暗号化されたコードまたは暗号化されるコードの入力を取得するために JFileChooser と JPassword を使用するコードを作成しようとしています。
これが暗号化されるコードです。.rtf または .txt ファイルに保存します。キーは「アニー」です。出力は
"Fv '$zi (# pzm"| (wy& `%ip(zzm%".
プロジェクト「Password」の下に 2 つの異なるクラス ファイルがあります。1 つのクラスは「File Opener」と呼ばれます。クラスを「Password1」と呼びます。
これが Password1.java です。
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import java.util.Arrays;
/* PasswordDemo.java requires no other files. */
public class Password1 extends JPanel
implements ActionListener {
private String key;
private static String OK = "ok";
private JFrame controllingFrame; //needed for dialogs
private JPasswordField passwordField;
public Password1(JFrame f) {
//Use the default FlowLayout.
controllingFrame = f;
//Create everything.
passwordField = new JPasswordField(10);
passwordField.setActionCommand(OK);
passwordField.addActionListener(this);
JLabel label = new JLabel("Enter the key: ");
label.setLabelFor(passwordField);
JComponent buttonPane = createButtonPanel();
//Lay out everything.
JPanel textPane = new JPanel(new FlowLayout(FlowLayout.TRAILING));
textPane.add(label);
textPane.add(passwordField);
add(textPane);
add(buttonPane);
}
protected JComponent createButtonPanel() {
JPanel p = new JPanel(new GridLayout(0,1));
JButton okButton = new JButton("OK");
okButton.setActionCommand(OK);
okButton.addActionListener(this);
p.add(okButton);
return p;
}
public void actionPerformed(ActionEvent e) {
String cmd = e.getActionCommand();
controllingFrame.dispose();
if (OK.equals(cmd)) { //Process the password.
char[] input = passwordField.getPassword();
key = new String(input);
//Zero out the possible password, for security.
Arrays.fill(input,'0');
passwordField.selectAll();
resetFocus();
} else {
System.out.println("Please enter a key.");
}
}
public String getKey(){
return key;
}
//Must be called from the event dispatch thread.
protected void resetFocus() {
passwordField.requestFocusInWindow();
}
public static void createAndShowGUI() {
//Create and set up the window.
JFrame frame = new JFrame("Key");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
//Create and set up the content pane.
final Password1 newContentPane = new Password1(frame);
newContentPane.setOpaque(true); //content panes must be opaque
frame.setContentPane(newContentPane);
//Make sure the focus goes to the right component
//whenever the frame is initially given the focus.
frame.addWindowListener(new WindowAdapter() {
public void windowActivated(WindowEvent e) {
newContentPane.resetFocus();
}
});
//Display the window.
frame.pack();
frame.setVisible(true);
}
public static void main(String[] args) {
//Schedule a job for the event dispatch thread:
//creating and showing this application's GUI.
SwingUtilities.invokeLater(new Runnable() {
public void run() {
//Turn off metal's use of bold fonts
UIManager.put("swing.boldMetal", Boolean.FALSE);
createAndShowGUI();
}
});
}
}
そして、これが FileOpener.java です。
import javax.swing.*;
import java.io.*;
import javax.swing.filechooser.*;
import java.awt.event.*;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.PrintWriter;
import java.util.Scanner;
public class FileOpener extends JPanel implements ActionListener {
static private final String newline = "\n";
private Password1 p1;
JButton decodeButton, encodeButton;
JFileChooser fc;
JTextArea log;
Scanner in = new Scanner(System.in);
JFrame frame;
File file;
int count;
public FileOpener(){
// create and set up the window.
frame = new JFrame("Open Your File");
// make the program close when the window closes
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
// create the box layout
frame.getContentPane( ).setLayout(new BoxLayout(frame.getContentPane( ), BoxLayout.Y_AXIS));
//label prompting user for input
JLabel label1 = new JLabel ("Would you like to encode or decode your file?", JLabel.CENTER);
frame.getContentPane().add(label1);
//create a filer chooser
fc = new JFileChooser();
// add a button object
decodeButton = new JButton("Decode");
decodeButton.addActionListener(this);
frame.getContentPane( ).add(decodeButton);
encodeButton = new JButton("Encode");
encodeButton.addActionListener(this);
frame.getContentPane( ).add(encodeButton);
// display the window.
frame.pack( );
frame.setVisible(true);
}
public void actionPerformed(ActionEvent e) {
//Handle open button action.
if (e.getSource() == encodeButton) {
frame.dispose();
int returnVal = fc.showOpenDialog(FileOpener.this);
if (returnVal == JFileChooser.APPROVE_OPTION ) {
try {
file = fc.getSelectedFile();
p1 = new Password1(frame);
p1.createAndShowGUI();
//get length of key
String key = p1.getKey();
int length3 = key.length();
count = 0;
int keyAsciiValues[] = new int[length3];
String name1 ="";
//get ascii value of each letter in key
for (int k=0; k<length3; k++){
char a = key.charAt(k);
int ascii1 = (int)a;
//put ascii value of letter in key to array
keyAsciiValues[k]= ascii1;
}
FileInputStream file2= new FileInputStream(file);
//create a scanner for it
in = new Scanner(file2);
//read in message
String name;
name = in.nextLine();
for (int k=0; k<length3; k++){
char a = key.charAt(k);
int ascii1 = (int)a;
//put ascii value of letter in key to array
keyAsciiValues[k]= ascii1;
}
//measure length of code message array
int length1 = name.length();
//measures length of strings in code message array
for(int j=0;j<length1;j++){
char c = name.charAt(j);
int ascii = (int)c;
ascii += keyAsciiValues[count];
if(c != ' '){
count++;
}
if(count>length3-1){
count = 0;
}
while(ascii>126){
ascii-= 93;
}
char b=(char)ascii;
if(c == ' '){
b = ' ';
}
name1 += b;
}
System.out.println(name1);
} catch (FileNotFoundException k){
//the file was not found!
System.out.println("File could not be opened!");
}
}
//Handle save button action.
} else if (e.getSource() == decodeButton) {
frame.dispose();
int returnVal = fc.showOpenDialog(FileOpener.this);
if (returnVal == JFileChooser.APPROVE_OPTION) {
try {
file = fc.getSelectedFile();
p1 = new Password1(frame);
p1.createAndShowGUI();
//open the file
//get length of key
String key = p1.getKey();
int length3 = key.length();
count = 0;
int keyAsciiValues[] = new int[length3];
String name1 ="";
//get ascii value of each letter in key
for (int k=0; k<length3; k++){
char a = key.charAt(k);
int ascii1 = (int)a;
//put ascii value of letter in key to array
keyAsciiValues[k]= ascii1;
}
//create a scanner for it
in = new Scanner(file);
//read in message
String name;
name = in.nextLine();
for (int k=0; k<length3; k++){
char a = key.charAt(k);
int ascii1 = (int)a;
//put ascii value of letter in key to array
keyAsciiValues[k]= ascii1;
}
//measure length of code message array
int length1 = name.length();
//measures length of strings in code message array
for(int j=0;j<length1;j++){
char c = name.charAt(j);
int ascii = (int)c;
ascii -= keyAsciiValues[count];
if(c != ' '){
count++;
}
if(count>length3-1){
count = 0;
}
while(ascii<33){
ascii+= 93;
}
char b=(char)ascii;
if(c == ' '){
b = ' ';
}
name1 += b;
}
System.out.print(name1);
} catch (FileNotFoundException k){
//the file was not found!
System.out.println("File could not be opened!");
}
}
in.close();
log.append("Opening: " + file.getName() + "." + newline);
}
}
public static void main(String args[]) {
//Schedule a job for the event dispatch thread:
//creating and showing this application's GUI.
FileOpener f = new FileOpener();
}
}
JFileChooser と Password を追加する前は問題なく動作していました。別名、コードの実際の暗号化部分に問題はないはずです。
java.lang.NullPointerExceptionFileOpener の 70 行目に at 行が表示されます。
int length3 = key.length();
ありがとう！