这里是Java Starter，因此在我的密码生成程序中，
因此，我尝试了一个选项来生成多个密码，并在它们之间留有一个空格。
例：
密码1
密码2
但是，当我将“密码”文本设置为文本字段时，我会不断得到如下内容：ADWADjava.lang.StringQE_Q12
我未在代码中发现任何错误，或导致弹出java.lang.String的错误，如果您知道有什么问题，请回复此问题或发送答案。
我的代码：
createPass.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
field.setText(null);
field.setText("");
String[] pass = new String[5];
for(int i = 0; i < pass.length ; i++) {
pass[i] = allrandom();
}
for(int i = 0; i < pass.length ; i++) {
field.setText(field.getText() + pass[i]);
}
}});
}
public static String allrandom() {
String cpass = "";
password = "";
String[] pass = new String[15];
Random r = new Random();
for(int i = 0 ; i < pass.length ; i++) {
int ch = 0;
ch = r.nextInt(3);
switch(ch) {
case 0:
if(passsettings.isIfDots()) {
String newchar = "";
newchar = dotpass();
pass[i] = newchar;
break;
}
case 1:
if(passsettings.isIfNum()) {
String newchar2 = "";
newchar2 = Numpass();
pass[i] = newchar2;
break;
}
case 2:
String newchar3 = "";
newchar3 = charchose();
pass[i] = newchar3;
break;
}
}
for(int i = 0 ; i < pass.length ; i++) {
String newpasschar = "";
newpasschar = pass[i];
cpass = pass + newpasschar;
}
cpass = cpass + "\n";
return cpass;
// random() end
}
public static String uppercasepass() {
String[] abc = {"A","B","C","D","E","F","G","H","I","J","K","L","M","N","O","P","Q","R","S","T","U","V","W","X","Y","Z"};
Random r = new Random();
String passletter = "";
int rN3 = 0;
rN3 = r.nextInt(26);
passletter = abc[rN3];
return passletter;
// uppercase() end
}
public static String lowercasepass() {
Random r = new Random();
String passletter = "";
int rN3 = 0;
rN3 = r.nextInt(26);
String[] abc = {"a","b","c","d","e","f","g","h","i","j","k","l","m","n","o","p","q","r","s","t","u","v","w","x","y","z"};
passletter = abc[rN3];
return passletter;
}
public static String Numpass() {
Random r = new Random();
String passletter = "";
int rN = 0;
rN = r.nextInt(9);
String[] nums = {"1","2","3","4","5","6","7","8","9"};
passletter = nums[rN];
return passletter;
}
public static String dotpass() {
Random r = new Random();
String passletter = "";
int rN5 = 0;
rN5 = r.nextInt(6);
String[] dots = {"_","]","$","#","=","@"};
passletter = dots[rN5];
return passletter;
}
public static String charchose() {
Random r = new Random();
String line = "";
int rN = 0;
rN = r.nextInt(2);
String[] random = {"Low","Up"};
String random2 = random[rN];
switch(random2) {
case "Low":
if(passsettings.isIfLowercase()) {
line = lowercasepass();
}else {
charchose();
}
case "Up":
if(passsettings.isIfUpprcase()) {
line = uppercasepass();
}else {
charchose();
}
}
return line;
}
谢谢，
Java入门
最佳答案
调试代码时，我遇到了很多问题，但主要是...
public static String allrandom() {
String cpass = "";
password = "";
String[] pass = new String[15];
//...
for (int i = 0; i < pass.length; i++) {
String newpasschar = "";
newpasschar = pass[i];
cpass = pass + newpasschar;
}
cpass = cpass + "\n";
return cpass;
// random() end
}
pass + newpasschar试图连接一个数组和一个String对象。这基本上与pass.toString() + newpasschar.toString()相同为什么执行此操作，我不知道
cpass += newpasschar是否会达到您想要的结果。我真的不想尝试所有问题并指出所有问题，但可以说...学习如何使用
StringBuilder-效率更高整件事都让我大叫定制类，例如，特别是使用生成器模式。
public class PasswordBuilder {
private List<String> characters;
private List<String> numbers;
private List<String> dots;
private boolean useDots = true;
private boolean useNumbers = true;
private boolean useLowerCase = true;
private boolean useUpperCase = true;
private int length;
public PasswordBuilder(int length) {
this.length = length;
}
public PasswordBuilder useDots(boolean use) {
useDots = use;
return this;
}
public PasswordBuilder useNumbers(boolean use) {
useNumbers = use;
return this;
}
public PasswordBuilder userLowerCase(boolean use) {
useLowerCase = use;
return this;
}
public PasswordBuilder useUpperCase(boolean use) {
useUpperCase = use;
return this;
}
protected int getLength() {
return length;
}
protected boolean isUsingDots() {
return useDots;
}
protected boolean isUsingNumbers() {
return useNumbers;
}
protected boolean isUsingLowerCase() {
return useLowerCase;
}
protected boolean isUsingUpperCase() {
return useUpperCase;
}
public String build() {
characters = new ArrayList<>(Arrays.asList("A", "B", "C", "D", "E", "F", "G", "H", "I", "J", "K", "L", "M", "N", "O", "P", "Q", "R", "S", "T", "U", "V", "W", "X", "Y", "Z"));
numbers = new ArrayList<>(Arrays.asList("1", "2", "3", "4", "5", "6", "7", "8", "9"));
dots = new ArrayList<>(Arrays.asList("_", "]", "$", "#", "=", "@"));
Random r = new Random();
StringBuilder sb = new StringBuilder(getLength());
for (int i = 0; sb.length() < getLength(); i++) {
switch (r.nextInt(3)) {
case 0:
if (isUsingDots()) {
sb.append(dotpass());
break;
}
case 1:
if (isUsingNumbers()) {
sb.append(Numpass());
break;
}
case 2:
sb.append(charchose());
break;
}
}
return sb.toString();
}
protected String randomFrom(List<String> values) {
Collections.shuffle(values);
return values.get(0);
}
protected String uppercasepass() {
return randomFrom(characters).toLowerCase();
}
protected String lowercasepass() {
return randomFrom(characters).toLowerCase();
}
protected String Numpass() {
return randomFrom(numbers);
}
public String dotpass() {
return randomFrom(dots);
}
protected String charchose() {
Random r = new Random();
int value = r.nextInt(2);
String text = "";
switch (value) {
case 0:
text = lowercasepass();
case 1:
text = uppercasepass();
}
return text;
}
}
这意味着您可以简单地做类似...
System.out.println(new PasswordBuilder(15).build());
System.out.println(new PasswordBuilder(15).useNumbers(false).build());
System.out.println(new PasswordBuilder(15).userLowerCase(false).build());
System.out.println(new PasswordBuilder(15).userLowerCase(false).useUpperCase(false).build());
并输出类似...
xt7$93l]]#]@$xc
]o#r=#pxhk@lyth
@_s5q6]#8i$h]##
2#ccw_1]m3kaz_1
代码中有很多点可能导致递归（堆栈）溢出，一遍又一遍地调用方法，因此，您确实需要检查可用标志的状态，并确保至少一个是
true您仍然可以使用数组（而不是
List），但是基本思想保持不变