com.github.life.lab.leisure.common.utils.reflect.DynamicClassLoader Maven / Gradle / Ivy

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package com.github.life.lab.leisure.common.utils.reflect;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.URL;
import java.net.URLConnection;

public class DynamicClassLoader extends ClassLoader {
    private static final Log LOGGER = LogFactory.getLog(DynamicClassLoader.class);

    public DynamicClassLoader(ClassLoader parent) {
        super(parent);
    }

    public Class loadClass(String classPath, String className) throws ClassNotFoundException {
        try {
            String url = classPathParser(classPath) + classNameParser(className);
            LOGGER.debug(url);
            URL myUrl = new URL(url);
            URLConnection connection = myUrl.openConnection();
            InputStream input = connection.getInputStream();
            ByteArrayOutputStream buffer = new ByteArrayOutputStream();
            int data = input.read();
            while (data != -1) {
                buffer.write(data);
                data = input.read();
            }
            input.close();
            byte[] classData = buffer.toByteArray();
            return defineClass(noSuffix(className), classData, 0, classData.length);
        } catch (IOException e) {
            LOGGER.error(e.getMessage(), e);
        }
        return null;
    }

    public Class loadClass(byte[] classData, String className) throws ClassNotFoundException {
        return defineClass(noSuffix(className), classData, 0, classData.length);
    }

    private String pathParser(String path) {
        return path.replaceAll("\\\\", "/");
    }

    private String classPathParser(String path) {
        String classPath = pathParser(path);
        if (!classPath.startsWith("file:")) {
            classPath = "file:" + classPath;
        }
        if (!classPath.endsWith("/")) {
            classPath = classPath + "/";
        }
        return classPath;
    }

    private String classNameParser(String className) {
        return className.replaceAll("\\.", "/") + ".class";
    }

    private String noSuffix(String className) {
        return className.endsWith(".class") ? className.substring(0, className.lastIndexOf(".")) : className;
    }
}