bmob-database-android

Bmob Database — Android Native SDK

Bmob provides a native Java/Kotlin SDK for Android, published in the Maven repository io.github.bmob:android-sdk. The model layer uses the extend BmobObject approach (one JavaBean subclass = one table), and CRUD is returned via the Listener callbacks provided by the SDK.

Core Principles

1. SDK integration: app/build.gradle add:

dependencies {
    implementation 'io.github.bmob:android-sdk:4.2.1'
    implementation 'io.reactivex.rxjava3:rxjava:3.1.9'
    implementation 'io.reactivex.rxjava3:rxandroid:3.0.2'
    implementation 'com.squareup.okhttp3:okhttp:4.8.1'
    implementation 'com.squareup.okio:okio:2.2.2'
    implementation 'com.google.code.gson:gson:2.8.5'
}

2. Application subclass initialization: in one-time, and must be before any Bmob call.

public class BmobApp extends Application {
    @Override public void onCreate() {
        super.onCreate();
        Bmob.initialize(this, "你的Application ID");
    }
}

AndroidManifest.xml specify android:name=".BmobApp"。

3. Required permissions and ContentProvider: see references/manifest-and-deps.md（INTERNET / ACCESS_NETWORK_STATE / READ_PHONE_STATE / <provider> , etc.).

4. JavaBean extends BmobObject： table name = class name, field name = member variable name.Do notmanually write objectId / createdAt / updatedAt / ACL, BmobObject already provides getters.

5. Number fields must use wrapper classes（Integer / Long / Double , etc.), do not use primitive int / long / double, otherwise default values cannot be distinguished when saving.

6. Android 6.0+ network compatibility: see references/manifest-and-deps.md in useLibrary 'org.apache.http.legacy' and network_security_config.xml。

Security Checklist

Do not leak the Master Key in the APK. The client only uses the Application ID (configure the Secret Key + encrypted authorization when necessary).
Disable debug mode in release builds：Bmob.setIsDebug(true) only enable it in debug builds.
Obfuscation configuration must keep SDK classes: see references/manifest-and-deps.md in the ProGuard section.
Tables with write operations must be configured with ACL: otherwise any user can modify any row.
Replace with the registered domain before release：Bmob.resetDomain("http://你的SDK域名/8/") must be before Bmob.initialize before。
Use wrapper classes for Number types: avoid 0 being indistinguishable from "not set".

FAQ

Cross-platform Q&A:shared/faq.md。

Anti-patterns

see shared/anti-patterns.md. Key points for this platform:success uncaught exception inside the callback → false 9015; do not use primitive int to store Number.

Custom JavaBean

public class Category extends BmobObject {
    private String name;
    private String desc;
    private Integer sequence;        // 必须是 Integer，不是 int

    public String getName() { return name; }
    public Category setName(String name) { this.name = name; return this; }
    public String getDesc() { return desc; }
    public Category setDesc(String desc) { this.desc = desc; return this; }
    public Integer getSequence() { return sequence; }
    public Category setSequence(Integer sequence) { this.sequence = sequence; return this; }
}

Console type	Java type
String	`String`
Boolean	`Boolean`
Number	`Integer` / `Long` / `Double` / `Float` / `Short` / `Byte` / `Character`
Array	`List`
File	`BmobFile`
GeoPoint	`BmobGeoPoint`
Date	`BmobDate`
Pointer	Any subclass of `BmobObject` subclass
Relation	`BmobRelation`

Single-record CRUD

Add

Category c = new Category();
c.setName("football");
c.setDesc("足球");
c.setSequence(1);
c.save(new SaveListener<String>() {
    @Override public void done(String objectId, BmobException e) {
        if (e == null) Log.i("BMOB", "new id=" + objectId);
        else Log.e("BMOB", e.toString());
    }
});

Update (by objectId)

Category c = new Category();
c.setSequence(2);                         // 只设要改的字段
c.update("6b6c11c537", new UpdateListener() {
    @Override public void done(BmobException e) {
        if (e == null) Log.i("BMOB", "updated");
    }
});

Delete (by objectId)

Category c = new Category();
c.delete("6b6c11c537", new UpdateListener() {
    @Override public void done(BmobException e) {
        if (e == null) Log.i("BMOB", "deleted");
    }
});

Query one (by objectId)

BmobQuery<Category> q = new BmobQuery<>();
q.getObject("6b6c11c537", new QueryListener<Category>() {
    @Override public void done(Category obj, BmobException e) {
        if (e == null) Log.i("BMOB", obj.getName());
    }
});

Conditional query

BmobQuery provides chained calls (v3.5.2+):

BmobQuery<Book> q = new BmobQuery<>();
q.setLimit(20).setSkip(0).order("-createdAt")
 .addWhereEqualTo("status", "published")
 .findObjects(new FindListener<Book>() {
     @Override public void done(List<Book> list, BmobException e) {
         if (e == null) /* ... */;
     }
 });

Method	Meaning
`addWhereEqualTo(field, value)`	=
`addWhereNotEqualTo`	!=
`addWhereGreaterThan` / `addWhereGreaterThanOrEqualTo`	> / >=
`addWhereLessThan` / `addWhereLessThanOrEqualTo`	< / <=
`addWhereContainedIn(field, List)`	IN
`addWhereNotContainedIn`	NOT IN
`addWhereExists(field)` / `addWhereDoesNotExists`	Field exists / does not exist
`addWhereContains(field, substr)`	LIKE (paid)
`order("-field")` / `order("field")`	Sort
`setLimit(n)` / `setSkip(n)`	Pagination (default 10, max 1000)
`include("pointerField")`	Also fetch Pointer

For more, see references/query.md。

Batch operations (≤ 50)

List<BmobObject> list = new ArrayList<>();
for (int i = 0; i < 50; i++) {
    Category c = new Category();
    c.setName("name" + i);
    list.add(c);
}
new BmobBatch().insertBatch(list).doBatch(new QueryListListener<BatchResult>() {
    @Override public void done(List<BatchResult> results, BmobException e) { /* ... */ }
});

See references/batch.md。

Integration with MCP

If already configured Bmob MCP，first get_project_tables get the real schema, then generate the corresponding BmobObject subclass skeleton. This avoids:

JavaBean field names / types do not match the table (wrong fields do not report errors, and cannot be queried after writing)
The className pointed to by the Pointer is misspelled

Troubleshooting Quick Reference

For cross-platform symptoms, first check shared/faq.md。

Symptom	Troubleshooting
`9001 AppKey is Null`	Did not call `Bmob.initialize` or the call timing is later than other SDK APIs
`9013 ObjectName format incorrect`	Table name / field name contains illegal characters (must start with a letter)
`9015`	Catch-all error code—be sure to read the response description, it may be `success` Business exceptions are swallowed in the callback, see `bmob-error-codes` for the 9015 topic
`9016`	Client has no network
`9021`	Missing `WAKE_LOCK` permission
Crash after ProGuard release	Did not add `-keep class cn.bmob.v3.** { *; }` and other rules, see references for details
HTTP cleartext request rejected by Android P	Add `network_security_config.xml`, see references
`release` package request rejected / 403	The console has not configured a registered domain for the SDK type;`Bmob.resetDomain` was not called or was called at the wrong time (must be before `initialize` )

Advanced capabilities (read references/ as needed)

Topic	Path
End-to-end scenarios (blog, Todo ACL, migration, etc.)	`shared/recipes/`
BmobDocs sync code snippets	`references/snippets/`
Manifest + dependencies + ProGuard + Android P/6.0 compatibility	`references/manifest-and-deps.md`
Batch operations (insert/update/delete 50 per batch)	`references/batch.md`
Full query set (or / regex / pointer subquery)	`references/query.md`
Pointer and Relation usage	`references/pointer-and-relation.md`
User system, email, phone number SMS, third-party login	（P1: `bmob-auth-android`, not covered in detail by this skill)
File upload / download (BmobFile)	（P1: `bmob-storage-android`）
Data monitoring (real-time data)	（P1: `bmob-realtime-android`）
Geolocation (BmobGeoPoint)	`references/query.md` last segment

Reference

Full API:BmobDocs/mds/data/android/develop_doc.md
Quick start:BmobDocs/mds/data/android/index.md
Official quickstart project:https://github.com/bmob/bmob-android-quickstart
Examples: image-text community Wonderful / SMS login bmob_android_demo_sms / Campus Xiaocai Shop
Error codes:bmob-error-codes
MCP integration:bmob-mcp