Question

该程序允许用户计算输入销售额并计算每个州的销售税。该程序在阅读双字状态时会出错（例如新泽西州）。我需要部分内容。

    import java.text.DecimalFormat;
import java.util.*;
import java.io.*;
import java.lang.reflect.Array;
import java.nio.CharBuffer;
import java.awt.*;
//import java.awt.event.*;
import javax.lang.model.type.ArrayType;
import javax.swing.*;
import javax.swing.event.*;
public class PJ5 extends JFrame implements ListSelectionListener
{String []States = new String[100];
    double []statetax = new double[100];
double sales;
JPanel p1;
JList  StateList;



JTextField salesField;
private JTextField taxField;
public static void main(String []args)    
  {
  PJ5  x = new PJ5();
  x.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
  x.setTitle("Sales tax calculator");
  x.setSize(350, 250);
  x.setVisible(true);

  } // main

public PJ5() // constructor
{
String s;
StringTokenizer st;
int k=0;
try 
{
BufferedReader inFile = new BufferedReader(new FileReader("C:\\Users\\Owner\\Documents\\taxrates.txt"));
    while ((s= inFile.readLine()) != null)
    {


st = new StringTokenizer(s);
        States[k]=(st.nextToken());

    statetax[k] = Double.valueOf(st.nextToken());

    ++k;
    } // while not EOF
  inFile.close();
} catch (Exception e) { System.err.println(e); }



JPanel p1 =new JPanel();

 p1.setLayout(new GridLayout(2,1));

p1.add(new JLabel("Sales amount:"));
salesField= new JTextField(5);
salesField.setEditable(true);
p1.add(salesField);


p1.add(new JLabel("tax:"));
taxField= new JTextField(4);
taxField.setEditable(false);
p1.add(taxField);


add(p1,BorderLayout.NORTH);
pack();
setVisible(true);

JPanel p = new JPanel();
StateList = new JList(States);  // create a JList object
StateList.setSelectionMode(ListSelectionModel.SINGLE_SELECTION); 
JScrollPane sp = new JScrollPane(StateList);  // adding scrolling capability
p.add(sp);
getContentPane().add(p, BorderLayout.SOUTH);
// Event registration
StateList.addListSelectionListener(this);
} // constructor

// Event handling
public void valueChanged(ListSelectionEvent event)
     {
    DecimalFormat dollar = new DecimalFormat("0.00");   
    double tax;
     sales=Double.parseDouble(salesField.getText());

tax=sales* (statetax[StateList.getSelectedIndex()]/100);
     taxField.setText("$"+dollar.format(tax));

     } // valueChanged
}

这是包含州税率的文本文件。

Alabama 4.0
Alaska 0.
Arizona 5.6
Arkansas 6.0
California 8.25
Colorado 2.9
Connecticut 6.0
Delaware  2.07
Florida 6.0
Georgia 4.0
Hawaii 4.0
Idaho 6.0
Illinois 6.25
Indiana 7.0
Iowa    6.0
Kansas  5.3
Kentucky    6.0
Louisian,   4.0
Maine   5.0
Maryland    6.0
Massachusetts   6.25
Michigan    6.0
Minnesota   6.875
Mississippi 7.0
Missouri    4.225
Montana 0.
Nebraska    5.5
Nevada  6.85
New Hampshire 0.0
New Jersey  7.0
New Mexico  5.375
New York    4.0
North Carolina  4.5
North Dakota    5.0
Ohio    5.5
Oklahoma    4.5
Oregon  0.
Pennsylvania    6.0
Rhode Island    7.0
South Carolina  6.0
South Dakota    4.0
Tennessee   7.0
Texas   6.25
Utah    5.95
Vermont     6.0
Virginia    5.0
West Virginia   6.0
Wisconsin   5.0
Washington  6.5
Washington DC   5.75
Wyoming 4.0

Answer 1

因为，tokenizer将 New 解析为字符串，然后下一个代码将 Hampshire 解析为double，您可能需要重新构建代码

尝试使用字符串标记生成器读取状态名称时出错

1 个答案: