org.openxma.dsl.common.jdt.ChildFirstUrlClassloader Maven / Gradle / Ivy

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package org.openxma.dsl.common.jdt;

import java.net.URL;
import java.net.URLClassLoader;

public class ChildFirstUrlClassloader extends URLClassLoader {
    private final String[] childFirstClassName;
    private final String[] childFirstResourceName;
    private final String[] childFirstResourceSuffix;
    private final ClassLoader parent;

    public ChildFirstUrlClassloader(URL[] urls, ClassLoader parent, String[] childFirstClassName,
            String[] childFirstResourceName, String[] childFirstResourceSuffix) {
        super(urls, parent);
        this.parent = parent;
        this.childFirstClassName = childFirstClassName;
        this.childFirstResourceName = childFirstResourceName;
        this.childFirstResourceSuffix = childFirstResourceSuffix;
    }

    protected Class loadClass(String name, boolean resolve) throws ClassNotFoundException {
        Class clazz = findLoadedClass(name);
        if (clazz != null) {
            return clazz;
        }
        boolean childFirst = isChildFirstClass(name);
        ClassNotFoundException cnfe = null;
        if (childFirst) {
            try {
                clazz = findClass(name);
            } catch (ClassNotFoundException e) {
                // continue
                cnfe = e;
            }
        }
        if (clazz == null) {
            try {
                clazz = parent.loadClass(name);
            } catch (ClassNotFoundException e) {
                // continue
            }
        }

        if (clazz == null && cnfe != null) {
            throw cnfe;
        }
        if (clazz == null && !childFirst) {
            clazz = findClass(name);
        }
        if (resolve) {
            resolveClass(clazz);
        }
        return clazz;
    }

    public URL getResource(String name) {
        URL url = null;
        boolean childFirst = isChildFirstResource(name);
        if (childFirst) {
            url = findResource(name);
        }
        if (url == null) {
            url = super.getResource(name);
        }
        return url;
    }

    private boolean isChildFirstClass(String name) {
        for (int i = childFirstClassName.length - 1; i >= 0; i--) {
            if (name.startsWith(childFirstClassName[i])) {
                return true;
            }
        }
        return false;
    }

    private boolean isChildFirstResource(String name) {
        for (int i = childFirstResourceName.length - 1; i >= 0; i--) {
            if (name.startsWith(childFirstResourceName[i])) {
                return true;
            }
        }
        for (int i = childFirstResourceSuffix.length - 1; i >= 0; i--) {
            if (name.endsWith(childFirstResourceSuffix[i])) {
                return true;
            }
        }
        return false;
    }
}