A JavaBean is a Java class. Like other Java classes, JavaBeans are reusable code. They are unique in their design because they encapsulate several objects into one. There are three conventions that a JavaBean class must follow:

• The constructor should not take any arguments
• It must be serializable
• It must contain mutator and accessor methods for its properties

Here is an example JavaBean class:

public class MyBean implements java.io.Serializable {

  // instance variables
  private int studentId;
  private String studentName;

  // no-argument constructor
  public MyBean() {
  }

  // mutator/setter
  public void setStudentId(int theID) {
    this.studentId = theID;
  }

  // accessor/getter
  public int getStudentId() {
    return studentId;
  }

  // mutator/setter
  public void setStudentName(String theName) {
    this.studentName = theName;
  }

  // accessor/getter
  public String getStudentName(){
    return studentName;
  }
}

Accessing JavaBean classes is as simple as using the mutator and accessor methods. This is likely not new to you, but there is a good chance you did not know that those carefully coded classes you created were called JavaBean classes.