DuplicateChecker.java

package org.squirrelframework.foundation.util;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.net.URL;
import java.util.Enumeration;
import java.util.HashSet;
import java.util.Set;

public class DuplicateChecker {

    private static final Logger logger = LoggerFactory.getLogger(DuplicateChecker.class);

    private DuplicateChecker() {}

    public static void checkDuplicate(Class<?> cls) {
        checkDuplicate(cls.getName().replace('.', '/') + ".class");
    }

    public static void checkDuplicate(String path) {
        try {
            // Search file within classpath
            Enumeration<URL> urls = Thread.currentThread().getContextClassLoader().getResources(path);
            Set<String> files = new HashSet<String>();
            while (urls.hasMoreElements()) {
                URL url = urls.nextElement();
                if (url != null) {
                    String file = url.getFile();
                    if (file != null && file.length() > 0) {
                        files.add(file);
                    }
                }
            }
            // If there are multiple files, it means duplicate jar placed in the classpath
            if (files.size() > 1) {
                logger.error("Duplicate class " + path + " in " + files.size() + " jar " + files);
            }
        } catch (Throwable e) {
            logger.error(e.getMessage(), e);
        }
    }
}