自定义类加器——加载指定目录下的jar包

import sun.net.www.ParseUtil;

import java.io.File;
import java.io.IOException;
import java.net.URL;
import java.net.URLClassLoader;
import java.util.Arrays;
import java.util.stream.Collectors;


public class RbcClassLoader extends URLClassLoader {
    private RbcClassLoader(URL[] urls) {
        super(urls);
    }

    /**
     * 
     * @param classPath jar文件所在路径
     * @return 自定义的类加载器
     * @throws IOException
     */
    public static ClassLoader getRbcClassLoader(String classPath) throws IOException {
        File file = new File(classPath);
        
        if (!file.exists() || !file.isDirectory()) {
            throw new IOException("Please check if your path is correct!");
        }

        //获取所有的该目录下所有的jar文件
        File[] jars = Arrays.stream(file.listFiles())
                .filter((filePointer) -> filePointer.getName().endsWith(".jar"))
                .collect(Collectors.toList()).toArray(new File[0]);
        
        URL[] urls = new URL[jars.length];
        
        //将其所有的路径转换为URL
        for (int i = 0; i < urls.length; i++) {
            File var0 = jars[i].getCanonicalFile();
            urls[i] = ParseUtil.fileToEncodedURL(var0);
        }

        return new RbcClassLoader(urls);
    }

}