簡(jiǎn)介

GreenDAO是一個(gè)輕量、快速的ORM解決方案，它能高效地將對(duì)象映射到SQLite數(shù)據(jù)庫(kù),目前升級(jí)到了3.1版本，相較于之前的版本來(lái)說(shuō)，易用性大幅度增加了，不需要一些麻煩的配置，詳情參考官方文檔 http://greenrobot.org/greendao/features/

1. 導(dǎo)入依賴

在project的build.gradle中插入：

    buildscript {
    repositories {
        mavenCentral()
    }
    dependencies {
        classpath 'org.greenrobot:greendao-gradle-plugin:3.1.0'
    }
}

在module的build.gradle中插入：

buildscript {
    repositories {
        mavenCentral()
    }
    dependencies {
        classpath 'org.greenrobot:greendao-gradle-plugin:3.1.0'
    }
}

2. 編寫需要存儲(chǔ)對(duì)象的實(shí)體類

/**
 * Created by GongCheng on 2016/8/20.
 * 聯(lián)系人數(shù)據(jù)庫(kù)實(shí)體類
 */
@Entity
public class Contact {
    @Id
    private Long id; //注意Id必須是包裝類

    @NonNull
    private String name;
    private String number;
 }

3. 編譯項(xiàng)目

直接Rebuild,發(fā)現(xiàn)生成了下面這些文件

而剛才寫的實(shí)體類也變成下面這樣

**
 * Created by GongCheng on 2016/8/20.
 * 聯(lián)系人數(shù)據(jù)庫(kù)實(shí)體類
 */
@Entity
public class Contact {
    @Id
    private Long id;

    @NonNull
    private String name;
    private String number;

    public String getNumber() {
        return this.number;
    }
    public void setNumber(String number) {
        this.number = number;
    }
    public String getName() {
        return this.name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public Long getId() {
        return this.id;
    }
    public void setId(Long id) {
        this.id = id;
    }
    @Generated(hash = 212132701)
    public Contact(Long id, @NonNull String name, String number) {
        this.id = id;
        this.name = name;
        this.number = number;
    }
    @Generated(hash = 672515148)
    public Contact() {
    }

}

這些都是通過(guò)插件生成的，不要隨意去改動(dòng)

4.初始化

初始化工作一般放在項(xiàng)目的Application里面執(zhí)行

/**
 * Created by GongCheng on 2016/8/5.
 */
public class MainApplication extends Application {

    private static  MainApplication INSTANCE ;

    private DaoSession daoSession;

    public static MainApplication getInstance(){
        return INSTANCE;
    }

    @Override
    public void onCreate() {
        super.onCreate();
        INSTANCE = this;
        //初始化SharedPreferences
        SharedPreferencesUtils.init();
        //初始化GreenDao
        DaoMaster.DevOpenHelper helper = new DaoMaster.DevOpenHelper(this,"contacts-db");
        Database db = helper.getWritableDb();
        daoSession = new DaoMaster(db).newSession();
    }

    //得到DaoSession
    public DaoSession getDaoSession() {
        return daoSession;
    }
}

5.正式使用

//Contact的查詢器
private Query<Contact> contactQuery;
//ContactDao
private ContactDao contactDao;

/**
 * 初始化Dao
 */
private void initDao() {
    //得到ContactDao
    DaoSession daoSession= MainApplication.getInstance().getDaoSession();
    contactDao= daoSession.getContactDao();
    //查詢所有聯(lián)系人(通過(guò)姓名)
    contactQuery = contactDao.queryBuilder().orderAsc(ContactDao.Properties.Name).build();
    updateContacts();
}

具體操作

//查詢
List<Note> notes = notesQuery.list();

//添加
Contact contact = new Contact(null,name,number);
contactDao.insert(contact);

//刪除
contactDao.deleteByKey(contactId);

還有一些其他操作沒(méi)有一一列舉了，GreenDao也提供了對(duì)RxJava的支持