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.
- package com.cng.utils;
- import java.sql.SQLException;
- import android.content.Context;
- import android.database.sqlite.SQLiteDatabase;
- import android.util.Log;
- import com.cng.modal.Hello;
- import com.j256.ormlite.android.apptools.OrmLiteSqliteOpenHelper;
- import com.j256.ormlite.dao.Dao;
- import com.j256.ormlite.support.ConnectionSource;
- import com.j256.ormlite.table.TableUtils;
- public class DataHelper extends OrmLiteSqliteOpenHelper
- {
- private static final String DATABASE_NAME = "HelloOrmlite.db";
- private static final int DATABASE_VERSION = 1;
- private Dao<Hello, Integer> helloDao = null;
- public DataHelper(Context context)
- {
- super(context, DATABASE_NAME, null, DATABASE_VERSION);
- }
- @Override
- public void onCreate(SQLiteDatabase db, ConnectionSource connectionSource)
- {
- try
- {
- TableUtils.createTable(connectionSource, Hello.class);
- } catch (SQLException e)
- {
- Log.e(DataHelper.class.getName(), "创建数据库失败", e);
- e.printStackTrace();
- }
- }
- @Override
- public void onUpgrade(SQLiteDatabase db, ConnectionSource connectionSource,
- int arg2, int arg3)
- {
- try
- {
- TableUtils.dropTable(connectionSource, Hello.class, true);
- onCreate(db, connectionSource);
- } catch (SQLException e)
- {
- Log.e(DataHelper.class.getName(), "更新数据库失败", e);
- e.printStackTrace();
- }
- }
- @Override
- public void close()
- {
- super.close();
- helloDao = null;
- }
- public Dao<Hello, Integer> getHelloDataDao() throws SQLException
- {
- if (helloDao == null)
- {
- helloDao = getDao(Hello.class);
- }
- return helloDao;
- }
- }
- package com.cng;
- import java.sql.SQLException;
- import java.util.List;
- import com.cng.modal.Hello;
- import com.cng.utils.DataHelper;
- import com.j256.ormlite.android.apptools.OrmLiteBaseActivity;
- import com.j256.ormlite.dao.Dao;
- import android.os.Bundle;
- import android.widget.TextView;
- public class OrmliteLoginActivity extends OrmLiteBaseActivity<DataHelper>
- {
- @Override
- public void onCreate(Bundle savedInstanceState)
- {
- super.onCreate(savedInstanceState);
- setContentView(R.layout.main);
- TextView tv = (TextView) this.findViewById(R.id.output);
- try
- {
- Dao<Hello, Integer> helloDao = getHelper().getHelloDataDao();
- // 添加数据
- for (int i = 0; i < 2; i++)
- {
- Hello hello = new Hello("Hello" + i);
- helloDao.create(hello);
- }
- tv.setText(tv.getText() + "\n" + "添加数据完成");
- // 查询添加的数据
- List<Hello> hellos = helloDao.queryForAll();
- for (Hello h : hellos)
- {
- tv.setText(tv.getText() + "\n" + h.toString());
- }
- // 删除数据第一条数据
- helloDao.delete(hellos.get(0));
- tv.setText(tv.getText() + "\n" + "删除数据完成");
- // 重新查询数据
- hellos = helloDao.queryForAll();
- for (Hello h : hellos)
- {
- tv.setText(tv.getText() + "\n" + h.toString());
- }
- // 修改数据
- Hello h1 = hellos.get(0);
- h1.setWord("这是修改过的数据");
- tv.setText(tv.getText() + "\n" + "修改数据完成");
- helloDao.update(h1);
- // 重新查询数据
- hellos = helloDao.queryForAll();
- for (Hello h : hellos)
- {
- tv.setText(tv.getText() + "\n" + h.toString());
- }
- } catch (SQLException e)
- {
- // TODO Auto-generated catch block
- e.printStackTrace();
- }
- }
- }
- package com.cng.modal;
- import android.R.integer;
- import com.j256.ormlite.field.DatabaseField;
- public class Hello
- {
- @DatabaseField(generatedId = true,unique=true)
- int id;
- @DatabaseField
- String word;
- //这是必须加的,否则会出错
- public Hello(){}
- public int getId()
- {
- return id;
- }
- public Hello(String word)
- {
- super();
- this.word = word;
- }
- public void setId(int id)
- {
- this.id = id;
- }
- public String getWord()
- {
- return word;
- }
- public void setWord(String word)
- {
- this.word = word;
- }
- @Override
- public String toString()
- {
- StringBuilder sb = new StringBuilder();
- sb.append("id=").append(id);
- sb.append(" ,word=").append(word);
- return sb.toString();
- }
- }
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。