BAEL-8140: code samples

Author: etrandafir93

persistence-modules/spring-boot-persistence-5/pom.xml

@@ -83,6 +83,9 @@
         <instancio.version>5.2.1</instancio.version>
         <spring-boot.version>3.4.1</spring-boot.version>
         <db2.version>12.1.0.0</db2.version>
+        <java.version>17</java.version>
+        <maven.compiler.source>17</maven.compiler.source>
+        <maven.compiler.target>17</maven.compiler.target>
     </properties>
 
 </project>

persistence-modules/spring-boot-persistence-5/src/main/java/com/baeldung/transactional/rollback/Article.java

@@ -0,0 +1,33 @@
+package com.baeldung.transactional.rollback;
+
+import jakarta.annotation.Nonnull;
+import jakarta.persistence.Column;
+import jakarta.persistence.Entity;
+import jakarta.persistence.GeneratedValue;
+import jakarta.persistence.GenerationType;
+import jakarta.persistence.Id;
+
+import lombok.Data;
+import lombok.NoArgsConstructor;
+
+@Data
+@Entity
+@NoArgsConstructor
+class Article {
+
+    @Id
+    @GeneratedValue(strategy = GenerationType.SEQUENCE)
+    private Long id;
+
+    @Column(nullable = false)
+    private String title;
+
+    @Column(nullable = false)
+    private String author;
+
+    public Article(String title, String author) {
+        this.title = title;
+        this.author = author;
+    }
+
+}

persistence-modules/spring-boot-persistence-5/src/main/java/com/baeldung/transactional/rollback/ArticleRepo.java

@@ -0,0 +1,8 @@
+package com.baeldung.transactional.rollback;
+
+import org.springframework.data.jpa.repository.JpaRepository;
+import org.springframework.stereotype.Repository;
+
+@Repository
+interface ArticleRepo extends JpaRepository<Article, Long> {
+}

spring-boot-modules/spring-boot-3-observation/src/main/java/com/baeldung/micrometer/tags/Application.java

@@ -3,14 +3,21 @@
 import org.springframework.boot.SpringApplication;
 import org.springframework.boot.autoconfigure.SpringBootApplication;
 import org.springframework.context.annotation.Bean;
+import org.springframework.expression.Expression;
+import org.springframework.expression.ExpressionParser;
+import org.springframework.expression.spel.SpelParserConfiguration;
+import org.springframework.expression.spel.standard.SpelExpressionParser;
+import org.springframework.expression.spel.support.SimpleEvaluationContext;
+import org.springframework.expression.spel.support.StandardEvaluationContext;
 
+import io.micrometer.common.annotation.ValueExpressionResolver;
 import io.micrometer.core.aop.CountedAspect;
 import io.micrometer.core.aop.CountedMeterTagAnnotationHandler;
 import io.micrometer.core.aop.MeterTagAnnotationHandler;
 import io.micrometer.core.aop.TimedAspect;
 
 @SpringBootApplication
-class Application {
+public class Application {
 
     public static void main(String[] args) {
         SpringApplication.run(Application.class, args);
@@ -27,10 +34,32 @@ public MeterTagAnnotationHandler meterTagAnnotationHandler() {
     public CountedAspect countedAspect() {
         CountedAspect aspect = new CountedAspect();
         CountedMeterTagAnnotationHandler tagAnnotationHandler = new CountedMeterTagAnnotationHandler(
-            aClass -> Object::toString,
-            aClass -> (exp, param) -> "");
+            aClass -> o -> new SpelValueExpressionResolver().resolve(o.toString(), null),
+            aClass -> new SpelValueExpressionResolver());
         aspect.setMeterTagAnnotationHandler(tagAnnotationHandler);
         return aspect;
     }
 
+    public static class SpelValueExpressionResolver implements ValueExpressionResolver {
+
+        @Override
+        public String resolve(String expression, Object parameter) {
+            try {
+                SpelParserConfiguration config = new SpelParserConfiguration(true, true);
+                StandardEvaluationContext context = new StandardEvaluationContext(parameter);
+
+                ExpressionParser expressionParser = new SpelExpressionParser(config);
+                return expressionParser.parseExpression(expression)
+                    .getValue(context, String.class);
+
+                //                ExpressionParser expressionParser = new SpelExpressionParser();
+//                Expression expressionToEvaluate = expressionParser.parseExpression(expression);
+//                return expressionToEvaluate.getValue(parameter, String.class);
+            }
+            catch (Exception ex) {
+                ex.printStackTrace(); // todo: proper logging
+            }
+            return String.valueOf(parameter);
+        }
+    }
 }

spring-boot-modules/spring-boot-3-observation/src/main/java/com/baeldung/micrometer/tags/dummy/DummyService.java

@@ -1,14 +1,18 @@
 package com.baeldung.micrometer.tags.dummy;
 
+import java.math.BigDecimal;
 import java.util.concurrent.ThreadLocalRandom;
 
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 import org.springframework.stereotype.Service;
 
+import com.baeldung.micrometer.tags.Application;
+
 import io.micrometer.core.annotation.Counted;
 import io.micrometer.core.annotation.Timed;
 import io.micrometer.core.aop.MeterTag;
+import io.micrometer.core.aop.MeterTags;
 import io.micrometer.core.instrument.Counter;
 import io.micrometer.core.instrument.Meter;
 import io.micrometer.core.instrument.MeterRegistry;
@@ -65,6 +69,23 @@ public String buzz(@MeterTag("device.type") String device) {
         return invokeSomeLogic();
     }
 
+    @Counted(value = "fizz")
+    public String fizz(
+        @MeterTag(key = "id", expression = "#order.id")
+        @MeterTag(key = "other.id", expression = "#order.otherOrder.id")
+        @MeterTag(key = "math", expression = "20 - 1")
+        @MeterTag(key = "total", expression = "#order.total")
+        @MeterTag(key = "other.total", expression = "#order.otherOrder.total")
+        @MeterTag(key = "total.group", expression = "#order.total > 50 ? 'high' : 'low'")
+        Order order
+    ) {
+        log.info("fizz({})", order);
+        return invokeSomeLogic();
+    }
+
+    public record Order(int id, int total, Order otherOrder) {
+    }
+
     private String invokeSomeLogic() {
         long sleepMs = ThreadLocalRandom.current()
             .nextInt(0, 100);

spring-boot-modules/spring-boot-3-observation/src/main/java/com/baeldung/micrometer/tags/dummy/DummyStartupListener.java

@@ -1,12 +1,15 @@
 package com.baeldung.micrometer.tags.dummy;
 
 import java.util.List;
+import java.util.concurrent.ThreadLocalRandom;
 import java.util.stream.IntStream;
 
 import org.springframework.boot.context.event.ApplicationReadyEvent;
 import org.springframework.context.event.EventListener;
 import org.springframework.stereotype.Component;
 
+import com.baeldung.micrometer.tags.dummy.DummyService.Order;
+
 @Component
 class DummyStartupListener {
 
@@ -24,9 +27,17 @@ void sendRequests() {
                 service.foo(deviceType);
                 service.bar(deviceType);
                 service.buzz(deviceType);
+                service.fizz(
+                    new Order(randomInt(), randomInt(),
+                        new Order(randomInt(), randomInt(), null)));
             });
     }
 
+    int randomInt() {
+        return ThreadLocalRandom.current()
+            .nextInt(1, 100);
+    }
+
     DummyStartupListener(DummyService service) {
         this.service = service;
     }