Spring Boot优化后启动速度快到飞起技巧示例

spring.main.lazy-initialization=true

<dependency>
  <groupId>org.springframework</groupId>
  <artifactId>spring-context-indexer</artifactId>
  <optional>true</optional>
</dependency>

spring.jmx.enabled=false

-XX:TieredStopAtLevel=1 -noverify

A.jar
com/A
B.jar
com/B
C.jar
com/C

com/A --> A.jar
com/B --> B.jar
com/C --> C.jar

java -XX:DumpLoadedClassList=test.lst

java -Xshare:dump -XX:SharedClassListFile=test.lst -XX:SharedArchiveFile=test.jsa

-Xshare:on -XX:SharedArchiveFile=test.jsa

<build>
  <finalName>helloworld</finalName>
  <plugins>
    <plugin>
      <groupId>org.apache.maven.plugins</groupId>
      <artifactId>maven-shade-plugin</artifactId>
      <configuration>
        <keepDependenciesWithProvidedScope>true</keepDependenciesWithProvidedScope>
        <createDependencyReducedPom>false</createDependencyReducedPom>
        <filters>
          <filter>
            <artifact>*:*</artifact>
            <excludes>
              <exclude>META-INF/*.SF</exclude>
              <exclude>META-INF/*.DSA</exclude>
              <exclude>META-INF/*.RSA</exclude>
            </excludes>
          </filter>
        </filters>
      </configuration>
      <executions>
        <execution>
          <phase>package</phase>
          <goals><goal>shade</goal></goals>
          <configuration>
            <transformers>
              <transformer implementation="org.apache.maven.plugins.shade.resource.AppendingTransformer">
                <resource>META-INF/spring.handlers</resource>
              </transformer>
              <transformer implementation="org.springframework.boot.maven.PropertiesMergingResourceTransformer">
                <resource>META-INF/spring.factories</resource>
              </transformer>
              <transformer implementation="org.apache.maven.plugins.shade.resource.AppendingTransformer">
                <resource>META-INF/spring.schemas</resource>
              </transformer>
              <transformer implementation="org.apache.maven.plugins.shade.resource.ServicesResourceTransformer" />
              <transformer implementation="org.apache.maven.plugins.shade.resource.ManifestResourceTransformer">
                <mainClass>${mainClass}</mainClass>
              </transformer>
            </transformers>
          </configuration>
        </execution>
      </executions>
    </plugin>
  </plugins>
</build>

public int getNumberOfRecords() {
  long numberOfRecords = Bytes.littleEndianValue(this.block, this.offset + 10, 2);
  if (numberOfRecords == 0xFFFF) {
    throw new IllegalStateException("Zip64 archives are not supported");
}

java -XX:+UnlockExperimentalVMOptions -XX:AOTLibrary=

server:
  shutdown: graceful
# 最大等待时间
spring:
  lifecycle:
    timeout-per-shutdown-phase: 30s

@SpringBootApplication
@RestController
public class Gh4657Application {
    public static void main(String[] args) {
        SpringApplication.run(Gh4657Application.class, args);
    }
    @RequestMapping("/pause")
    public String pause() throws InterruptedException {
        Thread.sleep(10000);
        return "Pause complete";
    }
    @Bean
    public GracefulShutdown gracefulShutdown() {
        return new GracefulShutdown();
    }
    @Bean
    public EmbeddedServletContainerCustomizer tomcatCustomizer() {
        return new EmbeddedServletContainerCustomizer() {
            @Override
            public void customize(ConfigurableEmbeddedServletContainer container) {
                if (container instanceof TomcatEmbeddedServletContainerFactory) {
                    ((TomcatEmbeddedServletContainerFactory) container)
                            .addConnectorCustomizers(gracefulShutdown());
                }
            }
        };
    }
    private static class GracefulShutdown implements TomcatConnectorCustomizer,
            ApplicationListener<ContextClosedEvent> {
        private static final Logger log = LoggerFactory.getLogger(GracefulShutdown.class);
        private volatile Connector connector;
        @Override
        public void customize(Connector connector) {
            this.connector = connector;
        }
        @Override
        public void onApplicationEvent(ContextClosedEvent event) {
            this.connector.pause();
            Executor executor = this.connector.getProtocolHandler().getExecutor();
            if (executor instanceof ThreadPoolExecutor) {
                try {
                    ThreadPoolExecutor threadPoolExecutor = (ThreadPoolExecutor) executor;
                    threadPoolExecutor.shutdown();
                    if (!threadPoolExecutor.awaitTermination(30, TimeUnit.SECONDS)) {
                        log.warn("Tomcat thread pool did not shut down gracefully within "
                                + "30 seconds. Proceeding with forceful shutdown");
                    }
                }
                catch (InterruptedException ex) {
                    Thread.currentThread().interrupt();
                }
            }
        }
    }
}