Android读写文件工具类详解

本文实例为大家分享了Android读写文件工具类的具体代码，供大家参考，具体内容如下

public class Utils { private static String path1 = Environment.getExternalStorageDirectory().getAbsolutePath(); private static String path2 = Environment.getDownloadCacheDirectory().getAbsolutePath(); private static String pathExt = '/111/222/333/444/555/'; private static String fileName = '6.txt'; public static void write(String str) { String filePath = null; boolean hasSDCard =Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED); if (hasSDCard) { filePath = path1 + pathExt + fileName; } else { filePath = path2 + pathExt + fileName; } try { File file = new File(filePath); if (!file.exists()) {//mkdirs()方法生成多层文件夹//mkdir()方法生成一层层文件夹//File dir = new File(file.getParent());//dir.mkdirs();file.getParentFile().mkdirs();//生成文件外层的文件夹file.createNewFile();//生成文件 } FileOutputStream os = new FileOutputStream(file); os.write(str.getBytes()); os.close(); } catch (Exception e) { e.printStackTrace(); } } public static String read() { String content = ''; String filePath; boolean sdcard = Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED); if (sdcard) { filePath = path1 + pathExt + fileName; } else { filePath = path2 + pathExt + fileName; } try { File file = new File(filePath); if (file.exists()) {FileInputStream is = new FileInputStream(file);InputStreamReader inputReader = new InputStreamReader(is);//设置流读取方式BufferedReader buffReader = new BufferedReader(inputReader);String line;try { while (null != (line = buffReader.readLine())) { content += line + 'n';//读取的文件容 } is.close();//关闭输入流} catch (IOException e) { e.printStackTrace();} finally { try { if (null != is) { is.close(); } } catch (IOException e) { e.printStackTrace(); }} } } catch (FileNotFoundException e) { e.printStackTrace(); } return content; }}

1. 清单文件中添加读写权限

<uses-permission android:name='android.permission.WRITE_EXTERNAL_STORAGE' /><uses-permission android:name='android.permission.READ_EXTERNAL_STORAGE' />

2.Android6.0以上版本要动态申请读写权限

ArrayList<String> permissionList = new ArrayList<>();private String[] permissions = { 'android.permission.READ_EXTERNAL_STORAGE', 'android.permission.WRITE_EXTERNAL_STORAGE' };//检测是否有写的权限//判断手机版本,如果低于6.0 则不用申请权限,直接拍照if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) { if (checkSelfPermission(permissions[0]) != PackageManager.PERMISSION_GRANTED) { permissionList.add(permissions[0]); } if (checkSelfPermission(permissions[1]) != PackageManager.PERMISSION_GRANTED) { permissionList.add(permissions[1]); } if (!permissionList.isEmpty()) { String[] permissions1 = permissionList.toArray(new String[permissionList.size()]); requestPermissions(permissions1, 1); } else { Utils.write('balabala'); Utils.read(); }} else { Utils.write('balabala'); Utils.read();} @Overridepublic void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) { switch (requestCode){ case 1: if (PackageManager.PERMISSION_GRANTED == grantResults[0]){ Utils.write('balabala'); Utils.read(); } else { Log.d(TAG, 'fail: '); } break; }}

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持好吧啦网。