多くのif文を避ける方法

Question

私は、データベースをスキャンしてデータを取得するクラスを実装しており、データベースの内容に応じてテーブルにデータを表示します。しかし、データベースからの可能な復帰をすべて満たすために、JTableがどのように情報を表示するかによって制約を受けるため、エラーが発生する可能性のある多くのif elseステートメントを自己書き込みにします。

package googo.pmms.project2.financialStatement; 

import googo.pmms.project2.frameHelper.ReportsModelData; 
import java.util.List; 
import java.util.Map; 
import javax.swing.JTable; 
import javax.swing.table.TableRowSorter; 

public class TheBalanceSheet implements BalanceSheet { 
    ReportsModelData model1; 
    String title; 
    List<String> tableHeaders; 
    List<Object> dataBody; 

    Map<Integer, List<Object>> data; 

    BalanceSheetUtility bUtility = new BalanceSheetUtility(); 

    public TheBalanceSheet() { 
    } 

    public boolean createBalanceSheet(JTable table, String materialDate) {  
     boolean bs = true;  
     AssetAccount asset = new AssetAccount(materialDate); 

     LiabilityEquityAccounts liabEqui = new LiabilityEquityAccounts(materialDate); 

     if (!asset.isAssetsEmpty()) {  
      this.setBodyMap(0, asset.mainAssetTitle()); 
      if (!asset.isCurrentAssetsEmpty()) { 
       this.setBodyMap(1, asset.currentAssetTitle()); 
       this.setBodyMap(2, asset.currentAssets()); 
       this.setBodyMap(3, asset.totalCurrentAssets()); 

       if (!asset.isNonCurrentAssetsEmpty()) { 
        this.setBodyMap(4, asset.nonCurrentAssetTitle()); 
        this.setBodyMap(5, asset.nonCurrentAssets()); 
        this.setBodyMap(6, asset.totalNonCurrentAssets()); 
        this.setBodyMap(7, this.totalAssets()); 

        if (!liabEqui.isLiabilitiesEmpty()) { 

         this.setBodyMap(8, liabEqui.mainLiabilitiesEquityTitle()); 

         if (!liabEqui.isCurrentLiabilityEmpty()) { 

          this.setBodyMap(9, liabEqui.currentLiabilitiesTitle()); 
          this.setBodyMap(10, liabEqui.currentLiabilities()); 
          this.setBodyMap(11, liabEqui.totalCurrentLiabilities()); 

          if (!liabEqui.isNonCurrentLiabilityEmpty()) { 
           this.setBodyMap(12, liabEqui.nonCurrentLiabilitiesTitle()); 
           this.setBodyMap(13, liabEqui.nonCurrentLiabilities()); 
           this.setBodyMap(14, liabEqui.totalNonCurrentLiabilities()); 
           this.setBodyMap(15, this.totalLiabilities()); 

           if (!liabEqui.isEquityEmpty()) { 
            this.setBodyMap(16, liabEqui.equityTitle()); 
            this.setBodyMap(17, liabEqui.equity()); 
            this.setBodyMap(18, liabEqui.totalEquity()); 
            this.setBodyMap(19, this.totalLiabilitiesEquity()); 
           } 

          } else if (!liabEqui.isEquityEmpty()) { 
           this.setBodyMap(12, liabEqui.equityTitle()); 
           this.setBodyMap(13, liabEqui.equity()); 
           this.setBodyMap(14, liabEqui.totalEquity()); 
           this.setBodyMap(15, this.totalLiabilitiesEquity()); 
          }  
         } else if (!liabEqui.isNonCurrentLiabilityEmpty()) { 

          this.setBodyMap(9, liabEqui.nonCurrentLiabilitiesTitle()); 
          this.setBodyMap(10, liabEqui.nonCurrentLiabilities()); 
          this.setBodyMap(11, liabEqui.totalNonCurrentLiabilities()); 
          this.setBodyMap(12, this.totalLiabilities()); 

          if (!liabEqui.isEquityEmpty()) { 
           this.setBodyMap(13, liabEqui.equityTitle()); 
           this.setBodyMap(14, liabEqui.equity()); 
           this.setBodyMap(15, liabEqui.totalEquity()); 
           this.setBodyMap(16, this.totalLiabilitiesEquity()); 
          } 
         } else { 
         } 
        } 
       } else { 
        this.setBodyMap(4, this.totalAssets()); 

        if (!liabEqui.isLiabilitiesEmpty()) { 
         this.setBodyMap(5, liabEqui.mainLiabilitiesEquityTitle()); 
        if (!liabEqui.isCurrentLiabilityEmpty()) { 
         this.setBodyMap(6, liabEqui.currentLiabilitiesTitle()); 
         this.setBodyMap(7, liabEqui.currentLiabilities()); 

          this.setBodyMap(8, liabEqui.totalCurrentLiabilities()); 

          if (!liabEqui.isNonCurrentLiabilityEmpty()) { 

           this.setBodyMap(9, liabEqui.nonCurrentLiabilitiesTitle()); 

           this.setBodyMap(10, liabEqui.nonCurrentLiabilities()); 

           this.setBodyMap(11, liabEqui.totalNonCurrentLiabilities()); 

           this.setBodyMap(12, this.totalLiabilities()); 

           if (!liabEqui.isEquityEmpty()) { 

            this.setBodyMap(13, liabEqui.equityTitle()); 
            this.setBodyMap(14, liabEqui.equity()); 
            this.setBodyMap(15, liabEqui.totalEquity()); 
            this.setBodyMap(16, this.totalLiabilitiesEquity()); 
           } 

          } else if (!liabEqui.isEquityEmpty()) { 
           this.setBodyMap(9, liabEqui.equityTitle()); 
           this.setBodyMap(10, liabEqui.equity()); 
           this.setBodyMap(11, liabEqui.totalEquity()); 
           this.setBodyMap(12, this.totalLiabilitiesEquity()); 
          } 

         } else if (!liabEqui.isNonCurrentLiabilityEmpty()) { 

          this.setBodyMap(6, liabEqui.nonCurrentLiabilitiesTitle()); 
          this.setBodyMap(7, liabEqui.nonCurrentLiabilities()); 
          this.setBodyMap(8, liabEqui.totalNonCurrentLiabilities()); 
          this.setBodyMap(9, this.totalLiabilities()); 

          if (!liabEqui.isEquityEmpty()) { 
           this.setBodyMap(10, liabEqui.equityTitle()); 
           this.setBodyMap(11, liabEqui.equity()); 
           this.setBodyMap(12, liabEqui.totalEquity()); 
           this.setBodyMap(13, this.totalLiabilitiesEquity()); 
          } 
         } else if (!liabEqui.isEquityEmpty()) { 
          this.setBodyMap(6, liabEqui.equityTitle()); 
          this.setBodyMap(7, liabEqui.equity()); 
          this.setBodyMap(8, liabEqui.totalEquity()); 
          this.setBodyMap(9, this.totalLiabilitiesEquity()); 
         } 

        } 
       } 

      } else if (!asset.isNonCurrentAssetsEmpty()) { 

       this.setBodyMap(1, asset.nonCurrentAssetTitle()); 
       this.setBodyMap(2, asset.nonCurrentAssets()); 
       this.setBodyMap(3, asset.totalNonCurrentAssets()); 
       this.setBodyMap(4, this.totalAssets()); 

       if (!liabEqui.isLiabilitiesEmpty()) { 

        this.setBodyMap(5, liabEqui.mainLiabilitiesEquityTitle()); 

        if (!liabEqui.isCurrentLiabilityEmpty()) { 

         this.setBodyMap(6, liabEqui.currentLiabilitiesTitle()); 
         this.setBodyMap(7, liabEqui.currentLiabilities()); 
         this.setBodyMap(8, liabEqui.totalCurrentLiabilities()); 
         if (!liabEqui.isNonCurrentLiabilityEmpty()) { 

          this.setBodyMap(9, liabEqui.nonCurrentLiabilitiesTitle()); 
          this.setBodyMap(10, liabEqui.nonCurrentLiabilities()); 
          this.setBodyMap(11, liabEqui.totalNonCurrentLiabilities()); 
          this.setBodyMap(12, this.totalLiabilities()); 

          if (!liabEqui.isEquityEmpty()) { 
           this.setBodyMap(13, liabEqui.equityTitle()); 
           this.setBodyMap(14, liabEqui.equity()); 
           this.setBodyMap(15, liabEqui.totalEquity()); 
           this.setBodyMap(16, this.totalLiabilitiesEquity()); 
          } 
         } else if (!liabEqui.isEquityEmpty()) { 
          this.setBodyMap(9, liabEqui.equityTitle()); 
          this.setBodyMap(10, liabEqui.equity()); 
          this.setBodyMap(11, liabEqui.totalEquity()); 
          this.setBodyMap(12, this.totalLiabilitiesEquity()); 
         } 

        } else if (!liabEqui.isNonCurrentLiabilityEmpty()) { 

         this.setBodyMap(6, liabEqui.nonCurrentLiabilitiesTitle()); 
         this.setBodyMap(7, liabEqui.nonCurrentLiabilities()); 
         this.setBodyMap(8, liabEqui.totalNonCurrentLiabilities()); 
         this.setBodyMap(9, this.totalLiabilities()); 

         if (!liabEqui.isEquityEmpty()) { 
          this.setBodyMap(10, liabEqui.equityTitle()); 
          this.setBodyMap(11, liabEqui.equity()); 
          this.setBodyMap(12, liabEqui.totalEquity()); 
          this.setBodyMap(13, this.totalLiabilitiesEquity()); 
         } 

        } else if (!liabEqui.isEquityEmpty()) { 

         this.setBodyMap(6, liabEqui.equityTitle()); 
         this.setBodyMap(7, liabEqui.equity()); 
         this.setBodyMap(8, liabEqui.totalEquity()); 
         this.setBodyMap(9, this.totalLiabilitiesEquity()); 

        } 
       } 
      } 

     } else if (!liabEqui.isLiabilitiesEmpty()) { 

      this.setBodyMap(0, liabEqui.mainLiabilitiesEquityTitle()); 

      if (!liabEqui.isCurrentLiabilityEmpty()) { 
       this.setBodyMap(1, liabEqui.currentLiabilitiesTitle()); 
       this.setBodyMap(2, liabEqui.currentLiabilities()); 
       this.setBodyMap(3, liabEqui.totalCurrentLiabilities()); 

       if (!liabEqui.isNonCurrentLiabilityEmpty()) { 

        this.setBodyMap(4, liabEqui.nonCurrentLiabilitiesTitle()); 
        this.setBodyMap(5, liabEqui.nonCurrentLiabilities()); 
        this.setBodyMap(6, liabEqui.totalNonCurrentLiabilities()); 

        this.setBodyMap(7, this.totalLiabilities()); 

        if (!liabEqui.isEquityEmpty()) { 

         this.setBodyMap(8, liabEqui.equityTitle()); 
         this.setBodyMap(9, liabEqui.equity()); 
         this.setBodyMap(10, liabEqui.totalEquity()); 
         this.setBodyMap(11, this.totalLiabilitiesEquity()); 
        } 

       } else if (!liabEqui.isEquityEmpty()) { 

        this.setBodyMap(4, liabEqui.equityTitle()); 
        this.setBodyMap(5, liabEqui.equity()); 
        this.setBodyMap(6, liabEqui.totalEquity()); 
        this.setBodyMap(7, this.totalLiabilitiesEquity()); 
       } 
      } else if (!liabEqui.isNonCurrentLiabilityEmpty()) { 

       this.setBodyMap(1, liabEqui.nonCurrentLiabilitiesTitle()); 
       this.setBodyMap(2, liabEqui.nonCurrentLiabilities()); 
       this.setBodyMap(3, liabEqui.totalNonCurrentLiabilities()); 

       this.setBodyMap(4, this.totalLiabilities()); 

       if (!liabEqui.isEquityEmpty()) { 

        this.setBodyMap(5, liabEqui.equityTitle()); 
        this.setBodyMap(6, liabEqui.equity()); 
        this.setBodyMap(7, liabEqui.totalEquity()); 
        this.setBodyMap(8, this.totalLiabilitiesEquity()); 
       } 

      } else if (!liabEqui.isEquityEmpty()) { 
      } 
      this.setBodyMap(1, liabEqui.equityTitle()); 
      this.setBodyMap(2, liabEqui.equity()); 
      this.setBodyMap(3, liabEqui.totalEquity()); 
      this.setBodyMap(4, this.totalLiabilitiesEquity()); 

     } else { 

      bs = false; 
     } 

     model1 = new ReportsModelData(getBodyMap(), getTableHeaders()); 
     table.setModel(model1); 

     TableRowSorter<ReportsModelData> sorter = new TableRowSorter<>(model1); 
     table.setRowSorter(sorter); 

     return bs; 
    } 

    private List totalAssets() { 

    } 

    private List totalLiabilities() { 

    } 

    private List totalEquity() { 

    } 

    private List totalLiabilitiesEquity() { 

    } 

    @Override 
    public String getTitle(String date) { 
     return title; 
    } 

    @Override 
    public List<String> getTableHeaders() { 
     return tableHeaders; 
    } 

    @Override 
    public List<Object> getBodyList() { 
     return dataBody; 
    } 

    @Override 
    public Map<Integer, List<Object>> getBodyMap() { 
     return data; 
    } 

    @Override 
    public void setTitle(String title) { 
     this.title = title; 
    } 

    @Override 
    public void setTableHeader(String header) { 
     tableHeaders.add(header); 
    } 

    @Override 
    public void setBodyList(String body) { 
     dataBody.add(body); 
    } 

    @Override 
    public void setBodyMap(Integer index, List<Object> body) { 
     data.put(index, body); 
    } 

} 

このクラスをよりうまく実装できましたか？

Answer 1

典型的な答えは、Single Responsbility Principleと多型を見てください。ここに出てくる他のルール：Tell don't ask。

意味：あなたのコードは、内部状態情報を提供するために他のオブジェクトに依頼しています。その情報に基づいて、そのコードが決定を下します。 "より多くのOO"アプローチは：ただ他のオブジェクト自体を行うことを指示してください。それは内部状態について最もよく知っています。

それ以上。あなたの問題は簡単に修正することはできません。あなたは歩いて、全体のことを見なければなりません。基本的には、入力から "出力"を構築する方法を決定するための "入力データ"と一連の "ルール"があります。実際の解決策はこれらの要素（入力、出力、の規則は）であり、必要な関係を「表形式」の形式で表現することができます。

Answer 2

位置を変更し続ける冗長なインデックスキーのため、これらのネストされたステートメントをすべて使用する必要があります。代わりに、マップのリストを使用して、問題のほとんどを解決する必要があります。

private List<List<Object>> data = new ArrayList<>(); 

public boolean createBalanceSheet(JTable table, String materialDate) { 
    //... 
    if (!asset.isAssetsEmpty()) { 
     data.add(asset.mainAssetTitle()); 
    } 

    if (!asset.isCurrentAssetsEmpty()) { 
     data.add(asset.currentAssetTitle()); 
     data.add(asset.currentAssets()); 
     data.add(asset.totalCurrentAssets()); 
    } 

    if (!asset.isNonCurrentAssetsEmpty()) { 
     data.add(asset.nonCurrentAssetTitle()); 
     data.add(asset.nonCurrentAssets()); 
     data.add(asset.totalNonCurrentAssets()); 
     data.add(this.totalAssets()); 
    } 

    // and so on... 
} 

あなたは絶対にMap<Integer, List<Object>>を返さなければならない場合、あなたは簡単に同じことを生成するためにあなたのリストを変換することができます。

@Override 
public Map<Integer, List<Object>> getBodyMap() { 
    Map<Integer, List<Object>> result = new HashMap<>(); 
    for (int i = 0; i < data.size(); i++) { 
     result.put(i, data.get(i)); 
    } 
    return result; 
}