(Java) to judge a palindrome string, ignoring characters that are not alphanumeric or not

Question: Detect whether the string is a palindrome string, excluding characters that are not letters and numbers

Solve:

1. Filter strings by removing non-alphanumeric characters

Creates an empty string buffer, adds each alphanumeric character in the string to a character buffer, and returns a string from the buffer, using the Isletterordigit (ch) method in the character class to detect whether the character Ch is alphanumeric.

2, inverted filtered string to get a new string, using the Equals () method to compare the inverted string and filtered string content is equal.

List of programs: Checkhuiwenstringignorenotletteranddidgit.java

to ignore characters that are not alphanumeric or not, judge a palindrome string public
class Checkhuiwenstringignorenotletteranddidgit {public

	static void main ( String[] args) {
		String s= "A?B2C\\D1E1%DC/2BA";
		System.out.println ("is" + "[" +s+ "]" + "palindrome string? + "--" +ishuiwen (s));
		String ss= "12?abc" (BA12);
		System.out.println ("is" + "[" +ss+ "]" + "palindrome string? + "--" +ishuiwen (ss));
	}
	public static Boolean Ishuiwen (string s) {
		string s1=filter (s);
		String S2=reverse (S1);
		Return s2.equals (S1);
	}
	public static string filter (string s) {//remove non-alphanumeric character filter strings
		StringBuffer strbuf=new stringbuffer ();
		for (int i=0;i<s.length (); i++) {
			if (Character.isletterordigit (S.charat (i))
				strbuf.append (S.charat (i) ));
		}
		return strbuf.tostring ();
	}
	public static string reverse (string s) {//filtered string inversion, returns the new string
		StringBuffer strbuf=new stringbuffer (s);
		Strbuf.reverse ();
		return strbuf.tostring ();
	}