Make `examples` an independent gradle project.

14 files changed, 846 insertions, 7 deletions

diff --git a/examples/README.md b/examples/README.md
index 2b67780e..eb37cd17 100644
--- a/examples/README.md
+++ b/examples/README.md
@@ -5,6 +5,8 @@
 ```
 $ ./gradlew installDist
 ```
+
+* Remember to change `opencensusVersion` in `build.gradle` to a released version you want to use.
 ## To run "StatsRunner" example use
 
 ```
@@ -21,4 +23,4 @@ Available pages:
 * For tracing config page go to [localhost:8080/traceconfigz][ZPagesTraceConfigZLink].
 
 [ZPagesTraceZLink]: http://localhost:8080/tracez
-[ZPagesTraceConfigZLink]: http://localhost:8080/traceconfigz
\ No newline at end of file
+[ZPagesTraceConfigZLink]: http://localhost:8080/traceconfigz
diff --git a/examples/build.gradle b/examples/build.gradle
index b4bb6fa5..fa3eb587 100644
--- a/examples/build.gradle
+++ b/examples/build.gradle
@@ -1,16 +1,193 @@
 description = 'OpenCensus Examples'
 
+buildscript {
+    repositories {
+        mavenCentral()
+        mavenLocal()
+        maven {
+            url "https://plugins.gradle.org/m2/"
+        }
+    }
+    dependencies {
+        classpath 'ru.vyarus:gradle-animalsniffer-plugin:1.4.2'
+        classpath 'net.ltgt.gradle:gradle-errorprone-plugin:0.0.13'
+        classpath "net.ltgt.gradle:gradle-apt-plugin:0.10"
+        classpath 'com.github.ben-manes:gradle-versions-plugin:0.15.0'
+        classpath "gradle.plugin.com.github.sherter.google-java-format:google-java-format-gradle-plugin:0.6"
+    }
+}
+
+// Display the version report using: ./gradlew dependencyUpdates
+// Also see https://github.com/ben-manes/gradle-versions-plugin.
+apply plugin: 'com.github.ben-manes.versions'
+apply plugin: "checkstyle"
+apply plugin: 'maven'
+apply plugin: 'idea'
+apply plugin: 'java'
+apply plugin: "signing"
+apply plugin: "jacoco"
+// The plugin only has an effect if a signature is specified
+apply plugin: 'ru.vyarus.animalsniffer'
+apply plugin: 'findbugs'
+apply plugin: 'net.ltgt.apt'
+// Plugins that require java8
+if (JavaVersion.current().isJava8Compatible()) {
+    apply plugin: "net.ltgt.errorprone"
+    apply plugin: 'com.github.sherter.google-java-format'
+}
+
+repositories {
+    mavenCentral()
+    mavenLocal()
+}
+
+group = "io.opencensus"
+version = "0.11.0-SNAPSHOT"
+
+// change to the version you want to use.
+def opencensusVersion = "0.11.0-SNAPSHOT" // CURRENT_OPENCENSUS_VERSION
+
+[compileJava, compileTestJava].each() {
+    // We suppress the "processing" warning as suggested in
+    // https://groups.google.com/forum/#!topic/bazel-discuss/_R3A9TJSoPM
+    it.options.compilerArgs += ["-Xlint:all", "-Xlint:-try", "-Xlint:-processing"]
+    if (JavaVersion.current().isJava8Compatible()) {
+        it.options.compilerArgs += ["-XepDisableWarningsInGeneratedCode"]
+        // TODO(bdrutu): Read files directly instead of reading from properties.
+        if (rootProject.hasProperty("errorProneWarnings")) {
+            it.options.compilerArgs += rootProject.properties["errorProneWarnings"].split(',').collect {
+                it as String
+            }
+        }
+        if (rootProject.hasProperty("errorProneExperimentalErrors")) {
+            it.options.compilerArgs += rootProject.properties["errorProneExperimentalErrors"].split(',').collect {
+                it as String
+            }
+        }
+        if (rootProject.hasProperty("errorProneExperimentalWarnings")) {
+            it.options.compilerArgs += rootProject.properties["errorProneExperimentalWarnings"].split(',').collect {
+                it as String
+            }
+        }
+        if (rootProject.hasProperty("errorProneExperimentalSuggestions")) {
+            it.options.compilerArgs += rootProject.properties["errorProneExperimentalSuggestions"].split(',').collect {
+                it as String
+            }
+        }
+    }
+    it.options.encoding = "UTF-8"
+    // TODO(bdrutu): Enable when fix the issue with configuring bootstrap class.
+    // [options] bootstrap class path not set in conjunction with -source 1.6
+    if (JavaVersion.current().isJava8Compatible()) {
+        it.options.compilerArgs += ["-Werror"]
+    }
+}
+
+compileTestJava {
+    // serialVersionUID is basically guaranteed to be useless in tests
+    options.compilerArgs += ["-Xlint:-serial"]
+    // It undeprecates DoubleSubject.isEqualTo(Double).
+    options.compilerArgs += ["-Xlint:-deprecation"]
+}
+
+jar.manifest {
+    attributes('Implementation-Title': name,
+            'Implementation-Version': version,
+            'Built-By': System.getProperty('user.name'),
+            'Built-JDK': System.getProperty('java.version'),
+            'Source-Compatibility': sourceCompatibility,
+            'Target-Compatibility': targetCompatibility)
+}
+
+javadoc.options {
+    encoding = 'UTF-8'
+    links 'https://docs.oracle.com/javase/8/docs/api/'
+}
+
+ext {
+    findBugsVersion = '3.0.1'
+}
+
+findbugs {
+    toolVersion = findBugsVersion
+    ignoreFailures = false   // bug free or it doesn't ship!
+    effort = 'max'
+    reportLevel = 'low'      // low = sensitive to even minor mistakes
+    omitVisitors = []        // bugs that we want to ignore
+}
+// Generate html report for findbugs.
+findbugsMain {
+    reports {
+        xml.enabled = false
+        html.enabled = true
+    }
+}
+// Disable findbugs for tests.
+findbugsTest.enabled = false
+
+checkstyle {
+    configFile = file("$rootDir/buildscripts/checkstyle.xml")
+    toolVersion = "8.0"
+    ignoreFailures = false
+    if (rootProject.hasProperty("checkstyle.ignoreFailures")) {
+        ignoreFailures = rootProject.properties["checkstyle.ignoreFailures"].toBoolean()
+    }
+    configProperties["rootDir"] = rootDir
+}
+
+// Disable checkstyle if no java8.
+checkstyleMain.enabled = JavaVersion.current().isJava8Compatible()
+checkstyleTest.enabled = JavaVersion.current().isJava8Compatible()
+
+// Google formatter works only on java8.
+if (JavaVersion.current().isJava8Compatible()) {
+    googleJavaFormat {
+        toolVersion '1.5'
+    }
+}
+
+signing {
+    required false
+    sign configurations.archives
+}
+
+task javadocJar(type: Jar) {
+    classifier = 'javadoc'
+    from javadoc
+}
+
+task sourcesJar(type: Jar) {
+    classifier = 'sources'
+    from sourceSets.main.allSource
+}
+
+artifacts {
+    archives javadocJar, sourcesJar
+}
+
+// At a test failure, log the stack trace to the console so that we don't
+// have to open the HTML in a browser.
+test {
+    testLogging {
+        exceptionFormat = 'full'
+        showExceptions true
+        showCauses true
+        showStackTraces true
+    }
+    maxHeapSize = '1500m'
+}
+
 tasks.withType(JavaCompile) {
     sourceCompatibility = '1.8'
     targetCompatibility = '1.8'
 }
 
 dependencies {
-    compile project(':opencensus-api'),
-            project(':opencensus-contrib-zpages'),
-            project(':opencensus-exporter-trace-logging')
+    compile "io.opencensus:opencensus-api:${opencensusVersion}",
+            "io.opencensus:opencensus-contrib-zpages:${opencensusVersion}",
+            "io.opencensus:opencensus-exporter-trace-logging:${opencensusVersion}"
 
-    runtime project(':opencensus-impl')
+    runtime "io.opencensus:opencensus-impl:${opencensusVersion}"
 }
 
 // Provide convenience executables for trying out the examples.
@@ -60,4 +237,4 @@ applicationDistribution.into('bin') {
     from(statsRunner)
     from(zPagesTester)
     fileMode = 0755
-}
\ No newline at end of file
+}
diff --git a/examples/buildscripts/checkstyle.license b/examples/buildscripts/checkstyle.license
new file mode 100644
index 00000000..27bac1a2
--- /dev/null
+++ b/examples/buildscripts/checkstyle.license
@@ -0,0 +1,15 @@
+^/\*$
+^ \* Copyright \d\d\d\d(-\d\d)?, OpenCensus Authors$
+^ \*$
+^ \* 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\.$
+^ \*/$
\ No newline at end of file
diff --git a/examples/buildscripts/checkstyle.xml b/examples/buildscripts/checkstyle.xml
new file mode 100644
index 00000000..fdea0c5e
--- /dev/null
+++ b/examples/buildscripts/checkstyle.xml
@@ -0,0 +1,233 @@
+<?xml version="1.0"?>
+<!DOCTYPE module PUBLIC
+          "-//Puppy Crawl//DTD Check Configuration 1.3//EN"
+          "http://www.puppycrawl.com/dtds/configuration_1_3.dtd">
+
+<!--
+    Checkstyle configuration that checks the Google coding conventions from Google Java Style
+    that can be found at https://google.github.io/styleguide/javaguide.html.
+
+    Checkstyle is very configurable. Be sure to read the documentation at
+    http://checkstyle.sf.net (or in your downloaded distribution).
+
+    To completely disable a check, just comment it out or delete it from the file.
+
+    Authors: Max Vetrenko, Ruslan Diachenko, Roman Ivanov.
+ -->
+
+<module name = "Checker">
+    <property name="charset" value="UTF-8"/>
+
+    <property name="severity" value="error"/>
+
+
+    <module name="RegexpHeader">
+        <property name="headerFile" value="${rootDir}/buildscripts/checkstyle.license"/>
+        <property name="fileExtensions" value="java"/>
+    </module>
+
+    <property name="fileExtensions" value="java, properties, xml"/>
+    <!-- Checks for whitespace                               -->
+    <!-- See http://checkstyle.sf.net/config_whitespace.html -->
+        <module name="FileTabCharacter">
+            <property name="eachLine" value="true"/>
+        </module>
+
+    <module name="TreeWalker">
+        <module name="OuterTypeFilename"/>
+        <module name="IllegalTokenText">
+            <property name="tokens" value="STRING_LITERAL, CHAR_LITERAL"/>
+            <property name="format" value="\\u00(09|0(a|A)|0(c|C)|0(d|D)|22|27|5(C|c))|\\(0(10|11|12|14|15|42|47)|134)"/>
+            <property name="message" value="Consider using special escape sequence instead of octal value or Unicode escaped value."/>
+        </module>
+        <module name="AvoidEscapedUnicodeCharacters">
+            <property name="allowEscapesForControlCharacters" value="true"/>
+            <property name="allowByTailComment" value="true"/>
+            <property name="allowNonPrintableEscapes" value="true"/>
+        </module>
+        <module name="LineLength">
+            <property name="max" value="100"/>
+            <property name="ignorePattern" value="^package.*|^import.*|a href|href|http://|https://|ftp://"/>
+        </module>
+        <module name="AvoidStarImport"/>
+        <module name="RedundantImport"/>
+        <module name="OneTopLevelClass"/>
+        <module name="NoLineWrap"/>
+        <module name="EmptyBlock">
+            <property name="option" value="TEXT"/>
+            <property name="tokens" value="LITERAL_TRY, LITERAL_FINALLY, LITERAL_IF, LITERAL_ELSE, LITERAL_SWITCH"/>
+        </module>
+        <module name="NeedBraces"/>
+        <module name="LeftCurly">
+            <property name="maxLineLength" value="100"/>
+        </module>
+        <module name="RightCurly">
+            <property name="id" value="RightCurlySame"/>
+            <property name="tokens" value="LITERAL_TRY, LITERAL_CATCH, LITERAL_FINALLY, LITERAL_IF, LITERAL_ELSE, LITERAL_DO"/>
+        </module>
+        <module name="RightCurly">
+            <property name="id" value="RightCurlyAlone"/>
+            <property name="option" value="alone"/>
+            <property name="tokens" value="CLASS_DEF, METHOD_DEF, CTOR_DEF, LITERAL_FOR, LITERAL_WHILE, STATIC_INIT, INSTANCE_INIT"/>
+        </module>
+        <module name="WhitespaceAround">
+            <property name="allowEmptyConstructors" value="true"/>
+            <property name="allowEmptyMethods" value="true"/>
+            <property name="allowEmptyTypes" value="true"/>
+            <property name="allowEmptyLoops" value="true"/>
+            <message key="ws.notFollowed"
+             value="WhitespaceAround: ''{0}'' is not followed by whitespace. Empty blocks may only be represented as '{}' when not part of a multi-block statement (4.1.3)"/>
+             <message key="ws.notPreceded"
+             value="WhitespaceAround: ''{0}'' is not preceded with whitespace."/>
+        </module>
+        <module name="OneStatementPerLine"/>
+        <module name="MultipleVariableDeclarations"/>
+        <module name="ArrayTypeStyle"/>
+        <!-- This rule conflicts with Error Prone's exhaustiveness checking. -->
+	    <!-- <module name="MissingSwitchDefault"/> -->
+        <module name="FallThrough"/>
+        <module name="UpperEll"/>
+        <module name="ModifierOrder"/>
+        <module name="EmptyLineSeparator">
+            <property name="allowNoEmptyLineBetweenFields" value="true"/>
+        </module>
+        <module name="SeparatorWrap">
+            <property name="id" value="SeparatorWrapDot"/>
+            <property name="tokens" value="DOT"/>
+            <property name="option" value="nl"/>
+        </module>
+        <module name="SeparatorWrap">
+            <property name="id" value="SeparatorWrapComma"/>
+            <property name="tokens" value="COMMA"/>
+            <property name="option" value="EOL"/>
+        </module>
+        <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 name="TypeName">
+            <message key="name.invalidPattern"
+             value="Type name ''{0}'' must match pattern ''{1}''."/>
+        </module>
+        <module name="MemberName">
+            <property name="format" value="^[a-z][a-z0-9][a-zA-Z0-9]*$"/>
+            <message key="name.invalidPattern"
+             value="Member name ''{0}'' must match pattern ''{1}''."/>
+        </module>
+        <module name="ParameterName">
+            <property name="format" value="^[a-z]([a-z0-9][a-zA-Z0-9]*)?$"/>
+            <message key="name.invalidPattern"
+             value="Parameter name ''{0}'' must match pattern ''{1}''."/>
+        </module>
+        <module name="CatchParameterName">
+            <property name="format" value="^[a-z]([a-z0-9][a-zA-Z0-9]*)?$"/>
+            <message key="name.invalidPattern"
+             value="Catch parameter name ''{0}'' must match pattern ''{1}''."/>
+        </module>
+        <module name="LocalVariableName">
+            <property name="tokens" value="VARIABLE_DEF"/>
+            <property name="format" value="^[a-z]([a-z0-9][a-zA-Z0-9]*)?$"/>
+            <message key="name.invalidPattern"
+             value="Local variable name ''{0}'' must match pattern ''{1}''."/>
+        </module>
+        <module name="ClassTypeParameterName">
+            <property name="format" value="(^[A-Z][0-9]?)$|([A-Z][a-zA-Z0-9]*[T]$)"/>
+            <message key="name.invalidPattern"
+             value="Class type name ''{0}'' must match pattern ''{1}''."/>
+        </module>
+        <module name="MethodTypeParameterName">
+            <property name="format" value="(^[A-Z][0-9]?)$|([A-Z][a-zA-Z0-9]*[T]$)"/>
+            <message key="name.invalidPattern"
+             value="Method type name ''{0}'' must match pattern ''{1}''."/>
+        </module>
+        <module name="InterfaceTypeParameterName">
+            <property name="format" value="(^[A-Z][0-9]?)$|([A-Z][a-zA-Z0-9]*[T]$)"/>
+            <message key="name.invalidPattern"
+             value="Interface type name ''{0}'' must match pattern ''{1}''."/>
+        </module>
+        <module name="NoFinalizer"/>
+        <module name="GenericWhitespace">
+            <message key="ws.followed"
+             value="GenericWhitespace ''{0}'' is followed by whitespace."/>
+             <message key="ws.preceded"
+             value="GenericWhitespace ''{0}'' is preceded with whitespace."/>
+             <message key="ws.illegalFollow"
+             value="GenericWhitespace ''{0}'' should followed by whitespace."/>
+             <message key="ws.notPreceded"
+             value="GenericWhitespace ''{0}'' is not preceded with whitespace."/>
+        </module>
+        <module name="Indentation">
+            <property name="basicOffset" value="2"/>
+            <property name="braceAdjustment" value="0"/>
+            <property name="caseIndent" value="2"/>
+            <property name="throwsIndent" value="4"/>
+            <property name="lineWrappingIndentation" value="4"/>
+            <property name="arrayInitIndent" value="2"/>
+        </module>
+        <module name="AbbreviationAsWordInName">
+            <property name="ignoreFinal" value="false"/>
+            <property name="allowedAbbreviationLength" value="1"/>
+        </module>
+        <module name="OverloadMethodsDeclarationOrder"/>
+        <module name="VariableDeclarationUsageDistance"/>
+        <module name="CustomImportOrder">
+            <property name="sortImportsInGroupAlphabetically" value="true"/>
+            <property name="separateLineBetweenGroups" value="true"/>
+            <property name="customImportOrderRules" value="STATIC###THIRD_PARTY_PACKAGE"/>
+        </module>
+        <module name="MethodParamPad"/>
+        <module name="ParenPad"/>
+        <module name="OperatorWrap">
+            <property name="option" value="NL"/>
+            <property name="tokens" value="BAND, BOR, BSR, BXOR, DIV, EQUAL, GE, GT, LAND, LE, LITERAL_INSTANCEOF, LOR, LT, MINUS, MOD, NOT_EQUAL, PLUS, QUESTION, SL, SR, STAR, METHOD_REF "/>
+        </module>
+        <module name="AnnotationLocation">
+            <property name="id" value="AnnotationLocationMostCases"/>
+            <property name="tokens" value="CLASS_DEF, INTERFACE_DEF, ENUM_DEF, METHOD_DEF, CTOR_DEF"/>
+        </module>
+        <module name="AnnotationLocation">
+            <property name="id" value="AnnotationLocationVariables"/>
+            <property name="tokens" value="VARIABLE_DEF"/>
+            <property name="allowSamelineMultipleAnnotations" value="true"/>
+        </module>
+        <module name="NonEmptyAtclauseDescription"/>
+        <module name="JavadocTagContinuationIndentation"/>
+        <module name="SummaryJavadoc">
+            <property name="forbiddenSummaryFragments" value="^@return the *|^This method returns |^A [{]@code [a-zA-Z0-9]+[}]( is a )"/>
+        </module>
+        <module name="JavadocParagraph"/>
+        <module name="AtclauseOrder">
+            <property name="tagOrder" value="@param, @return, @throws, @deprecated"/>
+            <property name="target" value="CLASS_DEF, INTERFACE_DEF, ENUM_DEF, METHOD_DEF, CTOR_DEF, VARIABLE_DEF"/>
+        </module>
+        <module name="JavadocMethod">
+            <property name="scope" value="public"/>
+            <property name="allowMissingParamTags" value="true"/>
+            <property name="allowMissingThrowsTags" value="true"/>
+            <property name="allowMissingReturnTag" value="true"/>
+            <property name="minLineCount" value="2"/>
+            <!-- Too restrictive for tests -->
+            <!-- <property name="allowedAnnotations" value="Override, Test"/-->
+            <property name="allowedAnnotations" value="Override, Test, Before, After, BeforeClass, AfterClass, Setup, TearDown"/>
+            <property name="allowThrowsTagsForSubclasses" value="true"/>
+        </module>
+        <module name="MethodName">
+            <property name="format" value="^[a-z][a-z0-9][a-zA-Z0-9_]*$"/>
+            <message key="name.invalidPattern"
+             value="Method name ''{0}'' must match pattern ''{1}''."/>
+        </module>
+        <module name="SingleLineJavadoc">
+            <!-- Wrong interpretation of the style guide; -->
+            <!-- <property name="ignoreInlineTags" value="false"/-->
+        </module>
+        <module name="EmptyCatchBlock">
+            <property name="exceptionVariableName" value="expected"/>
+        </module>
+        <module name="CommentsIndentation"/>
+        <module name="FileContentsHolder"/>
+        <module name="SuppressWarningsHolder"/>
+    </module>
+    <module name="SuppressionCommentFilter"/>
+    <module name="SuppressWarningsFilter"/>
+</module>
diff --git a/examples/gradle/errorprone/experimental_errors b/examples/gradle/errorprone/experimental_errors
new file mode 100644
index 00000000..5ce6e181
--- /dev/null
+++ b/examples/gradle/errorprone/experimental_errors
@@ -0,0 +1,27 @@
+errorProneExperimentalErrors = \
+-Xep:AssistedInjectAndInjectOnSameConstructor:ERROR,\
+-Xep:AutoFactoryAtInject:ERROR,\
+-Xep:ClassName:ERROR,\
+-Xep:ComparisonContractViolated:ERROR,\
+-Xep:DepAnn:ERROR,\
+-Xep:DivZero:ERROR,\
+-Xep:EmptyIf:ERROR,\
+-Xep:FuzzyEqualsShouldNotBeUsedInEqualsMethod:ERROR,\
+-Xep:InjectInvalidTargetingOnScopingAnnotation:ERROR,\
+-Xep:InjectMoreThanOneQualifier:ERROR,\
+-Xep:InjectScopeAnnotationOnInterfaceOrAbstractClass:ERROR,\
+-Xep:InjectScopeOrQualifierAnnotationRetention:ERROR,\
+-Xep:InjectedConstructorAnnotations:ERROR,\
+-Xep:InsecureCryptoUsage:ERROR,\
+-Xep:IterablePathParameter:ERROR,\
+-Xep:JMockTestWithoutRunWithOrRuleAnnotation:ERROR,\
+-Xep:JavaxInjectOnFinalField:ERROR,\
+-Xep:LockMethodChecker:ERROR,\
+-Xep:LongLiteralLowerCaseSuffix:ERROR,\
+-Xep:NoAllocation:ERROR,\
+-Xep:NumericEquality:ERROR,\
+-Xep:ParameterPackage:ERROR,\
+-Xep:ProtoStringFieldReferenceEquality:ERROR,\
+-Xep:QualifierOrScopeOnInjectMethod:ERROR,\
+-Xep:StaticOrDefaultInterfaceMethod:ERROR,\
+-Xep:UnlockMethod:ERROR
diff --git a/examples/gradle/errorprone/experimental_suggestions b/examples/gradle/errorprone/experimental_suggestions
new file mode 100644
index 00000000..1330b843
--- /dev/null
+++ b/examples/gradle/errorprone/experimental_suggestions
@@ -0,0 +1,25 @@
+# FieldMissingNullable is turned off due to
+# https://github.com/google/error-prone/issues/823.
+
+errorProneExperimentalSuggestions = \
+-Xep:ConstantField:ERROR,\
+-Xep:EmptySetMultibindingContributions:ERROR,\
+-Xep:FieldMissingNullable:OFF,\
+-Xep:MethodCanBeStatic:ERROR,\
+-Xep:MixedArrayDimensions:ERROR,\
+-Xep:MultiVariableDeclaration:ERROR,\
+-Xep:MultipleTopLevelClasses:ERROR,\
+-Xep:MultipleUnaryOperatorsInMethodCall:ERROR,\
+-Xep:PackageLocation:ERROR,\
+-Xep:ParameterComment:ERROR,\
+-Xep:ParameterNotNullable:ERROR,\
+-Xep:PrivateConstructorForNoninstantiableModuleTest:ERROR,\
+-Xep:PrivateConstructorForUtilityClass:ERROR,\
+-Xep:RemoveUnusedImports:ERROR,\
+-Xep:ReturnMissingNullable:ERROR,\
+-Xep:ThrowsUncheckedException:ERROR,\
+-Xep:UngroupedOverloads:ERROR,\
+-Xep:UnnecessarySetDefault:ERROR,\
+-Xep:UnnecessaryStaticImport:ERROR,\
+-Xep:UseBinds:ERROR,\
+-Xep:WildcardImport:ERROR
diff --git a/examples/gradle/errorprone/experimental_warnings b/examples/gradle/errorprone/experimental_warnings
new file mode 100644
index 00000000..b5a7df2b
--- /dev/null
+++ b/examples/gradle/errorprone/experimental_warnings
@@ -0,0 +1,23 @@
+errorProneExperimentalWarnings = \
+-Xep:AssertFalse:ERROR,\
+-Xep:AssistedInjectAndInjectOnConstructors:ERROR,\
+-Xep:BigDecimalLiteralDouble:ERROR,\
+-Xep:BindingToUnqualifiedCommonType:ERROR,\
+-Xep:ConstructorInvokesOverridable:ERROR,\
+-Xep:ConstructorLeaksThis:ERROR,\
+-Xep:EmptyTopLevelDeclaration:ERROR,\
+-Xep:ExpectedExceptionChecker:ERROR,\
+-Xep:HardCodedSdCardPath:ERROR,\
+-Xep:InconsistentOverloads:ERROR,\
+-Xep:MissingDefault:ERROR,\
+-Xep:MutableMethodReturnType:ERROR,\
+-Xep:NonCanonicalStaticMemberImport:ERROR,\
+-Xep:PrimitiveArrayPassedToVarargsMethod:ERROR,\
+-Xep:ProvidesFix:ERROR,\
+-Xep:QualifierWithTypeUse:ERROR,\
+-Xep:RedundantThrows:ERROR,\
+-Xep:StaticQualifiedUsingExpression:ERROR,\
+-Xep:StringEquality:ERROR,\
+-Xep:TestExceptionChecker:ERROR,\
+-Xep:UnnecessaryDefaultInEnumSwitch:ERROR,\
+-Xep:Var:OFF
diff --git a/examples/gradle/errorprone/warnings b/examples/gradle/errorprone/warnings
new file mode 100644
index 00000000..da7302dd
--- /dev/null
+++ b/examples/gradle/errorprone/warnings
@@ -0,0 +1,76 @@
+errorProneWarnings = \
+-Xep:AmbiguousMethodReference:ERROR,\
+-Xep:ArgumentSelectionDefectChecker:ERROR,\
+-Xep:AssertEqualsArgumentOrderChecker:ERROR,\
+-Xep:AssertionFailureIgnored:ERROR,\
+-Xep:BadAnnotationImplementation:ERROR,\
+-Xep:BadComparable:ERROR,\
+-Xep:BoxedPrimitiveConstructor:ERROR,\
+-Xep:CannotMockFinalClass:ERROR,\
+-Xep:CanonicalDuration:ERROR,\
+-Xep:ClassCanBeStatic:ERROR,\
+-Xep:ClassNewInstance:ERROR,\
+-Xep:CollectionToArraySafeParameter:ERROR,\
+-Xep:CollectorShouldNotUseState:ERROR,\
+-Xep:ComparableAndComparator:ERROR,\
+-Xep:DefaultCharset:ERROR,\
+-Xep:DoubleCheckedLocking:ERROR,\
+-Xep:EqualsHashCode:ERROR,\
+-Xep:EqualsIncompatibleType:ERROR,\
+-Xep:Finally:ERROR,\
+-Xep:FloatingPointLiteralPrecision:ERROR,\
+-Xep:FragmentInjection:ERROR,\
+-Xep:FragmentNotInstantiable:ERROR,\
+-Xep:FunctionalInterfaceClash:ERROR,\
+-Xep:FutureReturnValueIgnored:ERROR,\
+-Xep:GetClassOnEnum:ERROR,\
+-Xep:ImmutableAnnotationChecker:ERROR,\
+-Xep:ImmutableEnumChecker:ERROR,\
+-Xep:IncompatibleModifiers:ERROR,\
+-Xep:IncrementInForLoopAndHeader:ERROR,\
+-Xep:InjectOnConstructorOfAbstractClass:ERROR,\
+-Xep:InputStreamSlowMultibyteRead:ERROR,\
+-Xep:InstanceOfAndCastMatchWrongType:ERROR,\
+-Xep:IntLongMath:ERROR,\
+-Xep:IterableAndIterator:ERROR,\
+-Xep:JUnit3FloatingPointComparisonWithoutDelta:ERROR,\
+-Xep:JUnit4ClassUsedInJUnit3:ERROR,\
+-Xep:JUnitAmbiguousTestClass:ERROR,\
+-Xep:JavaLangClash:ERROR,\
+-Xep:JdkObsolete:ERROR,\
+-Xep:LogicalAssignment:ERROR,\
+-Xep:MissingFail:ERROR,\
+-Xep:MissingOverride:ERROR,\
+-Xep:MultipleParallelOrSequentialCalls:ERROR,\
+-Xep:MutableConstantField:ERROR,\
+-Xep:NamedParameters:ERROR,\
+-Xep:NarrowingCompoundAssignment:WARN,\
+-Xep:NestedInstanceOfConditions:ERROR,\
+-Xep:NonAtomicVolatileUpdate:ERROR,\
+-Xep:NonOverridingEquals:ERROR,\
+-Xep:NullableConstructor:ERROR,\
+-Xep:NullablePrimitive:ERROR,\
+-Xep:NullableVoid:ERROR,\
+-Xep:OperatorPrecedence:ERROR,\
+-Xep:OptionalNotPresent:ERROR,\
+-Xep:OverrideThrowableToString:ERROR,\
+-Xep:Overrides:ERROR,\
+-Xep:OverridesGuiceInjectableMethod:ERROR,\
+-Xep:ParameterName:ERROR,\
+-Xep:PreconditionsInvalidPlaceholder:ERROR,\
+-Xep:ProtoFieldPreconditionsCheckNotNull:ERROR,\
+-Xep:ReferenceEquality:ERROR,\
+-Xep:RequiredModifiers:ERROR,\
+-Xep:ShortCircuitBoolean:ERROR,\
+-Xep:SimpleDateFormatConstant:ERROR,\
+-Xep:StaticGuardedByInstance:ERROR,\
+-Xep:SynchronizeOnNonFinalField:ERROR,\
+-Xep:ThreadJoinLoop:ERROR,\
+-Xep:TruthConstantAsserts:ERROR,\
+-Xep:TypeParameterShadowing:ERROR,\
+-Xep:TypeParameterUnusedInFormals:ERROR,\
+-Xep:URLEqualsHashCode:ERROR,\
+-Xep:UnsynchronizedOverridesSynchronized:ERROR,\
+-Xep:UseCorrectAssertInTests:ERROR,\
+-Xep:WaitNotInLoop:ERROR,\
+-Xep:WakelockReleasedDangerously:ERROR
diff --git a/examples/gradle/wrapper/gradle-wrapper.jar b/examples/gradle/wrapper/gradle-wrapper.jar
new file mode 100644
index 00000000..7a3265ee
--- /dev/null
+++ b/examples/gradle/wrapper/gradle-wrapper.jar
diff --git a/examples/gradle/wrapper/gradle-wrapper.properties b/examples/gradle/wrapper/gradle-wrapper.properties
new file mode 100644
index 00000000..92165eed
--- /dev/null
+++ b/examples/gradle/wrapper/gradle-wrapper.properties
@@ -0,0 +1,5 @@
+distributionBase=GRADLE_USER_HOME
+distributionPath=wrapper/dists
+zipStoreBase=GRADLE_USER_HOME
+zipStorePath=wrapper/dists
+distributionUrl=https\://services.gradle.org/distributions/gradle-4.3-bin.zip
diff --git a/examples/gradlew b/examples/gradlew
new file mode 100755
index 00000000..cccdd3d5
--- /dev/null
+++ b/examples/gradlew
@@ -0,0 +1,172 @@
+#!/usr/bin/env sh
+
+##############################################################################
+##
+##  Gradle start up script for UN*X
+##
+##############################################################################
+
+# Attempt to set APP_HOME
+# Resolve links: $0 may be a link
+PRG="$0"
+# Need this for relative symlinks.
+while [ -h "$PRG" ] ; do
+    ls=`ls -ld "$PRG"`
+    link=`expr "$ls" : '.*-> \(.*\)$'`
+    if expr "$link" : '/.*' > /dev/null; then
+        PRG="$link"
+    else
+        PRG=`dirname "$PRG"`"/$link"
+    fi
+done
+SAVED="`pwd`"
+cd "`dirname \"$PRG\"`/" >/dev/null
+APP_HOME="`pwd -P`"
+cd "$SAVED" >/dev/null
+
+APP_NAME="Gradle"
+APP_BASE_NAME=`basename "$0"`
+
+# Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
+DEFAULT_JVM_OPTS=""
+
+# Use the maximum available, or set MAX_FD != -1 to use that value.
+MAX_FD="maximum"
+
+warn () {
+    echo "$*"
+}
+
+die () {
+    echo
+    echo "$*"
+    echo
+    exit 1
+}
+
+# OS specific support (must be 'true' or 'false').
+cygwin=false
+msys=false
+darwin=false
+nonstop=false
+case "`uname`" in
+  CYGWIN* )
+    cygwin=true
+    ;;
+  Darwin* )
+    darwin=true
+    ;;
+  MINGW* )
+    msys=true
+    ;;
+  NONSTOP* )
+    nonstop=true
+    ;;
+esac
+
+CLASSPATH=$APP_HOME/gradle/wrapper/gradle-wrapper.jar
+
+# Determine the Java command to use to start the JVM.
+if [ -n "$JAVA_HOME" ] ; then
+    if [ -x "$JAVA_HOME/jre/sh/java" ] ; then
+        # IBM's JDK on AIX uses strange locations for the executables
+        JAVACMD="$JAVA_HOME/jre/sh/java"
+    else
+        JAVACMD="$JAVA_HOME/bin/java"
+    fi
+    if [ ! -x "$JAVACMD" ] ; then
+        die "ERROR: JAVA_HOME is set to an invalid directory: $JAVA_HOME
+
+Please set the JAVA_HOME variable in your environment to match the
+location of your Java installation."
+    fi
+else
+    JAVACMD="java"
+    which java >/dev/null 2>&1 || die "ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
+
+Please set the JAVA_HOME variable in your environment to match the
+location of your Java installation."
+fi
+
+# Increase the maximum file descriptors if we can.
+if [ "$cygwin" = "false" -a "$darwin" = "false" -a "$nonstop" = "false" ] ; then
+    MAX_FD_LIMIT=`ulimit -H -n`
+    if [ $? -eq 0 ] ; then
+        if [ "$MAX_FD" = "maximum" -o "$MAX_FD" = "max" ] ; then
+            MAX_FD="$MAX_FD_LIMIT"
+        fi
+        ulimit -n $MAX_FD
+        if [ $? -ne 0 ] ; then
+            warn "Could not set maximum file descriptor limit: $MAX_FD"
+        fi
+    else
+        warn "Could not query maximum file descriptor limit: $MAX_FD_LIMIT"
+    fi
+fi
+
+# For Darwin, add options to specify how the application appears in the dock
+if $darwin; then
+    GRADLE_OPTS="$GRADLE_OPTS \"-Xdock:name=$APP_NAME\" \"-Xdock:icon=$APP_HOME/media/gradle.icns\""
+fi
+
+# For Cygwin, switch paths to Windows format before running java
+if $cygwin ; then
+    APP_HOME=`cygpath --path --mixed "$APP_HOME"`
+    CLASSPATH=`cygpath --path --mixed "$CLASSPATH"`
+    JAVACMD=`cygpath --unix "$JAVACMD"`
+
+    # We build the pattern for arguments to be converted via cygpath
+    ROOTDIRSRAW=`find -L / -maxdepth 1 -mindepth 1 -type d 2>/dev/null`
+    SEP=""
+    for dir in $ROOTDIRSRAW ; do
+        ROOTDIRS="$ROOTDIRS$SEP$dir"
+        SEP="|"
+    done
+    OURCYGPATTERN="(^($ROOTDIRS))"
+    # Add a user-defined pattern to the cygpath arguments
+    if [ "$GRADLE_CYGPATTERN" != "" ] ; then
+        OURCYGPATTERN="$OURCYGPATTERN|($GRADLE_CYGPATTERN)"
+    fi
+    # Now convert the arguments - kludge to limit ourselves to /bin/sh
+    i=0
+    for arg in "$@" ; do
+        CHECK=`echo "$arg"|egrep -c "$OURCYGPATTERN" -`
+        CHECK2=`echo "$arg"|egrep -c "^-"`                                 ### Determine if an option
+
+        if [ $CHECK -ne 0 ] && [ $CHECK2 -eq 0 ] ; then                    ### Added a condition
+            eval `echo args$i`=`cygpath --path --ignore --mixed "$arg"`
+        else
+            eval `echo args$i`="\"$arg\""
+        fi
+        i=$((i+1))
+    done
+    case $i in
+        (0) set -- ;;
+        (1) set -- "$args0" ;;
+        (2) set -- "$args0" "$args1" ;;
+        (3) set -- "$args0" "$args1" "$args2" ;;
+        (4) set -- "$args0" "$args1" "$args2" "$args3" ;;
+        (5) set -- "$args0" "$args1" "$args2" "$args3" "$args4" ;;
+        (6) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" ;;
+        (7) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" ;;
+        (8) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" "$args7" ;;
+        (9) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" "$args7" "$args8" ;;
+    esac
+fi
+
+# Escape application args
+save () {
+    for i do printf %s\\n "$i" | sed "s/'/'\\\\''/g;1s/^/'/;\$s/\$/' \\\\/" ; done
+    echo " "
+}
+APP_ARGS=$(save "$@")
+
+# Collect all arguments for the java command, following the shell quoting and substitution rules
+eval set -- $DEFAULT_JVM_OPTS $JAVA_OPTS $GRADLE_OPTS "\"-Dorg.gradle.appname=$APP_BASE_NAME\"" -classpath "\"$CLASSPATH\"" org.gradle.wrapper.GradleWrapperMain "$APP_ARGS"
+
+# by default we should be in the correct project dir, but when run from Finder on Mac, the cwd is wrong
+if [ "$(uname)" = "Darwin" ] && [ "$HOME" = "$PWD" ]; then
+  cd "$(dirname "$0")"
+fi
+
+exec "$JAVACMD" "$@"
diff --git a/examples/gradlew.bat b/examples/gradlew.bat
new file mode 100644
index 00000000..e95643d6
--- /dev/null
+++ b/examples/gradlew.bat
@@ -0,0 +1,84 @@
+@if "%DEBUG%" == "" @echo off

+@rem ##########################################################################

+@rem

+@rem  Gradle startup script for Windows

+@rem

+@rem ##########################################################################

+

+@rem Set local scope for the variables with windows NT shell

+if "%OS%"=="Windows_NT" setlocal

+

+set DIRNAME=%~dp0

+if "%DIRNAME%" == "" set DIRNAME=.

+set APP_BASE_NAME=%~n0

+set APP_HOME=%DIRNAME%

+

+@rem Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.

+set DEFAULT_JVM_OPTS=

+

+@rem Find java.exe

+if defined JAVA_HOME goto findJavaFromJavaHome

+

+set JAVA_EXE=java.exe

+%JAVA_EXE% -version >NUL 2>&1

+if "%ERRORLEVEL%" == "0" goto init

+

+echo.

+echo ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.

+echo.

+echo Please set the JAVA_HOME variable in your environment to match the

+echo location of your Java installation.

+

+goto fail

+

+:findJavaFromJavaHome

+set JAVA_HOME=%JAVA_HOME:"=%

+set JAVA_EXE=%JAVA_HOME%/bin/java.exe

+

+if exist "%JAVA_EXE%" goto init

+

+echo.

+echo ERROR: JAVA_HOME is set to an invalid directory: %JAVA_HOME%

+echo.

+echo Please set the JAVA_HOME variable in your environment to match the

+echo location of your Java installation.

+

+goto fail

+

+:init

+@rem Get command-line arguments, handling Windows variants

+

+if not "%OS%" == "Windows_NT" goto win9xME_args

+

+:win9xME_args

+@rem Slurp the command line arguments.

+set CMD_LINE_ARGS=

+set _SKIP=2

+

+:win9xME_args_slurp

+if "x%~1" == "x" goto execute

+

+set CMD_LINE_ARGS=%*

+

+:execute

+@rem Setup the command line

+

+set CLASSPATH=%APP_HOME%\gradle\wrapper\gradle-wrapper.jar

+

+@rem Execute Gradle

+"%JAVA_EXE%" %DEFAULT_JVM_OPTS% %JAVA_OPTS% %GRADLE_OPTS% "-Dorg.gradle.appname=%APP_BASE_NAME%" -classpath "%CLASSPATH%" org.gradle.wrapper.GradleWrapperMain %CMD_LINE_ARGS%

+

+:end

+@rem End local scope for the variables with windows NT shell

+if "%ERRORLEVEL%"=="0" goto mainEnd

+

+:fail

+rem Set variable GRADLE_EXIT_CONSOLE if you need the _script_ return code instead of

+rem the _cmd.exe /c_ return code!

+if  not "" == "%GRADLE_EXIT_CONSOLE%" exit 1

+exit /b 1

+

+:mainEnd

+if "%OS%"=="Windows_NT" endlocal

+

+:omega

diff --git a/examples/settings.gradle b/examples/settings.gradle
new file mode 100644
index 00000000..310e652f
--- /dev/null
+++ b/examples/settings.gradle
@@ -0,0 +1 @@
+rootProject.name = 'opencensus-examples'
diff --git a/settings.gradle b/settings.gradle
index e917496a..e94fb8f7 100644
--- a/settings.gradle
+++ b/settings.gradle
@@ -31,7 +31,6 @@ project(':opencensus-exporter-stats-stackdriver').projectDir = "$rootDir/exporte
 // Java8 projects only
 if (JavaVersion.current().isJava8Compatible()) {
     include ":opencensus-all"
-    include ":examples"
     include ":benchmarks"
     include ":opencensus-contrib-zpages"