File存对象--android 的File存储到SD卡();

 方法1：android File存对象--File存储到SD卡();

1、保存对象到本地或SD卡
需要注意的是，要保存的对象（OAuthV1）一定要实现了Serializable接口。
实现了Serializable接口对象才能被序列化。
public void fileSave(OAuthV1 oAuth_1){

//保存在本地
try {
// 通过openFileOutput方法得到一个输出流，方法参数为创建的文件名（不能有斜杠），操作模式
FileOutputStream fos = this.openFileOutput("oauth_1.out",Context.MODE_WORLD_READABLE);
ObjectOutputStream oos = new ObjectOutputStream(fos);
oos.writeObject(oAuth_1);// 写入
fos.close(); // 关闭输出流
//Toast.makeText(WebviewTencentActivity.this, "保存oAuth_1成功",Toast.LENGTH_LONG).show();

} catch (FileNotFoundException e) {
e.printStackTrace();
//Toast.makeText(WebviewTencentActivity.this, "出现异常1",Toast.LENGTH_LONG).show();
} catch (IOException e) {
e.printStackTrace();
//Toast.makeText(WebviewTencentActivity.this, "出现异常2",Toast.LENGTH_LONG).show();
}

//保存在sd卡
if(Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED)){

File sdCardDir = Environment.getExternalStorageDirectory();//获取SDCard目录
File sdFile = new File(sdCardDir, "oauth_1.out");
try {
FileOutputStream fos = new FileOutputStream(sdFile);
ObjectOutputStream oos = new ObjectOutputStream(fos);
oos.writeObject(oAuth_1);// 写入
fos.close(); // 关闭输出流
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
//Toast.makeText(WebviewTencentActivity.this, "成功保存到sd卡", Toast.LENGTH_LONG).show();

}
}

2、从本地或SD卡中取出对象

（从本地取得保存的对象）
public OAuthV1 readOAuth1() {
OAuthV1 oAuth_1 = null;
//String filename = "oauth_file.cfg";
try {
FileInputStream fis=this.openFileInput("oauth_1.out"); //获得输入流
ObjectInputStream ois = new ObjectInputStream(fis);
oAuth_1 = (OAuthV1)ois.readObject();

//tv.setText(per.toString()); //设置文本控件显示内容
// Toast.makeText(ShareTencentActivity.this,"读取成功",Toast.LENGTH_LONG).show();
} catch (StreamCorruptedException e) {

e.printStackTrace();
} catch (OptionalDataException e) {

e.printStackTrace();
} catch (FileNotFoundException e) {

e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} catch (ClassNotFoundException e) {

e.printStackTrace();
}
return oAuth_1;

 

（2）从SD卡中取得保存的对象

对SD卡操作别忘了加权限
<!-- 在SDCard中创建与删除文件的权限 -->
<uses-permission android:name="android.permission.MOUNT_UNMOUNT_FILESYSTEMS"/>
<!-- 往SDCard写入数据的权限 -->
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>

public OAuthV1 readOAuth2() {
OAuthV1 oAuth_1 = null;
File sdCardDir = Environment.getExternalStorageDirectory();//获取SDCard目录
File sdFile = new File(sdCardDir, "oauth_1.out");

try {
FileInputStream fis=new FileInputStream(sdFile); //获得输入流
ObjectInputStream ois = new ObjectInputStream(fis);
oAuth_1 = (OAuthV1)ois.readObject();
ois.close();
} catch (StreamCorruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (OptionalDataException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (FileNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (ClassNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}