這個Java應用程序爲什麼掛起/凍結？

Question

我目前正在編寫計算PI和E到第n項的代碼。我在TermsJTextField中輸入一個數字，選擇PI或E單選按鈕（一次只能有一個按鈕處於活動狀態），按下計算，它應該顯示適當的答案。然而，當我按下calculate時，應用程序會處於掛起狀態，並且沒有任何按鈕會響應，即使是x按鈕。答案從不顯示。

這是代碼。我已經收窄到讓我頭疼的部分：

private void CalculateJButtonActionPerformed(java.awt.event.ActionEvent evt) {             
    final double MAX_VALUE = 10000; //Max value 
    double Start, End;    //Star and end time 
    BigDecimal result = new BigDecimal ("0"); // Constants for result 
    BigDecimal Error = new BigDecimal ("0"); // And Error 
    DecimalFormat integerFormatter = new DecimalFormat("#0."); 
    Start = System.currentTimeMillis(); 
    int Terms; 
    int count = 1; 

    boolean PIchecked = PiJRadioButton.isSelected(); 
    boolean Echecked = EJRadioButton.isSelected(); 
    double PI = 0; 
    double E = 1; 
    try 
    { 
     Terms = Integer.parseInt(TermsJTextField.getText()); 
     if ((Terms <= 2) || (Terms >= 10000)) // This checks for the number of terms 
     { 
      throw new NumberFormatException(); 
     } 
     else 
     { 
      if (PIchecked) // If Pi butoon is selected, do the following calculation 
      { 
       for (int i =1 ; 1 <= (Terms);i++) 
       { 
        count++; 
        result = result.add(new BigDecimal (Math.pow((-1.0),count)/(2*i-1))); 
       } 
      EJRadioButton.setSelected(false); 
      result = result.multiply(new BigDecimal (4.0)); 
      Error = new BigDecimal(Math.abs(PI-result.doubleValue())/PI * 100.0); 
      } 
     else if (Echecked) // This calculates nth term for E 
     { 
      result = new BigDecimal("0"); 
       long factorial = 1L; 

       for (int i = 1; i < Terms ; i++) 
       { 
        factorial *= i; 
        result = result.add(new BigDecimal(1.0/factorial)); 
       } 
       result = result.add(new BigDecimal(1L)); 
       Error = new BigDecimal(Math.abs(E-result.doubleValue())/E * 100.0); 
      PiJRadioButton.setSelected(false); 

     } 

        End = System.currentTimeMillis(); //Time in ms to calculate the answer 

    //Output 
    DecimalFormat Number = new DecimalFormat("#####0.##"); 
    if (PIchecked) 
    { 
     EJTextField.setText(""); 
     PIJTextField.setText(String.valueOf(result)); 
     ErrorJTextField.setText(String.valueOf(Error + "%")); 
    } 
    else 
    { 
     PIJTextField.setText(""); 
     EJTextField.setText(String.valueOf(result)); 
     ErrorJTextField.setText(String.valueOf(Error + "%")); 
    } 
    PrintJButton.setEnabled(true); 
    PrintJMenuItem.setEnabled(true); 
    TimeJTextField.setText(String.valueOf(End-Start)); 
    } 
    } 


    catch(NumberFormatException exp) 

     { 

      Object ERROR_MESSAGE = null; 
       JOptionPane.showMessageDialog(null, "Don't be silly; Enter a vaule between 2 and 10000", 
       "Input Error", JOptionPane.ERROR_MESSAGE); 
       TermsJTextField.selectAll(); 
       TermsJTextField.setText(""); 
       TermsJTextField.requestFocus(); 
      }   

} 

Answer 1

看來，你的終止條件您的循環將永遠不會完成，如下所示：

for (int i =1 ; 1 <= (Terms);i++) 

它切換到下面應該修復它（改變1到i）：

for (int i = 1; i <= Terms; i++)