Creating new instance from Class with constructor parameter

I have situation where my Java class needs to create a ton of certain kind of objects. I would like to give the name of the class of the objects that are created as a parameter. In addition, I need to give the created class a parameter in its constructor. I have something like

class Compressor {

    Class ccos;

    public Compressor(Class开发者_开发百科 ccos) {
        this.ccos = ccos;
    }

    public int getCompressedSize(byte[] array) {
        OutputStream os = new ByteArrayOutputStream();
        // the following doesn't work because ccos would need os as its constructor's parameter
        OutputStream cos = (OutputStream) ccos.newInstance();
        // ..
    }
}

Do you have any ideas how I could remedy this?

Edit:

This is part of a research project where we need to evaluate the performance of multiple different compressors with multiple different inputs. Class ccos is a compressed OutputStream either from Java's standard library, Apache Compress Commons or lzma-java.

Currently I have the following which appears to work fine. Other ideas are welcome.

OutputStream os = new ByteArrayOutputStream();
OutputStream compressedOut = (OutputStream) ccos.getConstructor(OutputStream.class).newInstance(os);
final InputStream sourceIn = new ByteArrayInputStream(array);

You can use the Class.getConstructor(paramsTypes...) method and call newInstance(..) on the constructor. In your case:

Compressor.class.getConstructor(Class.class).newInstance(Some.class);

Using Spring ClassUtils and BeanUtils classes you can avoid dealing with those tedious exceptions that is Spring handling for you :

Constructor<Car> constructor = ClassUtils.getConstructorIfAvailable(Wheels.class, Etc.class);
Car car = BeanUtils.instantiateClass(constructor, new Wheels(), new Etc());

You have to get to the relevant Constructor object (e.g. via Class.getConstructors or Class.getConstructor) and then call constructor.newInstance, giving it the arguments it requires.

An example you can use is as follows: lets say conn is a connection to the database.

Class[] btarray = { conn.getClass() };      
try {
   if (classname != null) {
      pmap = (Mapper) Class.forName(classname)
                           .getConstructor(btarray)
                           .newInstance(
                              new Object[] { conn }
                           );
   }
} catch (Throwable x) {
   x.printStackTrace(Log.out);
}

btarray allows you to pass in arguments to the constructor.

class Compresor<T> {
    private Class<? extends T> clazz;
    Compresor(final Class<? extends T> cls){
        this.clazz = cls
    }
}