Android Realm初试

╰+攻爆jí腚メ 2022-09-25 15:25 188阅读 0赞

Realm is a mobile database that runs directly inside phones, tablets or wearables. This repository holds the source code for the Java version of Realm, which currently runs only on Android.

Realm是一个移动端的数据库，它可以在手机、平板。穿戴设备上运行。这个仓库的代码是一个Java版本的代码，目前只用在安卓端。

摘自：[https://github.com/realm/realm-java][https_github.com_realm_realm-java]

导入JAR

compile 'io.realm:realm-android:0.87.0'

在Application 中配置，不配置也可以，就是默认的哦。

public class MyApplication extends Application { 
    
        @Override
        public void onCreate() {
            super.onCreate();
            initRealm();
        }
        private void initRealm(){
            RealmConfiguration configuration = new RealmConfiguration
                    .Builder(this)
                    .name("test.realm")
                    .deleteRealmIfMigrationNeeded()
                    .schemaVersion(7).migration(new RealmMigration() {
    
                        @Override
                        public void migrate(DynamicRealm realm, long oldVersion, long newVersion) {
    
                        }
                    }).build();
    
            Realm.setDefaultConfiguration(configuration);
        }
    }

创建实体类，需集成RealmObject

public class User extends RealmObject{ 
        @PrimaryKey
        private String id;
        private String userName;
        private String mobile;
    
        public String getId() {
            return id;
        }
    
        public void setId(String id) {
            this.id = id;
        }
    
        public String getUserName() {
            return userName;
        }
    
        public void setUserName(String userName) {
            this.userName = userName;
        }
    
        public String getMobile() {
            return mobile;
        }
    
        public void setMobile(String mobile) {
            this.mobile = mobile;
        }
    }

在Activity中初始化

Realm myRealm ; myRealm= Realm.getInstance(this);

添加数据：

//Realm开始处理事物  方式1：
            myRealm.beginTransaction();
            User user = myRealm.createObject(User.class);
            user.setId("445115");
            user.setMobile("44545");
            user.setUserName("hha");
            myRealm.commitTransaction();
            //方式2：
      User user2=new User();
            user2.setId("1123");
            user2.setUserName("sss");
            user2.setMobile("445");
            myRealm.beginTransaction();
            User userCopy2 = myRealm.copyToRealm(user2);
            myRealm.commitTransaction();

查找数据

RealmResults<User> listUser = myRealm.where(User.class).findAll();
    
            StringBuilder stringBuilder=new StringBuilder();
    
            for(User u:listUser) {
                stringBuilder.append(u.getUserName()+"--------****--------- ");
                Log.d("results1",u.getUserName());
            }
            tv.setText(stringBuilder.toString());

代码并不难，希望通过我这个例子，一是巩固自己的学习和理解，二是希望更多的人更好的学习，我会再接再厉，写更多的博文。

[源码下载][Link 1]

[csdn博客][csdn]

[https_github.com_realm_realm-java]: https://github.com/realm/realm-java
[Link 1]: https://github.com/forezp/RealmJavaTest
[csdn]: http://blog.csdn.net/forezp