Test

package gap.ewp.api.controller.posts;

import java.util.regex.Pattern;

/**
 * Created by ethan on 14-3-18.
 */
public class Test {
    public static void main(String[] args) {
        String s = "update  where ";
        String s1 = "insertsdfsdkfsl";
        String s2 = "updat --- <";
        String s3 = "updat-- >";
        String s4 = "updat/";
        String s5 = "updat\\";
        String pattern = "(\\bupdate\\b|\\bdelete\\b|\\binsert\\b|--|<|>|/|\\\\)";

        System.out.println(Pattern.compile(pattern).matcher(s).find());
        System.out.println(Pattern.compile(pattern).matcher(s1).find());
        System.out.println(Pattern.compile(pattern).matcher(s2).find());
        System.out.println(Pattern.compile(pattern).matcher(s3).find());
        System.out.println(Pattern.compile(pattern).matcher(s4).find());
        System.out.println(Pattern.compile(pattern).matcher(s5).find());
    }
}


Result：
true
false
true
true
true
true