greendao的使用

一.准备工作
在工程的build.gradle文件中添加

repositories {
...
mavenCentral()
}
dependencies {
...
classpath 'org.greenrobot:greendao-gradle-plugin:3.3.0'
}

在项目的build.gradle文件中添加

apply plugin: 'org.greenrobot.greendao'

android {
...
greendao {
schemaVersion 1
}
}

dependencies {
...
implementation 'org.greenrobot:greendao:3.3.0'
}

（1）当Bean类对象发生改变时，schemaVersion的数值要增加。
（2）目前引用的版本是最新版，后续更新要注意上方的参考文档。

二. 创建实体类

例：

@Entity
public class TestUser {
@Id(autoincrement = true)
private Long id;
@NotNull
private String name;
@NotNull
private int age;
@NotNull
private String sex;
@Index(unique = true)
private String uid;
@Generated(hash = 1872927493)
public TestUser(Long id, @NotNull String name, int age, @NotNull String sex,
String uid) {
this.id = id;
this.name = name;
this.age = age;
this.sex = sex;
this.uid = uid;
}
@Generated(hash = 925009630)
public TestUser() {
}
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;
}
public String getSex() {
return this.sex;
}
public void setSex(String sex) {
this.sex = sex;
}
public String getUid() {
return this.uid;
}
public void setUid(String uid) {
this.uid = uid;
}
}

三.初始化

可以将初始化以及增删改查进行封装，在初始化时需要context而且只需要初始化一次，为防止内存泄露所以我们将初始化放在Application进行操作。

public class DbController {/*** Helper*/private DaoMaster.DevOpenHelper mHelper;//获取Helper对象/*** 数据库*/private SQLiteDatabase db;/*** DaoMaster*/private DaoMaster mDaoMaster;/*** DaoSession*/private DaoSession mDaoSession;/*** 上下文*/private Context context;/*** dao*/private PersonInforDao personInforDao;private static DbController mDbController;/*** 获取单例*/public static DbController getInstance(Context context){if(mDbController == null){synchronized (DbController.class){if(mDbController == null){mDbController = new DbController(context);}}}return mDbController;}/*** 初始化* @param context*/public DbController(Context context) {this.context = context;mHelper = new DaoMaster.DevOpenHelper(context,"person.db", null);mDaoMaster =new DaoMaster(getWritableDatabase());mDaoSession = mDaoMaster.newSession();personInforDao = mDaoSession.getPersonInforDao();}/*** 获取可读数据库*/private SQLiteDatabase getReadableDatabase(){if(mHelper == null){mHelper = new DaoMaster.DevOpenHelper(context,"person.db",null);}SQLiteDatabase db =mHelper.getReadableDatabase();return db;}/*** 获取可写数据库* @return*/private SQLiteDatabase getWritableDatabase(){if(mHelper == null){mHelper =new DaoMaster.DevOpenHelper(context,"person.db",null);}SQLiteDatabase db = mHelper.getWritableDatabase();return db;}/*** 会自动判定是插入还是替换* @param personInfor*/public void insertOrReplace(PersonInfor personInfor){personInforDao.insertOrReplace(personInfor);}/**插入一条记录，表里面要没有与之相同的记录** @param personInfor*/public long insert(PersonInfor personInfor){return  personInforDao.insert(personInfor);}/*** 更新数据* @param personInfor*/public void update(PersonInfor personInfor){PersonInfor mOldPersonInfor = personInforDao.queryBuilder().where(PersonInforDao.Properties.Id.eq(personInfor.getId())).build().unique();//拿到之前的记录if(mOldPersonInfor !=null){mOldPersonInfor.setName("张三");personInforDao.update(mOldPersonInfor);}}/*** 按条件查询数据*/public List<PersonInfor> searchByWhere(String wherecluse){List<PersonInfor>personInfors = (List<PersonInfor>) personInforDao.queryBuilder().where(PersonInforDao.Properties.Name.eq(wherecluse)).build().unique();return personInfors;}/*** 查询所有数据*/public List<PersonInfor> searchAll(){List<PersonInfor>personInfors=personInforDao.queryBuilder().list();return personInfors;}/*** 删除数据*/public void delete(String wherecluse){personInforDao.queryBuilder().where(PersonInforDao.Properties.Name.eq(wherecluse)).buildDelete().executeDeleteWithoutDetachingEntities();}
}

看看我们的MainActivity

public class MainActivity extends AppCompatActivity {private Button Add,Delete,Update,Search;private DbController mDbController;private PersonInfor personInfor1,personInfor2,personInfor3,personInfor4;private long insertTipId;private TextView dataArea;@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);mDbController = DbController.getInstance(MainActivity.this);initView();Envent();similateData();}private void similateData() {personInfor1 = new PersonInfor(null,"001","王大宝","男");personInfor2 = new PersonInfor(null,"002","李晓丽","女");personInfor3 = new PersonInfor(null,"003","王麻麻","男");personInfor4 = new PersonInfor(null,"004","王大锤","女");}private void Envent() {Add.setOnClickListener(new View.OnClickListener() {@Overridepublic void onClick(View v) {//AddmDbController.insertOrReplace(personInfor1);mDbController.insertOrReplace(personInfor2);mDbController.insertOrReplace(personInfor3);mDbController.insertOrReplace(personInfor4);showDataList();}});Delete.setOnClickListener(new View.OnClickListener() {@Overridepublic void onClick(View v) {//DeletemDbController.delete("王麻麻");showDataList();}});Update.setOnClickListener(new View.OnClickListener() {@Overridepublic void onClick(View v) {//UpdatemDbController.update(personInfor1);showDataList();}});Search.setOnClickListener(new View.OnClickListener() {@Overridepublic void onClick(View v) {//SearchshowDataList();}});}private void showDataList() {StringBuilder sb = new StringBuilder();List<PersonInfor>personInfors = mDbController.searchAll();for(PersonInfor personInfor:personInfors){// dataArea.setText("id:"+p);sb.append("id:").append(personInfor.getId()).append("perNo:").append(personInfor.getPerNo()).append("name:").append(personInfor.getName()).append("sex:").append(personInfor.getSex()).append("\n");}dataArea.setText(sb.toString());}private void initView() {Add = findViewById(R.id.Add);Delete = findViewById(R.id.Delete);Update = findViewById(R.id.Update);Search = findViewById(R.id.Search);dataArea= findViewById(R.id.tips);}
}