Java -jar命令如何运行外部依赖JAR包

java -jar main-app.jar

Main-Class: com.example.MainApp
Class-Path: lib/dependency1.jar lib/dependency2.jar

java -jar main-app.jar

public class JarLoader {
    public static void main(String[] args) throws Exception {
        URLClassLoader classLoader = new URLClassLoader(
            new URL[]{
                new File("plugins/payment-plugin.jar").toURI().toURL()
            },
            MainApp.class.getClassLoader()
        );
        
        Class<?> pluginClass = classLoader.loadClass("com.plugin.PaymentService");
        Plugin plugin = (Plugin) pluginClass.getDeclaredConstructor().newInstance();
        plugin.execute();
    }
}

java -cp "main-app.jar:libs/*" com.example.MainApp

@echo off
java -cp "main-app.jar;libs\*" com.example.MainApp

<build>
    <plugins>
        <plugin>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-maven-plugin</artifactId>
            <configuration>
                <layout>ZIP</layout> <!-- 使用PropertiesLauncher -->
                <mainClass>com.example.MainApp</mainClass>
            </configuration>
        </plugin>
    </plugins>
</build>

java -Dloader.path=external_libs/ -jar main-app.jar

module com.mainapp {
    requires com.external.module;
}

java --module-path "main-app.jar:external-modules/" \
     --module com.mainapp/com.example.MainApp

# 查看加载的类路径
java -verbose:class -cp "main-app.jar:libs/*" com.example.MainApp | grep "Loaded"

WatchService watcher = FileSystems.getDefault().newWatchService();
Paths.get("plugins/").register(watcher, ENTRY_CREATE, ENTRY_DELETE);

while (true) {
    WatchKey key = watcher.take();
    for (WatchEvent<?> event : key.pollEvents()) {
        reloadPlugin(event.context().toString()); // 重新加载插件
    }
    key.reset();
}

// 创建隔离的类加载器
URLClassLoader pluginLoader = new URLClassLoader(
    urls, 
    ClassLoader.getSystemClassLoader().getParent()  // 父级为扩展类加载器
);

# 检查JAR冲突
jdeps --multi-release base -R -cp "libs/*" main-app.jar

#!/bin/bash
APP_HOME=$(dirname "$0")
java -cp "$APP_HOME/app.jar:$APP_HOME/libs/*:$APP_HOME/plugins/*" \
     -Dlog4j.configurationFile=$APP_HOME/config/log4j2.xml \
     com.example.MainApp

FROM openjdk:17
COPY app.jar /app/
COPY libs/* /app/libs/
COPY plugins/* /app/plugins/
CMD ["java", "-cp", "app.jar:libs/*:plugins/*", "com.example.MainApp"]

# 版本校验示例
EXPECTED_LIBC_VERSION="3.2.1"
ACTUAL_VERSION=$(unzip -p libs/commons-lang3.jar META-INF/MANIFEST.MF | grep "Implementation-Version")
if [[ "$ACTUAL_VERSION" != *"$EXPECTED_LIBC_VERSION"* ]]; then
  echo "CRITICAL: Commons Lang version mismatch!"
  exit 1
fi