在键盘录入一个英文字符串，将所有的单词首字母大写，其余字母不变

可以先将字符串按空格分割成单词，再对每个单词进行首字母大写处理。代码如下：

import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        System.out.print("请输入英文字符串: ");
        String input = scanner.nextLine();

        String[] words = input.split(" ");
        StringBuilder result = new StringBuilder();
        for (String word : words) {
            if (word.length() > 0) {
                result.append(Character.toUpperCase(word.charAt(0)));
                result.append(word.substring(1));
                result.append(" ");
            }
        }

        System.out.println("处理结果: " + result.toString().trim());
    }
}

运行结果示例：

请输入英文字符串: hello world, how are you?
处理结果: Hello World, How Are You?