java - 程式碼重複求改進方法

Question

    @Override
    public Option getTrafficChartOption(String type, ReportType reportType, Integer deviceId, Integer direction) {
        Integer device = deviceId + 1010000;
        List<ChartData> data = chartDao.getTrafficChartData(reportType,device,direction);
        String title = Titlehelper.getChartTitle(reportType);
        String subtitle = Titlehelper.gettrafficSubText(reportType.getReportTime(),deviceId,direction);
        Option option = new Option();
        switch (type){
            case "bar":
                option = BarOption.BarOptionBuiler(title, subtitle, data);
                break;
            case "line":
                option = LineOption.OptionBuilerhelp(title, subtitle, data);
                break;
            case "pie":
                option = PieOption.PieOptionbuilder(title, subtitle, data);
                break;
        }
        return option;
    }

    @Override
    public Option getAmmeterChartOption(String type, ReportType reportType, Integer deviceId) {
        List<ChartData> data = chartDao.getAmmeterDataChartData(reportType,deviceId);
        String title = Titlehelper.getChartTitle(reportType);
        String subtitle = Titlehelper.gettrafficSubText(reportType.getReportTime(),deviceId,1);
        Option option = new Option();
        switch (type){
            case "bar":
                option = BarOption.BarOptionBuiler(title, subtitle, data);
                break;
            case "line":
                option = LineOption.OptionBuilerhelp(title, subtitle, data);
                break;
            case "pie":
                option = PieOption.PieOptionbuilder(title, subtitle, data);
                break;
        }
        return option;
    }

程式碼結構非常相似，只是dao層取資料不一樣，另外這個switch有沒有改進空間，我知道使用eumn來枚舉，沒寫以減少無關程式碼

Answer 1

你的程式碼是要建立Option類，適合使用工廠方法重構。

//方法参数尽量少于3个，3个以上时建议使用组合对象
class OptionParam {
    private String type;
    private ReportType reportType;
    private Integer piceId;
    private Integer direction;
   //getter and setter
}

//Option抽象工厂，每个具体工厂都必须继承自抽象工厂
public abstract class AbstractOptionFactory {

    @Autowired
    ChartDao chartDao;

     //希望具体工厂实现的方法，交于具体工厂实现
    abstract List<ChartData> getData(OptionParam optionParam);

    abstract String getSubtitle(OptionParam optionParam);

   //公共逻辑代码，创建对象调用该方法
    public Option create(OptionParam optionParam) {
        assert optionParam != null;
        assert optionParam.getReportType() != null;
        String type = optionParam.getType();
        List<ChartData> data = getData(optionParam);
        String title = Titlehelper.getChartTitle(optionParam.getReportType());
        String subtitle = getSubtitle(optionParam);
        Option option = new Option();
        switch (type) {
            case "bar":
                option = BarOption.BarOptionBuiler(title, subtitle, data);
                break;
            case "line":
                option = LineOption.OptionBuilerhelp(title, subtitle, data);
                break;
            case "pie":
                option = PieOption.PieOptionbuilder(title, subtitle, data);
                break;
        }
        return option;
    }

}

@Component
class TrafficChartOptionFactory extends AbstractOptionFactory {


    @Override
    List<ChartData> getData(OptionParam optionParam) {
        return chartDao.getTrafficChartData(optionParam.getReportType(),
                optionParam.getpiceId(),
                optionParam.getDirection());
    }

    @Override
    String getSubtitle(OptionParam optionParam) {
        return Titlehelper.gettrafficSubText(
                optionParam.getReportType().getReportTime(),
                optionParam.getpiceId(),
                optionParam.getDirection());
    }
}

@Component
class AmmeterChartOptionFactory extends AbstractOptionFactory {

    @Override
    List<ChartData> getData(OptionParam optionParam) {
        return chartDao.getAmmeterDataChartData(optionParam.getReportType(), optionParam.getpiceId());
    }

    @Override
    String getSubtitle(OptionParam optionParam) {
        return Titlehelper.gettrafficSubText(optionParam.getReportType().getReportTime(),
                optionParam.getpiceId(),
                1);
    }
}

使用工廠方法的好處就不多說了，具體可以閱讀我的部落格

Answer 2

        String title = Titlehelper.getChartTitle(reportType);
        String subtitle = Titlehelper.gettrafficSubText(reportType.getReportTime(),deviceId,1);
        Option option = new Option();
        switch (type){
            case "bar":
                option = BarOption.BarOptionBuiler(title, subtitle, data);
                break;
            case "line":
                option = LineOption.OptionBuilerhelp(title, subtitle, data);
                break;
            case "pie":
                option = PieOption.PieOptionbuilder(title, subtitle, data);
                break;
        }
        return option;

這幾行提取出來放在一個方法裡呼叫不就行了

Answer 3

可以試試看模板設計模式吧，將通用的演算法提取到父類別中，不同的地方交給子類別重寫。如果這樣的地方少些，還是提取一個公共方法，比較省事。

Answer 4

樓上說的可行，提取公共部分封裝成一個公共方法。

Answer 5

樓上說的提取公共方法簡單實用，一樓的答案太高深，需要好好琢磨一下