用java（intellij）进行周期表搜索

其目标是使元素周期表搜索引擎。向用户提问以缩小结果范围，或者询问用户是否知道要输入的元素的名称。一旦输入或找到元素，它将提供有关元素的信息。我只有一些细节和一些元素来让代码工作，更多的元素和细节将被添加，比如结构和原子量

每当发现结果时，它不会给出信息，只会给出一个空白屏幕。我想把它作为toString放在课堂上，然后在我的主调底部调用它就足够了，但我不知道我缺少了什么。这似乎是一个简单的系统输出命令，但也不起作用

非常感谢您的帮助

import java.util.ArrayList;
import javax.swing.*;

public class Main {

public static void main(String args[]) {

    ArrayList<Element> e = new ArrayList<Element>();
    String choice, element = "", searchBy, symbol, chemGroupBlock, list = "", str = "";

    e.add(new Element("Hydrogen", "Nonmetal", "H", 1));
    e.add(new Element("Helium", "Nobel Gas", "He", 2));
    e.add(new Element("Lithium", "Alkali Metal", "Li", 3));

    choice = JOptionPane.showInputDialog(null,
            "Do you know the name of the element you're looking for?"
                    + "(Yes/No)", "Welcome to the Chem Table!", 3);

    if (choice.equalsIgnoreCase("yes")) {
        element = JOptionPane.showInputDialog(null,
                "Enter the name of the Element.. ",
                "Welcome to the Chem Table!", JOptionPane.PLAIN_MESSAGE);
    }else if (choice.equalsIgnoreCase("no")) {
        searchBy = JOptionPane.showInputDialog(null,
                "Search by: 'chemical group block' or 'symbol'?", "Welcome to the Chem Table", 3);

        if (searchBy.equalsIgnoreCase("chemGroupBlock")) {
            chemGroupBlock = JOptionPane.showInputDialog(null,
                    "Enter Chemical Group Block (Nonmetal/Nobel Gases/Alkalies)",
                    "Welcome to The Chem Table", JOptionPane.PLAIN_MESSAGE);
            for (int i = 0; i < e.size(); i++){
                if (e.get(i).getchemGroupBlock().equals(chemGroupBlock)){
                    list = list + e.get(i).getName() + "\n";
                }
            }

            element = JOptionPane.showInputDialog(null, list,
                    JOptionPane.PLAIN_MESSAGE);

        } else if (searchBy.equalsIgnoreCase("symbol")) {
            symbol = JOptionPane.showInputDialog(null,
                    "Enter the element symbol:(He/NaCl/Xe)",
                    "Welcome to the Chem Table",
                    JOptionPane.PLAIN_MESSAGE);
            for (int i = 0; i < e.size(); i++) {
                if (e.get(i).getSymbol().equals(symbol)) {
                    list = list + e.get(i).getName() + "\n";
                }
            }
            element = JOptionPane.showInputDialog(null, list,
                    JOptionPane.PLAIN_MESSAGE);

        }
    }
    for (int i = 0; i < e.size(); i++) {
        if (e.get(i).getName().equals(element)) {
            str = e.get(i).toString();
        }
    }

    JOptionPane.showMessageDialog(null, str, "Element Results", 1);


 }
}

---

我认为问题在于这种情况：

if（e.get（i）.getName（）.equals（element））

是否输入了元素的确切区分大小写的名称？例如，“氢”将不会被发现，但“氢”将工作良好

您应将此条件更改为：

if（e.get（i）.getName（）.equalsIgnoreCase（元素））

---

代码的其他部分也存在其他类似的问题。我建议你对你的逻辑做一个全面的回顾。请密切注意何时调用

equals

以及它是否应为

equalsIgnoreCase

当用户输入元素名称时，只要元素名称正确，搜索就会成功。如上所述，搜索现在区分大小写，因此您可以使用

.equalsIgnoreCase

对于按符号或化学组搜索，有冗余输入对话框，在输入字段中打印-1（它是

JOptionPane.PLAIN_MESSAGE

）的值：

最好使用“选项对话框”，用户只需单击按钮即可选择选项，而无需键入

接下来，当您按符号搜索时，您将提供数据中不可用的选项（例如，

NaCl

和

Xe

）

因此，要解决这些问题，您可能需要按如下方式更新代码：

int result = JOptionPane.showConfirmDialog(null,
                "Do you know the name of the element you're looking for?", 
                "Welcome to the Chem Table!", JOptionPane.YES_NO_CANCEL_OPTION);

if (result == JOptionPane.YES_OPTION) {
    element = JOptionPane.showInputDialog(
        null, "Enter the name of the Element.. ",
        "Welcome to the Chem Table!", JOptionPane.PLAIN_MESSAGE);
} else if (result == JOptionPane.NO_OPTION) {
    String[] byOptions = {"chemical group block",  "symbol"};
    result = JOptionPane.showOptionDialog(
                null, 
                "Search by: 'chemical group block' or 'symbol'?",
                "Welcome to the Chem Table", 
                JOptionPane.DEFAULT_OPTION, JOptionPane.QUESTION_MESSAGE,
                null, byOptions, byOptions[0]);

    if (result == 0) {
        String[] byGroup = {"Nonmetal", "Nobel Gases", "Alkalies"};
        result = JOptionPane.showOptionDialog(
                    null,
                    "Select Chemical Group", 
                    "Welcome to The Chem Table",
                    JOptionPane.DEFAULT_OPTION, JOptionPane.QUESTION_MESSAGE,
                    null, byGroup, byGroup[0]);
        for (Element el : e) {
            if (el.getchemGroupBlock().equalsIgnoreCase(byGroup[result])) {
                element = el.getName();
                break;
            }
        }
    } else { // search by symbol
        symbol = JOptionPane.showInputDialog(
                    null, "Enter the element symbol:(H/He/Li)",
                    "Welcome to the Chem Table",
                    JOptionPane.PLAIN_MESSAGE);
        for (Element el : e) {
            if (el.getSymbol().equalsIgnoreCase(symbol)) {
                element = el.getName();
                break;
            }
        }
        if (element.isEmpty()) {
            JOptionPane.showMessageDialog(
                null, "Symbol" + symbol + " not found!", "Not found!", JOptionPane.WARNING_MESSAGE);
            return;
        }
    }
}

element = JOptionPane.showInputDialog(null, list, JOptionPane.PLAIN_MESSAGE);

int result = JOptionPane.showConfirmDialog(null,
                "Do you know the name of the element you're looking for?", 
                "Welcome to the Chem Table!", JOptionPane.YES_NO_CANCEL_OPTION);

if (result == JOptionPane.YES_OPTION) {
    element = JOptionPane.showInputDialog(
        null, "Enter the name of the Element.. ",
        "Welcome to the Chem Table!", JOptionPane.PLAIN_MESSAGE);
} else if (result == JOptionPane.NO_OPTION) {
    String[] byOptions = {"chemical group block",  "symbol"};
    result = JOptionPane.showOptionDialog(
                null, 
                "Search by: 'chemical group block' or 'symbol'?",
                "Welcome to the Chem Table", 
                JOptionPane.DEFAULT_OPTION, JOptionPane.QUESTION_MESSAGE,
                null, byOptions, byOptions[0]);

    if (result == 0) {
        String[] byGroup = {"Nonmetal", "Nobel Gases", "Alkalies"};
        result = JOptionPane.showOptionDialog(
                    null,
                    "Select Chemical Group", 
                    "Welcome to The Chem Table",
                    JOptionPane.DEFAULT_OPTION, JOptionPane.QUESTION_MESSAGE,
                    null, byGroup, byGroup[0]);
        for (Element el : e) {
            if (el.getchemGroupBlock().equalsIgnoreCase(byGroup[result])) {
                element = el.getName();
                break;
            }
        }
    } else { // search by symbol
        symbol = JOptionPane.showInputDialog(
                    null, "Enter the element symbol:(H/He/Li)",
                    "Welcome to the Chem Table",
                    JOptionPane.PLAIN_MESSAGE);
        for (Element el : e) {
            if (el.getSymbol().equalsIgnoreCase(symbol)) {
                element = el.getName();
                break;
            }
        }
        if (element.isEmpty()) {
            JOptionPane.showMessageDialog(
                null, "Symbol" + symbol + " not found!", "Not found!", JOptionPane.WARNING_MESSAGE);
            return;
        }
    }
}