package modules;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.security.SecureClassLoader;
import java.util.ArrayList;
import java.util.jar.JarFile;
import java.util.zip.ZipEntry;
import java.util.zip.ZipFile;
public class MyClassLoader extends SecureClassLoader {
private ArrayList<File> path = new ArrayList<File>();
public MyClassLoader(File classPath) {
super();
addPath(classPath);
}
public void addPath(File classPath) {
if (!classPath.exists())
throw new IllegalArgumentException(classPath+" does not exist!");
this.path.add(classPath);
}
@Override
protected Class<?> findClass(String name) throws ClassNotFoundException {
byte[] b = loadClassData(name);
return super.defineClass(name, b, 0, b.length);
}
private byte[] loadClassData(String name) throws ClassNotFoundException {
for(File dir : path) {
byte[] b = loadClassData(dir, name);
if (b != null) return b;
}
throw new ClassNotFoundException(name);
}
private byte[] loadClassData(File base, String name) {
System.out.println("load "+name+" in "+base);
name = name.replace('.', File.separatorChar)+".class";
try {
InputStream is = getFile(base, name);
if (is==null) return null;
byte[] buf = new byte[is.available()];
is.read(buf);
return buf;
} catch (IOException e) {
e.printStackTrace();
throw new ExceptionInInitializerError("Error loading "+name+":"+e.getMessage());
}
}
private InputStream getFile(File base, String name) throws IOException {
if (base.isDirectory()) {
File f = new File(base, name);
if (f.exists())
return new FileInputStream(f);
else return null;
}
else {
ZipFile zipFile = null;
if (base.getName().endsWith(".jar"))
zipFile = new JarFile(base);
else if (base.getName().endsWith(".zip"))
zipFile = new ZipFile(base);
else return null;
ZipEntry entry = zipFile.getEntry(name);
if (entry == null) return null;
return zipFile.getInputStream(entry);
}
}
}