Erreur d'exception de format de nombre dans le code

Question

Je rencontre une erreur dans mon code qui indique cette erreur d'exception de format de nombre. J'essaie de prendre l'adresse IP ex.172.16.10.100 & masque de sous-réseau 255.255.255.0. Après avoir pris la valeur, j'essaie de les convertir en format décimal au format binaire. Je reçois erreur dans cette ligne IPaddress = IPaddress + printBinaryFormat(octet[i]);

Pourriez-vous s'il vous plaît me suggérer comment résoudre ce problème?

import java.awt.*; 
import java.awt.event.*; 
import javax.swing.text.MaskFormatter; 
import javax.swing.*; 
import java.text.ParseException; 
import java.util.regex.Pattern; 
import java.math.BigInteger; 
import java.util.Arrays; 
import java.util.StringTokenizer; 

public class update extends JPanel implements ActionListener 
{ 
private JButton cmdCalculate; 
public JFormattedTextField txtIP, txtSub;//Object name txtIP,txtSub 
private JLabel lblCalculate, lblIP, lblSub, lblNetwork, lblHost; 
private static String IPaddress = "",Subenetaddress= "", Networkaddress= "", Lastaddress= ""; 
private JPanel panAnswerArea, panNorthArea, panBase, panAddressGrid, panIP, panSub, panButton; 

public update() 
{ 

    super.setLayout(new BorderLayout());  
    cmdCalculate = new JButton("Calculate"); 
    cmdCalculate.addActionListener(this); 
    lblIP = new JLabel("IP Address: "); 
    lblSub = new JLabel("Subnet Mask: "); 
    panIP = new JPanel(); 
    panSub = new JPanel(); 
    panIP.add(lblIP); 
    panSub.add(lblSub); 
    MaskFormatter mf = null; 

    try { 
     mf = new MaskFormatter("***.***.***.***"); 

    } catch (ParseException e) { 
     e.printStackTrace(); 
    } 

    txtIP = new JFormattedTextField(mf); 
    panIP.add(txtIP); 
    txtIP.setFont(new Font(Font.MONOSPACED, Font.PLAIN, 12)); 
    txtIP.setPreferredSize(new Dimension(150, 24)); 


    txtSub = new JFormattedTextField(mf); 
    panSub.add(txtSub); 
    txtSub.setFont(new Font(Font.MONOSPACED, Font.PLAIN, 12)); 
    txtSub.setPreferredSize(new Dimension(150, 24)); 

    lblCalculate = new JLabel("Calculate Network and Host parts: ", JLabel.LEFT); 
    lblNetwork = new JLabel("Network address: ", JLabel.LEFT); 
    lblHost = new JLabel("Host address: ", JLabel.LEFT); 

    lblNetwork.setText("Network address: "); 
    lblHost.setText("Host address: "); 

    panAnswerArea = new JPanel(new BorderLayout()); //Stores the network and host addresses 
    panNorthArea = new JPanel(new BorderLayout()); //North has the base radio buttons, the south has the IP/Subnet 
    panAddressGrid = new JPanel(new GridLayout(4,2)); //Stores the IP, subnet address and the calculate button 
    panButton = new JPanel(); 


    panAnswerArea = new JPanel(new BorderLayout()); //Stores the network and host addresses 
    this.add(panAnswerArea, BorderLayout.SOUTH); 
    panAnswerArea.add(lblNetwork, BorderLayout.NORTH); 
    panAnswerArea.add(lblHost, BorderLayout.SOUTH); 

    panNorthArea = new JPanel(new BorderLayout()); 
    this.add(panNorthArea, BorderLayout.NORTH); 
    panNorthArea.add(panAddressGrid, BorderLayout.SOUTH); 
    panAddressGrid.add(panIP); 
    panAddressGrid.add(panSub); 
    panAddressGrid.add(panButton); 
    panButton.add(lblCalculate); 
    panButton.add(cmdCalculate); 
} 
public void actionPerformed (ActionEvent e) 
{ 
    String strIP= ""; 
    String strSub= ""; 
    String IPaddress = "",Subenetaddress= "", Networkaddress= "", Lastaddress= "", inversbits= "",inversesubnetmask= ""; 
    strIP = txtIP.getText(); 
    strSub = txtSub.getText(); 

    StringTokenizer st; 
    String[]octet=new String[4]; 
    st = new StringTokenizer(strIP,"."); 

    for(int i =0;i!=4;i++) 
    { 
     octet[i]=st.nextToken(); 
     IPaddress = IPaddress + printBinaryFormat(octet[i]);//problem is here 


    } 


} 

private static String printBinaryFormat(String number) 
{ 
    int decNum = Integer.parseInt(number),length = 0; 
    String binary = "", answer = ""; 

    while(decNum > 0){ 

     binary += Integer.toString (decNum %2); 

     decNum= decNum/2; 

    } 
    length = binary.length(); 

    for (int padding = (8 - length); padding > 0; padding--) 
    { 
     answer += "0"; 
    } 

    for (int i = length; i > 0; i--) 
    { 
     answer += binary.charAt(i - 1); 
    } 

    return answer; 
} 
public static void main(String[] args) 
{ 
    JFrame.setDefaultLookAndFeelDecorated(true);// decorated the border 
    JFrame frame = new JFrame("Subnet Calculators"); //Title 
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); 
    //frame.setSize(500, 600); 

    JComponent paneMain = new update(); 
    paneMain.setOpaque(true); 
    paneMain.setPreferredSize(new Dimension(500, 300));// It works of the size of the frame 
    frame.setContentPane(paneMain); 
    frame.pack(); 
    frame.setVisible(true); 
} 

}

Answer 1

modifier cette ligne:

int decNum = Integer.parseInt(number), length = 0; 

Pour:

int decNum = Integer.parseInt(number.trim()), length = 0; 

Ou:

int decNum = Integer.parseInt(number.replaceAll(" ", "")), length = 0;