BAEL-2102 - Configure a Tomcat Connection Pool in Spring Boot (#5095)

* Initial Commit

* Initial Commit

* Initial Commit

* Update CommandLineCrudRunner.java

* Update pom.xml

* Update Customer.java

* Update application.properties

* Update pom.xml

* Update SpringBootConsoleApplication.java

* Update SpringBootConsoleApplication.java

* Update SpringBootConsoleApplication.java

* Update CommandLineCrudRunner.java

* Update pom.xml

spring-boot-persistence/pom.xml

@@ -1,57 +1,75 @@
-<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+<?xml version="1.0" encoding="UTF-8"?>
-	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+<project xmlns="http://maven.apache.org/POM/4.0.0"
-	<modelVersion>4.0.0</modelVersion>
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd"
+         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
+    <modelVersion>4.0.0</modelVersion>
+    
+    <groupId>com.baeldung</groupId>
+    <artifactId>spring-boot-persistence</artifactId>
+    <version>0.1.0</version>
+    
+    <parent>
+        <artifactId>parent-boot-2</artifactId>
 	<groupId>com.baeldung</groupId>
-	<artifactId>spring-boot-persistence</artifactId>
 	<version>0.0.1-SNAPSHOT</version>
-	<packaging>jar</packaging>
+	<relativePath>../parent-boot-2</relativePath>
-	<name>spring-boot-persistence</name>
+    </parent>
-	<description>This is a simple Spring Data Repositories test</description>
+    
-
+    <dependencies>
-	<parent>
+        <dependency>
-		<artifactId>parent-boot-2</artifactId>
+            <groupId>org.springframework.boot</groupId>
-		<groupId>com.baeldung</groupId>
+            <artifactId>spring-boot-starter-data-jpa</artifactId>
-		<version>0.0.1-SNAPSHOT</version>
+            <exclusions>
-		<relativePath>../parent-boot-2</relativePath>
+                <exclusion>
-	</parent>
+                    <groupId>com.zaxxer</groupId>
-
+                    <artifactId>HikariCP</artifactId>
-	<dependencies>
+                </exclusion>
-		<dependency>
+            </exclusions>
-			<groupId>org.springframework.boot</groupId>
+        </dependency>
-			<artifactId>spring-boot-starter-data-jpa</artifactId>
+        <dependency>
-		</dependency>
+            <groupId>org.springframework.boot</groupId>
-		<dependency>
+            <artifactId>spring-boot-starter-test</artifactId>
-			<groupId>com.h2database</groupId>
+            <scope>test</scope>
-			<artifactId>h2</artifactId>
+        </dependency>
-		</dependency>
+        <dependency>
-		<dependency>
+            <groupId>org.apache.tomcat</groupId>
-			<groupId>org.springframework.boot</groupId>
+            <artifactId>tomcat-jdbc</artifactId>
-			<artifactId>spring-boot-starter</artifactId>
+            <version>${tomcat-jdbc.version}</version>
-		</dependency>
+        </dependency>
-	</dependencies>
+        <dependency>
-
+            <groupId>mysql</groupId>
-	<build>
+            <artifactId>mysql-connector-java</artifactId>
-		<finalName>spring-boot-persistence</finalName>
+            <version>${mysql-connector-java.version}</version>
-		<resources>
+        </dependency>
-			<resource>
+        <dependency>
-				<directory>src/main/resources</directory>
+            <groupId>com.h2database</groupId>
-				<filtering>true</filtering>
+            <artifactId>h2</artifactId>
-			</resource>
+            <version>${h2database.version}</version>
-		</resources>
+            <scope>runtime</scope>
-		<plugins>
+        </dependency>
-			<plugin>
+    </dependencies>
-				<groupId>org.apache.maven.plugins</groupId>
+    
-				<artifactId>maven-war-plugin</artifactId>
+    <properties>
-			</plugin>
+        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
-			<plugin>
+        <java.version>1.8</java.version>
-				<groupId>pl.project13.maven</groupId>
+        <mysql-connector-java.version>8.0.12</mysql-connector-java.version>
-				<artifactId>git-commit-id-plugin</artifactId>
+        <tomcat-jdbc.version>9.0.10</tomcat-jdbc.version>
-				<version>${git-commit-id-plugin.version}</version>
+        <h2database.version>1.4.197</h2database.version>
-			</plugin>
+    </properties>
-		</plugins>
+    
-	</build>
+    <build>
-
+        <finalName>spring-boot-persistence</finalName>
-	<properties>
+        <resources>
-		<git-commit-id-plugin.version>2.2.4</git-commit-id-plugin.version>
+	    <resource>
-	</properties>
+	        <directory>src/main/resources</directory>
-</project>
+		<filtering>true</filtering>
+	    </resource>
+        </resources>
+        <plugins>
+            <plugin>
+                <groupId>org.springframework.boot</groupId>
+                <artifactId>spring-boot-maven-plugin</artifactId>
+            </plugin>
+        </plugins>
+    </build>
+</project>

spring-boot-persistence/src/main/java/com/baeldung/tomcatconnectionpool/application/SpringBootConsoleApplication.java

@@ -0,0 +1,22 @@
+package com.baeldung.tomcatconnectionpool.application;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+import org.springframework.boot.autoconfigure.domain.EntityScan;
+import org.springframework.context.annotation.ComponentScan;
+import org.springframework.data.jpa.repository.config.EnableJpaRepositories;
+import org.springframework.transaction.annotation.EnableTransactionManagement;
+
+@SpringBootApplication  
+@EnableAutoConfiguration
+@ComponentScan(basePackages={"com.baeldung.tomcatconnectionpool.application"})
+@EnableJpaRepositories(basePackages="com.baeldung.tomcatconnectionpool.application.repositories")
+@EnableTransactionManagement
+@EntityScan(basePackages="com.baeldung.tomcatconnectionpool.application.entities")
+public class SpringBootConsoleApplication {
+    
+    public static void main(String[] args) {
+        SpringApplication.run(SpringBootConsoleApplication.class);
+    }
+}

spring-boot-persistence/src/main/java/com/baeldung/tomcatconnectionpool/application/entities/Customer.java

@@ -0,0 +1,53 @@
+package com.baeldung.tomcatconnectionpool.application.entities;
+
+import javax.persistence.Column;
+import javax.persistence.Entity;
+import javax.persistence.GeneratedValue;
+import javax.persistence.GenerationType;
+import javax.persistence.Id;
+import javax.persistence.Table;
+
+@Entity
+@Table(name = "customers")
+public class Customer {
+
+    @Id
+    @GeneratedValue(strategy = GenerationType.AUTO)
+    private long id;
+    @Column(name = "first_name")
+    private String firstName;
+    @Column(name = "last_name")
+    private String lastName;
+    
+    public Customer() {}
+    
+    public Customer(String firstName, String lastName) {
+        this.firstName = firstName;
+        this.lastName = lastName;
+    }
+    
+    public long getId() {
+        return id;
+    }
+
+    public void setLastName(String lastName) {
+        this.lastName = lastName;
+    }
+
+    public String getFirstName() {
+        return firstName;
+    }
+
+    public void setFirstName(String firstName) {
+        this.firstName = firstName;
+    }
+    
+    public String getLastName() {
+        return lastName;
+    }
+
+    @Override
+    public String toString() {
+        return "Customer{" + "id=" + id + ", firstName=" + firstName + ", lastName=" + lastName + '}';
+    }
+}

spring-boot-persistence/src/main/java/com/baeldung/tomcatconnectionpool/application/repositories/CustomerRepository.java

@@ -0,0 +1,12 @@
+package com.baeldung.tomcatconnectionpool.application.repositories;
+
+import com.baeldung.tomcatconnectionpool.application.entities.Customer;
+import java.util.List;
+import org.springframework.data.repository.CrudRepository;
+import org.springframework.stereotype.Repository;
+
+@Repository
+public interface CustomerRepository extends CrudRepository<Customer, Long> {
+    
+    List<Customer> findByLastName(String lastName);
+}

spring-boot-persistence/src/main/java/com/baeldung/tomcatconnectionpool/application/runners/CommandLineCrudRunner.java

@@ -0,0 +1,37 @@
+package com.baeldung.tomcatconnectionpool.application.runners;
+
+import com.baeldung.tomcatconnectionpool.application.entities.Customer;
+import com.baeldung.tomcatconnectionpool.application.repositories.CustomerRepository;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.CommandLineRunner;
+import org.springframework.stereotype.Component;
+
+@Component
+public class CommandLineCrudRunner implements CommandLineRunner {
+    
+    private static final Logger logger = LoggerFactory.getLogger(CommandLineCrudRunner.class);
+    
+    @Autowired
+    private CustomerRepository customerRepository;
+    
+    @Override
+    public void run(String... args) throws Exception {
+        customerRepository.save(new Customer("John", "Doe"));
+        customerRepository.save(new Customer("Jennifer", "Wilson"));
+        
+        logger.info("Customers found with findAll():");
+        customerRepository.findAll().forEach(c -> logger.info(c.toString()));
+        
+        logger.info("Customer found with findById(1L):");
+        Customer customer = customerRepository.findById(1L)
+                .orElseGet(() -> new Customer("Non-existing customer", ""));
+        logger.info(customer.toString());
+        
+        logger.info("Customer found with findByLastName('Wilson'):");
+        customerRepository.findByLastName("Wilson").forEach(c -> {
+            logger.info(c.toString());
+        });
+    }
+}

spring-boot-persistence/src/main/resources/application.properties

@@ -1,2 +1,16 @@
-spring.jpa.show-sql=true
+spring.datasource.tomcat.initial-size=15
-spring.jpa.hibernate.ddl-auto=none
+spring.datasource.tomcat.max-wait=20000
+spring.datasource.tomcat.max-active=50
+spring.datasource.tomcat.max-idle=15
+spring.datasource.tomcat.min-idle=8
+spring.datasource.tomcat.default-auto-commit=true   
+spring.datasource.url=jdbc:h2:mem:test
+spring.datasource.username=root
+spring.datasource.password=
+spring.datasource.driver-class-name=org.h2.Driver
+
+spring.jpa.show-sql=false
+spring.jpa.hibernate.ddl-auto=update
+spring.jpa.hibernate.naming-strategy=org.hibernate.cfg.ImprovedNamingStrategy
+spring.jpa.properties.hibernate.dialect=org.hibernate.dialect.H2Dialect
+spring.jpa.properties.hibernate.id.new_generator_mappings=false

spring-boot-persistence/src/test/java/com/baeldung/tomcatconnectionpool/test/application/SpringBootTomcatConnectionPoolIntegrationTest.java

@@ -0,0 +1,22 @@
+package com.baeldung.tomcatconnectionpool.test.application;
+
+import javax.sql.DataSource;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.test.context.junit4.SpringRunner;
+import static org.assertj.core.api.Assertions.*;
+import org.springframework.boot.test.context.SpringBootTest;
+
+@RunWith(SpringRunner.class)
+@SpringBootTest
+public class SpringBootTomcatConnectionPoolIntegrationTest {
+    
+    @Autowired
+    private DataSource dataSource;
+    
+    @Test
+    public void givenTomcatConnectionPoolInstance_whenCheckedPoolClassName_thenCorrect() {
+        assertThat(dataSource.getClass().getName()).isEqualTo("org.apache.tomcat.jdbc.pool.DataSource");
+    }
+}