자바 컴포넌트 질문

import java.awt.BorderLayout; import java.awt.Container; import java.util.HashMap; import java.util.Map; import javax.swing.JComboBox; import javax.swing.JFrame; import javax.swing.JTextField; public class Fruit { public static void main(String[] args) { Map<String, String> fruitDesc = new HashMap<>(); fruitDesc.put("사과", "빨간색 과일"); fruitDesc.put("바나나", "노란색 과일"); fruitDesc.put("키위", "연두색 과일"); JTextField tfDesc = new JTextField(); JComboBox<String> cbFruit = new JComboBox<>(fruitDesc.keySet().toArray(new String[fruitDesc.size()])); cbFruit.addActionListener(e -> { String selectedFruit = (String) cbFruit.getSelectedItem(); if (selectedFruit != null) { tfDesc.setText(fruitDesc.getOrDefault(selectedFruit, "")); } }); cbFruit.setSelectedIndex(0); JFrame frame = new JFrame(); frame.setTitle("과일"); frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); frame.setSize(400, 200); Container c = frame.getContentPane(); c.setLayout(new BorderLayout()); c.add(cbFruit, BorderLayout.PAGE_START); c.add(tfDesc, BorderLayout.CENTER); frame.setVisible(true); } }

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