Added checkstyle

.circleci/config.yml

@@ -51,9 +51,25 @@ jobs:
             - ~/android
           key: v1-android-{{ checksum "build.gradle" }}
 
+  checkstyle:
+    docker:
+      - image: circleci/android:api-28
+    working_directory: ~/AntennaPod
+
+    steps:
+      - checkout
+
+      - run:
+          name: Checkstyle
+          command: ./gradlew checkstyle
+
 workflows:
   version: 2
 
   test:
     jobs:
       - test
+
+  checkstyle:
+    jobs:
+      - checkstyle

build.gradle

@@ -82,3 +82,14 @@ wrapper {
 def doFreeBuild() {
     return hasProperty("freeBuild")
 }
+
+apply plugin: "checkstyle"
+checkstyle {
+    toolVersion '8.24'
+}
+
+task checkstyle(type: Checkstyle) {
+    classpath = files()
+    source "${project.rootDir}"
+    exclude("**/gen/**")
+}

config/checkstyle/checkstyle.xml

@@ -0,0 +1,28 @@
+<?xml version="1.0"?>
+<!DOCTYPE module PUBLIC
+          "-//Checkstyle//DTD Checkstyle Configuration 1.3//EN"
+          "https://checkstyle.org/dtds/configuration_1_3.dtd">
+<module name = "Checker">
+    <property name="charset" value="UTF-8"/>
+
+    <property name="severity" value="error"/>
+
+    <property name="fileExtensions" value="java, xml"/>
+
+    <module name="TreeWalker">
+        <module name="AvoidEscapedUnicodeCharacters">
+            <property name="allowEscapesForControlCharacters" value="true"/>
+            <property name="allowByTailComment" value="true"/>
+            <property name="allowNonPrintableEscapes" value="true"/>
+        </module>
+        <module name="AvoidStarImport"/>
+        <module name="OneTopLevelClass"/>
+        <module name="OneStatementPerLine"/>
+        <module name="ModifierOrder"/>
+        <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>
+</module>