GreenDao的小小使用

//全布局的依赖

buildscript {
    repositories {
        jcenter()
        mavenCentral()
    }
    dependencies {
        classpath 'com.android.tools.build:gradle:2.3.1'
        classpath 'org.greenrobot:greendao-gradle-plugin:3.2.1'
    }
}

App里的依赖

要先在顶上加

apply plugin: 'org.greenrobot.greendao'

然后加依赖

dependencies {
    compile 'com.android.support:appcompat-v7:26.+'
    compile 'com.android.support.constraint:constraint-layout:1.0.2'
    testCompile 'junit:junit:4.12'
    compile 'org.greenrobot:greendao:3.2.0'
}

User类Bean类的书写要特别注意

@Entity
public class User {
    @Id(autoincrement = true)
    private long id;
    private String name;
    @Generated(hash = 1144922831)
    public User(long id, String name) {
        this.id = id;
        this.name = name;
    }
    @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;
    }
}

MainActivity实现

public class MainActivity extends AppCompatActivity {

    UserDao userDao;
    private EditText etId;
    private EditText etName;
    private Button btnAdd;
    private Button btnDelete;
    private Button btnQuery;
    private TextView tvQuery;

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

        /*新增一条数据*/
        btnAdd.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                String id = etId.getText().toString();
                String name = etName.getText().toString();
                if (isNotEmpty(id) && isNotEmpty(name)) {
                    QueryBuilder qb = userDao.queryBuilder();
                    ArrayList list = (ArrayList) qb.where(UserDao.Properties.Id.eq(id)).list();
                    if (list.size() > 0) {
                        Toast.makeText(MainActivity.this, "主键重复", Toast.LENGTH_SHORT).show();
                    } else {
                        userDao.insert(new User(Long.valueOf(id), name));
                        Toast.makeText(MainActivity.this, "插入数据成功", Toast.LENGTH_SHORT).show();
                    }
                } else {
                    if (isEmpty(id) && isNotEmpty(name)) {
                        Toast.makeText(MainActivity.this, "id为空", Toast.LENGTH_SHORT).show();
                    }
                    if (isEmpty(name) && isNotEmpty(id)) {
                        Toast.makeText(MainActivity.this, "姓名为空", Toast.LENGTH_SHORT).show();
                    }
                    if (isEmpty(id) && isEmpty(name)) {
                        Toast.makeText(MainActivity.this, "请填写信息", Toast.LENGTH_SHORT).show();
                    }

                }
                etId.setText("");
                etName.setText("");
            }
        });

        /*删除指定数据*/
        btnDelete.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                String id = etId.getText().toString();
                if (isNotEmpty(id)) {
                    userDao.deleteByKey(Long.valueOf(id));
                    QueryBuilder qb = userDao.queryBuilder();
                    ArrayList list = (ArrayList) qb.where(UserDao.Properties.Id.eq(id)).list();
                    if (list.size() < 1) {
                        Toast.makeText(MainActivity.this, "删除数据成功", Toast.LENGTH_SHORT).show();
                        etId.setText("");
                        etName.setText("");
                    }
                } else {
                    Toast.makeText(MainActivity.this, "id为空", Toast.LENGTH_SHORT).show();
                }
            }
        });

        /*查询数据*/
        btnQuery.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                String id = etId.getText().toString();
                if (isNotEmpty(id)) {
                    QueryBuilder qb = userDao.queryBuilder();
                    ArrayList list = (ArrayList) qb.where(UserDao.Properties.Id.eq(id)).list();
                    if (list.size() > 0) {
                        String text = "";
                        for (User user : list) {
                            text = text + "\r\n" + user.getName();
                        }
                        tvQuery.setText(text);
                    } else {
                        tvQuery.setText("");
                        Toast.makeText(MainActivity.this, "不存在该数据", Toast.LENGTH_SHORT).show();
                    }
                    etId.setText("");
                    etName.setText("");
                } else {
                    Toast.makeText(MainActivity.this, "id为空", Toast.LENGTH_SHORT).show();
                }
            }
        });
    }

    /*初始化数据库相关*/
    private void initDbHelp() {
        DaoMaster.DevOpenHelper helper = new DaoMaster.DevOpenHelper(this, "recluse-db", null);
        SQLiteDatabase db = helper.getWritableDatabase();
        DaoMaster daoMaster = new DaoMaster(db);
        DaoSession daoSession = daoMaster.newSession();
        userDao = daoSession.getUserDao();
    }

    private void initView() {
        etId = (EditText) findViewById(R.id.etId);
        etName = (EditText) findViewById(R.id.etName);
        btnAdd = (Button) findViewById(R.id.btnAdd);
        btnDelete = (Button) findViewById(R.id.btnDelete);
        btnQuery = (Button) findViewById(R.id.btnQuery);
        tvQuery = (TextView) findViewById(R.id.tvQuery);
    }

    private boolean isNotEmpty(String s) {
        if (s != null && !s.equals("") || s.length() > 0) {
            return true;
        } else {
            return false;
        }
    }

    private boolean isEmpty(String s) {
        if (isNotEmpty(s)) {
            return false;
        } else {
            return true;
        }
    }

}

布局

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="center_horizontal"
        android:layout_margin="10dp"
        android:text="greenDao lib test"
        android:textColor="@android:color/black" />

    <EditText
        android:id="@+id/etId"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:hint="请输入用户id"
        android:inputType="number"
        android:textSize="15sp" />

    <EditText
        android:id="@+id/etName"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:hint="请输入用户名"
        android:textSize="15sp" />

    <Button
        android:id="@+id/btnAdd"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="新增" />

    <Button
        android:id="@+id/btnDelete"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="删除" />

    <Button
        android:id="@+id/btnQuery"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="查询" />

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="center_horizontal"
        android:layout_margin="10dp"
        android:text="查询结果"
        android:textColor="@android:color/black" />

    <TextView
        android:id="@+id/tvQuery"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="center_horizontal"
        android:layout_margin="10dp"
        android:textColor="@android:color/black" />

LinearLayout>