Android App将数据写入内部存储和外部存储的示例

易采站长站为您分析Android App将数据写入内部存储和外部存储的示例,使用外部存储即访问并写入SD卡,需要的朋友可以参考下  

File存储（内部存储）
一旦程序在设备安装后，data/data/包名/ 即为内部存储空间，对外保密。
Context提供了2个方法来打开输入、输出流

• FileInputStream openFileInput(String name)
• FileOutputStream openFileOutput(String name, int mode)

  public class MainActivity extends Activity {
  
    private TextView show;
    private EditText et;
    private String filename = "test";
    @Override
    protected void onCreate(Bundle savedInstanceState) {
      super.onCreate(savedInstanceState);
      setContentView(R.layout.activity_main);
      show = (TextView) findViewById(R.id.show);
      et = (EditText) findViewById(R.id.et);
  
      findViewById(R.id.write).setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
          try {
            FileOutputStream fos = openFileOutput(filename, Context.MODE_PRIVATE);
            //FileOutputStream是字节流，如果是写文本的话，需要进一步把FileOutputStream包装 UTF-8是编码
            OutputStreamWriter osw = new OutputStreamWriter(fos, "UTF-8");
            //写
            osw.write(et.getText().toString());
            osw.flush();
            fos.flush();
            osw.close();
            fos.close();
          } catch (FileNotFoundException e) {
            e.printStackTrace();
          } catch (UnsupportedEncodingException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
          } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
          }
        }
      });  
  
      findViewById(R.id.read).setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
          try {
            FileInputStream fis = openFileInput(filename);
            //当输入输出都指定字符集编码的时候，就不会出现乱码的情况
            InputStreamReader isr = new InputStreamReader(fis, "UTF-8");
            //获取文件的可用长度，构建一个字符数组
            char[] input = new char[fis.available()];
            isr.read(input);
            isr.close();
            fis.close();
            String readed = new String(input);
            show.setText(readed);
          } catch (FileNotFoundException e) {
            e.printStackTrace();
          } catch (UnsupportedEncodingException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
          } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
          }
        }
      });      
    }  
  }
  
  								 
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