我正在看hadoop框架中的产品代码，这是没有意义的。为什么我们要使用transient，为什么我不能使实用方法成为静态方法（领导告诉我不要使isthinger成为静态方法）？我查找了transient关键字，它与序列化有关。这里真的用序列化吗？

//extending from MapReduceBase is a requirement of hadoop
public static class MyMapper extends MapReduceBase {

    // why the use of transient keyword here?
    transient Utility utility;

    public void configure(JobConf job) {

        String test = job.get("key");

        // seems silly that we have to create Utility instance.
        // can't we use a static method instead?
        utility = new Utility();

        boolean res = utility.isThinger(test);

        foo (res);
    }

    void foo (boolean a) { }
}

public class Utility {
   final String stringToSearchFor = "ineverchange";

   // it seems we could make this static.  Why can't we?
   public boolean isThinger(String word) {
      boolean val = false;
      if (word.indexOf(stringToSearchFor) > 0) {
           val = true;
      }
      return val;
   }
}