Static code analysis: run findbugs, pmd and lint at 'gradle check' #92

As a start, the build won't abort on any serious errors.

app/build.gradle

@@ -1,4 +1,8 @@
 apply plugin: 'com.android.application'
+apply plugin: 'findbugs'
+apply plugin: 'pmd'
+
+def ABORT_ON_CHECK_FAILURE=false
 
 android {
     compileSdkVersion 21
@@ -17,13 +21,22 @@ android {
             proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
         }
     }
+
+    lintOptions {
+        abortOnError ABORT_ON_CHECK_FAILURE
+        lintConfig file("${project.rootDir}/config/lint/lint.xml")
+
+// if true, generate an HTML report (with issue explanations, sourcecode, etc)
+        htmlReport true
+// optional path to report (default will be lint-results.html in the builddir)
+        htmlOutput file("$project.buildDir/reports/lint/lint.html")
+    }
 }
 
 dependencies {
     compile fileTree(dir: 'libs', include: ['*.jar'])
     compile 'com.android.support:appcompat-v7:21.0.3'
     compile 'com.android.support:support-v4:21.0.3'
-//    compile 'com.noveogroup.android:android-logger:1.3.5'
     compile 'com.github.tony19:logback-android-classic:1.1.1-3'
     compile 'org.slf4j:slf4j-api:1.7.7'
     compile 'com.github.PhilJay:MPAndroidChart:2.1.0'
@@ -32,3 +45,67 @@ dependencies {
     testCompile 'junit:junit:4.12'
 //    testCompile "org.mockito:mockito-core:1.9.5"
 }
+
+check.dependsOn 'findbugs', 'pmd', 'lint'
+
+task pmd(type: Pmd) {
+    ruleSetFiles = files("${project.rootDir}/config/pmd/pmd-ruleset.xml")
+    ignoreFailures = !ABORT_ON_CHECK_FAILURE
+    ruleSets = [
+            'java-android',
+            'java-basic',
+            'java-braces',
+            'java-clone',
+            'java-codesize',
+            'java-controversial',
+            'java-coupling',
+            'java-design',
+            'java-empty',
+            'java-finalizers',
+            'java-imports',
+            'java-junit',
+            'java-optimizations',
+            'java-strictexception',
+            'java-strings',
+            'java-sunsecure',
+            'java-typeresolution',
+            'java-unnecessary',
+            'java-unusedcode'
+    ]
+
+    source 'src'
+    include '**/*.java'
+    exclude '**/gen/**'
+
+    reports {
+        xml.enabled = false
+        html.enabled = true
+        xml {
+            destination "$project.buildDir/reports/pmd/pmd.xml"
+        }
+        html {
+            destination "$project.buildDir/reports/pmd/pmd.html"
+        }
+    }
+}
+
+
+task findbugs(type: FindBugs) {
+    ignoreFailures = !ABORT_ON_CHECK_FAILURE
+    effort = "default"
+    reportLevel = "medium"
+    excludeFilter = new File("${project.rootDir}/config/findbugs/findbugs-filter.xml")
+    classes = files("${project.rootDir}/app/build/intermediates/classes")
+    source = fileTree('src/main/java/')
+    classpath = files()
+    reports {
+        xml.enabled = false
+        html.enabled = true
+        xml {
+            destination "$project.buildDir/reports/findbugs/findbugs-output.xml"
+        }
+        html {
+            destination "$project.buildDir/reports/findbugs/findbugs-output.html"
+        }
+    }
+}

config/findbugs/findbugs-filter.xml

@@ -0,0 +1,19 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<FindBugsFilter>
+    <Match>
+        <!-- ignore all issues in resource generation -->
+        <Class name="~.*\.R\$.*"/>
+    </Match>
+    <Match>
+        <Class name="~.*\.Manifest\$.*"/>
+    </Match>
+
+    <!-- ignore all bugs in test classes, except for those bugs specifically relating to JUnit tests -->
+    <Match>
+        <Class name="~.*\.*Test" />
+        <!-- test classes are suffixed by 'Test' -->
+        <Not>
+            <Bug code="IJU" /> <!-- 'IJU' is the code for bugs related to JUnit test code -->
+        </Not>
+    </Match>
+</FindBugsFilter>

config/pmd/pmd-ruleset.xml

@@ -0,0 +1,52 @@
+<?xml version="1.0"?>
+<!--
+  ~ Copyright 2015 Vincent Brison.
+  ~
+  ~ Licensed 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.
+  -->
+
+<ruleset xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" name="Android Application Rules"
+    xmlns="http://pmd.sf.net/ruleset/1.0.0"
+    xsi:noNamespaceSchemaLocation="http://pmd.sf.net/ruleset_xml_schema.xsd"
+    xsi:schemaLocation="http://pmd.sf.net/ruleset/1.0.0 http://pmd.sf.net/ruleset_xml_schema.xsd">
+
+    <description>Custom ruleset for Android application</description>
+
+    <exclude-pattern>.*/R.java</exclude-pattern>
+    <exclude-pattern>.*/gen/.*</exclude-pattern>
+
+    <rule ref="rulesets/java/android.xml">
+        <!-- Config.LOGD deprecated in API level 4 !-->
+        <exclude name="ProtectLogD" />
+        <!-- Config.LOGV deprecated in API level 4 !-->
+        <exclude name="ProtectLogV" />
+    </rule>
+    <rule ref="rulesets/java/clone.xml" />
+    <rule ref="rulesets/java/finalizers.xml" />
+    <rule ref="rulesets/java/imports.xml">
+        <!-- Espresso is designed this way !-->
+        <exclude name="TooManyStaticImports" />
+    </rule>
+    <rule ref="rulesets/java/logging-java.xml" />
+    <rule ref="rulesets/java/braces.xml" />
+    <rule ref="rulesets/java/strings.xml" />
+    <rule ref="rulesets/java/basic.xml" />
+    <rule ref="rulesets/java/naming.xml">
+        <exclude name="AbstractNaming" />
+        <exclude name="LongVariable" />
+        <exclude name="LongMethodName" />
+        <exclude name="ShortMethodName" />
+        <exclude name="ShortVariable" />
+        <exclude name="VariableNamingConventions" />
+    </rule>
+</ruleset>