Add support for running FindBugs

.travis.yml

@@ -9,7 +9,7 @@ install:
 - echo y | android update sdk -u -a -t extra-google-m2repository
 - echo y | android update sdk -u -a -t extra-android-m2repository
 
-script: ./gradlew assembleRelease testReleaseUnitTest lintRelease
+script: ./gradlew assembleRelease testReleaseUnitTest lintRelease findbugs
 
 after_failure:
 - cat app/build/reports/findbugs/findbugs.html

app/build.gradle

@@ -1,4 +1,10 @@
 apply plugin: 'com.android.application'
+apply plugin: 'findbugs'
+
+findbugs {
+    sourceSets = []
+    ignoreFailures = false
+}
 
 android {
     compileSdkVersion 25
@@ -17,3 +23,22 @@ android {
         }
     }
 }
+
+task findbugs(type: FindBugs, dependsOn: 'assembleDebug') {
+
+    description 'Run findbugs'
+    group 'verification'
+
+    classes = fileTree('build/intermediates/classes/debug/')
+    source = fileTree('src/main/java')
+    classpath = files()
+
+    effort = 'max'
+
+    excludeFilter = file("./config/findbugs/exclude.xml")
+
+    reports {
+        xml.enabled = false
+        html.enabled = true
+    }
+}

app/config/findbugs/exclude.xml

@@ -0,0 +1,10 @@
+<FindBugsFilter>
+
+    <Match>
+        <Class name="~.*R\$.*"/>
+    </Match>
+    <Match>
+        <Class name="~.*Manifest\$.*"/>
+    </Match>
+
+</FindBugsFilter>