java把信息存到sd卡_Android（java）学习笔记125：保存数据到SD卡（附加：保存数据到内存）...

青旅半醒 2022-11-03 04:11 125阅读 0赞

1 packagecom.himi.filetosd.utils;2

3 importjava.io.BufferedReader;4 importjava.io.File;5 importjava.io.FileReader;6 importjava.io.FileWriter;7 importjava.io.IOException;8

9 importandroid.content.Context;10 importandroid.os.Environment;11

12 public classToolsFile \{13

14 public static final String FILE\_NAME = "info.txt";15 /\*\*

16 \* 保存文件到手机内存:data/data/包名/info.txt17 \*@paramcontext18 \*@paramusername19 \*@parampassword20 \*@return

21 \*/

22 public static booleansaveFileToPackage(Context context, String username,23 String password) \{24 File file = newFile(context.getFilesDir(),FILE\_NAME);25 try\{26 FileWriter fw = newFileWriter(file);27 fw.write(username+":"+password);28 fw.close();29 \} catch(IOException e) \{30 //TODO Auto-generated catch block

31 e.printStackTrace();32 return false;33 \}34 return true;35 \}36

37 /\*\*

38 \* 保存文件到手机内存:data/data/cache/info.txt39 \*@paramcontext40 \*@paramusername41 \*@parampassword42 \*@return

43 \*/

44 public static booleansaveFileToCache(Context context, String username,45 String password) \{46 File file = newFile(context.getCacheDir(),FILE\_NAME);47 try\{48 FileWriter fw = newFileWriter(file);49 fw.write(username+":"+password);50 fw.close();51 \} catch(IOException e) \{52 //TODO Auto-generated catch block

53 e.printStackTrace();54 return false;55 \}56 return true;57 \}58

59 /\*\*

60 \* 删除data/data/包名/info.txt文件61 \*@paramcontext62 \*@return

63 \*/

64 public static booleandelete(Context context) \{65 File file = newFile(context.getFilesDir(),FILE\_NAME);66 returnfile.delete();67 \}68

69 /\*\*

70 \* 保存文件到SD:/mnt/sdcard71 \*/

72 public static booleansaveFileToSD(Context context, String username,73 String password) \{74 //判断sd有没有安装

75 if(!Environment.getExternalStorageState()76 .equals(Environment.MEDIA\_MOUNTED)) \{77 return false;78 \}79

80 File file = newFile(Environment.getExternalStorageDirectory(),FILE\_NAME);81 try\{82 FileWriter fw = newFileWriter(file);83 fw.write(username+":"+password);84 fw.close();85 \} catch(IOException e) \{86 //TODO Auto-generated catch block

87 e.printStackTrace();88 return false;89 \}90

91 return true;92 \}93

94 /\*\*

95 \* 查询mnt/sdcard目录下info.txt文件信息,以字符串的形式反馈96 \*@paramcontext97 \*@return

98 \*/

99 public staticString findUser(Context context) \{100 File file = newFile(Environment.getExternalStorageDirectory(), FILE\_NAME);101 //如果文件不存在则返回 null

102 if (!file.exists()) \{103 return null;104 \}105 String result = null;106 try\{107 BufferedReader reader = new BufferedReader(newFileReader(file));108 result =reader.readLine();109 reader.close();110 \} catch(Exception e) \{111 e.printStackTrace();112 \}113 returnresult;114 \}115

116 \}