java - 如何使用 .equals() 方法比较两个 StringBuffer 对象？

Question

以下代码不起作用。谁能告诉我下面的代码有什么问题。从逻辑上讲它应该有效...

package assignments;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;

public class IsPalindrome {
public static void main(String[] args) throws IOException {
    BufferedReader br = new BufferedReader(
                                      new InputStreamReader(System.in));
    System.out.println("Enter a Word:");
    StringBuffer sb1 = new StringBuffer(br.readLine());
    StringBuffer sb2 = new StringBuffer(sb1);
    sb1.reverse();

    if(sb2.equals(sb1))
        System.out.println("Palindrome");
    else
        System.out.println("Not a Palindrome");
}
}

Answer 1

尝试

sb1.toString().equals(sb2.toString());

因为StringBuffer#toString方法返回缓冲区内存储的数据的字符串值:

Returns a string representing the data in this sequence. A new String object is allocated and initialized to contain the character sequence currently represented by this object. This String is then returned. Subsequent changes to this sequence do not affect the contents of the String.