BAEL-442 Adding spring-sleuth module and supporting code for application.

spring-sleuth/src/main/java/com/baeldung/spring/session/SchedulingService.java

@@ -0,0 +1,26 @@
+package com.baeldung.spring.session;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.scheduling.annotation.Scheduled;
+import org.springframework.stereotype.Service;
+
+@Service
+public class SchedulingService {
+
+    private Logger logger = LoggerFactory.getLogger(this.getClass());
+    private final SleuthService sleuthService;
+
+    @Autowired
+    public SchedulingService(SleuthService sleuthService) {
+        this.sleuthService = sleuthService;
+    }
+
+    @Scheduled(fixedDelay = 30000)
+    public void scheduledWork() throws InterruptedException {
+        logger.info("Start some work from the scheduled task");
+        sleuthService.asyncMethod();
+        logger.info("End work from scheduled task");
+    }
+}

spring-sleuth/src/main/java/com/baeldung/spring/session/SleuthController.java

@@ -0,0 +1,71 @@
+package com.baeldung.spring.session;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.RestController;
+
+import java.util.concurrent.Executor;
+
+@RestController
+public class SleuthController {
+
+    private Logger logger = LoggerFactory.getLogger(this.getClass());
+    private final SleuthService sleuthService;
+    private final Executor executor;
+
+    @Autowired
+    public SleuthController(SleuthService sleuthService, Executor executor) {
+        this.sleuthService = sleuthService;
+        this.executor = executor;
+    }
+
+    @GetMapping("/")
+    public String helloSleuth() {
+        logger.info("Hello Sleuth");
+        return "success";
+    }
+
+    @GetMapping("/same-span")
+    public String helloSleuthSameSpan() throws InterruptedException {
+        logger.info("Same Span");
+        sleuthService.doSomeWorkSameSpan();
+        return "success";
+    }
+
+    @GetMapping("/new-span")
+    public String helloSleuthNewSpan() throws InterruptedException {
+        logger.info("New Span");
+        sleuthService.doSomeWorkNewSpan();
+        return "success";
+    }
+
+    @GetMapping("/new-thread")
+    public String helloSleuthNewThread() {
+        logger.info("New Thread");
+        Runnable runnable = () -> {
+            try {
+                Thread.sleep(1000L);
+            } catch (InterruptedException e) {
+                e.printStackTrace();
+            }
+            logger.info("I'm inside the new thread - with a new span");
+        };
+        executor.execute(runnable);
+
+        logger.info("I'm done - with the original span");
+        return "success";
+    }
+
+    @GetMapping("/async")
+    public String helloSleuthAsync() throws InterruptedException {
+        logger.info("Before Async Method Call");
+        sleuthService.asyncMethod();
+        logger.info("After Async Method Call");
+        return "success";
+    }
+
+
+
+}

spring-sleuth/src/main/java/com/baeldung/spring/session/SleuthService.java

@@ -0,0 +1,46 @@
+package com.baeldung.spring.session;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.cloud.sleuth.Span;
+import org.springframework.cloud.sleuth.Tracer;
+import org.springframework.scheduling.annotation.Async;
+import org.springframework.stereotype.Service;
+
+@Service
+public class SleuthService {
+    private Logger logger = LoggerFactory.getLogger(this.getClass());
+    private final Tracer tracer;
+
+    @Autowired
+    public SleuthService(Tracer tracer) {
+        this.tracer = tracer;
+    }
+
+    public void doSomeWorkSameSpan() throws InterruptedException {
+        Thread.sleep(1000L);
+        logger.info("Doing some work");
+    }
+
+    public void doSomeWorkNewSpan() throws InterruptedException {
+        logger.info("I'm in the original span");
+
+        Span newSpan = tracer.createSpan("newSpan");
+        try {
+            Thread.sleep(1000L);
+            logger.info("I'm in the new span doing some cool work that needs its own span");
+        } finally {
+            tracer.close(newSpan);
+        }
+
+        logger.info("I'm in the original span");
+    }
+
+    @Async
+    public void asyncMethod() throws InterruptedException {
+        logger.info("Start Async Method");
+        Thread.sleep(1000L);
+        logger.info("End Async Method");
+    }
+}

spring-sleuth/src/main/java/com/baeldung/spring/session/SleuthWebApp.java

@@ -0,0 +1,11 @@
+package com.baeldung.spring.session;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+
+@SpringBootApplication
+public class SleuthWebApp {
+    public static void main(String[] args) {
+        SpringApplication.run(SleuthWebApp.class, args);
+    }
+}

spring-sleuth/src/main/java/com/baeldung/spring/session/ThreadConfig.java

@@ -0,0 +1,56 @@
+package com.baeldung.spring.session;
+
+import org.springframework.beans.factory.BeanFactory;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.cloud.sleuth.instrument.async.LazyTraceExecutor;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.scheduling.annotation.AsyncConfigurerSupport;
+import org.springframework.scheduling.annotation.EnableAsync;
+import org.springframework.scheduling.annotation.EnableScheduling;
+import org.springframework.scheduling.annotation.SchedulingConfigurer;
+import org.springframework.scheduling.concurrent.ThreadPoolTaskExecutor;
+import org.springframework.scheduling.config.ScheduledTaskRegistrar;
+
+import java.util.concurrent.Executor;
+import java.util.concurrent.Executors;
+
+@Configuration
+@EnableAsync
+@EnableScheduling
+public class ThreadConfig extends AsyncConfigurerSupport implements SchedulingConfigurer{
+
+    @Autowired
+    private BeanFactory beanFactory;
+
+    @Bean
+    public Executor executor() {
+        return makeExecutor();
+    }
+
+    @Override
+    public Executor getAsyncExecutor() {
+        return makeExecutor();
+    }
+
+    @Override
+    public void configureTasks(ScheduledTaskRegistrar scheduledTaskRegistrar) {
+        scheduledTaskRegistrar.setScheduler(schedulingExecutor());
+    }
+
+    @Bean(destroyMethod = "shutdown")
+    public Executor schedulingExecutor() {
+        return Executors.newScheduledThreadPool(100);
+    }
+
+    private Executor makeExecutor() {
+        ThreadPoolTaskExecutor threadPoolTaskExecutor = new ThreadPoolTaskExecutor();
+        threadPoolTaskExecutor.setCorePoolSize(5);
+        threadPoolTaskExecutor.setMaxPoolSize(10);
+        threadPoolTaskExecutor.initialize();
+
+        return new LazyTraceExecutor(beanFactory, threadPoolTaskExecutor);
+    }
+
+
+}

spring-sleuth/src/main/resources/application.properties

@@ -0,0 +1 @@
+spring.application.name=Baeldung Sleuth Tutorial