ジェネリックなListの詰替えサンプル(引数で変換先の型を取ればいける)

Converter.java

import java.lang.reflect.InvocationTargetException;
import java.util.ArrayList;
import java.util.List;

import org.apache.commons.beanutils.BeanUtils;

public class Converter {

	public static <T, U> List<U> convert(List<T> in, Class<U> type) {
		List<U> out = new ArrayList<U>();
		try {
			for (T t : in) {
				U u = type.newInstance();
				BeanUtils.copyProperties(u, t);
				out.add(u);
			}
		} catch (InstantiationException e) {
			throw new IllegalArgumentException(e);
		} catch (IllegalAccessException e) {
			throw new IllegalArgumentException(e);
		} catch (InvocationTargetException e) {
			throw new IllegalArgumentException(e);
		}

		return out;
	}
}

ConverterTest.java

import static org.hamcrest.CoreMatchers.is;
import static org.junit.Assert.assertThat;

import java.util.ArrayList;
import java.util.List;

import org.junit.Test;

public class ConverterTest {
	@Test
	public void リストの詰め替え() {
		List<A> source = new ArrayList<A>();
		source.add(new A());

		List<B> ret = Converter.convert(source, B.class);
		assertThat(ret.get(0).val, is("a"));
	}

	public static class A {
		private String val = "a";

		public String getVal() {
			return val;
		}

		public void setVal(String val) {
			this.val = val;
		}

	}

	public static class B {
		private String val;

		public String getVal() {
			return val;
		}

		public void setVal(String val) {
			this.val = val;
		}
	}
}