GreenDao的封装和使用

                                 GreenDao的封装和使用

        首先先集成GreenDao，在本人博客里有GreenDao3.2的集成步骤，可参考

 MainActivity

package com.example.greendaodemo;

import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.util.Log;

import com.example.greendaodemo.bean.User;
import com.example.greendaodemo.dao.MyUserDao;

import java.util.List;

public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        MyUserDao dao = new MyUserDao(this);

//        User u = new User();
//        u.setAge(10);
//        u.setName("22");
//        u.setId("001");
//        dao.insertUser(this,);

        for (int i = 20; i < 25; i++) {
            User user = new User();
            user.setId(Long.valueOf(i));
            user.setAge(i * 3);
            user.setName("第" + i + "人");
            dao.insertUser(user);
        }
        List userList = dao.queryUserList();
        for (User user : userList) {
            Log.e("TAG", "queryUserList--before-->" + user.getId() + "--" + user.getName() +"--"+user.getAge());
            if (user.getId() == 10) {
                dao.deleteUser(user);
            }
            if (user.getId() == 13) {
                user.setAge(25);
                dao.updateUser(user);
            }
        }
        userList = dao.queryUserList();
        for (User user : userList) {
            Log.e("TAG", "queryUserList--after--->" + user.getId() + "---" + user.getName()+"--"+user.getAge());
        }
    }
}

GreenDao封装

 

package com.example.greendaodemo.db;

import android.content.Context;
import android.database.sqlite.SQLiteDatabase;

import com.example.greendaodemo.bean.DaoMaster;

/**
 * Created by yfeng on 2017/11/23.
 * DBManager 数据库管理者
 *
 * 获取可读或者可写的数据库对象
 */

public class DBManager {
    private final static String dbName = "test_db";
    private static DBManager mInstance;
    private DaoMaster.DevOpenHelper openHelper;
    private Context context;

    private DBManager(Context context) {
        this.context = context;
        openHelper = new DaoMaster.DevOpenHelper(context, dbName, null);
    }

    /**
     * 获取单例引用
     *
     * @param context
     * @return
     */
    public static DBManager getInstance(Context context) {
        if (mInstance == null) {
            synchronized (DBManager.class) {
                if (mInstance == null) {
                    mInstance = new DBManager(context);
                }
            }
        }
        return mInstance;
    }

    public SQLiteDatabase getReadableDatabase() {
        if (openHelper == null) {
            openHelper = new DaoMaster.DevOpenHelper(context, dbName, null);
        }
        SQLiteDatabase db = openHelper.getReadableDatabase();
        return db;
    }

    public SQLiteDatabase getWritableDatabase() {
        if (openHelper == null) {
            openHelper = new DaoMaster.DevOpenHelper(context, dbName, null);
        }
        SQLiteDatabase db = openHelper.getWritableDatabase();
        return db;
    }
}

        UserBean

package com.example.greendaodemo.bean;

import org.greenrobot.greendao.annotation.Entity;
import org.greenrobot.greendao.annotation.Id;
import org.greenrobot.greendao.annotation.Property;
import org.greenrobot.greendao.annotation.Generated;

/**
 * Created by yfeng on 2017/11/23.
 */

@Entity
public class User {
    @Id
    private Long id;
    @Property
    private String name;
    @Property
    private int age;
    @Generated(hash = 1309193360)
    public User(Long id, String name, int age) {
        this.id = id;
        this.name = name;
        this.age = age;
    }
    @Generated(hash = 586692638)
    public User() {
    }
    public Long getId() {
        return this.id;
    }
    public void setId(Long id) {
        this.id = id;
    }
    public String getName() {
        return this.name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public int getAge() {
        return this.age;
    }
    public void setAge(int age) {
        this.age = age;
    }

    //下面省去了 setter/getter
}

UserDao

package com.example.greendaodemo.dao;

import android.content.Context;

import com.example.greendaodemo.db.DBManager;
import com.example.greendaodemo.bean.DaoMaster;
import com.example.greendaodemo.bean.DaoSession;
import com.example.greendaodemo.bean.User;
import com.example.greendaodemo.bean.UserDao;

import org.greenrobot.greendao.query.QueryBuilder;

import java.util.List;

/**
 * Created by yfeng on 2017/11/23.
 */

public class MyUserDao {
    Context context;
    public MyUserDao(Context context) {
        this.context = context;
    }

    /**
     * 插入一条记录
     *
     * @param user
     */
    public void insertUser(User user) {
        DaoMaster daoMaster = new DaoMaster(DBManager.getInstance(context).getWritableDatabase());
        DaoSession daoSession = daoMaster.newSession();
        UserDao userDao = daoSession.getUserDao();
        userDao.insert(user);
    }

    /**
     * 插入用户集合
     *
     * @param users
     */
    public void insertUserList(List users) {
        if (users == null || users.isEmpty()) {
            return;
        }
        DaoMaster daoMaster = new DaoMaster(DBManager.getInstance(context).getWritableDatabase());
        DaoSession daoSession = daoMaster.newSession();
        UserDao userDao = daoSession.getUserDao();
        userDao.insertInTx(users);
    }

    /**
     * 查询用户列表
     */
    public List queryUserList() {
        DaoMaster daoMaster = new DaoMaster(DBManager.getInstance(context).getReadableDatabase());
        DaoSession daoSession = daoMaster.newSession();
        UserDao userDao = daoSession.getUserDao();
        QueryBuilder qb = userDao.queryBuilder();
        List list = qb.list();
        return list;
    }

    /**
     * 查询用户列表
     */
    public List queryUserList(int age) {
        DaoMaster daoMaster = new DaoMaster(DBManager.getInstance(context).getReadableDatabase());
        DaoSession daoSession = daoMaster.newSession();
        UserDao userDao = daoSession.getUserDao();
        QueryBuilder qb = userDao.queryBuilder();
        qb.where(UserDao.Properties.Age.gt(age)).orderAsc(UserDao.Properties.Age);
        List list = qb.list();
        return list;
    }

    /**
     * 更新一条记录
     *
     * @param user
     */
    public void updateUser(User user) {
        DaoMaster daoMaster = new DaoMaster(DBManager.getInstance(context).getWritableDatabase());
        DaoSession daoSession = daoMaster.newSession();
        UserDao userDao = daoSession.getUserDao();
        userDao.update(user);
    }

    /**
     * 删除一条记录
     *
     * @param user
     */
    public void deleteUser(User user) {
        DaoMaster daoMaster = new DaoMaster(DBManager.getInstance(context).getWritableDatabase());
        DaoSession daoSession = daoMaster.newSession();
        UserDao userDao = daoSession.getUserDao();
        userDao.delete(user);
    }

}

运行结果