android orm映射框架（类似hibernate）基本使用

android orm映射框架，可像hibernate一样操作数据库。 以下代码是我从网上摘录下来的，仅供参考.

1. package com.cng.utils;
3. import java.sql.SQLException;
5. import android.content.Context;
6. import android.database.sqlite.SQLiteDatabase;
7. import android.util.Log;
9. import com.cng.modal.Hello;
11. import com.j256.ormlite.android.apptools.OrmLiteSqliteOpenHelper;
12. import com.j256.ormlite.dao.Dao;
13. import com.j256.ormlite.support.ConnectionSource;
14. import com.j256.ormlite.table.TableUtils;
16. public class DataHelper extends OrmLiteSqliteOpenHelper
17. {
19. private static final String DATABASE_NAME = "HelloOrmlite.db";
20. private static final int DATABASE_VERSION = 1;
21. private Dao<Hello, Integer> helloDao = null;
23. public DataHelper(Context context)
24. {
25. super(context, DATABASE_NAME, null, DATABASE_VERSION);
26. }
28. @Override
29. public void onCreate(SQLiteDatabase db, ConnectionSource connectionSource)
30. {
31. try
32. {
33. TableUtils.createTable(connectionSource, Hello.class);
34. } catch (SQLException e)
35. {
36. Log.e(DataHelper.class.getName(), "创建数据库失败", e);
37. e.printStackTrace();
38. }
39. }
41. @Override
42. public void onUpgrade(SQLiteDatabase db, ConnectionSource connectionSource,
43. int arg2, int arg3)
44. {
45. try
46. {
47. TableUtils.dropTable(connectionSource, Hello.class, true);
48. onCreate(db, connectionSource);
49. } catch (SQLException e)
50. {
51. Log.e(DataHelper.class.getName(), "更新数据库失败", e);
52. e.printStackTrace();
53. }
54. }
56. @Override
57. public void close()
58. {
59. super.close();
60. helloDao = null;
61. }
63. public Dao<Hello, Integer> getHelloDataDao() throws SQLException
64. {
65. if (helloDao == null)
66. {
67. helloDao = getDao(Hello.class);
68. }
69. return helloDao;
70. }
71. }

1. package com.cng;
3. import java.sql.SQLException;
4. import java.util.List;
6. import com.cng.modal.Hello;
7. import com.cng.utils.DataHelper;
8. import com.j256.ormlite.android.apptools.OrmLiteBaseActivity;
9. import com.j256.ormlite.dao.Dao;
11. import android.os.Bundle;
12. import android.widget.TextView;
17. public class OrmliteLoginActivity extends OrmLiteBaseActivity<DataHelper>
18. {
19. @Override
20. public void onCreate(Bundle savedInstanceState)
21. {
22. super.onCreate(savedInstanceState);
23. setContentView(R.layout.main);
24. TextView tv = (TextView) this.findViewById(R.id.output);
25. try
26. {
27. Dao<Hello, Integer> helloDao = getHelper().getHelloDataDao();
28. // 添加数据
29. for (int i = 0; i < 2; i++)
30. {
31. Hello hello = new Hello("Hello" + i);
32. helloDao.create(hello);
33. }
34. tv.setText(tv.getText() + "\n" + "添加数据完成");
35. // 查询添加的数据
36. List<Hello> hellos = helloDao.queryForAll();
37. for (Hello h : hellos)
38. {
39. tv.setText(tv.getText() + "\n" + h.toString());
40. }
41. // 删除数据第一条数据
42. helloDao.delete(hellos.get(0));
43. tv.setText(tv.getText() + "\n" + "删除数据完成");
44. // 重新查询数据
45. hellos = helloDao.queryForAll();
46. for (Hello h : hellos)
47. {
48. tv.setText(tv.getText() + "\n" + h.toString());
49. }
50. // 修改数据
51. Hello h1 = hellos.get(0);
52. h1.setWord("这是修改过的数据");
53. tv.setText(tv.getText() + "\n" + "修改数据完成");
54. helloDao.update(h1);
55. // 重新查询数据
56. hellos = helloDao.queryForAll();
57. for (Hello h : hellos)
58. {
59. tv.setText(tv.getText() + "\n" + h.toString());
60. }
62. } catch (SQLException e)
63. {
64. // TODO Auto-generated catch block
65. e.printStackTrace();
66. }
68. }
69. }

1. package com.cng.modal;
3. import android.R.integer;
5. import com.j256.ormlite.field.DatabaseField;
7. public class Hello
8. {
9. @DatabaseField(generatedId = true,unique=true)
10. int id;
11. @DatabaseField
12. String word;
13. //这是必须加的，否则会出错
14. public Hello(){}
15. public int getId()
16. {
17. return id;
18. }
19. public Hello(String word)
20. {
21. super();
22. this.word = word;
23. }
24. public void setId(int id)
25. {
26. this.id = id;
27. }
29. public String getWord()
30. {
31. return word;
32. }
34. public void setWord(String word)
35. {
36. this.word = word;
37. }
39. @Override
40. public String toString()
41. {
42. StringBuilder sb = new StringBuilder();
43. sb.append("id=").append(id);
44. sb.append(" ,word=").append(word);
45. return sb.toString();
46. }
48. }

就这三个类，datahelper是操作数据库的类，可新建，更新表，Hello是一个映射到数据库表的类，具体的看api 文档的下载地址是http://ormlite.com/releases/(其中的jar包也在这里下载) OrmliteLoginActivity就是activity类，它没继承activity，而是继承了OrmLiteBaseActivity类。