1 public class MainActivity extends ActionBarActivity {
2
3 final String FILE_NAME = "crazyit.bin";
4 @Override
5 protected void onCreate(Bundle savedInstanceState) {
6 super.onCreate(savedInstanceState);
7 setContentView(R.layout.activity_main);
8
9
10 System.out.println(new StringBuilder("a").append("b").append("c").toString());
11
12 Button read = (Button) findViewById(R.id.read);
13 Button write = (Button) findViewById(R.id.write);
14
15
16 final EditText edit1 = (EditText) findViewById(R.id.edit1);
17 final EditText edit2 = (EditText) findViewById(R.id.edit2);
18
19 write.setOnClickListener(new OnClickListener() {
20
21 public void onClick(View v) {
22 write(edit1.getText().toString());
23 edit1.setText("");
24 }
25 });
26
27 read.setOnClickListener(new OnClickListener() {
28
29 public void onClick(View v) {
30 edit2.setText(read());
31 }
32 });
33
34 }
35
36 public void write(String content){
37 try {
38 FileOutputStream fos = openFileOutput(FILE_NAME, MODE_APPEND);
39 PrintStream ps = new PrintStream(fos);
40 ps.println(content);
41 ps.close();
42
43 } catch (FileNotFoundException e) {
44 e.printStackTrace();
45 }
46
47 }
48
49 public String read(){
50 try {
51 FileInputStream fis = openFileInput(FILE_NAME);
52 byte [] buff = new byte[1024];
53 int hasRead = 0;
54 StringBuilder builder = new StringBuilder("");
55 while ( (hasRead = fis.read(buff)) > 0 ) {
56 builder.append(new String(buff, 0, hasRead));
57 }
58 fis.close();
59 return builder.toString();
60
61 } catch (FileNotFoundException e) {
62 e.printStackTrace();
63 } catch (IOException e) {
64 e.printStackTrace();
65 }
66
67 return null;
68
69
xml布局文件如下：
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical" >
<Button
android:id="@+id/read"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Read" />
<Button
android:id="@+id/write"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Write" />
<EditText
android:id="@+id/edit1"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:ems="10" >
<requestFocus />
</EditText>
<EditText
android:id="@+id/edit2"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:ems="10" />
</LinearLayout>
70 }