编写实现购物清单的程序

Question

问题遇到的现象和发生背景

这是题目要求：

UI control- JList

问题相关代码，请勿粘贴截图

import javax.swing.;
import java.awt.;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import java.util.HashMap;

public class lab03 {
    public static void main(String[] args) {
        Window window = new Window();
        window.run();
    }
}
class Window {
    private JFrame jFrame = new JFrame("Gu siyi_21321302");
    private Button button1 = new Button("Add new purchases info");
    private Button button2 = new Button("Remove the purchases by its number");
    private Button button3 = new Button("Print");
    private Button button4 = new Button("Print");
    private TextField textField1 = new TextField();
    private TextField textField2 = new TextField();
    private TextField textField3 = new TextField();
    private TextField textField4 = new TextField();
    private Box box1 = Box.createVerticalBox();
    private Box box = Box.createHorizontalBox();
    private Box box2 = Box.createHorizontalBox();
    private Box box3 = Box.createHorizontalBox();
    private Box box4 = Box.createHorizontalBox();
    private Box box5 = Box.createHorizontalBox();
    private Box box6 = Box.createVerticalBox();
    private List listTag = new List();
    private Label labelTag = new Label("name");
    private Label labelTitle = new Label("comment");
    private Label labelDes = new Label("amount of credits spent");
    private Label labelDate = new Label("data of purchase");
    private HashMap<String,Data> hashSetHashMap = new HashMap<>();
    public void run(){
        box2.add(labelTag);
        box2.add(textField1);
        box3.add(labelTitle);
        box3.add(textField2);
        box4.add(labelDes);
        box4.add(textField3);
        box5.add(labelDate);
        box5.add(textField4);
        box6.add(box2);
        box6.add(box3);
        box6.add(box4);
        box6.add(box5);
        box.add(button1);
        box.add(button2);
        box.add(button3);

        box.setSize(400,100);
        box1.add(listTag);
        box1.add(box);
        box1.add(box6);
        jFrame.add(box1);
        jFrame.setVisible(true);;
        jFrame.setSize(400,400);
        jFrame.setLocation(440,0);
        jFrame.addWindowFocusListener(new WindowAdapter() {
            @Override
            public void windowClosing(WindowEvent e) {
                System.exit(0);
            }
        });
        button1.addActionListener(new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent e) {
                String name = textField1.getText();
                String comment = textField2.getText();
                String amount = textField3.getText();
                String dataop = textField4.getText();
                Data data = new Data(name,comment,amount,dataop);
                hashSetHashMap.put(data.getName(),data);
                listTag.add(name);
            }
        });
        listTag.addActionListener(new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent e) {
                String target = listTag.getSelectedItem();
                Data data = hashSetHashMap.get(target);
                textField1.setText(data.getName());
                textField2.setText(data.getComment());
                textField3.setText(data.getAmount());
                textField4.setText(data.getData0f());
            }
        });
        button2.addActionListener(new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent e) {
                String target = listTag.getSelectedItem();
                String title = textField2.getText();
                String des = textField3.getText();
                String date = textField4.getText();
                Data data = new Data(target,title,des,date);
                hashSetHashMap.put(data.getName(),data);
            }
        });
        button3.addActionListener(new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent e) {
                String target = listTag.getSelectedItem();
                hashSetHashMap.remove(target);
                listTag.remove(target);
            }
        });
        button4.addActionListener(new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent e) {
                JFrame jFrame1 = new JFrame("search");
                JComboBox jComboBox = new JComboBox();
                jComboBox.addItem("name");
                jComboBox.addItem("comment");
                jComboBox.addItem("amount");
                jComboBox.addItem("data");
                TextField tf = new TextField();
                Button b1 = new Button("search");
                Box boxx = Box.createHorizontalBox();
                boxx.add(jComboBox);
                boxx.add(tf);
                boxx.add(b1);
                jFrame1.add(boxx);
                jFrame1.setVisible(true);;
                jFrame1.setLocation(840,200);
                jFrame1.setSize(400,80);
                jFrame1.addWindowFocusListener(new WindowAdapter() {
                    @Override
                    public void windowClosing(WindowEvent e) {
                        System.exit(0);
                    }
                });
                b1.addActionListener(new ActionListener() {
                    @Override
                    public void actionPerformed(ActionEvent e) {
                        String target = jComboBox.getSelectedItem().toString();
                        String m = tf.getText();
                        if(target==null) {
                            for(String s : hashSetHashMap.keySet()){
                                if(s.equals(m)){
                                    Data data = hashSetHashMap.get(m);
                                    textField1.setText(data.getName());
                                    textField2.setText(data.getComment());
                                    textField3.setText(data.getAmount());
                                    textField4.setText(data.getData0f());
                                }
                            }
                        }
                        switch (target){
                            case "name":
                                for(String s : hashSetHashMap.keySet()){
                                    if(s.equals(m)){
                                        Data data = hashSetHashMap.get(m);
                                        textField1.setText(data.getName());
                                        textField2.setText(data.getComment());
                                        textField3.setText(data.getAmount());
                                        textField4.setText(data.getData0f());
                                    }
                                }
                                break;
                            case "comment":
                                Data data = selectByTitle(m);
                                textField1.setText(data.getName());
                                textField2.setText(data.getComment());
                                textField3.setText(data.getAmount());
                                textField4.setText(data.getData0f());
                                break;
                            case "amount":
                                Data data1 = selectByDes(m);
                                textField1.setText(data1.getName());
                                textField2.setText(data1.getComment());
                                textField3.setText(data1.getAmount());
                                textField4.setText(data1.getData0f());
                                break;
                            case "data":
                                Data data2 = selectByDate(m);
                                textField1.setText(data2.getName());
                                textField2.setText(data2.getComment());
                                textField3.setText(data2.getAmount());
                                textField4.setText(data2.getData0f());
                                break;
                        }
                    }
                });
            }
        });
    }
    public Data selectByTitle(String title){
        for(String key :hashSetHashMap.keySet()){
            Data data = hashSetHashMap.get(key);
            if(data.getComment().equals(data)){
                return data;
            }
        }
        return null;
    }
    public Data selectByDes(String des){
        for(String key :hashSetHashMap.keySet()){
            Data data = hashSetHashMap.get(key);
            if(data.getAmount().equals(data)){
                return data;
            }
        }
        return null;
    }
    public Data selectByDate(String date){
        for(String key :hashSetHashMap.keySet()){
            Data data = hashSetHashMap.get(key);
            if(data.getData0f().equals(data)){
                return data;
            }
        }
        return null;
    }

}
class Data{
    private String name;
    private String comment;
    private String amount;
    private String data;

    public String getName() {
        return name;
    }

    public void setName(String tag) {
        this.name = name;
    }

    public String getComment() {
        return comment;
    }

    public void setComment(String comment) {
        this.comment = comment;
    }

    public String getAmount() {
        return amount;
    }

    public void setAmount(String amount) {
        this.amount = amount;
    }

    public String getData0f() {
        return data;
    }

    public void setDataOf(String data) {
        this.data = data;
    }

    public Data() {
    }

    public Data(String name, String comment, String amount, String data) {
        this.name = name;
        this.comment = comment;
        this.amount = amount;
        this.data = data;
    }

}

运行结果及报错内容

不知道怎么实现题目输入删除，打印之类的要求

我的解答思路和尝试过的方法

我想要达到的结果

程序能够满足题目要求的运行