通过将所有字段设为private，可以将类设为只读。 只读类将只有 getter 方法，将类的private属性返回给 main 方法。无法修改此属性，因为该类中没有可用的 setter 方法。 考虑以下示例:

  //A Java class which has only getter methods.    

public class Student {
   //private data member    

    private String college = "AKG";
  //getter method for college    

    public String getCollege() {
        return college;
    }
}