diff --git a/packages/hydrojudge/setting.yaml b/packages/hydrojudge/setting.yaml
index 202d11719..ebe69dfe2 100644
--- a/packages/hydrojudge/setting.yaml
+++ b/packages/hydrojudge/setting.yaml
@@ -43,6 +43,7 @@ langs:
             type: compiler
             compile: /usr/bin/javac -d ${dir} -encoding utf8 ./Main.java
             code_file: Main.java
+            target: Main.class
             execute: /usr/bin/java Main
         py:
             type: compiler
diff --git a/packages/hydrooj/src/model/domain.ts b/packages/hydrooj/src/model/domain.ts
index 9934d48ee..c3ea675e3 100644
--- a/packages/hydrooj/src/model/domain.ts
+++ b/packages/hydrooj/src/model/domain.ts
@@ -2,6 +2,7 @@ import { Dictionary } from 'lodash';
 import { FilterQuery } from 'mongodb';
 import { BUILTIN_ROLES, PRIV } from './builtin';
 import { DomainDoc } from '../interface';
+import * as bus from '../service/bus';
 import * as db from '../service/db';
 
 const coll = db.collection('domain');
@@ -39,20 +40,28 @@ export async function add(domainId: string, owner: number, name: string, bulleti
         gravatar: '',
         pidCounter: 0,
     };
+    await bus.serial('domain/create', ddoc);
     await coll.insertOne(ddoc);
     return domainId;
 }
 
-export function get(domainId: string): Promise<DomainDoc | null> {
-    return coll.findOne({ _id: domainId });
+export async function get(domainId: string): Promise<DomainDoc | null> {
+    const query: FilterQuery<DomainDoc> = { _id: domainId };
+    await bus.serial('domain/before-get', query);
+    const result = await coll.findOne(query);
+    await bus.serial('domain/get', result);
+    return result;
 }
 
 export function getMulti(query: FilterQuery<DomainDoc> = {}) {
     return coll.find(query);
 }
 
-export function edit(domainId: string, $set: Partial<DomainDoc>) {
-    return coll.updateOne({ _id: domainId }, { $set });
+export async function edit(domainId: string, $set: Partial<DomainDoc>) {
+    await bus.serial('domain/before-update', domainId, $set);
+    const result = await coll.findOneAndUpdate({ _id: domainId }, { $set }, { returnOriginal: false });
+    await bus.serial('domain/update', domainId, $set, result.value);
+    return result.value;
 }
 
 export async function inc(domainId: string, field: keyof DomainDoc, n: number): Promise<number | null> {
diff --git a/packages/hydrooj/src/service/bus.ts b/packages/hydrooj/src/service/bus.ts
index 7d4e6882a..dd0adaed7 100644
--- a/packages/hydrooj/src/service/bus.ts
+++ b/packages/hydrooj/src/service/bus.ts
@@ -6,6 +6,7 @@ import { Logger } from '../logger';
 import {
     Mdoc, Pdoc, Rdoc, TrainingDoc, User,
 } from '../interface';
+import { DomainDoc } from '../loader';
 
 type DocType = import('../model/document').DocType;
 
@@ -39,6 +40,12 @@ export interface EventMap {
     'user/message': (uid: number, mdoc: Mdoc, udoc: User) => void
     'user/get': (udoc: User) => void
 
+    'domain/create': (ddoc: DomainDoc) => void
+    'domain/before-get': (query: FilterQuery<DomainDoc>) => void
+    'domain/get': (ddoc: DomainDoc) => void
+    'domain/before-update': (domainId: string, $set: Partial<DomainDoc>) => void
+    'domain/update': (domainId: string, $set: Partial<DomainDoc>, ddoc: DomainDoc) => void
+
     'document/add': (doc: any) => VoidReturn
     'document/set': <T extends keyof DocType>
         (domainId: string, docType: T, docId: DocType[T], $set: any) => VoidReturn