[ISSUE apache#438] Enable Github Actions for Checkstyle (apache#439)

* enable github actions for checkstyle

* try to fix ci

* ...

* ...

* ...

* Enable Github Actions for Checkstyle

* accelerate

* -filter-mode=nofilter -fail-on-error

* remove -name

.github/workflows/ci.yml

@@ -71,6 +71,28 @@ jobs:
       - name: Upload coverage report to codecov.io
         run: bash <(curl -s https://codecov.io/bash) || echo 'Failed to upload coverage report!'
 
+  checkstyle:
+    name: Checkstyle
+
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v2
+
+      - name: Download checkstyle exectable
+        run: wget -O - -q https://github.com/checkstyle/checkstyle/releases/download/checkstyle-8.44/checkstyle-8.44-all.jar > ./checkstyle.jar
+
+      - name: Download reviewdog exectable
+        run: wget -O - -q https://raw.githubusercontent.com/reviewdog/reviewdog/master/install.sh | sh -s -- -b . v0.12.0
+
+      - name: Check code style
+        env:
+          REVIEWDOG_GITHUB_API_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+        run: |
+          java -jar ./checkstyle.jar -c ./style/checkStyle.xml -f xml ./eventmesh-* \
+               | ./reviewdog -f=checkstyle -reporter=github-pr-check -filter-mode=nofilter -fail-on-error
+
   license-check:
     name: License Check
 

style/checkStyle.xml

@@ -0,0 +1,47 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!--
+  ~ Licensed to the Apache Software Foundation (ASF) under one or more
+  ~ contributor license agreements.  See the NOTICE file distributed with
+  ~ this work for additional information regarding copyright ownership.
+  ~ The ASF licenses this file to You under the Apache License, Version 2.0
+  ~ (the "License"); you may not use this file except in compliance with
+  ~ the License.  You may obtain a copy of the License at
+  ~
+  ~     http://www.apache.org/licenses/LICENSE-2.0
+  ~
+  ~ Unless required by applicable law or agreed to in writing, software
+  ~ distributed under the License is distributed on an "AS IS" BASIS,
+  ~ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  ~ See the License for the specific language governing permissions and
+  ~ limitations under the License.
+  ~
+  -->
+
+<!DOCTYPE module PUBLIC
+  "-//Puppy Crawl//DTD Check Configuration 1.3//EN"
+  "http://checkstyle.org/dtds/configuration_1_3.dtd">
+<module name="Checker">
+  <module name="RegexpSingleline">
+    <property name="format" value="System\.out\.println"/>
+    <property name="message" value="Prohibit invoking System.out.println in source code !"/>
+  </module>
+
+  <module name="RegexpSingleline">
+    <property name="format" value="^\s*\*\s*@author"/>
+    <property name="minimum" value="0"/>
+    <property name="maximum" value="0"/>
+    <property name="message" value="ASF project doesn't allow @author copyright."/>
+  </module>
+
+  <module name="RegexpSingleline">
+    <property name="format"
+              value=".*[\u3400-\u4DB5\u4E00-\u9FA5\u9FA6-\u9FBB\uF900-\uFA2D\uFA30-\uFA6A\uFA70-\uFAD9\uFF00-\uFFEF\u2E80-\u2EFF\u3000-\u303F\u31C0-\u31EF]+.*"/>
+    <property name="message" value="Chinese characters are not allowed!"/>
+  </module>
+
+  <module name="TreeWalker">
+    <module name="PackageName">
+      <property name="format" value="^(org)\.apache(\.[a-zA-Z][a-zA-Z0-9]*)+$"/>
+    </module>
+  </module>
+</module>