Add Findbugs

.travis.yml

@@ -30,7 +30,7 @@ install:
   - '[ "${TRAVIS_PULL_REQUEST}" = "false" ] && ./gradlew :ui:jfxNative --stacktrace || ./gradlew --stacktrace '
 
 script:
-  - ./gradlew checkstyleMain checkstyleTest pmdMain jacocoTestReport jacocoRootReport test --stacktrace -Pheadless=true -PlogTests
+  - ./gradlew checkstyleMain checkstyleTest pmdMain findbugsMain 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 pmdMain jacocoTestReport jacocoRootReport test --stacktrace -Pheadless=true -PlogTests
+  - gradlew.bat checkstyleMain checkstyleTest pmdMain findbugsMain jacocoTestReport jacocoRootReport test --stacktrace -Pheadless=true -PlogTests
 
 platform:
   - x64

build.gradle

@@ -1,3 +1,5 @@
+import groovy.xml.XmlUtil
+
 buildscript {
     repositories {
         jcenter()
@@ -92,6 +94,7 @@ configure(allprojects - project(':ui:linuxLauncher')) {
     apply plugin: 'net.ltgt.errorprone'
     apply plugin: 'checkstyle'
     apply plugin: 'pmd'
+    apply plugin: 'findbugs'
 
     configurations.errorprone {
         resolutionStrategy.force 'com.google.errorprone:error_prone_core:2.0.9'
@@ -119,6 +122,29 @@ configure(allprojects - project(':ui:linuxLauncher')) {
         ruleSets = []
     }
 
+    findbugs {
+        sourceSets = [sourceSets.main]
+        excludeFilter = new File(rootDir, "findBugsSuppressions.xml")
+        effort = "max"
+        ignoreFailures = true // Error will be reported by checkFindBugsReport
+    }
+
+    task checkFindBugsReport << {
+        def xmlReport = findbugsMain.reports.getXml().destination
+        if (findbugsMain.reports.getXml().destination.exists()) {
+            def bugs = (new XmlParser().parse(xmlReport)).BugInstance
+            def bugsFound = bugs.size()
+            if (bugsFound > 0) {
+                bugs.each { System.out.println(new XmlUtil().serialize(it)) }
+                throw new GradleException("$bugsFound FindBugs rule violations were found. See the report at: $xmlReport")
+            }
+        }
+    }
+
+    tasks.withType(FindBugs) {
+        it.finalizedBy checkFindBugsReport
+    }
+
     repositories {
         mavenCentral()
         jcenter()
@@ -129,6 +155,7 @@ configure(allprojects - project(':ui:linuxLauncher')) {
 
 
     dependencies {
+        compile group: 'com.google.code.findbugs', name: 'annotations', version: '3.0.1'
         testCompile group: 'net.jodah', name: 'concurrentunit', version: '0.4.2'
         testCompile group: 'org.hamcrest', name: 'hamcrest-all', version: '1.3'
         testCompile group: 'junit', name: 'junit', version: '4.12'

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

@@ -9,6 +9,7 @@
 import java.util.Objects;
 import java.util.Optional;
 import java.util.Set;
+
 import javax.annotation.Nullable;
 import javax.annotation.concurrent.Immutable;
 

core/src/main/java/edu/wpi/grip/core/operations/composite/FilterContoursOperation.java

@@ -191,7 +191,7 @@ public void perform() {
         continue;
       }
 
-      final double ratio = bb.width() / bb.height();
+      final double ratio = (double) bb.width() / (double) bb.height();
       if (ratio < minRatio || ratio > maxRatio) {
         continue;
       }

core/src/main/java/edu/wpi/grip/core/operations/composite/PublishVideoOperation.java

@@ -9,6 +9,8 @@
 
 import com.google.common.collect.ImmutableList;
 
+import edu.umd.cs.findbugs.annotations.SuppressFBWarnings;
+
 import org.bytedeco.javacpp.BytePointer;
 import org.bytedeco.javacpp.IntPointer;
 
@@ -133,6 +135,7 @@ public class PublishVideoOperation implements Operation {
   };
 
   @SuppressWarnings("JavadocMethod")
+  @SuppressFBWarnings("ST_WRITE_TO_STATIC_FROM_INSTANCE_METHOD") // Don't need sync in constructor
   public PublishVideoOperation(InputSocket.Factory inputSocketFactory) {
     if (numSteps != 0) {
       throw new IllegalStateException("Only one instance of PublishVideoOperation may exist");
@@ -141,7 +144,7 @@ public PublishVideoOperation(InputSocket.Factory inputSocketFactory) {
         false));
     this.qualitySocket = inputSocketFactory.create(SocketHints.Inputs
         .createNumberSliderSocketHint("Quality", 80, 0, 100));
-    numSteps = numSteps + 1;
+    numSteps++;
 
     serverThread = new Thread(runServer, "Camera Server");
     serverThread.setDaemon(true);

core/src/main/java/edu/wpi/grip/core/operations/composite/ValveOperation.java

@@ -16,7 +16,7 @@
 
 public class ValveOperation implements Operation {
 
-  public static OperationDescription DESCRIPTION =
+  public static final OperationDescription DESCRIPTION =
       OperationDescription.builder()
           .name("Valve")
           .summary("Toggle an output socket on or off using a boolean")

core/src/main/java/edu/wpi/grip/core/operations/network/http/DataHandler.java

@@ -12,6 +12,8 @@
 import com.google.inject.Inject;
 import com.google.inject.Singleton;
 
+import edu.umd.cs.findbugs.annotations.SuppressFBWarnings;
+
 import org.eclipse.jetty.server.Request;
 
 import java.io.IOException;
@@ -69,6 +71,7 @@ public final class DataHandler extends PedanticHandler {
   }
 
   @Override
+  @SuppressFBWarnings("UW_UNCOND_WAIT") // Bug in FindBugs. There is a condition.
   protected void handleIfPassed(String target,
                                 Request baseRequest,
                                 HttpServletRequest request,

core/src/main/java/edu/wpi/grip/core/util/SafeShutdown.java

@@ -1,5 +1,7 @@
 package edu.wpi.grip.core.util;
 
+import edu.umd.cs.findbugs.annotations.SuppressFBWarnings;
+
 import javax.annotation.Nullable;
 
 /**
@@ -16,8 +18,10 @@ public final class SafeShutdown {
      * flagging a shutdown
      * that we can't control.
      */
+
     Runtime.getRuntime().addShutdownHook(new Thread() {
       @Override
+      @SuppressFBWarnings("ST_WRITE_TO_STATIC_FROM_INSTANCE_METHOD")
       public void run() {
         SafeShutdown.stopping = true;
       }

findBugsSuppressions.xml

@@ -0,0 +1,11 @@
+<FindBugsFilter>
+    <Match>
+        <Package name="~edu\.wpi\.grip\.generated.*" />
+    </Match>
+    <Match>
+        <Bug pattern="RV_RETURN_VALUE_IGNORED_BAD_PRACTICE" />
+    </Match>
+    <Match>
+        <Bug pattern="NP_METHOD_PARAMETER_TIGHTENS_ANNOTATION" />
+    </Match>
+</FindBugsFilter>

ui/src/main/java/edu/wpi/grip/ui/preview/BlobsSocketPreviewView.java

@@ -8,6 +8,8 @@
 
 import com.google.common.eventbus.Subscribe;
 
+import edu.umd.cs.findbugs.annotations.SuppressFBWarnings;
+
 import javafx.application.Platform;
 import javafx.geometry.Orientation;
 import javafx.scene.control.CheckBox;
@@ -38,7 +40,8 @@ public class BlobsSocketPreviewView extends SocketPreviewView<BlobsReport> {
   private final Mat tmp = new Mat();
   private final GripPlatform platform;
   @SuppressWarnings("PMD.ImmutableField")
-  private boolean showInputImage;
+  @SuppressFBWarnings("IS2_INCONSISTENT_SYNC") // No sync needed in constructor
+  private boolean showInputImage = false;
 
   /**
    * @param socket An output socket to preview.

ui/src/main/java/edu/wpi/grip/ui/preview/LinesSocketPreviewView.java

@@ -8,6 +8,8 @@
 
 import com.google.common.eventbus.Subscribe;
 
+import edu.umd.cs.findbugs.annotations.SuppressFBWarnings;
+
 import java.util.List;
 import javafx.application.Platform;
 import javafx.geometry.Orientation;
@@ -40,7 +42,8 @@ public class LinesSocketPreviewView extends SocketPreviewView<LinesReport> {
   private final Mat tmp = new Mat();
   private final GripPlatform platform;
   @SuppressWarnings("PMD.ImmutableField")
-  private boolean showInputImage;
+  @SuppressFBWarnings("IS2_INCONSISTENT_SYNC") // No sync needed in constructor
+  private boolean showInputImage = false;
 
   /**
    * @param socket An output socket to preview.