Android 读取本地txt文件和写入txt文件到本地

*/

public class SaveDeviceMessageInfo {

public static String fileName = "id.txt";//保存设备ID

public static String rateName = "rate.txt";//保存设备收费标准



/**

 * 保存设备ID

 *

 * @param deviceId 输入的设备ID

 */

public static boolean saveDeviceId(String deviceId) {

    File file = new File(Constant.PATH_SAVE_DEVICE + fileName);

    if (file.exists()) {

        FileUtil.delete(Constant.PATH_SAVE_DEVICE + fileName);

    }

    return writeTxtToFile(Base64Util.encode(deviceId), Constant.PATH_SAVE_DEVICE, fileName);//对保存的设备ID加密保存

}



/**

 * 保存收费标准

 *

 * @param rate 输入的收费标准

 */

public static boolean saveRate(String rate) {

    File file = new File(Constant.PATH_RATE + rateName);

    if (file.exists()) {

        FileUtil.delete(Constant.PATH_RATE + rateName);

    }

    return writeTxtToFile(rate, Constant.PATH_RATE, rateName);//对保存的收费标准

}



/**

 * 字符串写入本地txt

 *

 * @param strcontent 文件内容

 * @param filePath   文件地址

 * @param fileName   文件名

 * @return 写入结果

 */

private static boolean writeTxtToFile(String strcontent, String filePath, String fileName) {

    boolean isSavaFile = false;

    makeFilePath(filePath, fileName);

    String strFilePath = filePath + fileName;

    String strContent = strcontent + "\r\n";

    try {

        File file = new File(strFilePath);

        if (!file.exists()) {

            Log.d("TestFile", "Create the file:" + strFilePath);

            file.getParentFile().mkdirs();

            file.createNewFile();

        }

        RandomAccessFile raf = new RandomAccessFile(file, "rwd");

        raf.seek(file.length());

        raf.write(strContent.getBytes());

        raf.close();

        isSavaFile = true;

    } catch (Exception e) {

        isSavaFile = false;

        Log.e("TestFile", "Error on write File:" + e);

    }

    return isSavaFile;

}



/**

 * 生成文件

 *

 * @param filePath 文件地址

 * @param fileName 文件名

 */

private static File makeFilePath(String filePath, String fileName) {

    File file = null;

    makeRootDirectory(filePath);

    try {

        file = new File(filePath + fileName);

        if (!file.exists()) {

            file.createNewFile();

        }

    } catch (Exception e) {

        e.printStackTrace();

    }

    return file;

}



/**

 * 生成文件夹

 */

public static void makeRootDirectory(String filePath) {

    File file = null;

    try {

        file = new File(filePath);

        if (!file.exists()) {

            file.mkdir();

        }

    } catch (Exception e) {

        Log.i("error:", e + "");

    }

}



/**

 * 读取本地文件

 */

public static String readDeviceId() {

    String path = Constant.PATH_SAVE_DEVICE + fileName;

    StringBuilder stringBuilder = new StringBuilder();

    File file = new File(path);

    if (!file.exists()) {

        return "";

    }

    if (file.isDirectory()) {

        Log.e("TestFile", "The File doesn't not exist.");

        return "";

    } else {

        try {

            InputStream instream = new FileInputStream(file);

            if (instream != null) {

                InputStreamReader inputreader = new InputStreamReader(instream);

                BufferedReader buffreader = new BufferedReader(inputreader);

                String line;

                while ((line = buffreader.readLine()) != null) {

                    stringBuilder.append(line);

                }

                instream.close();

            }

        } catch (java.io.FileNotFoundException e) {

            Log.e("TestFile", "The File doesn't not exist.");

            return "";

        } catch (IOException e) {

            Log.e("TestFile", e.getMessage());

            return "";

        }

    }

    return Base64Util.decode(stringBuilder.toString());//对读到的设备ID解密

}



/**

 * 读取本地文件

 */

public static String readRate() {

    String path = Constant.PATH_RATE + rateName;

    StringBuilder stringBuilder = new StringBuilder();

    File file = new File(path);

    if (!file.exists()) {

        return "";

    }

    if (file.isDirectory()) {

        Log.e("TestFile", "The File doesn't not exist.");

        return "";

    } else {

        try {

            InputStream instream = new FileInputStream(file);

            if (instream != null) {

                InputStreamReader inputreader = new InputStreamReader(instream);

                BufferedReader buffreader = new BufferedReader(inputreader);

                String line;

                while ((line = buffreader.readLine()) != null) {

                    stringBuilder.append(line);

                }

                instream.close();

            }

        } catch (java.io.FileNotFoundException e) {

            Log.e("TestFile", "The File doesn't not exist.");

            return "";

        } catch (IOException e) {

            Log.e("TestFile", e.getMessage());

            return "";

        }

    }

    return stringBuilder.toString();//对读到的设备ID解密

}

}

import java.io.BufferedReader;

import java.io.File;

import java.io.FileInputStream;

import java.io.FileNotFoundException;

import java.io.IOException;

import java.io.InputStream;

import java.io.InputStreamReader;

import java.util.HashMap;

import java.util.Map;

public class FileUtil {

/**

 * 遍历所有文件

 *

 * @param fileAbsolutePath 传入的文件的父目录

 */

public static Map<String, String> getFileName(final String fileAbsolutePath) {

    Map<String, String> map = new HashMap<>();

    File file = new File(fileAbsolutePath);

    File[] subFile = file.listFiles();

    try {

        if (subFile.length > 0) {

            for (int iFileLength = 0; iFileLength < subFile.length; iFileLength++) {

                // 判断是否为文件夹

                if (!subFile[iFileLength].isDirectory()) {

                    String filename = subFile[iFileLength].getName();

                    map.put(String.valueOf(iFileLength), filename);

                }

            }

        }

    } catch (NullPointerException e) {

        e.toString();

    }

    return map;

}



/**

 * 读取日志文件

 *

 * @param file 本地txt或log文件

 * @return 返回读取到的文件内容

 */

public static String getFileContent(File file) {

    String content = null;

    try {

        InputStream is = new FileInputStream(file);

        InputStreamReader reader = new InputStreamReader(is);

        BufferedReader bufferedReader = new BufferedReader(reader);

        String line;

        while ((line = bufferedReader.readLine()) != null) {

            content = content + line + "\n";

        }

    } catch (FileNotFoundException e) {

        e.printStackTrace();

    } catch (IOException e) {

        e.printStackTrace();

    } catch (NullPointerException e) {

        e.toString();

    }

    return content;

}



/**

 * 删除文件，可以是文件或文件夹

 *

 * @param fileName 要删除的文件名

 * @return 删除成功返回true，否则返回false

 */

public static boolean delete(String fileName) {

    File file = new File(fileName);

    if (!file.exists()) {

        System.out.println("删除文件失败:" + fileName + "不存在！");

        return false;

    } else {

        if (file.isFile())

            return deleteFile(fileName);

        else

            return deleteDirectory(fileName);

    }

}



/**

 * 删除单个文件

 *

 * @param fileName 要删除的文件的文件名

 * @return 单个文件删除成功返回true，否则返回false

 */

public static boolean deleteFile(String fileName) {

    File file = new File(fileName.replaceAll(" ", ""));

    LogUtils.e("TAG", "fileName:" + fileName);

    LogUtils.e("TAG", "file.isFile():" + file.isFile());

    if (file.isFile() || file.exists()) {

        boolean isDel = file.delete();

        return isDel;

    } else {

        LogUtils.e("MainActivity", "删除单个文件失败：" + fileName + "不存在！");

        return false;

    }

}



/**

 * 删除目录及目录下的文件

 *

 * @param dir 要删除的目录的文件路径

 * @return 目录删除成功返回true，否则返回false

 */

public static boolean deleteDirectory(String dir) {

    // 如果dir不以文件分隔符结尾，自动添加文件分隔符

    if (!dir.endsWith(File.separator))

        dir = dir + File.separator;