尝试将char数组的元素转换为int时出错

Question

以下是我目前使用的代码：

public static String encrypt(String password) {
    String encrypted = null;
    char passChars[] = password.toCharArray();
    int ascii[] = null;
    for(int i=0;i<passChars.length;i++) {
        ascii[i] = Integer.parseInt(String.valueOf(passChars[i]));
        ascii[i] = ascii[i] + 17;
        passChars[i] = (char)ascii[i];
        encrypted = encrypted + String.valueOf(passChars[i]);
    }
    return encrypted;
}

当我尝试运行它时，它正在运行但是当我使用加密方法时，我收到以下错误：

Exception in thread "AWT-EventQueue-0" java.lang.NumberFormatException: For input string: "M"
at java.lang.NumberFormatException.forInputString(Unknown Source)
at java.lang.Integer.parseInt(Unknown Source)
at java.lang.Integer.parseInt(Unknown Source)
at com.package.program.Encryptor.encrypt(Encrypter.java:46)
at com.package.program.Main$3.actionPerformed(Main.java:136)
at javax.swing.AbstractButton.fireActionPerformed(Unknown Source)
at javax.swing.AbstractButton$Handler.actionPerformed(Unknown Source)
at javax.swing.DefaultButtonModel.fireActionPerformed(Unknown Source)
at javax.swing.DefaultButtonModel.setPressed(Unknown Source)
at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(Unknown Source)
at java.awt.Component.processMouseEvent(Unknown Source)
at javax.swing.JComponent.processMouseEvent(Unknown Source)
at java.awt.Component.processEvent(Unknown Source)
at java.awt.Container.processEvent(Unknown Source)
at java.awt.Component.dispatchEventImpl(Unknown Source)
at java.awt.Container.dispatchEventImpl(Unknown Source)
at java.awt.Component.dispatchEvent(Unknown Source)
at java.awt.LightweightDispatcher.retargetMouseEvent(Unknown Source)
at java.awt.LightweightDispatcher.processMouseEvent(Unknown Source)
at java.awt.LightweightDispatcher.dispatchEvent(Unknown Source)
at java.awt.Container.dispatchEventImpl(Unknown Source)
at java.awt.Window.dispatchEventImpl(Unknown Source)
at java.awt.Component.dispatchEvent(Unknown Source)
at java.awt.EventQueue.dispatchEventImpl(Unknown Source)
at java.awt.EventQueue.access$500(Unknown Source)
at java.awt.EventQueue$3.run(Unknown Source)
at java.awt.EventQueue$3.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(Unknown Source)
at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(Unknown Source)
at java.awt.EventQueue$4.run(Unknown Source)
at java.awt.EventQueue$4.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(Unknown Source)
at java.awt.EventQueue.dispatchEvent(Unknown Source)
at java.awt.EventDispatchThread.pumpOneEventForFilters(Unknown Source)
at java.awt.EventDispatchThread.pumpEventsForFilter(Unknown Source)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(Unknown Source)
at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
at java.awt.EventDispatchThread.run(Unknown Source)

我尝试过更改一些内容，例如更改char转换为int的方式但似乎没有任何效果......我做错了什么？

Answer 1

如果你想通过将每个字符偏移一定量来“加密”字符串，那么就直接这样做：

String encrypted = null;
char passChars[] = password.toCharArray();
for (int i=0; i < passChars.length; i++) {
    passChars[i] += 17;
}
encrypted = new String(passChars);

Demo

请注意，在某些ASCII字符上添加17可能会使您无法打印。目前尚不清楚你在这里想要达到的目标;如果你想系统地将密码加密成其他字符，那么我们可能必须使用模数进行包装。

Answer 2

这一行错了：

ascii[i] = Integer.parseInt(String.valueOf(passChars[i]));

您正在尝试将密码的字母转换为整数。无法保证密码仅由数字组成。

相反，您可以这样做：

ascii[i] = passChars[i] + 17;

直接

Answer 3

使用有效大小初始化ascii []，您可能会获得索引超出绑定的异常，并且此程序仅适用于仅作为数字字符串的密码。