java - 无法生成固定大小的字母数字符号字符串

Question

我正在构建一个应用程序，如果用户没有他/她自己的密码想法，它会为用户建议一个强密码。这个想法是用户选择密码的大小(4 个单选按钮)、密码特征(4 个复选框)和点击生成。基于这个选择，我正在尝试生成一个随机字符串:

private String generatedPassword(){
    int length = 0;
    StringBuilder generatedString = new StringBuilder();
    Random rand = new Random();

    if(radio4.isSelected()){length = 4;}
    else if(radio8.isSelected()){length = 8;}
    else if(radio12.isSelected()){length = 12;}
    else if(radio16.isSelected()){length = 16;}

    if(passwordABCD.isSelected()){totalCharacters += capitalLetters;}
    if(passwordabcd.isSelected()){totalCharacters += lowercaseLetters;}
    if(password0123.isSelected()){totalCharacters += numbers;}
    if(passwordSymbols.isSelected()){totalCharacters += characters;}

    char[] text = new char[length];

    for(int i = 0; i < length; i++){text[i] = totalCharacters.charAt(rand.nextInt(length));}

    for (char c : text) { generatedString.append(c); }

    return generatedString.toString();
}

并在用户点击“生成”时设置该字符串的EditText

GenerateDialog(@NonNull Context context) {
    super(context, android.R.style.Theme_NoTitleBar_Fullscreen);
    setContentView(R.layout.dialog_layout);

    ...

    generatePassword.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            passwordEditText.setText(generatedPassword());
        }
    });

    ...
}

但不幸的是，passwordEditText Edit Text 字段中看不到任何内容。

Answer 1

尝试在按钮上使用 isChecked() 方法而不是 isSelected()。

此外，您可能希望通过删除不必要的 char[] 数组来简化代码，而是执行如下操作:

for (int i = 0; i < length; i++) {
   generatedString.append(totalCharacters.charAt(rand.nextInt(totalCharacters.length()));
}