Spring Boot项目启动时输出PID、CPU和内存信息的4种方法示例总结

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import javax.annotation.PostConstruct;
import java.lang.management.ManagementFactory;
import java.lang.management.RuntimeMXBean;
@SpringBootApplication
public class YourApplication {
	public static void main(String[] args) {
		SpringApplication.run(YourApplication.class, args);
	}
	@PostConstruct
	public void printSystemInfo() {
		// 获取PID
		RuntimeMXBean runtimeBean = ManagementFactory.getRuntimeMXBean();
		String jvmName = runtimeBean.getName();
		long pid = Long.parseLong(jvmName.split("@")[0]);
		// 内存信息
		Runtime runtime = Runtime.getRuntime();
		long maxMemory = runtime.maxMemory();
		long allocatedMemory = runtime.totalMemory();
		long freeMemory = runtime.freeMemory();
		// 输出信息
		System.out.println("\n==========================================");
		System.out.println(" Application System Information");
		System.out.println("==========================================");
		System.out.println(" PID: " + pid);
		System.out.println(" CPU Cores: " + runtime.availableProcessors());
		System.out.println(" Memory Info:");
		System.out.println(" - Max: " + maxMemory / 1024 / 1024 + " MB");
		System.out.println(" - Allocated: " + allocatedMemory / 1024 / 1024 + " MB");
		System.out.println(" - Free: " + freeMemory / 1024 / 1024 + " MB");
		System.out.println(" - Used: " + (allocatedMemory - freeMemory) / 1024 / 1024 + " MB");
		System.out.println("==========================================\n");
	}
}

<configuration>
    <!-- 1. 从Spring环境变量中获取应用名称 -->
    <springProperty name="app.name" source="spring.application.name" defaultValue="spring-boot-app"/>
    <!-- 2. 定义控制台日志输出格式 -->
    <appender name="STDOUT" class="ch.qos.logback.core.ConsoleAppender">
        <encoder>
            <!-- 日志格式：时间 + 线程 + 日志级别 + 类名 + 消息 -->
            <pattern>%d{yyyy-MM-dd HH:mm:ss} [%thread] %-5level %logger{36} - %msg%n</pattern>
        </encoder>
    </appender>
    <!-- 3. 设置根日志级别和输出目标 -->
    <root level="INFO">
        <appender-ref ref="STDOUT"/>
    </root>
    <!-- 4. 定义SystemInfoLogger Bean并指定初始化方法 -->
    <bean id="systemInfoLogger" class="com.your.package.SystemInfoLogger" init-method="logSystemInfo"/>
</configuration>

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.stereotype.Component;
import java.lang.management.ManagementFactory;
import java.lang.management.RuntimeMXBean;
@Component
public class SystemInfoLogger {
    // 1. 通过SLF4J获取Logger实例
    private static final Logger logger = LoggerFactory.getLogger(SystemInfoLogger.class);
    // 2. Bean初始化后调用的方法
    public void logSystemInfo() {
        // 3. 获取PID（通过RuntimeMXBean）
        RuntimeMXBean runtimeBean = ManagementFactory.getRuntimeMXBean();
        long pid = Long.parseLong(runtimeBean.getName().split("@")[0]);
        // 4. 获取内存信息（通过Runtime）
        Runtime runtime = Runtime.getRuntime();
        long usedMemory = (runtime.totalMemory() - runtime.freeMemory()) / 1024 / 1024;
        // 5. 格式化输出到日志（使用占位符{}避免字符串拼接）
        logger.info("\n" +
                        "=========================================\n" +
                        " Application: {}\n" +
                        " PID: {}\n" +
                        " CPU Cores: {}\n" +
                        " Memory:\n" +
                        "  - Max: {} MB\n" +
                        "  - Total: {} MB\n" +
                        "  - Free: {} MB\n" +
                        "  - Used: {} MB\n" +
                        "=========================================",
                System.getProperty("spring.application.name", "Spring Boot Application"),
                pid,
                runtime.availableProcessors(),
                runtime.maxMemory() / 1024 / 1024,
                runtime.totalMemory() / 1024 / 1024,
                runtime.freeMemory() / 1024 / 1024,
                usedMemory
        );
    }
}

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.context.ApplicationListener;
import org.springframework.context.event.ContextRefreshedEvent;
import org.springframework.stereotype.Component;
import java.lang.management.ManagementFactory;
import java.lang.management.RuntimeMXBean;
@Component
public class SystemInfoPrinter implements ApplicationListener<ContextRefreshedEvent> {
    // 通过SLF4J获取Logger实例，用于记录日志信息
    private static final Logger logger = LoggerFactory.getLogger(SystemInfoPrinter.class);
    @Override
    public void onApplicationEvent(ContextRefreshedEvent event) {
        RuntimeMXBean runtimeBean = ManagementFactory.getRuntimeMXBean();
        // 获取PID（通过RuntimeMXBean）
        long pid = Long.parseLong(runtimeBean.getName().split("@")[0]);
        Runtime runtime = Runtime.getRuntime();
        // 格式化输出到日志（使用占位符{}避免字符串拼接）
        logger.info("\n" +
                        "=========================================\n" +
                        " Application: {}\n" +
                        " PID: {}\n" +
                        " CPU Cores: {}\n" +
                        " Memory:\n" +
                        "  - Max: {} MB\n" +
                        "  - Total: {} MB\n" +
                        "  - Free: {} MB\n" +
                        "  - Used: {} MB\n" +
                        "=========================================",
                System.getProperty("spring.application.name", "Spring Boot Application"),
                pid,
                runtime.availableProcessors(),
                runtime.maxMemory() / 1024 / 1024,
                runtime.totalMemory() / 1024 / 1024,
                runtime.freeMemory() / 1024 / 1024,
                (runtime.totalMemory() - runtime.freeMemory()) / 1024 / 1024
        );
    }
}

Spring启动流程：
1. 创建Bean实例
	└─ 方案二@PostConstruct执行 ← 此时部分依赖可能未就绪
2. 依赖注入
3. 初始化回调
4. 发布ContextRefreshedEvent
	└─ 方案一ApplicationListener执行 ← 此时所有Bean已就绪

<dependency>
	<groupId>com.github.oshi</groupId>
	<artifactId>oshi-core</artifactId>
	<version>6.4.0</version>
</dependency>

import oshi.SystemInfo;
import oshi.hardware.CentralProcessor;
import oshi.hardware.HardwareAbstractionLayer;
public void printDetailedSystemInfo() {
	SystemInfo si = new SystemInfo();
	HardwareAbstractionLayer hal = si.getHardware();
	CentralProcessor processor = hal.getProcessor();
	System.out.println("CPU: " + processor.getProcessorIdentifier().getName());
	System.out.println("Physical CPUs: " + processor.getPhysicalProcessorCount());
	System.out.println("Logical CPUs: " + processor.getLogicalProcessorCount());
	System.out.println("CPU Load: " + hal.getProcessor().getSystemLoadAverage());
}

==========================================
Application System Information
==========================================
PID: 12345
CPU Cores: 8
Memory Info:
- Max: 4096 MB
- Allocated: 1024 MB
- Free: 756 MB
- Used: 268 MB
==========================================