读写SD卡文件

权限


判断是否具备读写条件 如果手机存在SDcard,并且应用具有读写权限,则
Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED)返回true
路径 通过Environment.getExternalStorageDirectory()获取SDcard的根目录File
通过file.getCanonicalPath()获取规范化绝对路径
Tips:
1. getPath()定义路径,定义时为相对路径则返回相对路径;定义时为绝对路径则为绝对路径
2. getAbsolutePath()定义路径的绝对路径
3. getCanonicalPath规范化绝对路径
File file1 = new File(".\\test.txt"); file1.getPath(); //.\test.txt file1.getAbsolutePath(); //E:\workspace\Test\.\test.txt file1.getCanonicalPath(); //E:\workspace\Test\test.txtFile file2 = new File("/sdcard/tlib/test.txt"); file2.getPath(); ///sdcard/tlib/test.txt file2.getAbsolutePath(); ///sdcard/tlib/test.txt file2.getCanonicalPath(); ///sdcard/tlib/test.txt

目录 先判断目录是否存在,不存在则创建
File folder = new File(folderName); if (!folder.exists()) { folder.mkdir(); }

文件读 【读写SD卡文件】获取文件输入流
FileInputStream fis = new FileInputStream(BasePath + folderName + fileName);
包装输入流
BufferedReader br = new BufferedReader(new InputStreamReader(fis));
文件写
FileOutputStream fileOutputStream = new FileOutputStream(BasePath + folderPath + fileName); fileOutputStream.write(sb.toString().getBytes());

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