package com.github.eulerlcs.jmr.challenge.classloader.core;
import java.io.ByteArrayOutputStream;
import java.io.InputStream;
import java.net.URL;
public class NetworkClassLoader extends ClassLoader {
private String rootUrl;
public NetworkClassLoader(String rootUrl) {
this.rootUrl = rootUrl;
}
protected Class<?> findClass(String name) throws ClassNotFoundException {
byte[] classData = getClassData(name);
if (classData == null) {
throw new ClassNotFoundException();
} else {
return defineClass(name, classData, 0, classData.length);
}
}
private byte[] getClassData(String className) {
String path = classNameToPath(className);
try {
URL url = new URL(path);
InputStream ins = url.openStream();
ByteArrayOutputStream baos = new ByteArrayOutputStream();
int bufferSize = 4096;
byte[] buffer = new byte[bufferSize];
int bytesNumRead = 0;
while ((bytesNumRead = ins.read(buffer)) != -1) {
baos.write(buffer, 0, bytesNumRead);
}
return baos.toByteArray();
} catch (Exception e) {
e.printStackTrace();
}
return null;
}
private String classNameToPath(String className) {
return rootUrl + "/" + className.replace('.', '/') + ".class";
}
}