Java--用简单工厂来改进抽象工厂（反射）

public class DataAccess {
private static final String db = "SqlServer";
//private static final String db = "Access";
public static IUser createUser(){
IUser result = null;
switch (db) {
case "SqlServer":
result = new SqlServerUser();
break;
case "Access":
result = new AccessUser();
break;

default:
break;
}
return result;
}
public static IDepartment createDepartment(){
IDepartment result = null;
switch (db) {
case "SqlServer":
result = new SqlServerDepartment();
break;
case "Access":
result = new AccessDepartment();
break;

default:
break;
}
return result;
}
}

public class Test {
public static void main(String[] args) {
User user = new User();
Department department = new Department();
IUser iu = DataAccess.createUser();
iu.insert(user);
iu.getUser(1);
IDepartment id = DataAccess.createDepartment();
id.insert(department);
id.getDepartment(1);
}
}

public class DataAccess {
// 包名
private static final String AccemblyName = "com.test.factory.abstractmethod";
// 可以替换成Access
private static final String db = "Access";
public static IUser createUser(){
IUser result = null;
String className = AccemblyName + "." + db +"User";
Class<?> user = null;
try {
user = Class.forName(className);
result = (IUser)user.newInstance();
} catch (ClassNotFoundException e) {
e.printStackTrace();
} catch (InstantiationException e) {
e.printStackTrace();
} catch (IllegalAccessException e) {
e.printStackTrace();
}
return result;
}
public static IDepartment createDepartment(){
IDepartment result = null;
String className = AccemblyName + "." + db +"Department";
Class<?> department = null;
try {
department = Class.forName(className);
result = (IDepartment)department.newInstance();
} catch (ClassNotFoundException e) {
e.printStackTrace();
} catch (InstantiationException e) {
e.printStackTrace();
} catch (IllegalAccessException e) {
e.printStackTrace();
}
return result;
}
}