我实现了一个在数据库中扫描数据的类，它根据数据库中的内容在表中显示数据。但是，为了满足数据库的所有可能返回并受JTable显示信息的限制，我发现自己编写了很多if else语句，这些语句容易出错。
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);
}
}
我怎样才能更好地实现这个类？
答案 0 :(得分：4)
你强迫自己使用所有这些嵌套语句，因为冗余的索引键会不断改变位置。使用列表而不是地图应解决大部分问题：
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...
}
如果您绝对必须返回Map<Integer, List<Object>>，您可以轻松转换列表以生成相同内容：
@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;
}
答案 1 :(得分：3)
典型的答案是：查看Single Responsbility Principle和多态。另一个在这里发挥作用的规则是：Tell don't ask。
含义：您的代码要求其他对象提供一些内部状态信息。基于该信息，该代码可以做出决策。 ＆＃34;更多OO＆＃34;方法是：只是告诉其他对象自己做某事。它最了解其内部状态。
除此之外;您的问题无法轻易解决。你必须先看看＆＃34;整体＆＃34;事情。基本上你有一些＆＃34;输入数据＆＃34;和一套规则＆＃34;确定如何构建＆＃34;输出＆＃34;从那个输入。一个真正的解决方案是建模这些元素（输入，输出，规则），并允许您在表格中表达所需的关系＆＃34;例如。