android app 内部文件路径

Posted 2020-06-13

 1 public class MainActivity extends Activity {
 2 
 3     final String FILE_NAME = "crazyit.bin";
 4 
 5     @Override
 6     protected void onCreate(Bundle savedInstanceState) {
 7         super.onCreate(savedInstanceState);
 8         setContentView(R.layout.activity_main);
 9 
10         final EditText et1 = (EditText) findViewById(R.id.edt1);
11         final EditText et2 = (EditText) findViewById(R.id.edt2);
12 
13         Button btnWrite = (Button) findViewById(R.id.btnIn);
14         btnWrite.setOnClickListener(new OnClickListener() {
15 
16             @Override
17             public void onClick(View v) {
18                 write(et1.getText().toString());
19                 et1.setText("");
20             }
21         });
22         Button btnRead = (Button) findViewById(R.id.btnOut);
23         btnRead.setOnClickListener(new OnClickListener() {
24 
25             @Override
26             public void onClick(View v) {
27                 et2.setText(read());
28             }
29         });
30 
31     }
32 
33     /**
34      * 写入到/data/data/[包名]/files 路径下
35      * 
36      * @param content
37      */
38     private void write(String content) {
39         try {
40             FileOutputStream fos = openFileOutput(FILE_NAME, Context.MODE_APPEND);
41             PrintStream ps = new PrintStream(fos);
42             ps.println(content);
43             ps.close();
44 
45         } catch (FileNotFoundException e) {
46             e.printStackTrace();
47         }
48     }
49 
50     /**
51      * /data/data/[包名]/files 路径下读取文件
52      * 
53      * @return
54      */
55     private String read() {
56         try {
57 
58             FileInputStream fis = openFileInput(FILE_NAME);
59             byte[] buff = new byte[1024];
60             int hasRead = 0;
61             StringBuilder sb = new StringBuilder("");
62             while ((hasRead = fis.read(buff)) > 0) {
63                 sb.append(new String(buff, 0, hasRead));
64             }
65             fis.close();
66             return sb.toString();
67 
68         } catch (FileNotFoundException e) {
69             e.printStackTrace();
70         } catch (IOException e) {
71             e.printStackTrace();
72         }
73 
74         return null;
75     }
76 
77 }