运行中的jvm动态添加java类，让应用无限扩展

java程序启动后，在不终止进程的情况下，如何向jvm内动态的添加java类呢？办法如下：

1、增加如下依赖

<!-- 动态编译 -->
<dependency>
    <groupId>org.noear</groupId>
    <artifactId>liquor-eval</artifactId> <!-- or liquor -->
    <version>1.6.5</version>
</dependency>
<dependency>
    <groupId>org.noear</groupId>
    <artifactId>solon</artifactId>
    <version>3.3.3</version>
</dependency>

2、写个测试

import java.lang.annotation.Annotation;
import java.lang.reflect.Method;

import org.junit.jupiter.api.Test;
import org.noear.liquor.DynamicCompiler;
import org.noear.solon.core.util.ResourceUtil;
//import org.springframework.boot.test.context.SpringBootTest;

//@SpringBootTest
public class CompilerTest {

	@Test
	public void test() throws Exception {
		CompilerTest.compilerString();
		CompilerTest.compilerFile();
	}

	public static void compilerString() throws Exception {
		String className = "HelloWorld";
		String classCode = "public class HelloWorld { " + "   public static void helloWorld() { "
				+ "       System.out.println(\"Hello, world!\"); " + "   } " + "}";

		DynamicCompiler compiler = new DynamicCompiler();
		// 添加源码（可多个）并构建
		compiler.addSource(className, classCode).build();

		Class<?> clazz = compiler.getClassLoader().loadClass(className);
		clazz.getMethod("helloWorld").invoke(null);
		
		classCode = "public class HelloWorld { " + "   public static void helloWorld() { "
				+ "       System.out.println(\"Hello, world 哈哈哈!\"); " + "   } " + "}";
		compiler = new DynamicCompiler();
		// 添加源码（可多个）并构建
		compiler.addSource(className, classCode).build();
		clazz = compiler.getClassLoader().loadClass(className);
		clazz.getMethod("helloWorld").invoke(null);
	}

	public static void compilerFile() throws Exception {
		String className = "com.prostiger.agents.GroovyAgent";
		String classCode = ResourceUtil.getResourceAsString("GroovyAgent.txt", null);

		System.out.println(classCode);
		DynamicCompiler compiler = new DynamicCompiler();
		compiler.addSource(className, classCode).build();

		Class<?> clazz = compiler.getClassLoader().loadClass(className);
		System.out.println(clazz);
		
		for(Method m : clazz.getMethods()) {
			for(Annotation a : m.getAnnotations()) {
				System.out.println("方法注解:" + a.annotationType().getName());
			}
			for(java.lang.reflect.Parameter p : m.getParameters()) {
				for(Annotation a : p.getDeclaredAnnotations()) {
					System.out.println("参数注解:" + a.annotationType().getName());
				}
			}
		}
	}

}

参考：

http://solon.noear.org/article/liquor

https://gitee.com/noear/liquor