尝试从 .getText() 解析字符串时出现 NumberFormatException； [英] NumberFormatException when trying to parse Strings from .getText();
本文介绍了尝试从 .getText() 解析字符串时出现 NumberFormatException；的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！
问题描述
Exception in thread "AWT-EventQueue-0" java.lang.NumberFormatException: For input string: "Total: 8.78"
at sun.misc.FloatingDecimal.readJavaFormatString(Unknown Source)
at java.lang.Double.parseDouble(Unknown Source)
at PizzaOrder$BtnClicked.<init>(PizzaOrder.java:298)
at PizzaOrder$BtnClicked.<init>(PizzaOrder.java:295)
at PizzaOrder.addListeners(PizzaOrder.java:102)
at PizzaOrder.<init>(PizzaOrder.java:76)
at PizzaDriver$1.run(PizzaDriver.java:46)
at java.awt.event.InvocationEvent.dispatch(Unknown Source)
at java.awt.EventQueue.dispatchEventImpl(Unknown Source)
at java.awt.EventQueue.access$200(Unknown Source)
at java.awt.EventQueue$3.run(Unknown Source)
at java.awt.EventQueue$3.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(Unknown Source)
at java.awt.EventQueue.dispatchEvent(Unknown Source)
at java.awt.EventDispatchThread.pumpOneEventForFilters(Unknown Source)
at java.awt.EventDispatchThread.pumpEventsForFilter(Unknown Source)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(Unknown Source)
at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
at java.awt.EventDispatchThread.run(Unknown Source)
.
import java.awt.BorderLayout;
import java.awt.FlowLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.ItemEvent;
import java.awt.event.ItemListener;
import java.text.DecimalFormat;
import java.text.NumberFormat;
import javax.swing.*;
/**
* Window for ordering a pizza<br>
*
* <hr>
* Date created: Apr 14, 2014<br>
* <hr>
* @author Zach Latture
*/
public class PizzaOrder extends JFrame
{
private static final long serialVersionUID = 1L;
public static final double PIZZACOST = 8.00,
TAXRATE = 0.0975;
private JPanel headerPanel,
checkPanel,
buttonsPanel;
private JLabel pizzaLbl;
private JCheckBox pepperoni,
sausage,
peppers,
onions,
mushrooms,
cheese;
private JTextField numberOfPizzas;
private JLabel totalLbl,
subtotalLbl;
private JLabel taxLbl;
private NumberFormat fmt = new DecimalFormat();
private JButton submit,
cancel;
private double subtotal = 0;
private double tax = 0;
private double total = 0;
public PizzaOrder()
{
super ("Pizza Order - Latture");
this.setSize(250, 250);
this.setDefaultCloseOperation (JFrame.EXIT_ON_CLOSE);
setLayout(new BorderLayout(2, 5));
initComponents ( ); // instantiate and initial all labels, textfields, etc.
initHeaderPanel ( ); // put label and textfield in header panel
add(headerPanel, BorderLayout.NORTH);
initCheckPanel ( ); // put the checkboxes and totals in the CheckPanel
add(checkPanel, BorderLayout.CENTER);
initButtonPanel ( ); // put the buttons in the button panel
add(buttonsPanel, BorderLayout.SOUTH);
calculate(); // calculate the subtotal, tax, and total
addListeners ( ); // register listeners for all needed events
setLocationRelativeTo(null);
setVisible(true);
}
/**
* add listeners for all events <br>
*
* <hr>
* Date created: Apr 14, 2014 <br>
* Date last modified: Apr 14, 2014 <br>
*
* <hr>
*/
private void addListeners ( )
{
// Register listeners for all events for the components
// such as buttons, checkboxes, etc.
pepperoni.addItemListener(new Listener());
sausage.addItemListener(new Listener());
peppers.addItemListener(new Listener());
onions.addItemListener(new Listener());
mushrooms.addItemListener(new Listener());
cheese.addItemListener(new Listener());
submit.addActionListener(new BtnClicked());
cancel.addActionListener(new BtnClicked());
}
/**
* add buttons to button panel <br>
*
* <hr>
* Date created: Apr 14, 2014 <br>
*
* <hr>
*/
private void initButtonPanel ( )
{
buttonsPanel = new JPanel(new FlowLayout());
buttonsPanel.add (submit);
buttonsPanel.add (cancel);
}
/**
* Init checkboxes and totals <br>
*
* <hr>
* Date created: Apr 14, 2014 <br>
*
* <hr>
*/
private void initCheckPanel ( )
{
checkPanel = new JPanel(new FlowLayout(FlowLayout.CENTER, 5, 1));
checkPanel.add (pepperoni);
checkPanel.add (sausage);
checkPanel.add (peppers);
checkPanel.add (onions);
checkPanel.add (mushrooms);
checkPanel.add (cheese);
checkPanel.add (subtotalLbl);
checkPanel.add (taxLbl);
checkPanel.add (totalLbl);
// Add the checkboxes and labels for the totals and tax
}
/**
* Add label and textfield to header panel <br>
*
* <hr>
* Date created: Apr 14, 2014 <br>
*
* <hr>
*/
private void initHeaderPanel ( )
{
headerPanel = new JPanel(new FlowLayout(FlowLayout.CENTER));
headerPanel.add (pizzaLbl);
headerPanel.add (numberOfPizzas);
}
/**
* instantiate the buttons, checkboxes, labels, etc.<br>
*
* <hr>
* Date created: Apr 14, 2014 <br>
*
* <hr>
*/
private void initComponents ( )
{
submit = new JButton("Submit");
cancel = new JButton("Cancel");
fmt = NumberFormat.getCurrencyInstance ( );
pizzaLbl = new JLabel("Number of pizzas");
totalLbl = new JLabel("Total:");
subtotalLbl = new JLabel("Subtotal:");
taxLbl = new JLabel("Tax: ");
numberOfPizzas = new JTextField("3");
numberOfPizzas.setText("1");
pepperoni = new JCheckBox("Pepperoni");
sausage = new JCheckBox("Sausage");
peppers = new JCheckBox("Peppers");
onions = new JCheckBox("Onions");
mushrooms = new JCheckBox("Mushrooms");
cheese = new JCheckBox("Extra Cheese");
}
/**
* Use the values selected and entered to determine the cost<br>
*
* <hr>
* Date created: Apr 14, 2014 <br>
*
* <hr>
*/
public void calculate()
{
subtotal = 0;
double increase = 0;
String input = numberOfPizzas.getText();
double val = 0, determinedTotal, determinedSubtotal, determinedTax;
val = numberOfPizzas.getValue().doubleValue();
try
{
val = Double.parseDouble(input);
}catch(Exception e)
{
System.out.print("Invalid input. Error: " + e.getMessage());
}
determinedSubtotal = val * PIZZACOST;
determinedTax = determinedSubtotal * TAXRATE;
determinedTotal = determinedSubtotal + determinedTax;
if(pepperoni.isSelected())
{
pepperoni.setSelected(true);
increase += val * 1.00;
}
if(sausage.isSelected())
{
sausage.setSelected(true);
increase += val * 1.00;
}
if(peppers.isSelected())
{
peppers.setSelected(true);
increase += val * .50;
}
if(onions.isSelected())
{
onions.setSelected(true);
increase += val * .50;
}
if(mushrooms.isSelected())
{
mushrooms.setSelected(true);
increase += val * .50;
}
if(cheese.isSelected())
{
cheese.setSelected(true);
increase += val * 1.00;
}
subtotalLbl.setText("Subotal: " +String.valueOf(determinedSubtotal + increase));
taxLbl.setText("Tax: " +String.valueOf(determinedTax + increase));
totalLbl.setText("Total: " + String.valueOf(determinedTotal + increase));
numberOfPizzas.grabFocus ( );
numberOfPizzas.selectAll ( );
return;
}
/**
* Class handles ItemStateChanged events for checkboxes<br>
*
* <hr>
* Date created: Apr 14, 2014<br>
* <hr>
* @author Zach Latture
*/
private class Listener implements ItemListener
{
// Appropriate method calculates the results
public void itemStateChanged(ItemEvent e)
{
calculate();
}
}
/**
* Class handles button clicked events for both buttons<br>
*
* <hr>
* Date created: Apr 14, 2014<br>
* <hr>
* @author Zach Latture
*/
private class BtnClicked implements ActionListener
{
String input = totalLbl.getText();
Double d = Double.parseDouble(input) * 0.20;
public void actionPerformed(ActionEvent e)
{
Object src = e.getSource();
if(src == submit)
{
JOptionPane.showMessageDialog (null, "Thank you for your order - the tip will be" + fmt.format(d),"Thank you.", 1);
}
else if(src == cancel)
{
JOptionPane.showMessageDialog (null, "Order cancelled","Thank you.", 1);
}
}
/**
* Reset the choices to their defaults<br>
*
* <hr>
* Date created: Apr 14, 2014 <br>
*
* <hr>
*/
private void reset ( )
{
// Set the checkboxes and text fields to their original values
calculate();
}
}
}
我收到了上面提到的错误.我认为这是因为解析了一个空字符串，但我无法准确指出在哪里.它在错误的第一行显示总数，但尚未给出任何输入.我已经研究了一段时间了，希望有经验的新人能看到这个问题.
i'm getting the error mentioned above. I assume it's because of parsing an empty string, but i haven;t been able to pinpoint exactly where. It's displaying the total in the first line of the error, yet no input has been given yet. I've been looking at this for a while now, and hopefully a new pair experienced of eyes can see the problem.
推荐答案
我认为这是因为解析一个空字符串，
I assume it's because of parsing an empty string,
不，这是因为它试图解析的字符串是 Total: 8.78
No it is because the String it is attempting to parse is Total: 8.78
删除该标签的快速方法是(假设您可以控制标签
quick way to remove that label is (assumming you have control over the label
substring("Total:".length()).trim();
这篇关于尝试从 .getText() 解析字符串时出现 NumberFormatException；的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
查看全文
