android 保存对象到本地或SD卡

注意的是，要保存的对象一定要实现了Serializable接口。 

实现了Serializable接口对象才能被序列化。

//保存在本地
    public void fileSave2Local(Object obj) {
        FileOutputStream fos = null;
        ObjectOutputStream oos = null;
        try {
            //通过openFileOutput方法得到一个输出流
            fos = openFileOutput("obj.out", Context.MODE_WORLD_READABLE);
            oos = new ObjectOutputStream(fos);
            oos.writeObject(obj); //写入
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            try {
                if (oos != null) oos.close();
                if (fos != null) fos.close(); //最后关闭输出流
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }

//保存在sd卡
    public boolean fileSave2SDCard(Object obj) {
        if (Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED)) {
            File sdCardDir = Environment.getExternalStorageDirectory();//获取SDCard目录
            File sdFile = new File(sdCardDir, "obj.out");
            FileOutputStream fos = null;
            ObjectOutputStream oos = null;
            try {
                fos = new FileOutputStream(sdFile);
                oos = new ObjectOutputStream(fos);
                oos.writeObject(obj); //写入
                oos.flush();
                return true;
            } catch (IOException e) {
                e.printStackTrace();
            } finally {
                try {
                    if (fos != null) fos.close();
                    if (oos != null) oos.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }
        return false;
    }

读取文件

public Object readFileFromLocal(String fileName) {
        FileInputStream fileInputStream = null;
        ObjectInputStream objectInputStream = null;
        try {
            fileInputStream = new FileInputStream(fileName + ".out");
            objectInputStream = new ObjectInputStream(fileInputStream);
            Object obj = objectInputStream.readObject();

            return obj;
        } catch (IOException | ClassNotFoundException e) {
            e.printStackTrace();
        } finally {
            try {
                if (fileInputStream != null) fileInputStream.close();
                if (objectInputStream != null) objectInputStream.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        return null;
    }

public Object readObjFromSDCard(String fileName) {
        if (Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED)) {
            Object obj;
            File sdCardDir = Environment.getExternalStorageDirectory(); //获取SDCard目录
            File sdFile = new File(sdCardDir, fileName + ".out");
            FileInputStream fis = null;
            ObjectInputStream ois = null;
            try {
                fis = new FileInputStream(sdFile); //获得输入流
                ois = new ObjectInputStream(fis);
                obj = ois.readObject();
                return obj;
            } catch (IOException | ClassNotFoundException e) {
                e.printStackTrace();
            } finally {
                try {
                    if (fis != null) fis.close();
                    if (ois != null) ois.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }
        return null;
    }

作者:https://blog.csdn.net/qq_16628781

 https://blog.csdn.net/qq_16628781/article/details/68957762