Android开发集成AndroidxRoom+RxJava2

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• room是google官方推出的Androidx JectPack组件中的一员，闲话就不说了，room的介绍官方和网上很多，本篇只是记录集成的配置和步骤

引入依赖

• 根据当前最新版本来配置 implementation ‘io.reactivex.rxjava2:rxandroid:2.1.1’ implementation “io.reactivex.rxjava2:rxjava:2.2.7”

      def room_version = "2.1.0-alpha05"
      implementation "androidx.room:room-runtime:$room_version"
      annotationProcessor "androidx.room:room-compiler:$room_version" // For Kotlin use kapt instead of annotationProcessor
      // optional - Kotlin Extensions and Coroutines support for Room
      implementation "androidx.room:room-ktx:$room_version"
      // optional - RxJava support for Room
      implementation "androidx.room:room-rxjava2:$room_version"
  

创建Database

• 注意，实现的是一个抽象类 @Database(entities = {UserBean.class}, version = 1) public abstract class AppDatabase extends RoomDatabase { public abstract UserDao userDao(); private static volatile AppDatabase INSTANCE; public static AppDatabase getDatabase(Context context) { if (INSTANCE == null) { synchronized (AppDatabase.class) { if (INSTANCE == null) { INSTANCE = Room.databaseBuilder(context.getApplicationContext(), AppDatabase.class, “app_database”).build(); } } } return INSTANCE; } }

创建数据Bean

• 以创建简单的userBean为例子

    @Entity(tableName = "user_table")
    public class UserBean {
        @PrimaryKey
        public int uid;
  
        @ColumnInfo(name = "userName")
        @NonNull
        private String userName;
        @ColumnInfo(name = "password")
        private String password;
  
        public String getUserName() {
            return userName;
        }
  
        public void setUserName(String userName) {
            this.userName = userName;
        }
  
        public String getPassword() {
            return password;
        }
  
        public void setPassword(String password) {
            this.password = password;
        }
  
        public int getUid() {
            return uid;
        }
  
        public void setUid(int uid) {
            this.uid = uid;
        }
    }
  

创建Dao类

• 创建一个带有增加和查找方法的dao类，注意，用@Dao注解

    @Dao
    public interface UserDao {
        @Insert
        Single<Long> insert(UserBean userBean);
  
        @Query("SELECT * FROM user_table WHERE userName = :userName AND password = :password")
        Single<UserBean> findByUserNameAndPassword(String userName, String password);
    }
  

使用

• 简单的插入一个用户信息然后查询出来

    UserBean userBean = new UserBean();
            userBean.setUid(1);
            userBean.setPassword("yes");
            userBean.setUserName("user1");
            AppDatabase.getDatabase(this).userDao().insert(userBean)
                    .flatMap(new Function<Long, SingleSource<UserBean>>() {
                        @Override
                        public SingleSource<UserBean> apply(Long aLong) throws Exception {
                            return AppDatabase.
                                    getDatabase(MainActivity.this).
                                    userDao().
                                    findByUserNameAndPassword("user1", "yes");
                        }
                    })
                    .subscribeOn(Schedulers.io())
                    .observeOn(AndroidSchedulers.mainThread())
                    .subscribe(new SingleObserver<UserBean>() {
                        @Override
                        public void onSubscribe(Disposable d) {
  
                        }
  
                        @Override
                        public void onSuccess(UserBean userBean) {
                            printLog("插入的用户名为" + userBean.getUserName());
                        }
  
                        @Override
                        public void onError(Throwable e) {
                            e.printStackTrace();
                        }
                    });