webcam-capture-driver-native/src/main/java/capturemanager/classes/CustomClassLoader.java

75 lines
1.9 KiB
Java

package capturemanager.classes;
import java.io.BufferedInputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.util.HashMap;
import java.util.Map;
/**
*
* Simple custom class loader implementation
*
*/
public class CustomClassLoader extends ClassLoader {
/**
* The HashMap where the classes will be cached
*/
private Map<String, Class<?>> classes = new HashMap<String, Class<?>>();
@Override
public String toString() {
return CustomClassLoader.class.getName();
}
@Override
protected Class<?> findClass(String name) throws ClassNotFoundException {
if (classes.containsKey(name)) {
return classes.get(name);
}
byte[] classData;
try {
classData = loadClassData(name);
} catch (IOException e) {
throw new ClassNotFoundException("Class [" + name
+ "] could not be found", e);
}
Class<?> c = defineClass(name, classData, 0, classData.length);
resolveClass(c);
classes.put(name, c);
return c;
}
/**
* Load the class file into byte array
*
* @param name
* The name of the class e.g. com.codeslices.test.TestClass}
* @return The class file as byte array
* @throws IOException
*/
private byte[] loadClassData(String name) throws IOException {
BufferedInputStream in = new BufferedInputStream(
ClassLoader.getSystemResourceAsStream(name.replace(".", "/")
+ ".class"));
ByteArrayOutputStream out = new ByteArrayOutputStream();
int i;
while ((i = in.read()) != -1) {
out.write(i);
}
in.close();
byte[] classData = out.toByteArray();
out.close();
return classData;
}
}