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android 读取文件内容操作
在Android系统中,这些文件保存在 /data/data/PACKAGE_NAME/files 目录下。
数据读取- view plaincopy to clipboardprint?
- public static String read(Context context, String file) {
- String data = "";
- try {
- FileInputStream stream = context.openFileInput(file);
- StringBuffer sb = new StringBuffer();
- int c;
- while ((c = stream.read()) != -1) {
- sb.append((char) c);
- }
- stream.close();
- data = sb.toString();
- } catch (FileNotFoundException e) {
- } catch (IOException e) {
- }
- return data;
- }
- public static String read(Context context, String file) {
- String data = "";
- try {
- FileInputStream stream = context.openFileInput(file);
- StringBuffer sb = new StringBuffer();
- int c;
- while ((c = stream.read()) != -1) {
- sb.append((char) c);
- }
- stream.close();
- data = sb.toString();
- } catch (FileNotFoundException e) {
- } catch (IOException e) {
- }
- return data;
- }
复制代码 从代码上,看起来唯一的不同就是文件的打开方式了: context.openFileInput(file); Android中的文件读写具有权限控制,所以使用context(Activity的父类)来打开文件,文件在相同的Package中共享。这里的 Package的概念同Preferences中所述的Package,不同于Java中的Package。
数据写入- view plaincopy to clipboardprint?
- public static void write(Context context, String file, String msg) {
- try {
- FileOutputStream stream = context.openFileOutput(file,
- Context.MODE_WORLD_WRITEABLE);
- stream.write(msg.getBytes());
- stream.flush();
- stream.close();
- } catch (FileNotFoundException e) {
- } catch (IOException e) {
- }
- }
- public static void write(Context context, String file, String msg) {
- try {
- FileOutputStream stream = context.openFileOutput(file,
- Context.MODE_WORLD_WRITEABLE);
- stream.write(msg.getBytes());
- stream.flush();
- stream.close();
- } catch (FileNotFoundException e) {
- } catch (IOException e) {
- }
- }
复制代码 在这里打开文件的时候,声明了文件打开的方式。
一般来说,直接使用文件可能不太好用,尤其是,我们想要存放一些琐碎的数据,那么要生成一些琐碎的文件,或者在同一文件中定义一下格式。其实也可以将其包装成Properties来使用:- view plaincopy to clipboardprint?
- public static Properties load(Context context, String file) {
- Properties properties = new Properties();
- try {
- FileInputStream stream = context.openFileInput(file);
- properties.load(stream);
- } catch (FileNotFoundException e) {
- } catch (IOException e) {
- }
- return properties;
- }
- public static void store(Context context, String file, Properties properties) {
- try {
- FileOutputStream stream = context.openFileOutput(file,
- Context.MODE_WORLD_WRITEABLE);
- properties.store(stream, "");
- } catch (FileNotFoundException e) {
- } catch (IOException e) {
- }
- }
复制代码 |
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