Adds the PMD Plugin (#620)

* Add pmd rulesets

Author: AustinShalit

.travis.yml

@@ -30,7 +30,7 @@ install:
   - '[ "${TRAVIS_PULL_REQUEST}" = "false" ] && ./gradlew :ui:assemble --stacktrace || ./gradlew --stacktrace '
 
 script:
-  - ./gradlew checkstyleMain checkstyleTest jacocoTestReport jacocoRootReport test --stacktrace -Pheadless=true -PlogTests
+  - ./gradlew checkstyleMain checkstyleTest pmdMain jacocoTestReport jacocoRootReport test --stacktrace -Pheadless=true -PlogTests
 
 after_success:
   - if [[ "$TRAVIS_OS_NAME" != "osx" ]]; then codecov         ; fi

appveyor.yml

@@ -6,7 +6,7 @@ build_script:
 
 # to run your custom scripts instead of automatic tests
 test_script:
-  - gradlew.bat checkstyleMain checkstyleTest jacocoTestReport jacocoRootReport test --stacktrace -Pheadless=true -PlogTests
+  - gradlew.bat checkstyleMain checkstyleTest pmdMain jacocoTestReport jacocoRootReport test --stacktrace -Pheadless=true -PlogTests
 
 platform:
   - x64

build.gradle

@@ -90,6 +90,7 @@ allprojects {
     apply plugin: 'jacoco'
     apply plugin: 'net.ltgt.errorprone'
     apply plugin: 'checkstyle'
+    apply plugin: 'pmd'
 
     configurations.errorprone {
         resolutionStrategy.force 'com.google.errorprone:error_prone_core:2.0.9'
@@ -109,6 +110,14 @@ allprojects {
         it.dependsOn = []
     }
 
+    pmd {
+        consoleOutput = true
+        sourceSets = [sourceSets.main]
+        reportsDir = file("$project.buildDir/reports/pmd")
+        ruleSetFiles = files(new File(rootDir, "pmd-ruleset.xml"))
+        ruleSets = []
+    }
+
     repositories {
         mavenCentral()
         jcenter()

core/src/main/java/edu/wpi/grip/core/ConnectionValidator.java

@@ -19,14 +19,13 @@ public interface ConnectionValidator {
    * @return The return value of {@link #canConnect(OutputSocket, InputSocket)}
    */
   default boolean canConnect(Socket socket1, Socket socket2) {
-    final OutputSocket<?> outputSocket;
-    final InputSocket<?> inputSocket;
-
     // One socket must be an input and one must be an output
     if (socket1.getDirection() == socket2.getDirection()) {
       return false;
     }
 
+    final OutputSocket<?> outputSocket;
+    final InputSocket<?> inputSocket;
     if (socket1.getDirection().equals(Socket.Direction.OUTPUT)) {
       outputSocket = (OutputSocket) socket1;
       inputSocket = (InputSocket) socket2;

core/src/main/java/edu/wpi/grip/core/GripCoreModule.java

@@ -42,6 +42,9 @@
  */
 @SuppressWarnings("PMD.MoreThanOneLogger")
 public class GripCoreModule extends AbstractModule {
+
+  private final EventBus eventBus;
+
   private static final Logger logger = Logger.getLogger(GripCoreModule.class.getName());
 
   // This is in a static initialization block so that we don't create a ton of
@@ -93,8 +96,6 @@ public synchronized void publish(final LogRecord record) {
     }
   }
 
-  private final EventBus eventBus;
-
   /*
    * This class should not be used in tests. Use GRIPCoreTestModule for tests.
    */

core/src/main/java/edu/wpi/grip/core/Main.java

@@ -28,6 +28,8 @@
  */
 public class Main {
 
+  private static final Logger logger = Logger.getLogger(Main.class.getName());
+
   @Inject
   private Project project;
   @Inject
@@ -39,20 +41,18 @@ public class Main {
   @Inject
   private CVOperations cvOperations;
   @Inject
-  private Logger logger;
-  @Inject
   private GripServer gripServer;
   @Inject
   private HttpPipelineSwitcher pipelineSwitcher;
 
-  @SuppressWarnings({"PMD.SystemPrintln", "JavadocMethod"})
+  @SuppressWarnings("JavadocMethod")
   public static void main(String[] args) throws IOException, InterruptedException {
     final Injector injector = Guice.createInjector(Modules.override(
         new GripCoreModule(), new GripSourcesHardwareModule()).with(new GripNetworkModule()));
     injector.getInstance(Main.class).start(args);
   }
 
-  @SuppressWarnings({"PMD.SystemPrintln", "JavadocMethod"})
+  @SuppressWarnings("JavadocMethod")
   public void start(String[] args) throws IOException, InterruptedException {
     String projectPath = null;
     if (args.length == 1) {

core/src/main/java/edu/wpi/grip/core/OperationDescription.java

@@ -6,9 +6,9 @@
 import com.google.common.collect.ImmutableSet;
 
 import java.io.InputStream;
+import java.util.Objects;
 import java.util.Optional;
 import java.util.Set;
-
 import javax.annotation.Nullable;
 import javax.annotation.concurrent.Immutable;
 
@@ -105,39 +105,25 @@ public boolean equals(@Nullable Object o) {
 
     OperationDescription that = (OperationDescription) o;
 
-    if (name() != null ? !name().equals(that.name()) : that.name() != null) {
-      return false;
-    }
-    if (summary() != null ? !summary().equals(that.summary()) : that.summary() != null) {
-      return false;
-    }
-    if (category() != that.category()) {
-      return false;
-    }
-    if (icon() != null ? !icon().equals(that.icon()) : that.icon() != null) {
-      return false;
-    }
-    return aliases() != null ? aliases().equals(that.aliases()) : that.aliases() == null;
-
+    return Objects.equals(name, that.name)
+        && Objects.equals(summary, that.summary)
+        && Objects.equals(category, that.category)
+        && Objects.equals(icon, that.icon)
+        && Objects.equals(aliases, that.aliases);
   }
 
   @Override
   public int hashCode() {
-    int result = name() != null ? name().hashCode() : 0;
-    result = 31 * result + (summary() != null ? summary().hashCode() : 0);
-    result = 31 * result + (category() != null ? category().hashCode() : 0);
-    result = 31 * result + (icon() != null ? icon().hashCode() : 0);
-    result = 31 * result + (aliases() != null ? aliases().hashCode() : 0);
-    return result;
+    return Objects.hash(name, summary, category, icon, aliases);
   }
 
   @Override
   public String toString() {
     return MoreObjects.toStringHelper(this)
-        .add("name", name())
-        .add("summary", summary())
-        .add("aliases", aliases())
-        .add("category", category())
+        .add("name", name)
+        .add("summary", summary)
+        .add("aliases", aliases)
+        .add("category", category)
         .toString();
   }
 

core/src/main/java/edu/wpi/grip/core/Pipeline.java

@@ -61,7 +61,7 @@ public class Pipeline implements ConnectionValidator, SettingsProvider {
   @Inject
   @XStreamOmitField
   private EventBus eventBus;
-  private transient ReadWriteLock stepLock = new ReentrantReadWriteLock();
+  private final transient ReadWriteLock stepLock = new ReentrantReadWriteLock();
   private ProjectSettings settings = new ProjectSettings();
 
   /**

core/src/main/java/edu/wpi/grip/core/PipelineRunner.java

@@ -38,7 +38,7 @@
  */
 @Singleton
 public class PipelineRunner implements RestartableService {
-  private final Logger logger = Logger.getLogger(getClass().getName());
+  private static final Logger logger = Logger.getLogger(PipelineRunner.class.getName());
   /**
    * This is used to flag that the pipeline needs to run because of an update.
    */

core/src/main/java/edu/wpi/grip/core/Source.java

@@ -21,7 +21,7 @@
  * Base class for an input into the pipeline.
  */
 public abstract class Source {
-  private final Logger logger = Logger.getLogger(getClass().getName());
+  private static final Logger logger = Logger.getLogger(Source.class.getName());
   private final ExceptionWitness exceptionWitness;
 
   /**