DataConstants.NOTE.equals(mimeType)) {
                            // 导出普通笔记内容
                            // ...
                        }
                    } while (dataCursor.moveToNext());
                }
                dataCursor.close();
            }
        }

        // 导出到文本文件的主方法
        public int exportToText() {
            // 检查外部存储是否可用
            if (!externalStorageAvailable()) {
                Log.d(TAG, "Media was not mounted");
                return STATE_SD_CARD_UNMOUONTED;
            }

            // 获取文本文件打印流
            PrintStream ps = getExportToTextPrintStream();
            if (ps == null) {
                Log.e(TAG, "get print stream error");
                return STATE_SYSTEM_ERROR;
            }

            // 导出文件夹和笔记到文本文件
            // ...

            return STATE_SUCCESS;
        }

        // 获取导出到文本文件的打印流
        private PrintStream getExportToTextPrintStream() {
            // 生成文件
            File file = generateFileMountedOnSDcard(mContext, R.string.file_path,
                    R.string.file_name_txt_format);
            if (file == null) {
                Log.e(TAG, "create file to exported failed");
                return null;
            }
            mFileName = file.getName();
            mFileDirectory = mContext.getString(R.string.file_path);
            PrintStream ps = null;
            try {
                FileOutputStream fos = new FileOutputStream(file);
                ps = new PrintStream(fos);
            } catch (FileNotFoundException e) {
                e.printStackTrace();
                return null;
            } catch (NullPointerException e) {
                e.printStackTrace();
                return null;
            }
            return ps;
        }
    }

    // 导出状态常量
    public static final int STATE_SD_CARD_UNMOUONTED = 0;
    public static final int STATE_SUCCESS = 4;
    public static final int STATE_SYSTEM_ERROR = 3;

    // 构造导出工具
    public BackupUtils(Context context) {
        mTextExport = new TextExport(context);
    }

    // 外部存储是否可用
    private static boolean externalStorageAvailable
    // 外部存储是否可用
    private static boolean externalStorageAvailable() {
        return Environment.MEDIA_MOUNTED.equals(Environment.getExternalStorageState());
    }

    // 生成文件存储在SD卡上
    private static File generateFileMountedOnSDcard(Context context, int filePathResId, int fileNameFormatResId) {
        StringBuilder sb = new StringBuilder();
        sb.append(Environment.getExternalStorageDirectory()); // 获取SD卡路径
        sb.append(context.getString(filePathResId)); // 获取文件路径
        File filedir = new File(sb.toString()); // 创建文件路径对象
        sb.append(context.getString(
                fileNameFormatResId,
                DateFormat.format(context.getString(R.string.format_date_ymd),
                        System.currentTimeMillis())));
        File file = new File(sb.toString());

        try {
            if (!filedir.exists()) {
                filedir.mkdir(); // 如果路径不存在，则创建路径
            }
            if (!file.exists()) {
                file.createNewFile(); // 如果文件不存在，则创建文件
            }
            return file;
        } catch (SecurityException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
        return null;
    }
}