@Slf4j
public class URLClassLoaderTest {
private static final String remoteJarPath = "http://localhost:8080/operators/base-operator.jar";
@Test
public void testLoadRemoteJar() throws Exception {
URI uri = new URI(remoteJarPath);
URLClassLoader classLoader = new URLClassLoader(new URL[]{uri.toURL()});
Thread.currentThread().setContextClassLoader(classLoader);
ServiceLoader<Operator> loader = ServiceLoader.load(Operator.class);
Iterator<Operator> iterator = loader.iterator();
while (iterator.hasNext()) {
try {
Operator operator = iterator.next();
log.info("OperatorInfo: name={}, platform={}", operator.getName(), operator.getPlatform());
} catch (Exception e) {
log.warn("Failed to instantiate operator", e);
}
}
}
}以代码为例说明：
- 采用URLClassLoader的方式来加载jar包
- 在此基础上，加入SerivceLoader来加载类Operator的class
关于URLClassLoader部分
package com.jcg;
/**
* @author ashraf
*
*/
public class Bean {
public void sayHello() {
System.out.println("Hello from loaded Bean class !!!");
}
}
package com.jcg;
import java.lang.reflect.Constructor;
import java.lang.reflect.Method;
import java.net.URL;
import java.net.URLClassLoader;
/**
* @author ashraf
*
*/
public class URLClassLoaderTest {
/**
* @param args
* @throws Exception
*/
public static void main(String[] args) throws Exception {
// Getting the jar URL which contains target class
URL[] classLoaderUrls = new URL[]{new URL("file:///home/ashraf/Desktop/simple-bean-1.0.jar")};
// Create a new URLClassLoader
URLClassLoader urlClassLoader = new URLClassLoader(classLoaderUrls);
// Load the target class
Class<?> beanClass = urlClassLoader.loadClass("com.jcg.Bean");
// Create a new instance from the loaded class
Constructor<?> constructor = beanClass.getConstructor();
Object beanObj = constructor.newInstance();
// Getting a method from the loaded class and invoke it
Method method = beanClass.getMethod("sayHello");
method.invoke(beanObj);
}
}见上面的例子，利用反射的方式？