public abstract class

public class GoddessChemicalFactory extends ChemicalFactory {

@Override
public <T extends Chemical> T createChemical(Class<T> clz) {
Chemical chemical = null;

public abstract class Chemical {

/**
* 化肥特征之一——投放到地上
*/
public abstract void toGround();

public class NChemical extends Chemical {
@Override
public void toGround() {
Log.e("NChemical","氮肥被投放到白菜地裏");
}

@Override
public void becomeGas() {
Log.e("NChemical","氮肥釋放含N元素的氣體被白菜的葉子吸收");
}
}

public class PChemical extends Chemical {
@Override
public void toGround() {
Log.e("PChemical","磷肥被投放到西紅柿地裏");
}

@Override
public void becomeGas() {
Log.e("PChemical","磷肥釋放含P元素的氣體被西紅柿的果實吸收");
}
}

public class KChemical extends Chemical {
@Override
public void toGround() {
Log.e("KChemical","鉀肥被投放到胡蘿蔔地裏");
}

@Override
public void becomeGas() {
Log.e("KChemical","鉀肥釋放含K元素的氣體被胡蘿蔔的根系吸收");
}
}

public class Explosive extends Chemical {
@Override
public void toGround() {
Log.e("Explosive","炸藥被投放到敵人陣地裏");
}

@Override
public void becomeGas() {
Log.e("Explosive","炸藥釋放溫度高的氣體（火焰）和速度快的氣體（沖擊波）被敵人的身體吸收");
}
}

GoddessChemicalFactory factory = new GoddessChemicalFactory();

NChemical nChemical = factory.createChemical(NChemical.class);
nChemical.toGround();
nChemical.becomeGas();

PChemical pChemical = factory.createChemical(PChemical.class);
pChemical.toGround();
pChemical.becomeGas();

KChemical kChemical = factory.createChemical(KChemical.class);
kChemical.toGround();
kChemical.becomeGas();

Explosive explosive = factory.createChemical(Explosive.class);
explosive.toGround();
explosive.becomeGas();