Java Trim Prefix Check: Ignore Leading Spaces

You can ignore the spaces at the beginning of a string and check for a prefix by using the trim() method to remove spaces at the beginning and end of the string, and then using the startsWith() method to check if the string starts with the specified prefix. Below is an example code:

public class Main {
    public static void main(String[] args) {
        String str = "   Hello, World!";
        String prefix = "Hello";
        
        // 去除字符串开头和结尾的空格
        str = str.trim();
        
        // 检查字符串是否以指定的前缀开头
        if (str.startsWith(prefix)) {
            System.out.println("字符串以前缀开头");
        } else {
            System.out.println("字符串不以前缀开头");
        }
    }
}

In the example above, we start by using the trim() method to remove any leading and trailing spaces of the string, and then use the startsWith() method to check if the string begins with a specified prefix. If the string does start with the prefix, the output will be “The string starts with the prefix”, otherwise it will be “The string does not start with the prefix”.