Android directly reads the sqlite database in the project, androidsqlite

Android directly reads the sqlite database in the project, androidsqlite

To read sqlite database files for android in a recent project, here is an example of an English-Chinese dictionary. It is mainly used to input English to the database to query the corresponding Chinese meaning and output the answer. The database uses sqlite3.

The implementation process is as described in the reference document. It should be noted that when the program is started for the first time, it will install the database on the memory card to read the database.

 

Related code:

Java code

1. Package com. easymorse;
3. Import java. io. File;
4. Import java. io. FileOutputStream;
5. Import java. io. InputStream;
7. Import android. app. Activity;
8. Import android. app. AlertDialog;
9. Import android. database. Cursor;
10. Import android. database. sqlite. SQLiteDatabase;
11. Import android. OS. Bundle;
12. Import android. text. Editable;
13. Import android. text. TextWatcher;
14. Import android. util. Log;
15. Import android. view. View;
16. Import android. view. View. OnClickListener;
17. Import android. widget. AutoCompleteTextView;
18. Import android. widget. Button;
20. Public class Dictionary extends Activity implements OnClickListener, TextWatcher {
21. Private final String DATABASE_PATH = android. OS. Environment
22. . GetExternalStorageDirectory (). getAbsolutePath ()
23. + "/Dictionary ";
24. Private final String DATABASE_FILENAME = "dictionary. db3 ";
25. SQLiteDatabase database;
26. Button btnSelectWord;
27. AutoCompleteTextView actvWord;
28. @ Override
29. Public void onCreate (Bundle savedInstanceState ){
30. Super. onCreate (savedInstanceState );
31. SetContentView (R. layout. main );
32. // Open the database. The database is a variable of the SQLiteDatabase type defined in the Main class.
33. Database = openDatabase ();
34. // The following code loads related components and sets corresponding events
35. BtnSelectWord = (Button) findViewById (R. id. btnSelectWord );
36. ActvWord = (AutoCompleteTextView) findViewById (R. id. actvWord );
37. BtnSelectWord. setOnClickListener (this );
38. ActvWord. addTextChangedListener (this );
39. }
40. Public void onClick (View view)
41. {
42. // SQL statement for searching words
43. String SQL = "select chinese from t_words where english =? ";
44. Cursor cursor = database. rawQuery (SQL, new String []
45. {ActvWord. getText (). toString ()});
46. String result = "this word is not found .";
47. // If a word is searched, its Chinese information is displayed.
48. If (cursor. getCount ()> 0)
49. {
50. // The moveToFirst method must be used to move the record pointer to the position of 1st records
51. Cursor. moveToFirst ();
52. Result = cursor. getString (cursor. getColumnIndex ("chinese "));
53. Log. I ("tran", "success" + result );
54. }
55. // Display the query result dialog box
56. New AlertDialog. Builder (this). setTitle ("query result"). setMessage (result)
57. . SetPositiveButton ("off", null). show ();
59. }
61. Private SQLiteDatabase openDatabase (){
62. Try {
63. // Obtain the absolute path of the dictionary. db File
64. String databaseFilename = DATABASE_PATH + "/" + DATABASE_FILENAME;
65. File dir = new File (DATABASE_PATH );
66. // If the/sdcard/dictionary directory exists, create this directory
67. If (! Dir. exists ())
68. Dir. mkdir ();
69. // If the directory does not exist in the/sdcard/dictionary directory
70. // Dictionary. db file, copy this file from the res \ raw directory
71. // Directory of the SD card (/sdcard/dictionary)
72. If (! (New File (databaseFilename). exists ()){
73. // Obtain the InputStream object that encapsulates the dictionary. db File
74. InputStream is = getResources (). openRawResource (
75. R. raw. dictionary );
76. FileOutputStream fos = new FileOutputStream (databaseFilename );
77. Byte [] buffer = new byte [8192];
78. Int count = 0;
79. // Start copying the dictionary. db File
80. While (count = is. read (buffer)> 0 ){
81. Fos. write (buffer, 0, count );
82. }
84. Fos. close ();
85. Is. close ();
86. }
87. // Open the dictionary. db file in the/sdcard/dictionary directory
88. SQLiteDatabase database = SQLiteDatabase. openOrCreateDatabase (
89. DatabaseFilename, null );
90. Return database;
91. } Catch (Exception e ){
92. }
93. Return null;
94. }
95. @ Override
96. Public void afterTextChanged (Editable s ){
97. }
98. @ Override
99. Public void beforeTextChanged (CharSequence s, int start, int count,
100. Int after ){
101. }
102. @ Override
103. Public void onTextChanged (CharSequence s, int start, int before, int count ){
104. }
106. }