我在另一个类中创建了3个类的实例。
Customer kyle = new Customer(true,false,false,"Kyle",1000.00);
Customer andrew = new Customer(false,true,false,"Andrew",0.00);
Customer connor = new Customer(false,false,true,"Connor",5000.00);
如果你需要看它，这是构造函数。
public Customer(boolean regular, boolean payAhead, boolean loyal, String userName, double amountOfStorage) {
this.regular = regular;
this.payAhead = payAhead;
this.loyal = loyal;
this.userName = userName;
this.amtOfStore = amountOfStorage;
}
用户将通过jTextField输入三个用户名之一。我如何获取输入并让它选择将运行该类的实例？目前我有：
if (usernameInputField.getText().equals(kyle.getUserName())
|| usernameInputField.getText().equals(andrew.getUserName())
|| usernameInputField.getText().equals(connor.getUserName())){
}
但我不知道应该在if声明中加入什么。
答案 0 :(得分：4)
用户将通过jTextField输入三个用户名之一。 我如何接受输入并让它选择什么实例 上课会跑？
您可以将所有Customer个对象存储到Map（客户名称为密钥，Customer对象作为值），然后在收到用户输入后，检索相应的{{1来自Customer：
Map现在，获取用户输入并使用密钥检索Map<String, Customer> map = new HashMap<>();
map.add("Kyle", new Customer(true,false,false,"Kyle",1000.00));
map.add("Andrew", new Customer(false,true,false,"Andrew",0.00));
map.add("Connor", new Customer(false,false,true,"Connor",5000.00));
对象（用户输入的客户名称）：
Customer答案 1 :(得分：2)
不要使用Map，ArrayList或JTextField，而是将Customers放入JComboBox，并让用户直接选择可用的Customers。这就是我要做的事情，因为它会更加白痴 - 因为使用它，用户无法进行无效选择。
DefaultComboBoxModel<Customer> custComboModel = new DefaultComboBoxModel<>();
custComboModel.addElement(new Customer(true,false,false,"Kyle",1000.00));
custComboModel.addElement(new Customer(false,true,false,"Andrew",0.00));
custComboModel.addElement(new Customer(false,false,true,"Connor",5000.00));
JComboBox<Customer> custCombo = new JComboBox<>(custComboModel);
请注意，要使其正常工作，您必须覆盖Customer的toString方法并让它返回name字段，否则为JComboBox提供自定义渲染器，以便正确呈现名称。这些教程将为您提供帮助。
如，
import javax.swing.*;
@SuppressWarnings("serial")
public class SelectCustomer extends JPanel {
private DefaultComboBoxModel<SimpleCustomer> custComboModel = new DefaultComboBoxModel<>();
private JComboBox<SimpleCustomer> custCombo = new JComboBox<>(custComboModel);
private JTextField nameField = new JTextField(10);
private JTextField loyalField = new JTextField(10);
private JTextField storageField = new JTextField(10);
public SelectCustomer() {
custComboModel.addElement(new SimpleCustomer("Kyle", true, 1000.00));
custComboModel.addElement(new SimpleCustomer("Andrew", false, 0.00));
custComboModel.addElement(new SimpleCustomer("Connor", false, 5000.00));
custCombo.setSelectedIndex(-1);
custCombo.addActionListener(e -> {
SimpleCustomer cust = (SimpleCustomer) custCombo.getSelectedItem();
nameField.setText(cust.getUserName());
loyalField.setText("" + cust.isLoyal());
storageField.setText(String.format("%.2f", cust.getAmtOfStore()));
});
add(custCombo);
add(new JLabel("Name:"));
add(nameField);
add(new JLabel("Loyal:"));
add(loyalField);
add(new JLabel("Storage:"));
add(storageField);
}
private static void createAndShowGui() {
JFrame frame = new JFrame("SelectCustomer");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.getContentPane().add(new SelectCustomer());
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(() -> createAndShowGui());
}
}
public class SimpleCustomer {
private String userName;
private boolean loyal;
private double amtOfStore;
public SimpleCustomer(String userName, boolean loyal, double amtOfStore) {
this.userName = userName;
this.loyal = loyal;
this.amtOfStore = amtOfStore;
}
public String getUserName() {
return userName;
}
public boolean isLoyal() {
return loyal;
}
public double getAmtOfStore() {
return amtOfStore;
}
@Override
public String toString() {
return userName;
}
}
答案 2 :(得分：1)
您可以为所有客户创建查找地图。您甚至可以对此进行扩展以添加和删除客户。
String username = textField.getText().toLowerCase();
if (customerMap.containsKey(username)) {
output.setText(customerMap.get(username).toString());
} else {
output.setText("Not found!");
}
import java.awt.*;
import java.awt.event.*;
import java.util.*;
import javax.swing.*;
public class App implements Runnable {
private static class Customer {
private String userName;
private boolean regular;
private boolean payAhead;
private boolean loyal;
private double amountOfStorage;
public Customer(String userName, boolean regular, boolean payAhead, boolean loyal, double amountOfStorage) {
this.userName = userName;
this.regular = regular;
this.payAhead = payAhead;
this.loyal = loyal;
this.amountOfStorage = amountOfStorage;
}
@Override
public String toString() {
return String.format("{ userName: %s, regular: %s, payAhead: %s, loyal: %s, amountOfStorage: %s }",
userName, regular, payAhead, loyal, amountOfStorage);
}
}
private static class MainPanel extends JPanel {
private static final long serialVersionUID = -1911007418116659180L;
private static Map<String, Customer> customerMap;
static {
customerMap = new HashMap<String, Customer>();
customerMap.put("kyle", new Customer("Kyle", true, false, false, 1000.00));
customerMap.put("andrew", new Customer("Andrew", false, true, false, 0.00));
customerMap.put("connor", new Customer("Connor", false, false, true, 5000.00));
}
public MainPanel() {
super(new GridBagLayout());
JTextField textField = new JTextField("", 16);
JButton button = new JButton("Check");
JTextArea output = new JTextArea(5, 16);
button.addActionListener(new AbstractAction() {
private static final long serialVersionUID = -2374104066752886240L;
@Override
public void actionPerformed(ActionEvent e) {
String username = textField.getText().toLowerCase();
if (customerMap.containsKey(username)) {
output.setText(customerMap.get(username).toString());
} else {
output.setText("Not found!");
}
}
});
output.setLineWrap(true);
addComponent(this, textField, 0, 0, 1, 1);
addComponent(this, button, 1, 0, 1, 1);
addComponent(this, output, 0, 1, 1, 2);
}
}
protected static void addComponent(Container container, JComponent component, int x, int y, int cols, int rows) {
GridBagConstraints constraints = new GridBagConstraints();
constraints.gridx = x;
constraints.gridy = y;
constraints.gridwidth = cols;
constraints.gridwidth = rows;
container.add(component, constraints);
}
@Override
public void run() {
JFrame frame = new JFrame();
MainPanel panel = new MainPanel();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setContentPane(panel);
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new App());
}
}