import com.sun.deploy.config.DefaultConfig;

import javax.security.auth.login.Configuration;
import java.util.PropertyResourceBundle;
import java.util.ResourceBundle;

public class Test {
}


interface AccountManager{
    Account findAccountForUser(String userId);

    void updateAccount(Account account);
}
 
class LogFactory{
    public static Log getLog(Class cls){return null;}
}
class Account { }
class Log { void debug(String string){}}

//原版本的代碼
class DefaultAccountManager implements AccountManager{
    Log logger = LogFactory.getLog(AccountManager.class);



    public Account findAccountForUser(String userId) {
        logger.debug(
 
"hahahahahaha");
        ResourceBundle bundle = PropertyResourceBundle.getBundle("test");
        String sql = bundle.getString("test");
        return null;
    }

    public void updateAccount(Account account) {

    }
}


//為測試進行重構的代碼
class DefaultAccountManager1 implements AccountManager{
    Log logger;
    
 
private Configuration configuration;

    public DefaultAccountManager1() {
        this(LogFactory.getLog(DefaultAccountManager.class),new DefaultConfiguration())
    }

    public DefaultAccountManager1(Log logger, Configuration configuration) {
        this.logger = logger;
        this.configuration = configuration;
    }

    public Account findAccountForUser(String userId) {
        logger.debug("hahahahahaha");
        this.configuration.getSql("test");

        return null;
    }

    public void updateAccount(Account account) {

    }
}

//測試時候的代碼
class TestDefaultAccountManager{
    public void testFindAccountByUser(){
        MockLog logger = new MockLog();
        MockConfiguration configuration = new MockConfiguration();
        configuration.setSQl("testtesttest");
        DefaultAccountManager am = new DefaultAccountManager(logger, configuration);

        Account account = am.findAccountForUser("1234");
    }
}

為使用mock方案測試，而重構代碼的小小案例