File sdCardDir = new File("/sdcard"); //获取SDCard目录
File saveFile = new File(sdCardDir, "itcast.txt");
//上面两句代码可以合成一句： File saveFile = new File("/sdcard/a.txt");
FileOutputStream outStream = new FileOutputStream(saveFile);
outStream.write("test".getBytes());
outStream.close();
最后附上一个使用openFileOutput的例子存取对象：
public class MainActivity extends Activity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
}
public void button(View view){
Person p = new Person();
p.setAge(10);
p.setName("Lee");
saveObject(p, "MainActivity.dat");
}
public void button2(View view){
Person p = (Person) readObject("MainActivity.dat");
System.out.println(p.getAge());
}
public boolean saveObject(Serializable ser, String file) {
FileOutputStream fos = null;
ObjectOutputStream oos = null;
try{
fos = openFileOutput(file, MODE_PRIVATE);
oos = new ObjectOutputStream(fos);
oos.writeObject(ser);
oos.flush();
return true;
}catch(Exception e){
e.printStackTrace();
return false;
}finally{
try {
oos.close();
} catch (Exception e) {}
try {
fos.close();
} catch (Exception e) {}
}
}
/**
* 读取对象
* @param file
* @return
* @throws IOException
*/
public Serializable readObject(String file){
FileInputStream fis = null;
ObjectInputStream ois = null;
try{
fis = openFileInput(file);
ois = new ObjectInputStream(fis);
return (Serializable)ois.readObject();
}catch(FileNotFoundException e){
}catch(Exception e){
e.printStackTrace();
//反序列化失败 - 删除缓存文件
if(e instanceof InvalidClassException){
File data = getFileStreamPath(file);
data.delete();
}
}finally{
try {
ois.close();
} catch (Exception e) {}
try {
fis.close();
} catch (Exception e) {}
}
return null;
}
}
class Person implements Serializable{
int age;
String name;
public int getAge() {
return age;
}
public void setAge(int age) {
this.age = age;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
}
