[Checkstyle] Add java checkstyle (#1367)

pom.xml

@@ -60,6 +60,7 @@
 		<mssql.jdbc.version>6.1.0.jre8</mssql.jdbc.version>
 		<jsp.version>6.1.14</jsp.version>
 		<spotbugs.version>3.1.12</spotbugs.version>
+		<checkstyle.version>3.0.0</checkstyle.version>
 		<apache.rat.version>0.13</apache.rat.version>
 		<zookeeper.version>3.4.14</zookeeper.version>
 	</properties>
@@ -589,6 +590,40 @@
 					</dependency>
 				</dependencies>
 			</plugin>
+			<plugin>
+				<groupId>org.apache.maven.plugins</groupId>
+				<artifactId>maven-checkstyle-plugin</artifactId>
+				<version>${checkstyle.version}</version>
+				<dependencies>
+					<dependency>
+						<groupId>com.puppycrawl.tools</groupId>
+						<artifactId>checkstyle</artifactId>
+						<version>8.18</version>
+					</dependency>
+				</dependencies>
+				<configuration>
+					<consoleOutput>true</consoleOutput>
+					<encoding>UTF-8</encoding>
+					<configLocation>style/checkstyle.xml</configLocation>
+					<suppressionsLocation>style/checkstyle-suppressions.xml</suppressionsLocation>
+					<suppressionsFileExpression>checkstyle.suppressions.file</suppressionsFileExpression>
+					<failOnViolation>true</failOnViolation>
+					<violationSeverity>warning</violationSeverity>
+					<includeTestSourceDirectory>true</includeTestSourceDirectory>
+					<sourceDirectories>
+						<sourceDirectory>${project.build.sourceDirectory}</sourceDirectory>
+					</sourceDirectories>
+					<excludes>**\/generated-sources\/</excludes>
+				</configuration>
+				<executions>
+					<execution>
+						<phase>compile</phase>
+						<goals>
+							<goal>check</goal>
+						</goals>
+					</execution>
+				</executions>
+			</plugin>
 		</plugins>
 
 	</build>

style/checkstyle-suppressions.xml

@@ -0,0 +1,24 @@
+<?xml version="1.0"?>
+<!--
+ 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 suppressions PUBLIC
+     "-//Puppy Crawl//DTD Suppressions 1.0//EN"
+     "http://www.puppycrawl.com/dtds/suppressions_1_0.dtd">
+ 
+<suppressions>
+
+</suppressions>

style/checkstyle.xml

@@ -0,0 +1,254 @@
+<?xml version="1.0"?>
+<!--
+  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.sourceforge.net/dtds/configuration_1_3.dtd">
+
+<module name="Checker">
+    <property name="charset" value="UTF-8"/>
+
+    <property name="severity" value="info"/>
+
+    <property name="fileExtensions" value="java, properties, xml"/>
+
+    <module name="FileTabCharacter">
+        <property name="eachLine" value="true"/>
+    </module>
+
+    <module name="SuppressionFilter">
+        <property name="file" value="${checkstyle.suppressions.file}" default="checkstyle-suppressions.xml"/>
+        <property name="optional" value="true"/>
+    </module>
+
+    <module name="TreeWalker">
+
+        <module name="OuterTypeFilename"/>
+
+        <module name="OneTopLevelClass"/>
+
+        <module name="NoLineWrap"/>
+
+        <module name="NeedBraces"/>
+
+        <module name="LeftCurly"/>
+
+        <module name="AvoidNestedBlocks">
+            <property name="allowInSwitchCase" value="true"/>
+        </module>
+
+        <module name="IllegalTokenText">
+            <property name="tokens" value="STRING_LITERAL, CHAR_LITERAL"/>
+            <property name="format"
+                      value="\\u00(09|0(a|A)|0(c|C)|0(d|D)|22|27|5(C|c))|\\(0(10|11|12|14|15|42|47)|134)"/>
+            <property name="message"
+                      value="Consider using special escape sequence instead of octal value or Unicode escaped value."/>
+        </module>
+
+        <module name="AvoidEscapedUnicodeCharacters">
+            <property name="allowEscapesForControlCharacters" value="true"/>
+            <property name="allowByTailComment" value="true"/>
+            <property name="allowNonPrintableEscapes" value="true"/>
+        </module>
+
+        <module name="LineLength">
+            <property name="max" value="200"/>
+            <property name="ignorePattern" value="^ *\* *[^ ]+$"/>
+        </module>
+
+        <module name="EmptyBlock">
+            <property name="option" value="TEXT"/>
+            <property name="tokens" value="LITERAL_TRY, LITERAL_FINALLY, LITERAL_IF, LITERAL_ELSE, LITERAL_SWITCH"/>
+        </module>
+
+        <module name="WhitespaceAround">
+            <property name="allowEmptyConstructors" value="true"/>
+            <property name="allowEmptyMethods" value="true"/>
+            <property name="allowEmptyTypes" value="true"/>
+            <property name="allowEmptyLoops" value="true"/>
+            <message key="ws.notFollowed"
+                     value="WhitespaceAround: ''{0}'' is not followed by whitespace. Empty blocks may only be represented as '{}' when not part of a multi-block statement (4.1.3)"/>
+            <message key="ws.notPreceded"
+                     value="WhitespaceAround: ''{0}'' is not preceded with whitespace."/>
+        </module>
+
+        <module name="OneStatementPerLine"/>
+
+        <module name="MultipleVariableDeclarations"/>
+
+        <module name="ArrayTypeStyle"/>
+
+        <module name="MissingSwitchDefault"/>
+
+        <module name="FallThrough"/>
+
+        <module name="UpperEll"/>
+
+        <module name="ModifierOrder"/>
+
+        <module name="EmptyLineSeparator">
+            <property name="allowMultipleEmptyLines" value="false"/>
+            <property name="allowMultipleEmptyLinesInsideClassMembers" value="false"/>
+            <property name="tokens" value="PACKAGE_DEF, IMPORT, STATIC_IMPORT, CLASS_DEF,
+                                            INTERFACE_DEF, ENUM_DEF, STATIC_INIT, INSTANCE_INIT, METHOD_DEF,
+                                            CTOR_DEF"/>
+        </module>
+
+        <module name="PackageName">
+            <property name="format" value="^[a-z]+(\.[a-z][a-z0-9]*)*$"/>
+            <message key="name.invalidPattern"
+                     value="Package name ''{0}'' must match pattern ''{1}''."/>
+        </module>
+
+        <module name="TypeName">
+            <message key="name.invalidPattern"
+                     value="Type name ''{0}'' must match pattern ''{1}''."/>
+        </module>
+
+        <module name="MemberName">
+            <property name="format" value="^[a-z][a-zA-Z0-9]*$"/>
+            <message key="name.invalidPattern"
+                     value="Member name ''{0}'' must match pattern ''{1}''."/>
+        </module>
+
+        <module name="ParameterName">
+            <property name="format" value="^[a-z]([a-zA-Z0-9]*)?$"/>
+            <message key="name.invalidPattern"
+                     value="Parameter name ''{0}'' must match pattern ''{1}''."/>
+        </module>
+
+        <module name="CatchParameterName">
+            <property name="format" value="^[a-z]([a-zA-Z0-9]*)?$"/>
+            <message key="name.invalidPattern"
+                     value="Catch parameter name ''{0}'' must match pattern ''{1}''."/>
+        </module>
+
+        <module name="LocalVariableName">
+            <property name="tokens" value="VARIABLE_DEF"/>
+            <property name="format" value="^[a-z]([a-zA-Z0-9]*)?$"/>
+            <message key="name.invalidPattern"
+                     value="Local variable name ''{0}'' must match pattern ''{1}''."/>
+        </module>
+
+        <module name="ClassTypeParameterName">
+            <property name="format" value="(^[A-Z][0-9]?)$|([A-Z][a-zA-Z0-9]*[T]$)"/>
+            <message key="name.invalidPattern"
+                     value="Class type name ''{0}'' must match pattern ''{1}''."/>
+        </module>
+
+        <module name="MethodTypeParameterName">
+            <property name="format" value="(^[A-Z][0-9]?)$|([A-Z][a-zA-Z0-9]*[T]$)"/>
+            <message key="name.invalidPattern"
+                     value="Method type name ''{0}'' must match pattern ''{1}''."/>
+        </module>
+
+        <module name="InterfaceTypeParameterName">
+            <property name="format" value="(^[A-Z][0-9]?)$|([A-Z][a-zA-Z0-9]*[T]$)"/>
+            <message key="name.invalidPattern"
+                     value="Interface type name ''{0}'' must match pattern ''{1}''."/>
+        </module>
+
+        <module name="NoFinalizer"/>
+
+        <module name="GenericWhitespace">
+            <message key="ws.followed"
+                     value="GenericWhitespace ''{0}'' is followed by whitespace."/>
+            <message key="ws.preceded"
+                     value="GenericWhitespace ''{0}'' is preceded with whitespace."/>
+            <message key="ws.illegalFollow"
+                     value="GenericWhitespace ''{0}'' should followed by whitespace."/>
+            <message key="ws.notPreceded"
+                     value="GenericWhitespace ''{0}'' is not preceded with whitespace."/>
+        </module>
+
+        <module name="Indentation">
+            <property name="basicOffset" value="2"/>
+            <property name="braceAdjustment" value="0"/>
+            <property name="caseIndent" value="2"/>
+            <property name="throwsIndent" value="4"/>
+            <property name="lineWrappingIndentation" value="4"/>
+            <property name="arrayInitIndent" value="2"/>
+        </module>
+
+        <module name="UnusedImports"/>
+
+        <module name="RedundantImport"/>
+
+        <module name="MethodParamPad"/>
+
+        <module name="NoWhitespaceBefore">
+            <property name="tokens" value="COMMA, SEMI, POST_INC, POST_DEC, DOT, ELLIPSIS, METHOD_REF"/>
+            <property name="allowLineBreaks" value="true"/>
+        </module>
+
+        <module name="ParenPad"/>
+
+        <module name="OperatorWrap">
+            <property name="option" value="NL"/>
+            <property name="tokens"
+                      value="BAND, BOR, BSR, BXOR, DIV, EQUAL, GE, GT, LAND, LE, LITERAL_INSTANCEOF, LOR, LT, MINUS, MOD, NOT_EQUAL, PLUS, QUESTION, SL, SR, STAR, METHOD_REF "/>
+        </module>
+
+        <module name="AnnotationLocation">
+            <property name="allowSamelineMultipleAnnotations" value="false"/>
+            <property name="allowSamelineSingleParameterlessAnnotation"
+                      value="false"/>
+            <property name="allowSamelineParameterizedAnnotation" value="true"/>
+            <property name="tokens" value="METHOD_DEF, CTOR_DEF"/>
+        </module>
+
+        <module name="MethodName">
+            <property name="format" value="^[a-z][a-z0-9][a-zA-Z0-9_]*$"/>
+            <message key="name.invalidPattern"
+                     value="Method name ''{0}'' must match pattern ''{1}''."/>
+        </module>
+
+        <module name="EmptyCatchBlock">
+            <property name="exceptionVariableName" value="expected"/>
+        </module>
+
+        <module name="CommentsIndentation"/>
+
+        <module name="IllegalImport">
+            <property name="illegalPkgs" value="org.apache.commons"/>
+            <property name="illegalClasses" value="java.util.Optional, com.google.common.base.Optional"/>
+        </module>
+
+        <module name="EmptyStatement"/>
+
+        <module name="JavadocStyle"/>
+
+        <module name="JavadocType">
+            <property name="scope" value="protected"/>
+            <property name="allowMissingParamTags" value="true"/>
+        </module>
+
+        <module name="ImportOrder">
+            <property name="groups" value="org.apache.dolphinscheduler, *, javax, java, scala"/>
+            <property name="separated" value="true"/>
+            <property name="sortStaticImportsAlphabetically" value="true"/>
+            <property name="option" value="bottom"/>
+            <property name="tokens" value="STATIC_IMPORT, IMPORT"/>
+            <message key="import.ordering"
+                     value="Import {0} appears after other imports that it should precede"/>
+        </module>
+
+        <module name="AvoidStarImport"/>
+
+    </module>
+</module>