如何判断一个字符串是否是回文字符串

/**
 * 判断一个字符串是不是回文串，比如：abcba是回文串
 * @author zhaizhg
 *
 */
public class Test3 {
    
    

	public static void main(String[] args) {
    
    
		String str = "abcba";
		boolean calc = calc(str);
		System.out.println(calc);
	}
	
	static boolean calc(String s) {
    
    
		int left = 0; 
		int right = s.length() - 1;
		while(left < right) {
    
    
			if (s.charAt(left) != s.charAt(right)) return false;
			left++;
			right--;
		}
		return true;
	}

}