GreenDao使用

官网地址：http://greendao-orm.com/

需要下载的jar包

greendao:greendao jar

greendap-generator:generator jar

freemark:http://freemarker.org/

官方实例：官方demo

参考文章

参考文章

GreenDao的使用可以分为步，首先是生成关联的数据库实体类，接着是在android项目中导入生成的文件，配置好环境后就可以使用了。

1.生成相关数据库文件。

生成表(在这只写了一个NoteEntity表),在表中你可以定义属性的类型，只是不能设定默认值。

package com.cn;

import java.io.IOException;

import de.greenrobot.daogenerator.DaoGenerator;
import de.greenrobot.daogenerator.Entity;
import de.greenrobot.daogenerator.Schema;

public class TestMain {

    public static void main(String[] args) {
        try {
            createEntity();
        } catch (IOException e) {
            e.printStackTrace();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    /**
     * 创建数据表
     * createEntity
     * @throws Exception 
     * @throws IOException 
     */
    private static void createEntity() throws IOException, Exception {
        //你保存greendao 文件路径
        Schema schema = new Schema(1, "com.cn.greenandroid.green");

        Entity note = schema.addEntity("NoteEntity");
        note.addIdProperty().primaryKey();
        note.addStringProperty("noteName").notNull();
        note.addStringProperty("noteContent");
        note.addDateProperty("date");

        new DaoGenerator().generateAll(schema, "../TestJGreen/dao");
    }
}

执行过后，刷新项目就可以在dao文件夹下得到生成的相关文件了。
2.使用greendao

将生成的文件导入到你的项目中（记得存放的路径最好跟你生成文件的路径一样）。

推荐在BaseApplication中配置DaoMaster和DaoSession。

package com.cn.greenandroid;

import com.cn.greenandroid.green.DaoMaster;
import com.cn.greenandroid.green.DaoMaster.OpenHelper;
import com.cn.greenandroid.green.DaoSession;

import android.app.Application;
import android.content.Context;

public class BaseApplication extends Application {
    @Override
    public void onCreate() {
        super.onCreate();
    }

    private static DaoMaster daoMaster;

    private static DaoSession daoSession;

    /** 
     * 取得DaoMaster 
     */
    public static DaoMaster getDaoMaster(Context context) {
        if (daoMaster == null) {
            OpenHelper helper = new DaoMaster.DevOpenHelper(context, "green.db", null);
            daoMaster = new DaoMaster(helper.getWritableDatabase());
        }
        return daoMaster;
    }

    /** 
     * 取得DaoSession 
     */
    public static DaoSession getDaoSession(Context context) {
        if (daoSession == null) {
            if (daoMaster == null) {
                daoMaster = getDaoMaster(context);
            }
            daoSession = daoMaster.newSession();
        }
        return daoSession;
    }
}

然后为写一个工具类，来执行表的相关操作。

package com.cn.greenandroid.util;

import java.util.List;

import com.cn.greenandroid.BaseApplication;
import com.cn.greenandroid.green.DaoSession;
import com.cn.greenandroid.green.NoteEntity;
import com.cn.greenandroid.green.NoteEntityDao;
import com.cn.greenandroid.green.NoteEntityDao.Properties;

import android.content.Context;
import de.greenrobot.dao.query.DeleteQuery;
import de.greenrobot.dao.query.QueryBuilder;

public class GreenHelper {
	private static GreenHelper greenHelper;

	private static Context mContext;

	private DaoSession daoSession;

	private static NoteEntityDao noteEntityDao;

	private GreenHelper() {
	}

	public static GreenHelper getInstance(Context context) {
		if (null == greenHelper) {
			greenHelper = new GreenHelper();
			if (null == mContext) {
				mContext = context.getApplicationContext();
			}

			greenHelper.daoSession = BaseApplication.getDaoSession(context);
			greenHelper.noteEntityDao = greenHelper.daoSession.getNoteEntityDao();
		}
		return greenHelper;
	}

	public static void insertNoteEntity(NoteEntity note) {
		noteEntityDao.insertOrReplace(note);
	}

	public static void insertNoteEntity(List<NoteEntity> list) {
		noteEntityDao.insertInTx(list);
	}

	public static void deleteNoteEntity(NoteEntity note) {
		noteEntityDao.delete(note);
	}

	public static void updateNoteEntity(NoteEntity note) {
		// noteEntityDao.insertOrReplace(note);//当存在条数据 也可以更新
		noteEntityDao.update(note);
	}

	public static List<NoteEntity> selectNoteEntity() {
		// return noteEntityDao.loadAll();
		return noteEntityDao.loadAll();
	}

	public static List<NoteEntity> selectOrderNoteEntity() {
		QueryBuilder<NoteEntity> qb = noteEntityDao.queryBuilder();
		qb.orderDesc(Properties.Date);
		return qb.list();
	}

	public static List<NoteEntity> selectIdNoteEntity(long id) {
		QueryBuilder<NoteEntity> qb = noteEntityDao.queryBuilder();
		qb.where(NoteEntityDao.Properties.Id.eq(id));
		return qb.list();
	}

	public static void deleteNoteEntity() {
		QueryBuilder<NoteEntity> qb = noteEntityDao.queryBuilder();
		DeleteQuery<NoteEntity> bd = qb.where(NoteEntityDao.Properties.NoteContent.isNotNull()).buildDelete();
		bd.executeDeleteWithoutDetachingEntities();
	}
}

最后就是在项目中使用工具类的方法了。

package com.cn.greenandroid;

import java.util.ArrayList;
import java.util.Date;
import java.util.List;

import com.cn.greenandroid.green.NoteEntity;
import com.cn.greenandroid.util.GreenHelper;

import android.app.Activity;
import android.os.Bundle;
import android.widget.TextView;

public class MainActivity extends Activity {
	private String Tag = "MainActivity";

	private GreenHelper mHelper;

	private TextView tv;

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

		mHelper = GreenHelper.getInstance(this);

		tv = (TextView) findViewById(R.id.textView);

		// insertEntity();
		// insertListEntity();
		// deleteEntity();
		// updateEntity();

		// selectCount(2L);
		// deleteSome();
		selectAll();
	}

	private void insertEntity() {// 插入3条数据
		for (int i = 0; i < 3; i++) {
			NoteEntity note = new NoteEntity();
			note.setNoteName("name" + i);
			note.setNoteContent("content" + i);
			note.setDate(new Date());
			mHelper.insertNoteEntity(note);
		}
	}

	private void insertListEntity() {// 插入3条数据
		List<NoteEntity> list = new ArrayList<NoteEntity>();
		for (int i = 0; i < 3; i++) {
			NoteEntity note = new NoteEntity();
			note.setNoteName("name" + i);
			note.setNoteContent("content" + i);
			note.setDate(new Date());
			list.add(note);
		}
		mHelper.insertNoteEntity(list);
	}

	private void deleteEntity() {// 删除一条数据
		NoteEntity note = new NoteEntity();
		note.setId(1L);
		mHelper.deleteNoteEntity(note);
	}

	private void updateEntity() {
		NoteEntity note = new NoteEntity();
		note.setId(2L);
		note.setNoteName("shenma");
		note.setNoteContent("xyz");
		mHelper.updateNoteEntity(note);
	}

	private void selectCount(long id) {
		List<NoteEntity> list = mHelper.selectIdNoteEntity(id);
		listNote(list);
	}

	private void deleteSome() {
		mHelper.deleteNoteEntity();
	}

	private void selectAll() {
		// List<NoteEntity> list = mHelper.selectNoteEntity();
		List<NoteEntity> list = mHelper.selectOrderNoteEntity();
		listNote(list);
	}

	private void listNote(List<NoteEntity> list) {
		StringBuffer buf = new StringBuffer();
		for (NoteEntity note : list) {
			buf.append(note.getId() + note.getNoteName() + note.getNoteContent());
			buf.append("\n");
		}
		tv.setText(buf.toString());
	}
}