//保存文件到手机内存
public void save(String fileName,String content) throws IOException{
FileOutputStream fos = context.openFileOutput("a.txt", Context.MODE_PRIVATE);
fos.write(content.getBytes());
fos.close();
}
// 从手机内存读取文件
public String read(String fileName) throws IOException {
ByteArrayOutputStream baos = new ByteArrayOutputStream(); // 向内存输入字节数据的流
FileInputStream fis = context.openFileInput(fileName);
byte[] buffer = new byte[1024];
int len = 0;
while ((len = fis.read(buffer)) != -1) {
baos.write(buffer, 0, len);
}
byte[] data = baos.toByteArray();
return data.toString();
}
// 判断SD卡状态,插入可读写
if (Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED)) {
service.saveToSDCard(fileName, content);
} else {
// sdcard不存在时,保存到手机内存
service.save(fileName, content);
}
//保存文件到SD卡
public void saveToSDCard(String fileName, String content) throws IOException{
File file = new File(Environment.getExternalStorageDirectory(),fileName);
FileOutputStream fos = new FileOutputStream(file);
fos.write(content.getBytes());
fos.close();
}
<uses-permission android:name="android.permission.MOUNT_UNMOUNT_FILESYSTEMS">uses-permission>
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE">uses-permission>