Explanation with an example.
1. import java.io.Serializable
As for the Serialization, see the documentation.
2. private fields
Fields should be private for prevent outer classes to easily modify those fields. Instead of directly accesing to those fields, usuagly getter/setter methods are used.
3. Constructor
A public constructor without any argument.
4. getter/setter
Getter and setter methods for accessing and modifying private fields.
/** 1. import java.io.Serializable */
public class User implements java.io.Serializable {
/** 2. private fields */
private int id;
private String name;
/** 3. Constructor */
public User() {
}
public User(int id, String name) {
this.id = id;
this.name = name;
}
/** 4. getter/setter */
// getter
public int getId() {
return id;
}
public String getName() {
return name;
}
// setter
public void setId(int id) {
this.id = id;
}
public void setName(String name) {
this.name = name;
}
}