mcj:新增kmp非空判断

src/main/java/com/zjty/inspect/utils/KmpUtil.java

@@ -39,7 +39,7 @@ public class KmpUtil {
      */
     public static int kmpMatch(String s, String t){
         char[] s_arr = s.toCharArray();
-        if(t.isEmpty()){
+        if(t == null || t.isEmpty()){
             return -1;
         }
         char[] t_arr = t.toCharArray();
@@ -61,4 +61,9 @@ public class KmpUtil {
             return -1;
         }
     }
+
+    public static void main(String[] args) {
+        int fdf = KmpUtil.kmpMatch("fdf", "");
+        System.out.println(fdf);
+    }
 }