हम GraalVM का उपयोग करके स्प्रिंग बूट एप्लिकेशन को मूल में संकलित करते हैं

sdk install java 20.0.0.r8-grl

export JAVA_HOME=$HOME/.sdkman/candidates/java/current/

package com.example.reactive;

import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;
import lombok.extern.log4j.Log4j2;
import org.springframework.boot.ApplicationRunner;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.data.annotation.Id;
import org.springframework.data.r2dbc.core.DatabaseClient;
import org.springframework.data.repository.reactive.ReactiveCrudRepository;
import org.springframework.web.reactive.function.server.RouterFunction;
import org.springframework.web.reactive.function.server.ServerResponse;
import org.springframework.web.reactive.handler.SimpleUrlHandlerMapping;
import org.springframework.web.reactive.socket.WebSocketHandler;
import org.springframework.web.reactive.socket.WebSocketMessage;
import org.springframework.web.reactive.socket.server.support.WebSocketHandlerAdapter;
import reactor.core.publisher.Flux;

import java.time.Duration;
import java.time.Instant;
import java.util.Collections;
import java.util.stream.Stream;

import static org.springframework.web.reactive.function.server.RouterFunctions.route;
import static org.springframework.web.reactive.function.server.ServerResponse.ok;

@Log4j2
@SpringBootApplication(proxyBeanMethods = false)
public class ReactiveApplication {

    @Bean
    RouterFunction<ServerResponse> routes(ReservationRepository rr) {
        return route()
            .GET("/reservations", r -> ok().body(rr.findAll(), Reservation.class))
            .build();
    }

    @Bean
    ApplicationRunner runner(DatabaseClient databaseClient, ReservationRepository reservationRepository) {
        return args -> {

            Flux<Reservation> names = Flux
                .just("Andy", "Sebastien")
                .map(name -> new Reservation(null, name))
                .flatMap(reservationRepository::save);

            databaseClient
                .execute("create table reservation ( id   serial primary key, name varchar(255) not null )")
                .fetch()
                .rowsUpdated()
                .thenMany(names)
                .thenMany(reservationRepository.findAll())
                .subscribe(log::info);
        };
    }


    public static void main(String[] args) {
        SpringApplication.run(ReactiveApplication.class, args);
    }
}

interface ReservationRepository extends ReactiveCrudRepository<Reservation, Integer> {
}


@Data
@AllArgsConstructor
@NoArgsConstructor
class Reservation {

    @Id
    private Integer id;
    private String name;
}

<?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 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.3.0.M4</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.example</groupId>
    <artifactId>reactive</artifactId>
    <version>0.0.1-SNAPSHOT</version>

    <properties>
        <start-class>
            com.example.reactive.ReactiveApplication
        </start-class>
        <java.version>1.8</java.version>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.springframework.experimental</groupId>
            <artifactId>spring-graal-native</artifactId>
            <version>0.6.0.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-context-indexer</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-r2dbc</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-webflux</artifactId>
        </dependency>

        <dependency>
            <groupId>io.r2dbc</groupId>
            <artifactId>r2dbc-h2</artifactId>
        </dependency>

        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <optional>true</optional>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
            <exclusions>
                <exclusion>
                    <groupId>org.junit.vintage</groupId>
                    <artifactId>junit-vintage-engine</artifactId>
                </exclusion>
            </exclusions>
        </dependency>
    </dependencies>

    <build>
        <finalName>
            ${project.artifactId}
        </finalName>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>

    <repositories>
        <repository>
            <id>spring-milestones</id>
            <name>Spring Milestones</name>
            <url>https://repo.spring.io/milestone</url>
        </repository>
    </repositories>
    <pluginRepositories>
        <pluginRepository>
            <id>spring-milestones</id>
            <name>Spring Milestones</name>
            <url>https://repo.spring.io/milestone</url>
        </pluginRepository>
    </pluginRepositories>


    <profiles>
        <profile>
            <id>graal</id>
            <build>
                <plugins>
                    <plugin>
                        <groupId>org.graalvm.nativeimage</groupId>
                        <artifactId>native-image-maven-plugin</artifactId>
                        <version>20.0.0</version>
                        <configuration>
                            <buildArgs>
-Dspring.graal.mode=initialization-only -Dspring.graal.dump-config=/tmp/computed-reflect-config.json -Dspring.graal.verbose=true -Dspring.graal.skip-logback=true --initialize-at-run-time=org.springframework.data.r2dbc.connectionfactory.ConnectionFactoryUtils --initialize-at-build-time=io.r2dbc.spi.IsolationLevel,io.r2dbc.spi --initialize-at-build-time=io.r2dbc.spi.ConstantPool,io.r2dbc.spi.Assert,io.r2dbc.spi.ValidationDepth --initialize-at-build-time=org.springframework.data.r2dbc.connectionfactory -H:+TraceClassInitialization --no-fallback --allow-incomplete-classpath --report-unsupported-elements-at-runtime -H:+ReportExceptionStackTraces --no-server --initialize-at-build-time=org.reactivestreams.Publisher --initialize-at-build-time=com.example.reactive.ReservationRepository --initialize-at-run-time=io.netty.channel.unix.Socket --initialize-at-run-time=io.netty.channel.unix.IovArray --initialize-at-run-time=io.netty.channel.epoll.EpollEventLoop --initialize-at-run-time=io.netty.channel.unix.Errors
                            </buildArgs>
                        </configuration>
                        <executions>
                            <execution>
                                <goals>
                                    <goal>native-image</goal>
                                </goals>
                                <phase>package</phase>
                            </execution>
                        </executions>
                    </plugin>
                    <plugin>
                        <groupId>org.springframework.boot</groupId>
                        <artifactId>spring-boot-maven-plugin</artifactId>
                    </plugin>
                </plugins>
            </build>
        </profile>
    </profiles>

</project>

<dependency>
    <groupId>org.springframework.experimental</groupId>
    <artifactId>spring-graal-native</artifactId>
    <version>0.6.0.RELEASE</version>
</dependency>

• सामान्य तरीके से जावा एप्लिकेशन को संकलित करें
• जानकारी एकत्र करने के लिए जावा एजेंट के साथ जावा एप्लिकेशन लॉन्च करें। इस स्तर पर, हमें यह सुनिश्चित करने की आवश्यकता है कि एप्लिकेशन काम कर रहा है। आपको सभी संभव उपयोग मामलों से गुजरने की आवश्यकता है। वैसे, CI और परीक्षणों का उपयोग करने के लिए यह एक बहुत अच्छा मामला है! हर कोई लगातार एप्लिकेशन के परीक्षण और प्रदर्शन में सुधार के बारे में बात कर रहा है। अब, GraalVM के साथ, आप दोनों कर सकते हैं!
• फिर एप्लिकेशन को फिर से बनाएं, इस बार सक्रिय ग्रेफ प्रोफाइल के साथ, मूल एप्लिकेशन में संकलन करने के लिए, पहली शुरुआत में एकत्रित जानकारी का उपयोग करके।

mvn -DskipTests=true clean package
export MI=src/main/resources/META-INF
mkdir -p $MI 
java -agentlib:native-image-agent=config-output-dir=${MI}/native-image -jar target/reactive.jar

## it's at this point that you need to exercise the application: http://localhost:8080/reservations 
## then hit CTRL + C to stop the running application.

tree $MI
mvn -Pgraal clean package

./target/com.example.reactive.reactiveapplication

2020-04-15 23:25:08.826  INFO 7692 --- [           main] c.example.reactive.ReactiveApplication   : Started ReactiveApplication in 0.099 seconds (JVM running for 0.103)