BAEL-6005: Enable HTTP2 with Tomcat in Spring Boot (#18374)

Author: manfred106

spring-boot-modules/pom.xml

@@ -126,6 +126,7 @@
         <module>spring-boot-openapi</module>
         <module>spring-boot-brave</module>
         <module>spring-boot-simple</module>
+        <module>spring-boot-http2</module>
     </modules>
 
     <build>

spring-boot-modules/spring-boot-http2/pom.xml

@@ -0,0 +1,53 @@
+<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>
+    <artifactId>spring-boot-http2</artifactId>
+    <version>0.0.1-SNAPSHOT</version>
+    <name>spring-boot-http2</name>
+    <description>Demo project for Spring Boot</description>
+    <parent>
+        <groupId>com.baeldung.spring-boot-modules</groupId>
+        <artifactId>spring-boot-modules</artifactId>
+        <version>1.0.0-SNAPSHOT</version>
+    </parent>
+    <dependencies>
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-web</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>ch.qos.logback</groupId>
+            <artifactId>logback-classic</artifactId>
+            <version>${logback.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>ch.qos.logback</groupId>
+            <artifactId>logback-core</artifactId>
+            <version>${logback.version}</version>
+        </dependency>
+    </dependencies>
+    <build>
+        <plugins>
+            <plugin>
+                <groupId>org.springframework.boot</groupId>
+                <artifactId>spring-boot-maven-plugin</artifactId>
+            </plugin>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-compiler-plugin</artifactId>
+                <configuration>
+                    <source>11</source>
+                    <target>11</target>
+                    <compilerArgs>
+                        <arg>-parameters</arg>
+                    </compilerArgs>
+                </configuration>
+            </plugin>
+        </plugins>
+    </build>
+    <properties>
+        <spring-boot.version>3.4.3</spring-boot.version>
+        <logback.version>1.5.17</logback.version>
+    </properties>
+</project>

spring-boot-modules/spring-boot-http2/src/main/java/com/baeldung/http2/Http2Application.java

@@ -0,0 +1,13 @@
+package com.baeldung.http2;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+
+@SpringBootApplication
+public class Http2Application {
+
+    public static void main(String[] args) {
+        SpringApplication.run(Http2Application.class, args);
+    }
+
+}

spring-boot-modules/spring-boot-http2/src/main/java/com/baeldung/http2/config/Http2Config.java

@@ -0,0 +1,25 @@
+package com.baeldung.http2.config;
+
+import org.apache.catalina.connector.Connector;
+import org.apache.coyote.http2.Http2Protocol;
+import org.springframework.boot.web.embedded.tomcat.TomcatServletWebServerFactory;
+import org.springframework.boot.web.server.WebServerFactoryCustomizer;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.context.annotation.Profile;
+
+@Configuration
+@Profile("config-class")
+public class Http2Config {
+
+    @Bean
+    public WebServerFactoryCustomizer<TomcatServletWebServerFactory> getWebServerFactoryCustomizer() {
+        return factory -> {
+            Connector httpConnector = new Connector(TomcatServletWebServerFactory.DEFAULT_PROTOCOL);
+            httpConnector.setPort(8080);
+            factory.addConnectorCustomizers(connector -> connector.addUpgradeProtocol(new Http2Protocol()));
+            factory.addAdditionalTomcatConnectors(httpConnector);
+        };
+    }
+
+}

spring-boot-modules/spring-boot-http2/src/main/java/com/baeldung/http2/controller/Http2Controller.java

@@ -0,0 +1,15 @@
+package com.baeldung.http2.controller;
+
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.RequestParam;
+import org.springframework.web.bind.annotation.RestController;
+
+@RestController
+public class Http2Controller {
+
+    @GetMapping("/http2/echo")
+    public String getEcho(@RequestParam String message) {
+        return message;
+    }
+
+}

spring-boot-modules/spring-boot-http2/src/main/resources/application-config-class.yml

@@ -0,0 +1,12 @@
+server:
+  http2:
+    enabled: false
+
+  port: 8443
+
+  ssl:
+    enabled: true
+    key-store: classpath:keystore.p12
+    key-store-password: abcd1234
+    key-store-type: PKCS12
+    key-alias: http2-alias

spring-boot-modules/spring-boot-http2/src/main/resources/application.yml

@@ -0,0 +1,12 @@
+server:
+  http2:
+    enabled: true
+
+  port: 8443
+
+  ssl:
+    enabled: true
+    key-store: classpath:keystore.p12
+    key-store-password: abcd1234
+    key-store-type: PKCS12
+    key-alias: http2-alias

spring-boot-modules/spring-boot-http2/src/main/resources/keystore.p12

@@ -0,0 +1,18 @@
+package com.baeldung.http2;
+
+import javax.net.ssl.X509TrustManager;
+import java.security.cert.X509Certificate;
+
+public class AllCertsTrustManager implements X509TrustManager {
+
+    public X509Certificate[] getAcceptedIssuers() {
+        return null;
+    }
+
+    public void checkClientTrusted(X509Certificate[] certs, String authType) {
+    }
+
+    public void checkServerTrusted(X509Certificate[] certs, String authType) {
+    }
+
+}

spring-boot-modules/spring-boot-http2/src/test/java/com/baeldung/http2/AllCertsTrustManager.java

@@ -0,0 +1,65 @@
+package com.baeldung.http2;
+
+import org.junit.jupiter.api.BeforeAll;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+
+import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.boot.test.web.server.LocalServerPort;
+
+import javax.net.ssl.SSLContext;
+import javax.net.ssl.TrustManager;
+
+import java.net.URI;
+import java.net.http.HttpClient;
+import java.net.http.HttpRequest;
+import java.net.http.HttpResponse;
+import java.security.KeyManagementException;
+import java.security.NoSuchAlgorithmException;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+// Integration test based on enabling HTTP/2 using the configuration in application.yml
+@SpringBootTest(webEnvironment = SpringBootTest.WebEnvironment.RANDOM_PORT)
+class Http2ApplicationIntegrationTest {
+
+    private static SSLContext sslContext;
+
+    @LocalServerPort
+    private int port;
+
+    private HttpClient httpClient;
+
+    @BeforeAll
+    static void setupOnce() throws NoSuchAlgorithmException, KeyManagementException {
+        // Get rid of cert validation due to the self-signed certificate
+        sslContext = SSLContext.getInstance("TLS");
+        sslContext.init(null,
+                new TrustManager[] { new AllCertsTrustManager() },
+                new java.security.SecureRandom());
+    }
+
+    @BeforeEach
+    void setup() {
+        httpClient = HttpClient.newBuilder()
+                .sslContext(sslContext)
+                .version(HttpClient.Version.HTTP_2)
+                .build();
+    }
+
+    @Test
+    void whenSendHttp2Request_thenReturnHttp2Response() throws Exception {
+        // when
+        HttpRequest request = HttpRequest.newBuilder()
+                .uri(new URI(String.format("https://localhost:%s/http2/echo?message=test", port)))
+                .GET()
+                .build();
+        HttpResponse<?> response = httpClient.send(request, HttpResponse.BodyHandlers.ofString());
+
+        // then
+        assertThat(response.statusCode()).isEqualTo(200);
+        assertThat(response.body()).isEqualTo("test");
+        assertThat(response.version()).isEqualTo(HttpClient.Version.HTTP_2);
+    }
+
+}