一時変数がJavaでシリアル化されないのはなぜですか？

構文

private transient <member-variable>;

例

import java.io.*;
class EmpInfo implements Serializable {
   String name;
   private transient int age;
   String occupation;
   public EmpInfo(String name, int age, String occupation) {
      this.name = name;
      this.age = age;
      this.occupation = occupation;
   }
   public String toString() {
      StringBuffer sb = new StringBuffer();
      sb.app*end("Name:"+"\n");
      sb.append(this.name+"\n");
      sb.append("Age:"+ "\n");
      sb.append(this.age + "\n");
      sb.append("Occupation:" + "\n");
      sb.append(this.occupation);
      return sb.toString();
   }
}
// main class
public class TransientVarTest {
   public static void main(String args[]) throws Exception {
      EmpInfo empInfo = new EmpInfo("Adithya", 30, "Java Developer");
      ObjectOutputStream oos = new ObjectOutputStream(new FileOutputStream("empInfo"));
      oos.writeObject(empInfo);
      oos.close();
      ObjectInputStream ois = new ObjectInputStream(new FileInputStream("empInfo"));
      EmpInfo empInfo1 = (EmpInfo)ois.readObject();
      System.out.println(empInfo1);
   }
}

出力

Name:
Adithya
Age:
0
Occupation:
Java Developer