spring servlet example. (#1939)
* spring servlet example.
* add gradle wrapper jar to fix build error.
* rename function and added configurable port number.
- also changed opencensus version to fix the maven build error.
diff --git a/buildscripts/import-control.xml b/buildscripts/import-control.xml
index 1044de7..38e4a67 100644
--- a/buildscripts/import-control.xml
+++ b/buildscripts/import-control.xml
@@ -330,5 +330,6 @@
<allow pkg="org.apache.log4j"/>
<allow pkg="org.eclipse.jetty"/>
<allow pkg="javax.servlet"/>
+ <allow pkg="org.springframework"/>
</subpackage>
</import-control>
diff --git a/buildscripts/travis_script b/buildscripts/travis_script
index 8d167c0..c5a0c43 100755
--- a/buildscripts/travis_script
+++ b/buildscripts/travis_script
@@ -54,9 +54,11 @@
;;
"BUILD_EXAMPLES_GRADLE")
pushd examples && ./gradlew clean assemble --stacktrace && ./gradlew check && ./gradlew verGJF && popd
+ pushd examples/spring/servlet && ./gradlew clean assemble --stacktrace && ./gradlew check && ./gradlew verGJF && popd
;;
"BUILD_EXAMPLES_MAVEN")
pushd examples && mvn clean package appassembler:assemble -e && popd
+ pushd examples/spring/servlet && mvn clean package appassembler:assemble -e && popd
;;
*)
echo "Unknown task $TASK"
diff --git a/examples/README.md b/examples/README.md
index 4851da6..1c0b76d 100644
--- a/examples/README.md
+++ b/examples/README.md
@@ -12,6 +12,13 @@
mvn package appassembler:assemble
```
+To build Spring Servlet example
+```bash
+cd spring/servlet
+mvn package appassembler:assemble
+```
+
+
## To run "TagContextExample" use
### Gradle
@@ -162,3 +169,32 @@
You also need to install and start OpenCensus-Agent in order to receive the traces and metrics.
For more information on setting up Agent, see [tutorial](https://opencensus.io/agent/).
+
+## To run Spring HTTP Server and Client
+
+`SpringServletApplication` is a web service application using Spring framework. The application
+is instrumented with opencensus simply by incuding opencensus-contrib-spring-starter package.
+The instrumentation enables tracing on incoming and outgoing http requests. On receiving GET
+request, the server originates multiple GET requests to itself using AsyncRestTemplate on different
+endpoint.
+
+Send a http GET request using curl to see the traces on console.
+```
+curl http://localhost:8080
+```
+
+Stats are available from Prometheus server running at
+- http://localhost:9090/metrics - for server and client stats
+
+### Gradle
+```bash
+cd spring/servlet
+./gradlew bootRun
+```
+
+### Maven
+```bash
+cd spring/servlet
+./target/appassembler/bin/SpringServletApplication
+```
+
diff --git a/examples/spring/servlet/.gitignore b/examples/spring/servlet/.gitignore
new file mode 100644
index 0000000..51f2f98
--- /dev/null
+++ b/examples/spring/servlet/.gitignore
@@ -0,0 +1,3 @@
+.mvn/**
+mvn**
+
diff --git a/examples/spring/servlet/application.properties b/examples/spring/servlet/application.properties
new file mode 100644
index 0000000..d934d4d
--- /dev/null
+++ b/examples/spring/servlet/application.properties
@@ -0,0 +1,2 @@
+opencensus.spring.enabled = true
+opencensus.spring.trace.publicEndpoint = false
diff --git a/examples/spring/servlet/build.gradle b/examples/spring/servlet/build.gradle
new file mode 100644
index 0000000..515e381
--- /dev/null
+++ b/examples/spring/servlet/build.gradle
@@ -0,0 +1,107 @@
+description = 'OpenCensus Examples Spring Servlet'
+
+buildscript {
+ repositories {
+ mavenCentral()
+ mavenLocal()
+ maven {
+ url "https://plugins.gradle.org/m2/"
+ }
+ }
+ dependencies {
+ classpath 'org.springframework.boot:spring-boot-gradle-plugin:2.0.5.RELEASE'
+ classpath 'com.github.ben-manes:gradle-versions-plugin:0.20.0'
+ classpath "gradle.plugin.com.github.sherter.google-java-format:google-java-format-gradle-plugin:0.8"
+ }
+}
+
+apply plugin: "checkstyle"
+apply plugin: 'com.github.sherter.google-java-format'
+apply plugin: 'idea'
+apply plugin: 'java'
+
+// Display the version report using: ./gradlew dependencyUpdates
+// Also see https://github.com/ben-manes/gradle-versions-plugin.
+apply plugin: 'com.github.ben-manes.versions'
+
+repositories {
+ mavenCentral()
+ mavenLocal()
+}
+
+group = "io.opencensus"
+version = "0.24.0-SNAPSHOT" // CURRENT_OPENCENSUS_VERSION
+
+def opencensusVersion = "0.23.0" // LATEST_OPENCENSUS_RELEASE_VERSION
+def prometheusVersion = "0.6.0"
+def httpasyncclientVersion = "4.1.4"
+
+
+tasks.withType(JavaCompile) {
+ sourceCompatibility = '1.8'
+ targetCompatibility = '1.8'
+}
+
+googleJavaFormat {
+ toolVersion '1.7'
+ source = 'src/main'
+ include '**/*.java'
+}
+
+verifyGoogleJavaFormat {
+ source = 'src/main'
+ include '**/*.java'
+}
+
+// Inform IDEs like IntelliJ IDEA, Eclipse or NetBeans about the generated code.
+sourceSets {
+ main {
+ java {
+ srcDir 'src'
+ }
+ }
+}
+
+checkstyle {
+ configFile = file("$rootDir/../../../buildscripts/checkstyle.xml")
+ toolVersion = "8.12"
+ ignoreFailures = false
+ configProperties["rootDir"] = "$rootDir/../../.."
+}
+
+// Disable checkstyle if no java8.
+checkstyleMain.source = 'src/main'
+checkstyleTest.source = 'src/main'
+buildscript {
+ dependencies {
+ classpath 'org.springframework.boot:spring-boot-gradle-plugin:2.0.5.RELEASE'
+ }
+}
+
+apply plugin: 'java'
+apply plugin: 'org.springframework.boot'
+apply plugin: 'io.spring.dependency-management'
+
+bootJar {
+ mainClassName = 'com.baeldung.Application'
+ baseName = 'opencensus-examples-spring-servlet'
+ version = "0.24.0-SNAPSHOT" // CURRENT_OPENCENSUS_VERSION
+}
+
+sourceCompatibility = 1.8
+targetCompatibility = 1.8
+
+dependencyManagement {
+ imports {
+ mavenBom "io.opencensus:opencensus-contrib-spring-starter:${opencensusVersion}"
+ }
+}
+
+dependencies {
+ compile("io.opencensus:opencensus-contrib-spring-starter:${opencensusVersion}")
+
+ compile("io.opencensus:opencensus-exporter-stats-prometheus:${opencensusVersion}",
+ "io.opencensus:opencensus-exporter-trace-logging:${opencensusVersion}",
+ "io.prometheus:simpleclient_httpserver:${prometheusVersion}",
+ "org.apache.httpcomponents:httpasyncclient:${httpasyncclientVersion}")
+}
diff --git a/examples/spring/servlet/gradle/wrapper/gradle-wrapper.jar b/examples/spring/servlet/gradle/wrapper/gradle-wrapper.jar
new file mode 100644
index 0000000..758de96
--- /dev/null
+++ b/examples/spring/servlet/gradle/wrapper/gradle-wrapper.jar
Binary files differ
diff --git a/examples/spring/servlet/gradle/wrapper/gradle-wrapper.properties b/examples/spring/servlet/gradle/wrapper/gradle-wrapper.properties
new file mode 100644
index 0000000..a95009c
--- /dev/null
+++ b/examples/spring/servlet/gradle/wrapper/gradle-wrapper.properties
@@ -0,0 +1,5 @@
+distributionBase=GRADLE_USER_HOME
+distributionPath=wrapper/dists
+distributionUrl=https\://services.gradle.org/distributions/gradle-4.9-bin.zip
+zipStoreBase=GRADLE_USER_HOME
+zipStorePath=wrapper/dists
diff --git a/examples/spring/servlet/gradlew b/examples/spring/servlet/gradlew
new file mode 100755
index 0000000..cccdd3d
--- /dev/null
+++ b/examples/spring/servlet/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/spring/servlet/gradlew.bat b/examples/spring/servlet/gradlew.bat
new file mode 100644
index 0000000..e95643d
--- /dev/null
+++ b/examples/spring/servlet/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/spring/servlet/pom.xml b/examples/spring/servlet/pom.xml
new file mode 100644
index 0000000..8486a36
--- /dev/null
+++ b/examples/spring/servlet/pom.xml
@@ -0,0 +1,93 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+ xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+ xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+ <modelVersion>4.0.0</modelVersion>
+
+ <groupId>io.opencensus</groupId>
+ <artifactId>opencensus-examples-spring-servlet</artifactId>
+ <version>0.24.0-SNAPSHOT</version>
+ <packaging>jar</packaging>
+
+ <properties>
+ <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
+ <!-- change to the version you want to use. -->
+ <apachehttp.version>4.1.4</apachehttp.version>
+ <opencensus.version>0.23.0</opencensus.version><!-- LATEST_OPENCENSUS_RELEASE_VERSION -->
+ <prometheus.version>0.6.0</prometheus.version>
+ <springboot.version>2.0.5.RELEASE</springboot.version>
+ <java.version>1.8</java.version>
+ </properties>
+
+ <dependencies>
+ <dependency>
+ <groupId>org.springframework.boot</groupId>
+ <artifactId>spring-boot-starter-web</artifactId>
+ <version>${springboot.version}</version>
+ </dependency>
+ <dependency>
+ <groupId>io.opencensus</groupId>
+ <artifactId>opencensus-contrib-spring-starter</artifactId>
+ <version>${opencensus.version}</version>
+ </dependency>
+ <dependency>
+ <groupId>io.opencensus</groupId>
+ <artifactId>opencensus-exporter-stats-prometheus</artifactId>
+ <version>${opencensus.version}</version>
+ </dependency>
+ <dependency>
+ <groupId>io.opencensus</groupId>
+ <artifactId>opencensus-exporter-trace-logging</artifactId>
+ <version>${opencensus.version}</version>
+ </dependency>
+ <dependency>
+ <groupId>io.prometheus</groupId>
+ <artifactId>simpleclient_httpserver</artifactId>
+ <version>${prometheus.version}</version>
+ </dependency>
+ <dependency>
+ <groupId>org.apache.httpcomponents</groupId>
+ <artifactId>httpasyncclient</artifactId>
+ <version>${apachehttp.version}</version>
+ </dependency>
+ </dependencies>
+
+ <build>
+ <extensions>
+ <extension>
+ <groupId>kr.motd.maven</groupId>
+ <artifactId>os-maven-plugin</artifactId>
+ <version>1.5.0.Final</version>
+ </extension>
+ </extensions>
+ <pluginManagement>
+ <plugins>
+ <plugin>
+ <groupId>org.apache.maven.plugins</groupId>
+ <artifactId>maven-compiler-plugin</artifactId>
+ <version>3.7.0</version>
+ <configuration>
+ <source>1.8</source>
+ <target>1.8</target>
+ </configuration>
+ </plugin>
+ </plugins>
+ </pluginManagement>
+ <plugins>
+ <plugin>
+ <groupId>org.codehaus.mojo</groupId>
+ <artifactId>appassembler-maven-plugin</artifactId>
+ <version>1.10</version>
+ <configuration>
+ <programs>
+ <program>
+ <id>SpringServletApplication</id>
+ <mainClass>io.opencensus.examples.spring.servlet.Application</mainClass>
+ </program>
+ </programs>
+ </configuration>
+ </plugin>
+ </plugins>
+ </build>
+
+</project>
diff --git a/examples/spring/servlet/settings.gradle b/examples/spring/servlet/settings.gradle
new file mode 100644
index 0000000..4de5678
--- /dev/null
+++ b/examples/spring/servlet/settings.gradle
@@ -0,0 +1 @@
+rootProject.name = 'opencensus-examples-spring-servlet'
diff --git a/examples/spring/servlet/src/main/java/io/opencensus/examples/spring/servlet/Application.java b/examples/spring/servlet/src/main/java/io/opencensus/examples/spring/servlet/Application.java
new file mode 100644
index 0000000..fba3ba3
--- /dev/null
+++ b/examples/spring/servlet/src/main/java/io/opencensus/examples/spring/servlet/Application.java
@@ -0,0 +1,59 @@
+/*
+ * Copyright 2019, 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.
+ */
+
+package io.opencensus.examples.spring.servlet;
+
+import io.opencensus.contrib.http.util.HttpViews;
+import io.opencensus.exporter.stats.prometheus.PrometheusStatsCollector;
+import io.opencensus.exporter.trace.logging.LoggingTraceExporter;
+import io.opencensus.trace.Tracing;
+import io.opencensus.trace.config.TraceConfig;
+import io.opencensus.trace.samplers.Samplers;
+import io.prometheus.client.exporter.HTTPServer;
+import java.io.IOException;
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+import org.springframework.context.ApplicationContext;
+
+@SpringBootApplication
+public class Application {
+
+ private static void initStatsExporter() throws IOException {
+ HttpViews.registerAllServerViews();
+ HttpViews.registerAllClientViews();
+
+ // Register Prometheus exporters and export metrics to a Prometheus HTTPServer.
+ // Refer to https://prometheus.io/ to run Prometheus Server.
+ PrometheusStatsCollector.createAndRegister();
+ HTTPServer prometheusServer = new HTTPServer(9090, true);
+ }
+
+ private static void initTracingAndLoggingExporter() {
+ TraceConfig traceConfig = Tracing.getTraceConfig();
+ traceConfig.updateActiveTraceParams(
+ traceConfig.getActiveTraceParams().toBuilder().setSampler(Samplers.alwaysSample()).build());
+
+ LoggingTraceExporter.register();
+ }
+
+ /** Main launcher for the SpringServletApplication. */
+ public static void main(String[] args) throws IOException {
+ ApplicationContext ctx = SpringApplication.run(Application.class, args);
+
+ initTracingAndLoggingExporter();
+ initStatsExporter();
+ }
+}
diff --git a/examples/spring/servlet/src/main/java/io/opencensus/examples/spring/servlet/ApplicationAutoConfiguration.java b/examples/spring/servlet/src/main/java/io/opencensus/examples/spring/servlet/ApplicationAutoConfiguration.java
new file mode 100644
index 0000000..deaa67c
--- /dev/null
+++ b/examples/spring/servlet/src/main/java/io/opencensus/examples/spring/servlet/ApplicationAutoConfiguration.java
@@ -0,0 +1,47 @@
+/*
+ * Copyright 2019, 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.
+ */
+
+package io.opencensus.examples.spring.servlet;
+
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.http.client.AsyncClientHttpRequestFactory;
+import org.springframework.http.client.HttpComponentsAsyncClientHttpRequestFactory;
+import org.springframework.web.client.AsyncRestTemplate;
+
+@Configuration
+public class ApplicationAutoConfiguration {
+
+ /* Instance of AsyncRestTemplate. */
+ @Bean
+ public AsyncRestTemplate getAsyncRestTemplate(AsyncClientHttpRequestFactory factory) {
+ return new AsyncRestTemplate(factory);
+ }
+
+ /**
+ * Factory for AsyncClientHttpRequest.
+ *
+ * @return AsyncClientHttpRequestFactory
+ */
+ @Bean
+ public AsyncClientHttpRequestFactory getAsyncClientHttpRequestFactory() {
+ int timeout = 5000;
+ HttpComponentsAsyncClientHttpRequestFactory asyncClientHttpRequestFactory =
+ new HttpComponentsAsyncClientHttpRequestFactory();
+ asyncClientHttpRequestFactory.setConnectTimeout(timeout);
+ return asyncClientHttpRequestFactory;
+ }
+}
diff --git a/examples/spring/servlet/src/main/java/io/opencensus/examples/spring/servlet/HelloController.java b/examples/spring/servlet/src/main/java/io/opencensus/examples/spring/servlet/HelloController.java
new file mode 100644
index 0000000..c85a7c5
--- /dev/null
+++ b/examples/spring/servlet/src/main/java/io/opencensus/examples/spring/servlet/HelloController.java
@@ -0,0 +1,91 @@
+/*
+ * Copyright 2019, 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.
+ */
+
+package io.opencensus.examples.spring.servlet;
+
+import java.util.concurrent.ExecutionException;
+import java.util.logging.Level;
+import java.util.logging.Logger;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.http.ResponseEntity;
+import org.springframework.http.client.ClientHttpRequestFactory;
+import org.springframework.http.client.HttpComponentsClientHttpRequestFactory;
+import org.springframework.util.concurrent.ListenableFuture;
+import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.RestController;
+import org.springframework.web.client.AsyncRestTemplate;
+import org.springframework.web.client.RestTemplate;
+
+/* Controller for Web server. */
+@RestController
+public class HelloController {
+ private static final Logger logger = Logger.getLogger(HelloController.class.getName());
+
+ /**
+ * Serves index page.
+ *
+ * @return String
+ */
+ @RequestMapping("/")
+ public String index() {
+ String str = "Hello from servlet instrumented with opencensus-spring";
+ String resp = restTemplate.getForObject("http://localhost:8080/loopback", String.class);
+
+ String asyncUrl = "http://localhost:8080/asyncloopback";
+ ListenableFuture<ResponseEntity<String>> future1 =
+ asyncRestTemplate.getForEntity(asyncUrl, String.class);
+ ListenableFuture<ResponseEntity<String>> future2 =
+ asyncRestTemplate.getForEntity(asyncUrl, String.class);
+ ListenableFuture<ResponseEntity<String>> future3 =
+ asyncRestTemplate.getForEntity(asyncUrl, String.class);
+
+ String resp1 = null;
+ String resp2 = null;
+ String resp3 = null;
+ try {
+ resp1 = future1.get().toString();
+ resp2 = future2.get().toString();
+ resp3 = future3.get().toString();
+ } catch (InterruptedException | ExecutionException e) {
+ logger.log(Level.WARNING, "request failed", e);
+ }
+ return str + resp + "\n" + resp1 + "\n" + resp2 + "\n" + resp3;
+ }
+
+ /* Serves loopback endpoint. */
+ @RequestMapping("/loopback")
+ public String loopback() {
+ return "Loopback. Hello from servlet!";
+ }
+
+ /* Serves asyncloopback endpoint. */
+ @RequestMapping("/asyncloopback")
+ public String asyncLoopback() {
+ return "Async Loopback. Hello from servlet!";
+ }
+
+ @Autowired AsyncRestTemplate asyncRestTemplate;
+
+ RestTemplate restTemplate = new RestTemplate(getClientHttpRequestFactory());
+
+ private ClientHttpRequestFactory getClientHttpRequestFactory() {
+ int timeout = 5000;
+ HttpComponentsClientHttpRequestFactory clientHttpRequestFactory =
+ new HttpComponentsClientHttpRequestFactory();
+ clientHttpRequestFactory.setConnectTimeout(timeout);
+ return clientHttpRequestFactory;
+ }
+}
diff --git a/examples/spring/servlet/src/resources/META-INF/spring.factories b/examples/spring/servlet/src/resources/META-INF/spring.factories
new file mode 100644
index 0000000..4dd75dd
--- /dev/null
+++ b/examples/spring/servlet/src/resources/META-INF/spring.factories
@@ -0,0 +1,3 @@
+# Auto Configuration
+org.springframework.boot.autoconfigure.EnableAutoConfiguration=\
+io.opencensus.examples.spring.servlet.ApplicationAutoConfiguration
diff --git a/examples/spring/servlet/src/resources/application.properties b/examples/spring/servlet/src/resources/application.properties
new file mode 100644
index 0000000..04c0b54
--- /dev/null
+++ b/examples/spring/servlet/src/resources/application.properties
@@ -0,0 +1 @@
+opencensus.spring.trace.propagation=B3
\ No newline at end of file
