Question

我被要求制作一个保存条目并打电话给他们的电话簿。然后老师又添加了一项新任务。该计划应删除条目。他给了我们一个方法，并说我们不允许使用ArrayList或Hashmaps，只有Arrays。我尝试了很多，但似乎无法做到正确，有人可以帮我纠正我的错误吗？共有2个类：PhoneBook和UI

    import javax.swing.ButtonGroup;
import javax.swing.JOptionPane;
import javax.swing.JRadioButton;
public class PhoneBook {
    private static int maxSize = 100; 
    private static int actSize = 0; 
    private static String[] name = new String[maxSize]; 
    private static String[] firstName = new String[maxSize]; 
    private static String[] number = new String[maxSize]; 
    public static String findEntry(String nameP, String firstNameP) {
        for (int i = 0; i < actSize; i++) {
            if (name[i].equals(nameP) && firstName[i].equals(firstNameP)) {
                return number[i];
            }
        }
        return null;
    }
    public static void addEntry(String nameP, String firstNameP, String numberP) {
        if (actSize == maxSize) {
            System.err.println("Memory full!");
            return;
        }
        for (int i = 0; i < actSize; i++) {
            if (name[i].equals(nameP) && firstName[i].equals(firstNameP)) {
                System.err.println("It exists already!");
                return;
            }
        }
        name[actSize] = nameP;
        firstName[actSize] = firstNameP;
        number[actSize] = numberP;
        actSize = actSize + 1;
    }
    public static String getActionDialog(String... actions) { 
        JRadioButton[] buttons = new JRadioButton[actions.length];
        ButtonGroup group = new ButtonGroup();
        for (int i = 0; i<actions.length; i++) {
            buttons[i] = new JRadioButton(actions[i]);
            group.add(buttons[i]);
        }
    buttons[0].setSelected(true);
    Object[] message = buttons;
    Object[] options = { "OK", "Cancel"};
    int n= JOptionPane.showOptionDialog(null,
            message,
            "Choose an Action",
            JOptionPane.YES_NO_OPTION,
            JOptionPane.QUESTION_MESSAGE,
            null,
            options,
            options[0]);
    if(n==JOptionPane.OK_OPTION){
        for (int i = 0; i<actions.length; i++) {
            if(buttons[i].isSelected()){
                return actions[i];
            }
        }
    }
    return null;
    }
    /**
     * Deletes Entries.
     * An entry matches the pattern if it fits in all components (name, first name, number).
     * A component fits, when it is equal to the sample component, or the component pattern of the empty string.
     * 
     * @param nameP         Pattern for the name of the entries to be deleted.
     * @param firstNameP    Pattern for the first names of the entries to be deleted.
     * @param numberP       Pattern for the number of entries to be deleted.
     * @post  all matching entries are deleted. The capacity remains unchanged.
     *        The size is adjusted.
     * @return Number of deleted entries.
     */
    public static int deleteMatchingEntries(String nameP, String firstNameP,
        String numberP) {
    for (int i = 0; i < actSize; i++) {
        if (name[i].equals(nameP)) {
            name[i] = name[i + 1];

            actSize--;
        } else if (firstName[i].equals(firstNameP)) {
            firstName[i] = firstName[i + 1];

            actSize--;
        } else if (number[i].equals(numberP)) {
            number[i] = number[i + 1];

            actSize--;
        }
    }
    return actSize;
}
}



import javax.swing.JOptionPane;
import javax.swing.JTextField;
public class UI {
    public static void main(String[] args) {
        while (true) {
            String action = PhoneBook.getActionDialog(
                    "Create an entry", "Call up an entry","Delete Entry");
            if (action == null) {
                break;
            }
            if (action.equals("Create an entry")) {
                String[] entryData = getEntryDataDialog();
                if (entryData != null) {
                    PhoneBook.addEntry(entryData[0], entryData[1],
                            entryData[2]);
                }
            } else if (action.equals("Call up an entry")) {
                String[] queryData = getQueryDataDialog();
                if (queryData != null) {
                    String nr = PhoneBook.findEntry(queryData[0],
                            queryData[1]);
                    if (nr == null) {
                        JOptionPane.showMessageDialog(null, "Not found");
                    } else {
                        JOptionPane.showMessageDialog(null, "Last Name: "
                                + queryData[0] + ", First Name: " + queryData[1]
                                + ", Number:" + nr);
                    }
                }else if (action.equals("Delete Entry")) {
            String[] delete = getEntryDataDialog();
            if (delete != null) {
                TelephoneDirectory.deleteMatchingEntries(delete[0],
                        delete[1], delete[2]);

                JOptionPane.showMessageDialog(null, "Entry deleted");

            }
        } else {
                System.err.println("Error: unknow Action " + action);
                break;
            }
        }
    }
    private static String[] getEntryDataDialog() {
        JTextField nameTF = new JTextField();
        JTextField firstNameTF = new JTextField();
        JTextField numberTF = new JTextField();
        Object[] message = { "Last Name", nameTF, "First Name", firstNameTF, "Number",
                numberTF };
        Object[] options = { "OK", "Cancel" };
        int n = JOptionPane.showOptionDialog(null, message, "Create an entry",
                JOptionPane.YES_NO_OPTION, JOptionPane.QUESTION_MESSAGE, null,
                options, options[0]);
        if (n == JOptionPane.OK_OPTION) { 
            return new String[] { nameTF.getText(), firstNameTF.getText(),
                    numberTF.getText() };
        } else if (n == JOptionPane.NO_OPTION
                || n == JOptionPane.CLOSED_OPTION) { 
            return null;
        } else {
            return null;
        }
    }
    private static String[] getQueryDataDialog() {
        JTextField nameTF = new JTextField();
        JTextField firstNameTF = new JTextField();
        Object[] message = { "Last Name", nameTF, "First Name", firstNameTF };
        Object[] options = { "OK", "Cancel" };
        int n = JOptionPane.showOptionDialog(null, message, "Call up an entry",
                JOptionPane.YES_NO_OPTION, JOptionPane.QUESTION_MESSAGE, null,
                options, options[0]);
        if (n == JOptionPane.OK_OPTION) { 
            return new String[] { nameTF.getText(), firstNameTF.getText() };
        } else if (n == JOptionPane.NO_OPTION 
                || n == JOptionPane.CLOSED_OPTION) { 
            return null;
        } else {
            return null;
        }
    }
}

Answer 1

您遇到的问题是，在删除条目时，您只移动了一条记录。

您可以执行以下一些更改：

1 - （如果老师允许的话）创建一个包含一个名称，姓氏和号码的PhoneEntry类

2 - （如果允许，再次）将3个数组更改为一个PhoneEntry对象数组（这样可以更容易处理）

3 - 删除时，您不需要移动下一个条目，只需将null放在删除PhoneEntry的位置即可。您还将actSize的含义更改为actQuantity，对于下一个条目添加，您将搜索数组中具有空值的第一个位置。

干杯

Answer 2

你应该使用一个例如班级联系或其他什么。

如果你看一下：

public static int deleteMatchingEntries(String nameP, String firstNameP,
        String numberP) {
    for (int i = 0; i < actSize; i++) {
        if (name[i].equals(nameP)) {
            name[i] = name[i + 1];

            actSize--;
        } else if (firstName[i].equals(firstNameP)) {
            firstName[i] = firstName[i + 1];

            actSize--;
        } else if (number[i].equals(numberP)) {
            number[i] = number[i + 1];

            actSize--;
        }
    }
    return actSize;
}

假设您在阵列的[0]位置都有类似“Doe，John，555-5555”的内容。你的函数将删除Doe，然后保留John和555.突然你的索引不匹配。

此外，我将把deleteMatchingEntries和重构数组删除逻辑重构为一个单独的函数，你可以单独测试。

删除电话簿中的条目

2 个答案: