Android SD卡文件存储
Android SD卡文件存储
1、在AndroidManifest清单文件中要对SD卡读取进行支持
<!-- 在SDCard中创建与删除文件权限 -->
<uses-permission android:name="android.permission.MOUNT_UNMOUNT_FILESYSTEMS"/>
<!-- 往SDCard写入数据权限 -->
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
2、文件读写
private String read() {
// 如果手机插入了SD卡,而且应用程序具有访问SD的权限
try {
if (Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED)) {
// 获取SD卡的目录
File sdDirFile = Environment.getExternalStorageDirectory();
//获取指定文件对应的输入流
FileInputStream fis = new FileInputStream(sdDirFile.getCanonicalPath()+ FILE);
//将指定输入流包装成BufferedReader
BufferedReader br = new BufferedReader(new InputStreamReader(fis));
StringBuilder sb = new StringBuilder("");
String line = null;
while ((line =br.readLine())!=null) {
sb.append(line);
}
return sb.toString();
}
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
return null;
}
private void write(String context){
try {
if(Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED)){
File sdDir = Environment.getExternalStorageDirectory();
File targetFile = new File(sdDir.getCanonicalPath()+ FILE);
RandomAccessFile raf = new RandomAccessFile(targetFile, "rw");
raf.seek(targetFile.length());
raf.write(context.getBytes());
raf.close();
}
} catch (Exception e) {
}
}
1、在AndroidManifest清单文件中要对SD卡读取进行支持
<!-- 在SDCard中创建与删除文件权限 -->
<uses-permission android:name="android.permission.MOUNT_UNMOUNT_FILESYSTEMS"/>
<!-- 往SDCard写入数据权限 -->
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
2、文件读写
private String read() {
// 如果手机插入了SD卡,而且应用程序具有访问SD的权限
try {
if (Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED)) {
// 获取SD卡的目录
File sdDirFile = Environment.getExternalStorageDirectory();
//获取指定文件对应的输入流
FileInputStream fis = new FileInputStream(sdDirFile.getCanonicalPath()+ FILE);
//将指定输入流包装成BufferedReader
BufferedReader br = new BufferedReader(new InputStreamReader(fis));
StringBuilder sb = new StringBuilder("");
String line = null;
while ((line =br.readLine())!=null) {
sb.append(line);
}
return sb.toString();
}
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
return null;
}
private void write(String context){
try {
if(Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED)){
File sdDir = Environment.getExternalStorageDirectory();
File targetFile = new File(sdDir.getCanonicalPath()+ FILE);
RandomAccessFile raf = new RandomAccessFile(targetFile, "rw");
raf.seek(targetFile.length());
raf.write(context.getBytes());
raf.close();
}
} catch (Exception e) {
}
}
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