Question

我的Java（applet）中的简单二进制代码转换器出现了问题：

import java.awt.*;
import java.awt.event.*;
import java.applet.Applet;

public class dual_convert extends Applet implements ActionListener{
  TextField dual;
  TextField decimal;
  Button dual_b;
  Button decimal_b;
  Label dual_l;
  Label decimal_l;
  int decimal_i;
  String dual_s [];
  int dual_i;
  int decimal_e;

  public void init() {
    setLayout(null);

    dual = new TextField();
    dual.setBounds(90,10,100,25);
    add(dual);

    decimal = new TextField();
    decimal.setBounds(90,40,100,25);
    add(decimal);

    decimal_l = new Label("Decimal:");
    decimal_l.setBounds(10,40,80,25);
    add(decimal_l);

    dual_l = new Label("Binary:");
    dual_l.setBounds(10,10,80,25);
    add(dual_l);

    dual_b = new Button ("Convert");
    dual_b.setBounds(200,10,80,25);
    add(dual_b);
    dual_b.addActionListener(this);

    decimal_b = new Button ("Convert");
    decimal_b.setBounds(200,40,80,25);
    add(decimal_b);
    decimal_b.addActionListener(this);

  }

  public void actionPerformed (ActionEvent e) {
    if (e.getSource()==decimal_b) {
      decimal_i = Integer.parseInt(decimal.getText());  
      int ih = 0;
      dual.setText("");
      while (decimal_i>0) {
        dual.setText((decimal_i % 2)+dual.getText());
        decimal_i = decimal_i / 2; 
        ih++;
      }    
    }

    if (e.getSource()==dual_b) {
      dual_s = dual.getText().split("");
      dual_i = dual_s.length;
      decimal.setText("");
      for (int i=0;dual_i>0;dual_i--) {
        decimal_e = decimal_e + (Integer.parseInt(dual_s[dual_i]) * 2^i); 
        i++;
      } 
      decimal.setText(decimal_e+"");       
    } 
  }
}

通过按Convert Binary to Decimal：

抛出此异常

线程“AWT-EventQueue-1”中的异常 java.lang.ArrayIndexOutOfBoundsException：8 at dual.actionPerformed（dual.java:65）at java.awt.Button.processActionEvent（Button.java:409）at java.awt.Button.processEvent（Button.java:377）at java.awt.Component.dispatchEventImpl（Component.java:4861）at java.awt.Component.dispatchEvent（Component.java:4687）at java.awt.EventQueue.dispatchEventImpl（EventQueue.java:729）at at java.awt.EventQueue.access $ 200（EventQueue.java:103）at java.awt.EventQueue $ 3.run（EventQueue.java:688）at java.awt.EventQueue $ 3.run（EventQueue.java:686）at java.security.AccessController.doPrivileged（Native Method）at java.security.ProtectionDomain $ 1.doIntersectionPrivilege（ProtectionDomain.java:76）在 java.security.ProtectionDomain $ 1.doIntersectionPrivilege（ProtectionDomain.java:87）在java.awt.EventQueue $ 4.run（EventQueue.java:702）at java.awt.EventQueue $ 4.run（EventQueue.java:700）at java.security.AccessController.doPrivileged（Native Method）at java.security.ProtectionDomain $ 1.doIntersectionPrivilege（ProtectionDomain.java:76）在java.awt.EventQueue.dispatchEvent（EventQueue.java:699）at java.awt.EventDispatchThread.pumpOneEventForFilters（EventDispatchThread.java:242）在 java.awt.EventDispatchThread.pumpEventsForFilter（EventDispatchThread.java:161）在 java.awt.EventDispatchThread.pumpEventsForHierarchy（EventDispatchThread.java:150）在 java.awt.EventDispatchThread.pumpEvents（EventDispatchThread.java:146）在 java.awt.EventDispatchThread.pumpEvents（EventDispatchThread.java:138） at java.awt.EventDispatchThread.run（EventDispatchThread.java:91）

对于二进制 - ＆gt;十进制转换，我使用这个系统（还有其他吗？）：

100101 = [（1）×25] + [（0）×24] + [（0）×23] + [（1）×22] + [（0）×21] + [（1）× 20]

100101 = [1×32] + [0×16] + [0×8] + [1×4] + [0×2] + [1×1]

100101 = 3710

https://en.wikipedia.org/wiki/Binary_number

编辑：Talas发布后有一个新的例外：

线程“AWT-EventQueue-1”中的异常 java.lang.NumberFormatException：对于输入字符串：“”at java.lang.NumberFormatException.forInputString（NumberFormatException.java:65）在java.lang.Integer.parseInt（Integer.java:504）at java.lang.Integer.parseInt（Integer.java:527）at dual_convert.actionPerformed（dual_convert.java:64）at java.awt.Button.processActionEvent（Button.java:409）at java.awt.Button.processEvent（Button.java:377）at java.awt.Component.dispatchEventImpl（Component.java:4861）at java.awt.Component.dispatchEvent（Component.java:4687）at java.awt.EventQueue.dispatchEventImpl（EventQueue.java:729）at at java.awt.EventQueue.access $ 200（EventQueue.java:103）at java.awt.EventQueue $ 3.run（EventQueue.java:688）at java.awt.EventQueue $ 3.run（EventQueue.java:686）at java.security.AccessController.doPrivileged（Native Method）at java.security.ProtectionDomain $ 1.doIntersectionPrivilege（ProtectionDomain.java:76）在 java.security.ProtectionDomain $ 1.doIntersectionPrivilege（ProtectionDomain.java:87）在java.awt.EventQueue $ 4.run（EventQueue.java:702）at java.awt.EventQueue $ 4.run（EventQueue.java:700）at java.security.AccessController.doPrivileged（Native Method）at java.security.ProtectionDomain $ 1.doIntersectionPrivilege（ProtectionDomain.java:76）在java.awt.EventQueue.dispatchEvent（EventQueue.java:699）at java.awt.EventDispatchThread.pumpOneEventForFilters（EventDispatchThread.java:242）在 java.awt.EventDispatchThread.pumpEventsForFilter（EventDispatchThread.java:161）在 java.awt.EventDispatchThread.pumpEventsForHierarchy（EventDispatchThread.java:150）在 java.awt.EventDispatchThread.pumpEvents（EventDispatchThread.java:146）在 java.awt.EventDispatchThread.pumpEvents（EventDispatchThread.java:138） at java.awt.EventDispatchThread.run（EventDispatchThread.java:91）

Answer 1

你有这个类和一个名为dual的文本域。我对这个编译感到有些惊讶，但这可能就是问题所在。

Answer 2

问题在于：

 for (int i=0;dual_i>0;dual_i--) {
    decimal_e = decimal_e + (Integer.parseInt(dual_s[dual_i - 1]) * 2^i); 
    i++;
  }

您应该使用dual_s[dual_i - 1]代替dual_s[dual_i]，因为dual_i = dual_s.length;和数组索引以0开头

使用简单的二进制代码转换器的例外

2 个答案: