Android存儲——SD卡或者文件存儲實現

Android存儲——SD卡或者文件存儲實現。Android實現SD卡和實現內存文件存儲的做法基本是一樣的。只是取得文件路徑的方法不一樣，基本上跟java的文件操作是一致的，下面是程序的代碼。配置取的位置和實現有所不同，其他是一樣的，下面是代碼：

main.xml:

1. <?xml version="1.0" encoding="utf-8"?>
2. <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
3. android:orientation="vertical"
4. android:layout_width="fill_parent"
5. android:layout_height="fill_parent">
6. <EditText android:id="@+id/edit1"
7. android:layout_width="fill_parent"
8. android:layout_height="wrap_content"
9. android:lines="4"/>
10. <Button android:id="@+id/write"
11. android:layout_width="wrap_content"
12. android:layout_height="wrap_content"
13. android:text="@string/write"/>
14. <EditText android:id="@+id/edit2"
15. android:layout_width="fill_parent"
16. android:layout_height="wrap_content"
17. android:editable="false"
18. android:cursorVisible="false"
19. android:lines="4"/>
20. <Button android:id="@+id/read"
21. android:layout_width="wrap_content"
22. android:layout_height="wrap_content"
23. android:text="@string/read"/>
24. </LinearLayout>

1. <uses-permission android:name="android.permission.MOUNT_UNMOUNT_FILESYSTEMS"/>
2. <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>

1. <string name="read">讀取</string>
2. lt;string name="write">寫入</string>

1. package cn.jason.io;
3. import java.io.FileInputStream;
4. import java.io.FileOutputStream;
5. import java.io.IOException;
6. import java.io.PrintStream;
8. import android.app.Activity;
9. import android.os.Bundle;
10. import android.view.View;
11. import android.view.View.OnClickListener;
12. import android.widget.Button;
13. import android.widget.EditText;
15. public class FileTestActivity extends Activity {
17. final String FILE = "jason.bin";
19. @Override
20. public void onCreate(Bundle savedInstanceState) {
21. super.onCreate(savedInstanceState);
22. setContentView(R.layout.main);
24. Button read = (Button) findViewById(R.id.read);
25. Button write = (Button) findViewById(R.id.write);
27. final EditText edit1 = (EditText) findViewById(R.id.edit1);
28. final EditText edit2 = (EditText) findViewById(R.id.edit2);
31. write.setOnClickListener(new OnClickListener() {
33. @Override
34. public void onClick(View v) {
35. write(edit1.getText().toString());
36. edit1.setText("");
37. }
38. });
40. read.setOnClickListener(new OnClickListener() {
42. @Override
43. public void onClick(View v) {
44. edit2.setText(read());
45. }
46. });
47. }
50. private String read() {
51. try {
52. FileInputStream fis = openFileInput(FILE);
53. byte[] buffer = new byte[1024];
54. int hasRead = 0;
55. StringBuilder sb = new StringBuilder("");
56. while ((hasRead = fis.read(buffer)) > 0) {
57. sb.append(new String(buffer, 0, hasRead));
58. }
59. return sb.toString();
60. } catch (IOException e) {
61. e.printStackTrace();
62. }
63. return null;
64. }
66. private void write(String content)
67. {
68. try
69. {
70. // 以追加模式打開文件輸出流
71. FileOutputStream fos = openFileOutput(FILE, MODE_APPEND);
72. // 將FileOutputStream包裝成PrintStream
73. PrintStream ps = new PrintStream(fos);
74. // 輸出文件內容
75. ps.println(content);
76. ps.close();
77. }
78. catch (Exception e)
79. {
80. e.printStackTrace();
81. }
82. }
83. }