判断是否回文，帮忙看看哪里出错了？
下面是我的回文程序，麻烦大家帮我看看哪里出错了?
我输入不是回文的话，正常显示不是回文，但是如果我输入的是回文如abccba的话，就出问题阿。下面是我的class和test

=============Palindrome.java====================
public class Palindrome
{
static private String text;
static private int firstIndex;
static private int lastIndex;

public static boolean isPalindrome(String text, int firstIndex,int lastIndex)
{
text = text.toLowerCase();
firstIndex = 0;
lastIndex = text.length()-1;

while( !Character.isLetterOrDigit( text.charAt( firstIndex ) ))

firstIndex++;

while( !Character.isLetterOrDigit( text.charAt( lastIndex ) ))

lastIndex++;


if (firstIndex > = lastIndex)

return true; // Base Case

// The first and last letters are different,it is not a Palindrome
else if (text.charAt(firstIndex) != text.charAt(lastIndex))

return false;
else
// recursive case
{
return isPalindrome(text, firstIndex +1, lastIndex -1);
}

}

}


=================PalindromeTest.java====================
import javax.swing.JOptionPane;

public class PalindromeTest
{
public static void main( String [] args)
{
String input = new String( " ");
String output1 = "Programmed by Yuanyuan Li\n ";

do
{
input = JOptionPane.showInputDialog( "Please enter a string or quit to exit ");
if(Palindrome.isPalindrome(input,0,input.length()-1))

JOptionPane.showMessageDialog(null,output1 + input + "is a Palindrome ");

else
JOptionPane.showMessageDialog(null,output1 + input + " is not a Palindrome ");


} while( !(input.equalsIgnoreCase( "Quit ")));

}
}

[解决办法]
你的太复杂了吧！

public class Test {

public static void main(String[] args) {
String in = "abcdefgfedcba ";
if (in.equals(new StringBuffer(in).reverse().toString())) {
System.out.println( "回文 ");
}
else {
System.out.println( "不是回文 ");
}
}
}

[解决办法]

return isPalindrome(text.substring(1,lastIndex));

改一下 不好意思 写错了