FromMemoryClassLoader.java

package run.myCode.compiler;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

public class FromMemoryClassLoader extends ClassLoader {

    private static final boolean DEBUG = Boolean.getBoolean("run.mycode.debug");

    private final Map<String, MemoryByteCode> m = new HashMap<>();
    private final ClassLoader parent;

    public FromMemoryClassLoader(ClassLoader parent) {
        this.parent = parent;
        // System.err.println("new loader");
    }

    @Override
    public Class<?> findClass(String name) throws ClassNotFoundException {
        try {
            // System.out.println("Class search:" + name);
            MemoryByteCode mbc = m.get(name);
            if (mbc == null) {
                mbc = m.get(name.replace(".", "/"));
                if (mbc == null) {
                    return super.findClass(name);
                }
            }
            if (DEBUG) {
                System.out.println("Loading in-memory class " + name);
            }
            return defineClass(name, mbc.getBytes(), 0, mbc.getBytes().length);
        } catch (ClassNotFoundException e) {
            // System.err.println("Could not find: " + name);
            if (this.parent != null) {
                try {
                    return parent.loadClass(name);
                } catch (ClassNotFoundException e1) {
                    // System.err.println("Really couldn't find " + name);
                    throw e1;
                }
            }
            else {
                throw e;
            }
        }
    }

    public void addClass(String name, MemoryByteCode mbc) {
        // System.err.println("Added class: " + name);
        // System.out.println("Added class:" + name);
        m.put(name, mbc);
        if (DEBUG) {
            System.out.println("Added in-memory class " + name);
        }
    }
    
    public List<String> getClassNames() {
        return new ArrayList(m.keySet());
    }
}