java 动态加载jar包

目的：
动态加载jar包，实现插件的机制。

示例：

package com.alvin;
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;
import java.net.URL;
import java.net.URLClassLoader;
@SpringBootApplication
@RestController
public class MainApplication {
    public static void main(String[] args) {
        SpringApplication.run(MainApplication.class, args);
    }
    @GetMapping("/")
    public Boolean test(String query) throws Exception {
        String jarPath = "D:\\code\\java-plugin\\plugin1\\target\\plugin1-1.0-SNAPSHOT.jar";
        String className = "com.alvin.service.impl.Plugin1";
        String methodName = "isTrue";
        return (Boolean) exec(jarPath, className, methodName, query);
    }
    public static Object exec(String jarPath, String className, String methodName, String query) throws Exception {
        URLClassLoader classLoader = new URLClassLoader(new URL[]{new URL("file:" + jarPath)}, Thread.currentThread().getContextClassLoader());
        Class demo = classLoader.loadClass(className);
        Object object = demo.newInstance();
        Object invoke = demo.getMethod(methodName, String.class).invoke(object, new Object[]{query});
        return invoke;
    }
}