nohup command [arguments] &

// Application.java
package com.example.demo;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;

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

@RestController
class HelloController {
    @GetMapping("/hello")
    public String hello() {
        return "Hello from Spring Boot! Process ID: " + 
               java.lang.management.ManagementFactory.getRuntimeMXBean().getName().split("@")[0];
    }
}

<dependencies>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-web</artifactId>
        <version>3.2.0</version>
    </dependency>
</dependencies>

// SimpleHttpServer.java
import com.sun.net.httpserver.HttpServer;
import com.sun.net.httpserver.HttpHandler;
import com.sun.net.httpserver.HttpExchange;
import java.io.IOException;
import java.io.OutputStream;
import java.net.InetSocketAddress;

public class SimpleHttpServer {
    public static void main(String[] args) throws IOException {
        int port = 8080;
        HttpServer server = HttpServer.create(new InetSocketAddress(port), 0);
        server.createContext("/hello", new HelloHandler());
        server.setExecutor(null); // 使用默認線程池
        server.start();
        System.out.println("Server started on port " + port);
    }

    static class HelloHandler implements HttpHandler {
        public void handle(HttpExchange exchange) throws IOException {
            String response = "Hello from Pure Java! PID: " + 
                java.lang.management.ManagementFactory.getRuntimeMXBean().getName().split("@")[0];
            exchange.sendResponseHeaders(200, response.length());
            OutputStream os = exchange.getResponseBody();
            os.write(response.getBytes());
            os.close();
        }
    }
}

javac SimpleHttpServer.java
jar cfe simple-server.jar SimpleHttpServer SimpleHttpServer.class

cd /opt/myapp
nohup java -jar app.jar > app.log 2>&1 &

# 方法1：通過端口查找
lsof -i :8080

# 方法2：通過進程名查找
ps aux | grep java

# 方法3：查看后臺作業(yè)（僅限當前 shell 會話）
jobs -l

kill <PID>
# 或強制終止
kill -9 <PID>

tail -f app.log

# /etc/systemd/system/myapp.service
[Unit]
Description=My Java Application
After=network.target

[Service]
Type=simple
User=myuser
Group=mygroup
WorkingDirectory=/opt/myapp
ExecStart=/usr/bin/java -jar /opt/myapp/app.jar
Restart=always
RestartSec=10
StandardOutput=journal
StandardError=journal
SyslogIdentifier=myapp

[Install]
WantedBy=multi-user.target

sudo useradd -r -s /bin/false myuser
sudo chown -R myuser:myuser /opt/myapp

# 重新加載 systemd 配置
sudo systemctl daemon-reload

# 啟用開機自啟
sudo systemctl enable myapp.service

# 啟動服務
sudo systemctl start myapp.service

# 查看狀態(tài)
sudo systemctl status myapp.service

# 查看實時日志
sudo journalctl -u myapp.service -f

# 查看最近 100 行
sudo journalctl -u myapp.service -n 100

# 按時間過濾（今天）
sudo journalctl -u myapp.service --since today

ExecStart=/usr/bin/java \
  -Xms512m \
  -Xmx1g \
  -Dspring.profiles.active=prod \
  -jar /opt/myapp/app.jar

JAVA_OPTS=-Xms512m -Xmx1g -XX:+UseG1GC
SPRING_PROFILES_ACTIVE=prod
LOG_LEVEL=INFO

[Service]
EnvironmentFile=/etc/myapp/config
ExecStart=/usr/bin/java $JAVA_OPTS -Dspring.profiles.active=${SPRING_PROFILES_ACTIVE} -jar /opt/myapp/app.jar

# application.yml
server:
  shutdown: graceful

spring:
  lifecycle:
    timeout-per-shutdown-phase: 30s

Runtime.getRuntime().addShutdownHook(new Thread(() -> {
    System.out.println("Shutting down gracefully...");
    // 執(zhí)行清理邏輯
}));

[Service]
TimeoutStopSec=60

[Service]
CPUQuota=50%      # 最多使用 50% 的 CPU
MemoryMax=1G      # 最大內(nèi)存 1GB

# 查找 PID
ps aux | grep java
# 假設 PID 是 12345
kill 12345

sudo useradd -r -s /bin/false myappuser
sudo chown -R myappuser:myappuser /opt/myapp

# /etc/systemd/system/myapp.service
[Unit]
Description=My Production Java App
After=network.target

[Service]
Type=simple
User=myappuser
WorkingDirectory=/opt/myapp
ExecStart=/usr/bin/java -Xmx1g -jar /opt/myapp/app.jar
Restart=on-failure
RestartSec=5
StandardOutput=journal
StandardError=journal
SyslogIdentifier=myapp

[Install]
WantedBy=multi-user.target

sudo systemctl daemon-reload
sudo systemctl enable myapp
sudo systemctl start myapp

sudo systemctl status myapp
sudo journalctl -u myapp -f
curl http://localhost:8080/hello

sudo systemctl status myapp    # 查看狀態(tài)和最近日志
sudo journalctl -u myapp --since "5 minutes ago"  # 查看近期日志

/opt/myapp/app.log {
    daily
    rotate 7
    compress
    missingok
    notifempty
    copytruncate
}

# /etc/systemd/journald.conf
SystemMaxUse=500M

sudo systemctl restart systemd-journald

Environment="JAVA_OPTS=-Xms512m -Xmx2g -XX:+UseG1GC -Dfile.encoding=UTF-8"
ExecStart=/usr/bin/java $JAVA_OPTS -jar /opt/myapp/app.jar

[Service]
TimeoutStartSec=300